Report of the

WORKSHOP ON CITRUS LEAFMINER AND ITS CONTROL IN THE NEAR EAST

Safita (Tartous), Syria,30 September - 3 October 1996

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TABLE OF CONTENTSPage

I. Introduction 1

II. Opening Session 1

III. Keynote Address 3“World Status of Citrus Leafminer and its Control: Problem and Progress”, Mr. Jorge E. Peña

IV. Country Reports 5Cyprus 5Egypt 6Iran 7Iraq 7Lebanon 8Libya 8Malta 8Morocco 9Oman 9Pakistan 10Saudi Arabia 10Sudan 11Syria 11Tunisia 12Turkey 12

V. Invited Papers“Indigenous Parasitoids of the Citrus Leafminer in Florida: 13 Stepwise Approach to Basic Studies of the Dominant Parasitoid, Pnigallo minio”, Mr. J.E. Peña

“Biological Control of CLM in the Near East: Techniques 13 for Rearing, Releasing, Efficacy Evaluation and Tracing Information for Parasitoids”, Mr. Badar Munir

“Citrus Leafminer Mediterranean Network”, Mr. John LaSalle 14

VI. Round Table Session

a. Status of Citrus Leafminer in the Region 15

1. Citrus Leafminer 152. First records of CLM in the Near East 163. Possible explanations for the rapid spread of CLM 164. Economic importance 165. Varietal susceptibility 16

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6. Control measures 177. Farmer attitude to adoption and implemen-

tation of integrated control programme 218. Research activities 219. Extension activities 2110. Key institutions and personnel involved in

CLM control 2111. Donor support 21

b. Proposed Strategies for the Containment of Citrus Leafminer in the Region 22

1. Strategies proposed at the nursery level 222. Strategies proposed at the orchard level 223. Strategies proposed at the extension level 254. Research activities 25

V. Recommendations 25

VI. Follow-up Action 25

VII. Adoption of the Report 26

VIII. Closing Session 26

IX. ANNEXES

I. Proposed outline of a Regional TCP 27

II. Programme 30

III. List of Participants 32

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Workshop on Citrus Leafminer (Phyllocnistis citrella)and its Control in The Near East

I. INTRODUCTION

The workshop was organized by the FAO Regional Office for the Near East, Cairo (Egypt) and the FAO Plant Protection Service, Rome (Italy) and was hosted by the Syrian Citrus Board in Safita (Tartous) from 30 September to 3 October 1996. Prior to the workshop, member countries of the Near East Region were requested to prepare country reports on the status and management of citrus leafminer (CLM) in their territories. The main objectives of the Workshop were to:

a) review and assess the present status of CLM in the Region;b) evaluate the impact of the present control measures; andc) propose an environmentally-friendly strategy for the containment of

CLM in the Region.

Scientists from Cyprus, Egypt, Iran, Iraq, Lebanon, Libya, Malta, Morocco, Oman, Pakistan, Saudi Arabia, Sudan, Syria, Tunisia and Turkey, who prepared the country reports, participated in the workshop. Resource persons from the United States and the United Kingdom, as well as the Senior Officer (Entomology), Plant Protection Service at FAO Headquarters and the Senior Plant Protection Officer for the Near East, also took part in the meeting.

The Workshop Programme and the List of Participants are given in Annexes II and III, respectively.

II. OPENING SESSION

Mr. Wajih Al-Mouie, Director of the Syrian Citrus Board welcomed the workshop participants and expressed the hope that the workshop would draw up strategies which would assist countries of the Near East to contain the citrus leafminer problem, contribute to the well-being of farmers, and promote the production of citrus in the area. He emphasized the importance of citrus to Syria and indicated that since 1993 major citrus pests were subjected to integrated pest management, based mainly on biological control; no pesticides are now used in the citrus pest control programme. This programme was successful due to the collective efforts of the policy-makers, farmers, researchers and extension services. Mr. Al-Mouie appreciated the assistance of FAO in realizing the above achievements. He invited the workshop participants to examine Syrian experience in the containment of the citrus leafminer and benefit from its positive aspects. He also warned against dependence on pesticides as a main control measure of citrus leafminer and other major citrus pests, referring to their side- effects and cost-effectiveness. Mr. Al-Mouie hoped that the workshop would strengthen the relations between participating countries and lead to further cooperation in pest control programmes.

Mr. Mahmoud Taher, Senior Plant Protection Officer for the Near East, on behalf of FAO, welcomed the participants and invited speakers, and expressed appreciation to the Government of Syria and the Syrian Citrus Board for hosting the

workshop and providing support for its success. He informed the meeting that statistics available indicated that more than one million hectares are given over to citriculture in the Near East Region, producing more than ten million tons of citrus. This area is in continued expansion due to the favourable environmental conditions. Citrus provides nourishment, refreshment, labour and foreign revenue to most of the countries in the Region. It also provides a basis for the development of agro-industries. Mr. Taher stated that the citrus leafminer emerged in 1994 as a new major pest of citrus in the Region and spread in record time to all citrus growing areas in almost every country of the Near East. The pest demonstrated a devastating effect on nurseries and young trees and caused damage to productive orchards. This situation, which also occurred in most of citrus producing areas in the world, in the absence of adequate knowledge of the pest, triggered a series of short-term control measures mainly based on chemical control. In most cases, they did not prove successful.

The citrus leafminer became of concern to the international community. International meetings/sessions were held in Agadir (Morocco), Florida (USA) and Florence (Italy) to address this problem. The present workshop was convened to discuss the status of citrus leafminer and its control in countries of the Region and to propose a regional strategy for its containment. The workshop would benefit from experience gained in other parts of the world, as would be demonstrated by invited speakers, and also from the Syrian experience.

Mr. Taher indicated that the workshop was organized as part of FAO’s efforts to assist its Member Countries in the containment of the citrus leafminer problem. FAO had extended technical assistance to Morocco, Algeria and Tunisia, and had also implemented a Citrus IPM Project in Syria. Mr. Taher also spoke about the World Food Summit scheduled to take place in November 1996 in Rome, and indicated the importance of participating in this important event. He concluded by assuring the participants that FAO would endeavour to provide the necessary assistance, as far as its resources permitted, to support countries’ initiatives to implement the strategies resulting from the workshop.

Mr. Ghazi Khadra, Governor of Tartous, also welcomed the participants to the workshop and expressed appreciation for convening this important event in Tartous, Syria. He informed the meeting of the importance that Syria gives to the agricultural sector and achievements in the field of fruit tree, grain and vegetable production which contributed to the country’s self-sufficiency and were a source of foreign income. He gave the example of citrus where the production, which a few decades ago was 8000 tons, reached 700,000 tons in 1995, placing Syria among the citrus exporting countries.

Mr. Khadra indicated that the roots of agriculture in Syria go back thousands of years. Syria continue to give agriculture prime attention and support. He concluded that the development and implementation of Integrated Pest Management programmes in citrus and, in particular, integrated management of citrus leafminer demonstrate the efforts that Syria makes to ensure sustainability of agriculture and preservation of the environment.

III. KEYNOTE ADDRESS

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In his keynote address on “World Status of Citrus Leafminer and its Control: Problem and Progress”, Mr. Jorge E. Peña indicated that the citrus leafminer, P. citrella was first discovered in Southeast Asia in 1856 and slowly dispersed to Korea, and the Philippines (1915), Australia (1918), Japan (1927), East Africa (1967) and West Africa (1970). Since 1993, this insect has infested other citrus producing areas of the world. The first infestations occurred in Florida (USA), followed by Mexico and the Caribbean Region, the Mediterranean Region, Central America, the Near East countries and recently South America. The rapid spread of P. citrella has taken citrus producers by surprise; the leafminer colonization pattern is believed to be associated with development of resistance to some insecticides, involuntary movement of infested material from one region to another or even dispersion movement.

The biology of the leafminer is typical of other species of leafmining moths. Small eggs are laid on young leaves, and hatching larvae produce serpentine mines beneath the leaf epidermis, where they fed upon the liquid contents of leaf cells. Complete generation time can fluctuate between 13-52 days depending on temperature. The effect of other factors on CLM development, e.g., relative humidity and cultivar, have been given less priority. However, the adaptability of the leafminer to different climates - dry areas, tropical forests, temperate areas - demonstrates its value as a colonizer and exploiter of different Citrus agroecosystems.

Species, hybrids and genera of Citrus and other species of the family Rutacea appear to be the primary host plant group of P. citrella. Published accounts indicate that some cultivars are more susceptible than others; however, cultivar resistance should not be confused with a pattern of pseudo-resistance, i.e. those plant species or cultivars that manage to escape infestation of CLM by flushing early are escapees and not resistant varieties.

P. citrella injury to the plant can be manifested through reduction of the leaf surface area responsible for capturing energy for tree growth. In heavy populations, leafminer larvae prevent newly emerging leaves from expanding fully, causing leaves to remain curled and twisted. Depending on conditions of fertilization, drought periods, cultivar, presence of opportunistic pathogens on the leaf surface, leaf and plant response can range from leaf chlorosis to necrosis, defoliation and dieback-like symptoms. Despite the importance of this aspect, very few studies have addressed the relationship between P. citrella, damage and, ultimately, its effect on yield reduction. Most important, measurement of leafminer damage, remains an undefined term, where every researcher expresses his or her own visualization of damage without a proper definition.

Field observations from the People’s Republic of China, Australia and some areas of Florida indicate that spring flushes are the least damaged of seasonal growth periods, while summer and autumn flushes suffer the most serious infestations. Different seasonality is observed for subtropical areas or may be observed for the Mediterranean, North Africa and the Near East.

Very little work has been done on the study of egg and larva distribution patterns and sampling methodology. The procedures for sampling remain arbitrary

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and are left to the discretion of the researcher. Moreover, the relationship between adult trapping and larval infestation needs to be determined as a way of predicting insect outbreaks. The pheromone of P. citrella has not yet been determined. A lure is commercially available but has failed to indicate male activity in Florida, Spain, China or Korea. Male catches in pheromone traps may help to predict leafminer density in orchards before reaching outbreak densities.

Growers have relied on chemical control of P. citrella to reduce its population. Citrus leafminer, apparently developed resistance to some over-used pesticides during 1970-1980, although, in some cases, outbreaks of other pest problems is suspected after reduction of natural enemies. Effective chemical control of CLM is difficult to achieve and total reliance on chemical control has been demonstrated to be ineffective. Application of chemicals should take into consideration flushing pattern, actual population present, tree age (mature trees vs. young trees), production scheme (orchard vs. nursery), application method (foliar vs. soil application) and presence of natural enemy complex.

The most important aspect of citrus leafminer management is biological control. While, in many cases, the diversity of natural enemies of the leafminer (hymenopteropus parasitoids, predacious arachnids, ants, lacewings) accounts for significant reduction of the leafminer population, in other cases their presence and activity are low. Introduction of exotic species (e.g. Ageniaspis citricola) from the area of origin has proven to be successful in Australia and Florida. There is a clear need for other parasitoid species that can be adapted to different climatic areas. For instance, the success of A. citricola in the humid Florida climate has not been repeated in the dry areas of Texas.

Studies are needed to determine the role of indigenous parasitoids and predators and mortality factors of P. citrella. Parasitoids will vary in their species richness and seasonal abundance in the different geographic areas. Thus, research is needed to identify the host plant/leafminer reservoirs from which these indigenous parasitoid species are opportunistically recruited onto citrus leafminer. Utilization of common evaluation protocols by researchers in various parts of the world will allow comparisons of leafminer populations and parasitoid dynamics between areas representing tropical, subtropical, Mediterranean and dry citrus producing areas.

Parasitoid rearing has been improved and modified by different researchers. Because there is no artificial diet available for citrus leafminer, rearing of parasitoids requires an understanding of the biology of the leafminer and the parasitoid as well as the phenology and flushing patterns of the host plant.

In conclusion, the gathering of information on biology, seasonality, chemical and biological control of the citrus leafminer has made major steps during the last 3 years. However, much research is needed to clarify ambivalent, non-existent or misleading data on behaviour, sampling and monitoring, horticultural practices, plant resistance, damage assessment, economic thresholds and the role of the different mortality factors for different geographic areas. Most importantly, procedures for management of citrus leafminer would have to be based on the biology of the citrus leafminer and the characteristics of citrus production.

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IV. COUNTRY REPORTS

CYPRUS

The citrus leafminer was first noted in the autumn of 1994 and it spread rapidly to all citrus growing areas of the island. Since populations remained low during 1994, it did not cause much concern to the farmers. However, during 1995, its numbers increased dramatically in all coastal and mountainous areas. All citrus varieties suffered to some extent, but the most affected were lemons and mandarins. The economic losses in monetary terms have not yet been determined, but it is believed that the heavy loss of young foliage may result in yield reduction.

It is assumed that there are between 7 to12 generations of CLM per year with peak populations occurring during May-June and September-October. Several insecticides have been tested for their efficacy, including N1-25, Confidor 200SL, Marshal 25 EC summer oil, Admiral 10 EC + summer oil, Dimilin 25 WP, Consult 100 EC, Alsystin 25 WP, Evisect 50 SP, Bensultap 50 WP, Drawin 50 EC and Actellic 50 EC. It was found that CLM can be controlled by all these products with the exception of Drawin and Actellic, which proved ineffective. The main difference between the tested products is the duration of their effect. The most effective product, with a duration of activity of more than 15 days, was N1-25, followed by Admiral, Consult, Marshal, Confidor, Dimilin and Alsystin. These seven insecticides, as well as Vertimec which has been tested in previous trials, could be used for CLM control. It was concluded that chemical control is not a successful strategy. It should be used only as a supplementary method to cultural and biological control.

In 1996, the following measures were recommended to farmers:

Increased fertilization (especially nitrogen) before the end of January. If rainfall is insufficient, light irrigation should taken place during

February-March. Pruning should be completed before the end of January, if possible. Maintenance of the trees during summer and autumn with normal

irrigation and reduced fertilization.

Biological control is considered the most suitable method for the management of CLM. The following species of parasitoid were recorded from CLM in Cyprus: Cirrospilus sp., Pnigalio soemius, Pnigalio sp., Chrysocharis pentheus and Neochrysocharis formosa. No hyperparasitoids are as yet known from these species. In 1995, five species of parasitoid were introduced from Israel and released in the fields: Ageniaspis citricola, Citrostichus phyllocnistoides, Quadrastichus sp., Semielacher petiolatus and Cirrospilus quadristriatus. Post-release status is being studied in the fields where releases were made.

It is believed that an Integrated Pest Management (IPM) programme consisting of biological and cultural controls and selective insecticides, would prove the most economical and long lasting, without influencing the existing programmes of other pests of citrus. Government support is available for this plan.

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Current research activities include ecology, behavioural and biological studies of CLM, rearing and releasing of the introduced parasitoids, etc. Extension activities comprise seminars for farmers on the biology and ecology of CLM, nature of damage and control methods. Farmers seem to accept IPM/biological control as a good strategy for pest control. The Department of Agriculture and Agricultural Research Institute are involved in CLM research and extension activities. Funds are provided by the Government. No foreign funding is available.

EGYPT

CLM was first recorded in July 1994 on the eastern side of the Nile Delta. By the end of the year it had spread all over the country. It attacked all citrus varieties in the orchards and nurseries and was declared an economic pest in 1995. The precise extent of damage has not yet been assessed. There were about 13 generations of CLM during the year with highest populations from May to August. Chemical control research is in the experimental stage because no results can be accepted before 2-3 successive years of experimentation. In 1995, summer mineral oil, IGR, OPI and natural compounds were tested in nurseries and on producing trees. The results of the first year showed that organophosphorus compounds were not effective. The natural compound Vertimec EC 1.8%, at the rate of 25 cc + 250 cc mineral oil (KZ oil)/100 litre water, 1 litre mineral oil/100 litre water, and 50 cc Admiral (IGR) + 300 cc mineral oil (KZ oil)/100 litre water was effective against the CLM with no significant variation between treatments. According to the results of these trials, summer mineral oil at the rate of 1% was recommended because of the satisfactory control of CLM, the minimal effect on natural enemies and the low cost.

To date seven species of parasitoid have been recorded from CLM in Egypt; three are unidentified and four are identified as follows:

Cirrospilus pictus (Nees) in Giza and Benisuaife, Ratzeburgiola incompleta Boucek, in Kalubia, Baryscapus sp. in Kalubia, and Pnigalio sp. in Kalubia and Assiout.

Information on hyperparasitoids is not available. No exotic species of parasitoids has been introduced.

With government support, an IPM programme consisting of recommendations on cultural practices and chemical control is in place. Most farmers are willing to accept this programme. Further research activities include studies on the evaluation of pesticides, rearing and releasing of indigenous natural enemies, population dynamics of CLM, and testing alternative methods of pest control. A series of seminars has been given to agricultural engineers, and extension publications have been compiled and distributed to farmers. The key institutions engaged in CLM research are the Plant Protection Research Institute and Horticulture Research Institute. Government funds for the IPM programme are insufficient and no foreign donations are available.

IRAN

The first record of CLM from southern Iran dates back to 1961, but in northern Iran its presence was noted for the first time in September 1994. Since then,

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it has shown a dramatic increase and widespread dispersal. Almost all commercial varieties are affected but data on economic losses are not available. The pest has about 5-9 generations during the year, with peak periods in early summer and early autumn. Preliminary field trials with selected insecticides indicate the superiority of Dimilin (diflubenzuron) over diazinon, Zolone (phosalone) and Ekamet (etrimfos) in controlling CLM in the northern Iran, but it is not totally effective. The application rates with 1000 l. water were: Dimilin (50 gr); diazinon (150 gr); Zolone (200 gr); and Ekamet (150 gr). All were applied only once in late October. Dimilin was found partially effective while the other three proved ineffective. In southern Iran, diazinon (Easudin) 2-3 cc/l., endosulfan (Thiodan) 2-2 l./ha, fenvalerate (Sumicidin) 1-2 cc/l., fenpropathrin (Danitol) 1-2 cc/l., and chlorpyrifos (Dursban) 1-2 l./ha were tested against the CLM. A total of 2-3 sprays were made every two weeks. The most used material was diazinon. No information on other methods of control or on indigenous parasitoids is available. There is no programme for biological control of CLM but studies on the biology, ecology and nature of damage are underway for planned extension activities. The key institutions involved in CLM control are the Plant Pest and Diseases Research Institute and Plant Protection and Quarantine Organization. Funds for research are provided by the above-mentioned institutions.

IRAQ

The citrus leafminer was first observed in a nursery at Al-Iskenderiya in May 1992. By the end of 1993, it had spread to all citrus areas of the country and is now regarded as a serious pest, affecting all varieties. In nurseries, sour orange seedlings are most affected, rough lemon and Rangpur lime are moderately susceptible while Citrus volkameriana is the least susceptible. In orchards, sweet lime, sweet orange and grapefruit are most severely attacked but pummelo seems to be less susceptible. The exact amount of economic damage needs to be estimated. Evidently, there are no resistant varieties in the country. There are 3-4 generations of CLM per season with the peak population occurring during late October to mid-November.

Chemical control is the main strategy for dealing with the pest. It is implemented by the citrus farmers themselves as there are no government recommended insecticides. Of the several pesticides tested, Neemosan and Vertemic were found to be the most effective. No other control measures, except removal of infested shoots, are practised. There is no information available on indigenous parasitoids or hyperparasitoids. So far, there is no plan for introduction of exotic species of parasitoids. The government is considering assistance from UNDP to initiate an IPM programme. Current research is focused on screening of pesticides and their effect on natural enemies. There are no extension activities regarding CLM control as research results are not obtained yet, but farmers are usually receptive to recommendations broadcast by radio and television. The Plant Protection Research Division is the main institution engaged in CLM control. No foreign financial support is available at present.

LEBANON

The citrus leafminer was first observed in July 1994 in northern Lebanon; since then it has been found in every citrus producing areas and affects all citrus varieties. The peak of population occurs during autumn.

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A few pesticides have been used to control the pest. A mixture of 100 cm Traker and 100 g of Lannate is used as a first spray followed by 100 g of Lannate only as a second spray.

Another method of control consists in starting irrigation early in the season, using of nitrogen fertilizers before the end of June, shortening the interval of irrigation according to soil type in a way to avoid any water stress, removing water shoots from the trunk of the tree and minimizing pruning to prevent heavy new negative growth.

There is no information on indigenous natural enemies and none have been introduced.

LIBYA

The first record of CLM in Libya was in August 1995. The same year it spread to all citrus orchards in the coastal areas and was declared an economic pest of nurseries. In orchards, it attacked all varieties. The precise economic damage has not been calculated but nurseries are badly affected by this pest. No information is available on the phenology of the pest but studies are underway. A few pesticides have been used. Chemical control includes the use of Dursban, Superacid and Antio 33 EC at manufacturers’ recommended rates. The most effective pesticides were Dursban and Superacid, while Antio 33 EC was less effective. Cultural control is used in a limited manner because of labour costs. Biological control and IPM programmes are planned. Three local parasitoid species were found; Cirrospilus pictus, Cirrospilus variegatus, Pnigalio sp. The effectiveness of these parasitoids in controlling CLM population in general is satisfactory. Introduction of exotic parasitoids is under study. There is no record of the occurrence of hyperparasitoids. Farmers are expected to adopt biological control/IPM when their effectiveness is proven in the field.

Planned research activities include identification and evaluation of natural enemies, studies on population dynamics and seasonal occurrence, extent of damage and introduction of parasitoids from abroad. Extension activities comprise radio and television broadcasts regarding CLM and its control. The key institutes responsible for CLM control are the Agriculture Research Centre, Plant Protection and Quarantine Department and Extension Service Department. The Government provides financial support.

MALTA

CLM was first observed in the Maltese Islands in June/July 1995. Within a few weeks it was reported to be present throughout the citrus areas of both Malta and Gozo. It was found to infest all varieties of citrus, but the extent of damage has not yet been estimated. No ecological information on CLM is available. Summer and autumn flushes suffer the most damage. After the first introduction of CLM, plots of 1000 m2 were treated every 21 days with insecticides. The best result obtained was with diflubenzuron (Dimilin). As much as 78% mortality rate was recorded in all larval stages. Only the pupae seem to be more resistant, with only 30-55% mortality.

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Other chemicals which also proved quite effective include cartap (Sanvex) with upto 63% mortality in larvae, and deltametrin/dimethoate (1.1%: 36.4%) (Decis-D) with as much as 52% larval mortality. As a general rule, oil is always recommended together with the pesticides at a rate of 0.5% to 1%. In fact, in all trials a 1% oil solution was always added.

Efforts to collect indigenous parasitoids are in progress. Very recently, in isolated citrus groves in Malta where no insecticide application is carried out, only very low damage caused by CLM was observed, indicating the presence of natural parasites. Planned research activities include: evaluation of efficacy of indigenous natural enemies; introduction of natural enemies; biology and ecology of CLM; and mass-rearing and dissemination of parasitoids. Research facilities are concentrated at the Plant Health Division, Research Development Centre, Department of Agriculture.

MOROCCO

CLM was first detected in August 1994. By the end of 1995, it had assumed the status of an economic pest. Phyllocnistis citrella is present in all citrus growing areas and infests all varieties, but lemon, grapefruit and clementine mandarin “Nour” suffer more heavily. Severe physical damage to new foliage was noted on plants of all ages, mainly in nurseries, newly planted groves and grafted trees. Three marked peaks of population occur. Several chemical products were tested, of which the most frequently used by farmers are Consult, Dimilin, Vertimec and Confidor . Based on the results of trials, Consult, Dimilin, Vertimec, Confidor and Cascade were recommended to farmers only for use in nurseries and young trees of less than 5 years of age. Confidor is used only for stem painting.

Two indigenous species of parasitoid (Pnigalio sp. and Cirrospilus sp.) are known locally. One species, Ageniaspis citricola, was introduced from Florida and, after mass-rearing in the greenhouse, was released in the fields in 1996. A. citricola has already been recovered. In general, farmers are willing to adopt IPM/biological control programmes for implementation in their orchards. Private growers, associations of growers and government institutions (Plant Protection Services, Research Institutions, Extension Services) are involved in CLM research and control.

OMAN

CLM has been known in Oman since 1972 but became an economic pest in 1993. It is present in all orchards and backyard gardens and attacks all varieties. Maximum level of infestation occurs from January to April. Chemical control is the only method for crop protection. Recommended insecticides are: deltamethrin 12.5 g/l + dimethoate 400 g/l (Decis D) (1 ml/l), phosphamidon (Dimecron 50) (1.25 ml/l) and methidathion (Supracide 40) (1.5 ml/l).

Five indigenous species of parasitoid are already known to be present: Citrostichus phyllocnistoides, Cirrospilus ingenuus, Sympiesis sp., Neochrysocharis sp., and Baryscapus sp., and the following four exotic species have been introduced to enhance biological control of CLM: Ageniaspis citricola, Semielacher petiolatus,

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Sympiesis sp., and Cirrospilus ingenousus. The General Directorate of Agricultural Research is responsible for CLM control.

PAKISTAN

The earliest record of the presence of CLM in Pakistan was in 1916. In a paper published in 1990, this species is mentioned as a serious pest of citrus in hilly areas. CLM is widely distributed in the country and attacks all cultivated and wild varieties of citrus. Since the pest causes indirect damage, exact figures on economic losses are not available. In the coastal areas and plains, there are 12-13 generations of CLM whereas in the hilly areas in the North, there are 6-7 generations per year. Peak population periods are May and August - November.

Insecticides are very rarely used against CLM in Pakistan. Some small-scale efficacy tests were conducted on phosphamidon 100 SCW (Dimecron), methamidophos 60% EC (Tamaron), dimethoate 40% EC (Roxion), and triflumuron 25% WP (Alsystin). It was concluded that all of these provided good control but phosphamidon was the most effective. Alternate methods of control include pruning of infested shoots in small orchards and refraining from growing lemons in orange orchards. Five indigenous parasitoids (Sympiesis purpureus, Tetrastichus sp., Elasmus sp., Cirrospilus sp. and Citrostichus phyllocnistoides) are known from CLM in Pakistan. No hyperparasites have been recorded. No natural enemy has been introduced into Pakistan. There is no IPM programme and no biological or ecological research or extension activity going on in Pakistan. Farmers are expected to be receptive to any non-chemical control programme when such a programme becomes available. At present no donor support is available.

SAUDI ARABIA

CLM was first found on citrus in the eastern province in 1960. In 1982 it was declared an economic pest causing serious damage to nurseries and orchards throughout the Kingdom. All citrus varieties grown in the country are affected by CLM, but it is more severe on citron, orange, mandarin, lime, lemon and sweet lemon. No work has been done to estimate economic losses. No known resistant or tolerant varieties are grown in Saudi Arabia.

There are five generations per year with two population peaks during spring and autumn. Pesticides used against CLM were Dursban, Dipterex, Supracide, Dimethoate, Metasystox and Salut. Three sprays of each product were made at fortnightly intervals. No other control measure is taken against the pest. No work has been done on the natural enemies of CLM in the country, but Ageniaspis sp. has been known to be present in the country since 1960. No exotic parasitoids have been introduced. There is no IPM programme available for the pest; therefore, farmers’ attitude cannot be predicted. No research work on CLM is being carried out; however, some leaflets have been prepared by extension personnel for distribution to farmers. CLM control is the responsibility of the National Centre for Horticultural Research and Development. No donor support is available.

SUDAN

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There is no authenticated information on the first record of CLM in the Sudan, but the pest was considered an economic species as early as the 1960s. It is widely distributed in citrus producing areas and infests all varieties. There are about 8-10 generations per year, with population peaks occurring during February/March and October/November. Three insecticides, lannate, marlate and malathion, have been used and found to be fairly satisfactory. A formulation of pure petroleum oil ‘Albolinium’ is regarded as a potential product for CLM control.

The following four species of parasitoids have been recorded from CLM: Cirrospilus ingenuus, Cirrospilus cinctiventris, Citrostichus phyllocnistoides and Elasmus sp. A maximum combined parasitism rate of 40% has been observed during the cool season. With regard to other non-chemical control practices, a few steps are taken, e.g. establishing nursery beds under shade to provide a favourable habitat for natural enemies and to enhance vigorous growth of seedlings to enable them to compensate for the mild pest damage. Removal and burning of infested shoots is also recommended as an effective control measure. National attention has not yet been focused on the problem of CLM. Therefore, research and extension programmes for tackling this pest are non-existent in the Sudan.

SYRIA

CLM was first noted in July 1994 and in September of the same year it was declared an economic pest of nurseries. It is found in all citrus growing areas of the country and affects all varieties. There are no economic losses to mature trees but nurseries suffer major damage. No resistant or tolerant varieties are grown in Syria. There are about 8 generations of CLM per year with peaks occurring during summer and autumn. Several pesticides have been tested but only limited success was observed. Frequent applications of Neem Oil and Vertimec at 5-day intervals were found to be necessary for obtaining the desired results. No insecticide is recommended for use against CLM in commercial orchards in Syria. Pruning of infested shoots, management of fertilizers and irrigation are recommended as cultural practices. It was noted that plants kept under artificial light during the night did not suffer as much damage as plants kept in the dark.

Biological control is the main approach adopted by the Government. Three indigenous species of parasitoid have been recorded and four exotic ones have been introduced. Mass-rearing of indigenous and introduced parasitoids for dissemination is the main activity. In addition, a study of the biology and ecology of the pest and natural enemies is underway. Farmers are very receptive to biological control programmes. Excellent extension activities are available. A number of extension leaflets have been prepared for farmers’ benefit. The Citrus Board is the main research institute responsible for CLM control. Financial assistance is provided by the Government and UNDP, and technical assistance is provided by FAO.

TUNISIA

The CLM appeared suddenly during November 1994 at Tabarka, a town near the Algerian border, and spread rapidly across to northeastern citrus growing areas. In June 1995 CLM was also recorded in Djerba near the Libyan border. Its attack was so heavy that the same year it was proclaimed an economic pest. It has become

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established in all citrus producing regions of the country and no variety is resistant to attack. Some insecticides tested for its control included Oviron, Marcole, Cascade, Confidor and Consult. The most effective chemicals used were Confidor and Consult applied at intervals of 10 to 15 days in nurseries and young trees.

Sustained efforts to record indigenous parasitoids resulted in the discovery of Pnigalio sp., Cirrospilus pictus, Cirrospilus sp., Neochrysocharis formosa, Teleopterus erxias, Sympiesis gregori, Aprostocetus sp., Pteormalus sp. and Diglyphus isaea. These indigenous parasitoids provided 50% combined rate of parasitism. No hyperparasite has been found but Cirrospilus may occasionally be acting as a secondary. In addition, Ageniaspis citricola was introduced from Australia. It was mass-reared in plastic houses and released in the field during June 1996. Preliminary results indicate a recovery from the field.

Farmers are expected to adopt biological control with good extension activities. Studies are in progress on the biology and population dynamics of the pest and its natural enemies. Some leaflets on the biology and control of the pest have been produced. The key institute responsible for CLM control is the Plant Protection Section of the College of Agriculture at Sousse on the Mediterranean coast. The Government provides financial support for research and control programme, while FAO is providing technical and partial financial support.

TURKEY

The citrus leafminer was first noted in June 1994 and in July of the same year, it acquired the status of an economic pest warranting immediate pesticide applications. It is found in every citrus orchard expect those on the Black Sea coast and all varieties are susceptible. Economic losses are not known in monetary terms, but the fact that a large scale control campaign is being carried out is enough to justify its status as an economic pest. Laboratory and field studies on the biology and phenology of the pest are in progress. Two peaks of populations occur from June to mid-July and from mid- August to September. Pesticides are recommended only for young trees and nursery seedlings. Abamectin, hexaflumuron and their combinations with mineral oil are the most commonly used insecticides. Cultural control measures include minimum fertilization in early spring, prevention of excessive irrigation and pruning of infested extra shoots. About 10 indigenous species of parasitoid have been recorded from CLM. Recently, Ageniaspis citricola, Cirrospilus ingenuus and Semielacher petiolatus have been introduced from Australia. Their culture is being established in the laboratory for field release in the near future. An IPM programme is still underway in citrus orchards and the new pest is being accommodated in the prevailing IPM programme. Farmers have shown a great deal of interest in adopting IPM as a pest control strategy. Research activities comprise studies on the biology, ecology, distribution and dispersal of CLM, and economic impact and efficacy of control measures, particularly biological control. Extension activities include advice to farmers on pesticide applications for young trees only. Key institutions engaged in research on CLM are the Plant Protection Research Institute, Ministry of Agriculture, and the Plant Protection Department, University of Cukorova. No external funding received for CLM control programme.

V. INVITED PAPERS

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Mr. J. E. Peña in his presentation on “Indigenous Parasitoids of the Citrus Leafminer in Florida: Stepwise Approach to Basic Studies of the Dominant Parasitoid, Pnigalio minio” informed the meeting that seasonal abundance and parasitism of the citrus leafminer, Phyllocnistis citrella Stainton, had been investigated from summer 1993 to December 1995 on “tahiti” limes. Citrus leafminer densities increased from spring to autumn and declined during winter 1994 and 1995. Eight species of parasitoid attacked immatures citrus leafminers in commercial and experimental lime orchards. The eulophid Pnigalio minio, a primary ectoparasitoid of dipterous and lepidopterous leafminers, comprised about 80% of the parasitoids which emerged from parasitized P. citrella. Species and abundance of adult parasitoids varied considerably between leafminer generations. Based on the examination of 15,000 larvae and pupae of the leafminer, these parasitoids are apparently everywhere throughout the region, and by 1995 parasitism rates exceeding 50 percent had been observed. In general, a positive correlation between leafminer populations and parasitoid densities demonstrated that indigenous parasitoids significantly reduced leafminer densities 2.5 years after its invasion of Florida.

The biology of P. minio was studied under laboratory conditions at different temperatures (18, 21, 27 and 30o C) and 80 + 10 RH. The actoparasitoid prefers third instar larvae and prepupae, depositing a single egg near or on the body of the host. The total developmental time from egg to adult at 18o C was about 24.9 and 8.6 d at 30o C. Average fecundity was 186 eggs in a female lifetime, with maximum oviposition occurring 40 days after adult emergence. Studies were also conducted to gain knowledge on the rearing of citrus leafminer and to accommodate different phases of rearing P. minio so that rearing of the parasitoid could be maintained on a continued basis.

Mr. Badar Munir presented a paper on “Biological Control of CLM in the Near East: Techniques for rearing, releasing, efficacy evaluation and tracing information for parasitoids” and stated that the recent incursion of citrus leafminer into the Near East was initially dealt with by extensive applications of chemical pesticides. Results were not encouraging, and this dissatisfaction with chemical control led to the adoption of biological control as the most promising and permanent solution to the problem. Biological control involves studies on indigenous natural enemies and the introduction of exotic species to supplement natural control of the pest. Since there are no custom-made natural enemies for a particular pest, the selection of a promising species for introduction is the most important step in a biological control programme. The candidate species should be capable of acclimatizing to the new environment. It should have a better biotic potential in relation to the host, and should have good searching ability. More than 40 species of hymenopterous parasitoid are known to attack citrus leafminer throughout the world. Of these, some 25 species have recently been found to be associated with CLM in Near East countries. Seven exotic species of parasitoid have also been introduced into the Region from China, Thailand, Florida and Australia. Active biological control programmes are in force in Syria, Israel, Cyprus, Morocco, Oman, Tunisia and Turkey. Techniques for parasitoid rearing were started from scratch and gradually refined to produce sufficient numbers of exotic and indigenous parasitoids for field release. The most important introduced species were Ageniaspis citricola, Cirrospilus ingenuus and Semielacher petiolatus. These were mass-reared and

13

released in the fields in Syria, Israel, Morocco and Tunisia. Post-release studies have indicated their establishment. Rearing of these parasitoids involved three trophic levels, i.e. the plant, pest and parasitoids. Greenhouses were built to produce sufficient numbers of parasitoids for field releases. Evaluation of their efficacy based on rates of parasitism is in progress. Biological and ecological information on CLM and its native and introduced natural enemies is being accumulated to improve CLM management techniques. Cooperation among scientists of the Region in the exchange of ideas and information and transfer of technology has proven very useful in streamlining the biological control programmes for CLM in the Near East.

In his presentation on “Citrus Leafminer Mediterranean Network” Mr. John LaSalle discussed the parasitoid complex attacking CLM. There are now about 20 indigenous species of parasitoid which have switched over to attack CLM in the Near East. Of these species, 4 or possibly 5 have shown potential for providing partial to substantial levels of biological control on CLM: Cirrospilus pictus, Cirrospilus sp. nr. lyncus, Pnigalio sp., Ratzeburgiola incompleta and possibly, Baryscapus sp.

Six exotic species of parasitoid have been introduced into the Near East. Three of these are definitely established and show some promise as biological control agents: Quadrastichus sp., Cirrospilus ingenuus and Semielacher petiolatus.

There are now about 70 species of parasitoid recorded from CLM worldwide. Some of these may be suitable if further introductions into the Region are deemed necessary.

There is little evidence that exotic parasitoids are providing control levels higher than indigenous parasitoids, and it was felt that biological control efforts should begin with an effort to augment and incorporate indigenous parasitoids.

Efforts to establish a Citrus Leafminer Mediterranean Network to support regional biological control against this pest were discussed.

As a pre-requisite to formation of such a network, the following problems were identified which necessitated a network:

- Lack of communication/information transfer between countries - Lack of suitable infrastructure in many countries - Lack of trained experts in taxonomy and biology of parasitoids - Lack of biological information concerning parasitoids.

The following preliminary activities were identified as being necessary to promote the biological control of citrus leafminer in the Mediterranean Basin:1. Establish information exchange network.2. Provide local training fora on recognition of CLM parasitoids.3. Supplement survey work on local parasitoid complexes.4. Provide essential taxonomic underpinning for programme.

5. Conduct biological studies on potential biological control agents to ensure suitability for importation and release.

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6. Establish mass-rearing programmes of selected biological control agents to support a regional programme.7. Effect transfer of parasitoids among countries.

8. Implement post-release parasitoid efficacy studies and detailed documentation on effect of the programme.

Participants were invited to propose additional activities relevant to the needs of their countries.

VI. ROUND TABLE SESSION

The pest status of CLM and current measures for its control in the Near East region were thoroughly discussed during the round table session. The main conclusions drawn from the discussion are the following:

a. Status of Citrus Leafminer in the Region

1. Citrus leafminer

The citrus leafminer (Gracillariidae: Lepidoptera), commonly known as CLM, attacks several plants of the family Rutaceae but its main host is the genus Citrus. The adult moth, which is very small in size, lays eggs on very tender leaves of new flushes. The newly hatched larvae bore through the leaf surface and make serpentine mines. The infested leaves acquire a silvery gloss. The full-grown larvae make a chamber at the edge of the leaf to pupate. The total development period from egg to adult emergence ranges from 13-52 days, depending on the environmental conditions; there may be from 6 to 13 generations per year. Although CLM is an indirect pest, the nature of its attack on new foliage makes it a serious threat to the general health and appearance of the plant. The infested leaves curl down and may fall prematurely. A very heavy attack means there will be no mature leaves on the infested trees after a few years. Intensity of attack depends upon the season. The spring flush usually sustains low damage but summer and autumn foliage may be completely destroyed. Nurseries and young plantations are most severely damaged. In mature orchards, the effect of CLM on the yield is hard to calculate because of the fact that it is an indirect pest, and loss assessment is complicated because of the many parameters involved.

P. citrella is believed to have originated in Southeast Asia and China, but it was known to be present as far north as Korea and Japan and eastward as far as Saudi Arabia. Recently, it has shown a remarkable advance into other territories and has become a cosmopolitan species in the true sense of the word. Corollary to its rapid dispersal, an increase in its severity of attack has been noticed in all regions. At present, it is found in Asia, Africa, Australia, the Caribbean, South, Central and North America, the Mediterranean Basin and the Near East.

The sudden and large-scale invasion of CLM in this area has caused a great deal of concern to farmers, plant protectionists, researchers and concerned authorities. Campaigns to deal with the CLM problem were immediately initiated in every affected country. Since this pest was new to this area, very little information was available locally. Biological data and information on potential measures to control this pest were acquired through literature or correspondence with other scientists. Studies on intensity of attack, biology, phenology and natural enemies, and trials on

15

suitable pesticides were begun in departments responsible for crop protection. Chemical control was given the initial priority but Integrated Pest Management, with a strong biological control component, was soon acknowledged to be the most appropriate strategy for sustainable control of CLM.

2. First records of the CLM in the Near East

In the Near East, CLM has been known in Pakistan since 1916, in Saudi Arabia and in Sudan since 1960, in Iran since 1961, in Oman since 1972, and in Iraq since 1992. During 1994, it was recorded as a major pest in all Near East countries and assumed the status of an economically important pest almost immediately after its detection in every country, affecting commercial orchards, young plantations, nurseries and backyard gardens. Its extensive dispersal within a year after its arrival is unique in the history of outbreaks within the Region.

3. Possible explanations for the rapid spread of CLM

Possible explanations offered for the sudden worldwide spread of the citrus leafminer are:

Evolution of new and more virulent biotypes through mutation or hybridization of different geographical races;

Development of resistance to pesticides; Favourable effect of mild winters which produced additional numbers of

generations; Ecological changes brought about by weather disturbances; and Movement of plants from infested regions into previously uninfested

areas.

4. Economic importance

CLM causes severe damage to nurseries and young trees. Its effects on mature trees are not well understood. The economic losses caused by CLM still need to be assessed in monetary terms.

5. Varietal susceptibility

CLM seems to affect all varieties grown in various countries, but some varieties are more susceptible than others. In general, lemons and mandarins suffer the most, while grapefruits are the least affected. The extent of susceptibility seems to be related to flushing patterns of the varieties. No variety known to be resistant to CLM is grown in the Region. The low susceptibility observed in some varieties may be a case of ‘pseudo-resistance’.

6. Control measures

6.1 Chemical control

So far, chemical control, mainly practised as foliar applications of pesticides, has been the major strategy used against CLM in almost every country. A number of products, singly or in combination, has been tested and recommended for controlling

16

the CLM. Some of them have been found effective but, in general, their effect did not last more than two weeks. Effective chemical control is difficult to achieve as larvae are protected by the leaf cuticle and pupae are well concealed in pupal chambers. It is well known that the application of pesticides will disrupt the biological control of other pests of citrus such as whiteflies, scale insects and mites. Therefore, chemical control alone is obviously not a viable strategy for the CLM. Use of pesticides can be justified only for nurseries where weekly applications provide a fair amount of protection from leafminer attack. In non-bearing young orchards, selective pesticide applications have been used in some countries. There are, however, serious concerns about the cost of applications and development of resistance. A list of pesticides tested in the Region and considered to be effective against CLM is presented in Table 1.

6.2 Cultural and mechanical control

Cultural and mechanical control practices employed in a few countries consisted of reduced irrigation and fertilization to suppress the autumn flush, early fertilization to stimulate the spring flush, and pruning of infested shoots to destroy egg and larva populations. Pruning of infested shoots is considered impractical by most countries, although it is very useful in reducing CLM populations.

6.3 Biological control

6.3.1 Indigenous natural enemies

An inventory of the natural enemy fauna, in particular the parasitoids, is being made in most countries. Specific identifications of the majority of the these parasitoids have been made through the International Institute of Entomology, London. The parasitoids remained active throughout the flushing seasons. Combined parasitization rates over 50 percent were reported in many areas. Experience from Syria, Tunisia and Turkey shows that indigenous parasitoids play an important role in controlling CLM. Evaluation of the impact of native natural enemies on CLM population development needs further investigation. Parasitoids recorded from CLM during 1994-96 in the Near East are shown in Table 2.

6.3.2 Exotic natural enemies

Six species of parasitoid have been introduced into the Region for biological control of CLM. At least three species have become colonized in Cyprus, Morocco, Syria and Tunisia. Studies on their biologies and rates of parasitization to evaluate their efficacy are being carried out in these countries. So far, low rates of parasitization have been reported. Introduced parasitoids are listed in Table 3.

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18

19

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6.4 Integrated control programmes

In most countries, attempts are being made to deal with the problem through a combination of more than one control measure. However, well-defined IPM programmes are not in place as yet. In Syria and Turkey, considerable progress has been made to integrate CLM control in a comprehensive IPM programme for all citrus pests.

7. Farmer attitude to adoption and implementation of integrated control programme

For obvious reasons, such as, the failure rate and high cost of chemical control, the farmer community appears to be willing to adopt IPM programmes. It is, however, essential that their efficacy be demonstrated. The interests of farmers in bioagents is well demonstrated in Syria and Turkey.

8. Research activities

Field trials on various groups of pesticides and application techniques are being performed in all countries. In some countries, studies are being carried out or have been planned on the biology, ecology, phenology, extent of damage, quantitative and qualitative assessment of indigenous parasitoids, introduction of exotic natural enemies, efficient rearing techniques for CLM and its natural enemies, field releases and post-release situations, etc. The effect of keeping the nursery plants under artificial light at night to deter oviposition is being investigated in Syria .

9. Extension activities

Extension programmes exist in many countries. Leaflets, brochures, photomicrographs, diagrams and other extension material have been produced in some countries for the benefit of farmers. Workshops and seminars are occasionally held to train junior scientists and extension workers and acquaint them with CLM and its control. However, contact between researchers, extension workers and farmers regarding the CLM problem are not frequent. During 1995-96, Syria hosted study tours for researchers and extensionists from other countries.

10. Key institutions and personnel involved in CLM control

Institutions responsible for pest control are the plant protection departments and research centres of the Ministries of Agriculture and entomology departments of major universities. Some cooperation exists among various research groups.

11. Donor support

Algeria, Morocco, Syria and Tunisia have received technical support from FAO.

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b. Proposed Strategies for the Containment of Citrus Leafminer in the Region

The special characteristics of the CLM, i.e., recent incursion, prolific nature, concealed habitat of larvae and pupae, small size and elusive nature of the adults, specialized feeding habitat restricted to tender leaves, confinement of developmental thresholds between 12-35ºC, abundance of natural enemies, etc., make it a prime candidate for integrated control. It was evident from the discussion that control strategies will differ for nurseries and mature orchards. Based on the above analysis of the situation, the round table discussion proposed the following strategies:

1. Strategies proposed at the nursery level

1.1 Chemical control

Several pesticides were found to be effective against CLM. The effect, however, lasted for a maximum period of three weeks only. Applications with appropriate pesticides should be made at weekly intervals until the cessation of the susceptible period. Mixtures of pesticides such as abamectin + oil, etc. should be considered for control of existing infestations. Pesticides can also be used to deter egg deposition. The least expensive and safest of the selective pesticides should be used for this purpose. Pesticides should be rotated to avoid development of resistance.

1.2 Novel techniques

Since moths assume mating and oviposition activities only in the dark, the use of artificial light at night will reduce egg deposition. Trials should be carried out to assess the efficacy and economics of this novel technique. Side-effects, if any, on plants should be investigated.

1.3 Legislative control

Movement of infested seedlings from nurseries should not be allowed.

2. Strategies proposed at the orchard level

2.1 Cultural practices

Cultural practices might be useful to decrease CLM populations. Manual removal of early and late-growing flushes and pre-flush pruning promote uniform flushing. The goal of these actions is pre-flush population reduction by host deprivation followed by rapid and uniform flushing to desynchronize flushing and CLM population peaks. The CLM populations are lowest in the spring, so rapid growth of spring flush is promoted by well-managed fertilization and irrigation during the winter. Populations of CLM in summer and autumn are high, so these flushes are discouraged by reducing fertilizer and irrigation in a way that allows to maintain the health of trees.

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2.2 Mechanical control

Pruning of infested shoots and placing them under the trees is a valid method of destroying egg and larval populations of CLM. Clipped leaves soon dry up, causing the destruction of eggs on leaves and of larvae in the mines. Only pupae are able to survive. This action does not harm the parasitoids as their food source (parasitized larvae) are in a state of preservation. The adult parasitoids will be able to emerge even from dried leaves and resume their activity on the remaining host individuals. This method will be useful, especially during the autumn flush when only a reduced number of pests will be able to enter the overwintering stages. There will be fewer adults to infest the spring flush, which means that the summer flush will also be exposed to a smaller number of potential attackers.

2.3 Chemical control

The application of foliar sprays on mature trees is not recommended because of low effectiveness, high costs and negative impact on natural enemies of citrus pests. However, there may be a justification to treat young trees, and the following recommendations apply to young trees only (1-5 years). Chemical control of CLM on young trees should be conducted as much as possible within an IPM context. In selecting a pesticide, preference should be given to those that can be applied as a soil drench or as trunk application. The regular application of broad spectrum insecticides such as organophosphates and carbamates is not recommended. Third generation pesticides (such as growth regulators) combined with mineral oil have given good results in countries where they were tested; however, there is no information as yet of their impact on natural enemies of citrus pests.

As a rule of thumb, pesticide application should start when 30 percent of the leaves show mines, but further research on the cost-effectiveness of this action is required. The objective of chemical control should be population reduction of the CLM. Citrus plants can support a certain level of infestation without major effects on growth. Precise data on this, however, are not available.

2.4 Biological control

The conservation of indigenous natural enemies (parasitoids and predators) through none or limited use of insecticides in the citrus ecosystem should be the key element in a CLM control strategy. Over 20 species of parasitoid have been recorded from the Near East Region. If necessary, the indigenous parasitoid fauna can be enriched with exotic species. It is too early to conclude if these introductions will lead to a substantial improvement of CLM control.

Exotic parasitoids for introduction should be carefully selected with due attention to specificity to prevailing climatic conditions and the likelihood of complementarity to that of indigenous parasitoids. There are almost 70 species of parasitoid known to attack CLM worldwide, and these are listed in Table 4.

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3. Strategies proposed at the extension level

3.1 Farmer training

Farmers and nursery managers are the ultimate recipients of IPM programmes. Their acceptance or adoption of the programmes depends upon the proven performance of IPM options in farmers’ fields or pilot farms. They want to reduce the protection costs with minimal risk. Failure of a weak or untested programme can cause a rift in their trust in IPM. Farmers should become familiar with the biology, ecology, nature and extent of damage and proven methods of CLM control. Frequent contact between farmers and extensionists to discuss the pest situation is extremely necessary.

3.2 Extension aids

Brochures, leaflets and pamphlets on CLM biology and its control, natural enemies and other related information should be prepared for the benefit of farmers. Educational films and videos and radio and television programmes should be prepared for dissemination of CLM control strategies and recommendations.

3.3 Training of technical cadres

Extension agents and junior researchers play an important role in pest control. The quality of their training will be reflected in the extent of acceptance of IPM programmes for CLM. Regular training sessions are strongly emphasized. In-service training, study tours and fellowships for training abroad should be provided.

4. Research activities

The following research activities could be undertaken on a short-term or long- term basis:

a) Monitoring and assessment of indigenous natural enemies of CLMb) Performance of CLM in relation to citrus cultivarsc) Susceptibility of natural enemies to pesticides used in CLM controld) The effect of soil drenches and trunk treatment on CLM controle) Impact of pesticides used in CLM control on other citrus pests and natural

enemiesf) Studies on biology, ecology, host range and seasonal activities of CLM and its

natural enemies under local conditionsg) Action threshold levels

V. RECOMMENDATIONS

1. Governments should support the implementation of the proposed strategies through allocation of the required funds and resources, and by seeking further internal and external financial and technical assistance.

2. Countries should cooperate at the regional level to coordinate activities and facilitate exchange of information, natural enemies, technology and training.

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3. International cooperation should be fostered to exchange experiences and support regional activities and links with other regional networks and activities.

VI. FOLLOW-UP ACTION

Follow-up action on the recommendations made by the workshop was discussed. An outline of a Regional TCP project proposal on “CLM Control in the Near East” (Annex I), to initiate the implementation of the strategies recommended by the Workshop was reviewed and supported unanimously by the participants. The Workshop requested FAO to finalize the above project proposal and send the final project document to participants so they could take the necessary follow-up action with their respective governments.

VII. ADOPTION OF THE REPORT

The report was unanimously adopted by the meeting.

VIII. CLOSING SESSION

Mr. Schulten thanked the Syrian Government and in particular the Citrus Board for their support and hospitality. He also expressed appreciation and thanks to the participants and invited speakers for their technical inputs which enabled the Workshop to achieve its objectives.

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(Annex I)

Outline of a Regional TCP Project on Citrus Leafminer Control in the Near East

SUPPORT TO INTEGRATED CITRUS LEAFMINERCONTROL IN THE NEAR EAST

I. Background and Justification

Citrus is grown as a commercial and subsistence crop in the countries of the Near East. Various varieties are grown in over one million hectares which produce more than 10 million tones of fruit annually. Citrus fruit is an important source of nutrition and refreshment; it provides high levels of vitamin C and potassium and some of the daily requirements for essential nutrients such as folic acid and thiamine (vitamin B-1). In many Near East countries, citrus production plays a significant role in the local economy, providing employment for growers and farm workers and supporting industry personnel involved in packing, processing and transportation. Citrus also provides some countries of the Region with an important source of foreign revenue.

The citrus crop in the region has its share of pests, comprising about 25 species of arthropods. About half a dozen of these are regarded as economic pests. Techniques for their control are available through various pest management programmes in the Region. The situation has recently been drastically changed with the spread of citrus leafminer (CLM), Phyllocnistis citrella in all the countries of the Region. It attacks the new leaves of seasonal flushes and in severe cases, as noticed in the Region, causes complete loss of new foliage. Although CLM is an indirect pest, the nature of its attack makes it a serious threat to the general health and appearance of the infected plants. The infested leaves curl down and may drop prematurely. Very heavy attack means there will be no mature leaves on the trees after a few years, resulting in the demise of the whole citrus industry. The sudden invasion and extensive dispersal of the new pest have caused great concern to farmers, researchers and administrators. Affected countries are trying to manage the pest through chemical pesticides and in some areas exotic parasitoids have been introduced for biological control.

A Regional Workshop, organized by FAO and hosted by the Syrian Citrus Board in October 1996, reviewed the effectiveness of ongoing control methods and the experiences of the countries in the Region in dealing with the leafminer problem. Invariably, much emphasis was put on chemical control. The need for repeated applications leading to high costs, the risk of pesticide resistance and an overall disturbance of the citrus ecosystem, reoriented control efforts towards biological control. In some countries considerable progress has been made in initiating a biological control programme. In most countries, however, such activities still have to start. The main constraint for the development of biological control programmes in affected countries is lack of information and trained personnel in biological control of

26

citrus leafminer in the context of integrated control of citrus pests. In addition, there is a lack of effective extension campaigns to train growers in the biological control of citrus leafminer and to stop the heavy over-use of pesticides.

The workshop recommended a strong collaboration among the countries of the Region for the development and implementation of an integrated control programme. Effective use should also be made of the experienced gained in the Mediterranean Basin and North, Central and South America where countries are dealing with the same emergency situation.

Well-focused workshops for training and information exchange, study tours and consultancies are considered the most effective way to strengthen national leafminer control programmes. Technical cooperation between developing countries and FAO’s Partnership Programme with scientific institutions should play a key role in these activities. In this context, assistance from FAO’s Technical Cooperation Programme is urgently requested. II. Objective of the assistance

The objective is to provide technical support to the Region in successful implementation of biological control of CLM in order to prevent the decline in the quantity and quality of citrus yield caused by the new pest, and to extend expertise from citrus producing countries with advanced techniques to those that have less expertise and research capability.

The output of this project is the development and implementation of environmentally safe, effective, economical and sustainable biological control programmes for all citrus producing countries of the Region.

III. Workplan (To be further defined)

Activity 1.

Nomination of a National Coordinator and establishment of a coordinating committee by participating countries.

Nomination of a Regional Coordinator.

Activity 2.

Regional workshops on:

a) Collection and identification of natural enemiesb) Biological control techniquesc) Integrated citrus pest management with emphasis on leafminer controld) Training of trainers to train farmerse) Status of leafminer in the Region

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Activity 3.

Study tours to:

a) Countries in the Region that have made substantial progress in the integrated control of leafminer

b) Countries outside the Region

Activity 4.

Consultancies on specific topics

Activity 5.

Supply of required material

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(Annex II)

Workshop on Citrus Leafminer (Phyllocnistis Citrella)and its Control in the Near East

30 September - 3 October 1996Safita (Tartous), Syria

PROGRAMME

Monday, 30 September 1996

Inauguration Session:

09.00 - 10.00 Registration10.00 - 10.30 Opening Session10.30 - 11.00 Coffee Break11.00 - 12.00 Key note address

“World Status of Citrus Leaf Miner and its Control: Problem and Progress”. (Mr. J. Peña)

12.00 - 12.30 Organizational issues12.30 - 14.00 Lunch

Country Reports Session

14.30 - 14.45 CLM and its control in Cyprus (Andreas Patsias)14.45 - 15.00 CLM and its control in Egypt (Abdel Fatah Hashem)15.00 - 15.15 CLM and its control in Iran (M.Ibrahim Jafari)15.15 - 15.30 CLM and its control in Iraq (A.R. Khattat)

15.30 - 16.00 Coffee Break

16.00 - 16.15 CLM and its control in Lebanon (Aref Helou)16.15 - 16.30 CLM and its control in Libya ( Ali Amin Kafu)16.30 - 16.45 CLM and its control in Malta (David Mifsud)16.45 - 17.00 CLM and its control in Morocco(Ahmed Mazih)17.00 - 17.15 CLM and its control in Oman (Salim Al-Khatri)17.15 - 17.30 CLM and its control in Pakistan (Agha I. Mohyuddin)

Tuesday, 01 October 1996

Morning Visit to Citrus Board facilities and Citrus Orchards

Country Reports Session (Continued)

14.40 - 15.00 CLM and its control in Saudi Arabia (Majed Al-Fehaid)15.00 - 15.15 CLM and its control in Sudan (Musa Abdalla Ahmed)

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15.15 - 16.00 CLM and its control in Syria (Wajih Al-Mouie)16.00 - 16.15 CLM and its control in Tunisia (Brahim Chermiti)16.15 - 16.30 CLM and its control in Turkey (Rabia Yumruktepe)

16.30 - 17.00 Coffee Break

Invited Papers Session

17.00 - 17.45 “Indigenous Parasitoids of the Citrus Leafminer in Florida: Stepwise Approach to Basic Studies of the Dominant Parasitoid, Pnigallo minio”.

Mr. J. Peña

17.45 - 18.30 “Techniques for Rearing and Tracing Information on CLM Parasitoids”.

Mr. B. Munir

18.30 - 19.15 “Citrus Leaf Miner Mediterranean Network”.Mr. J. LaSalle

Wednesday, 02 October 1996

Round Table Session

09.00 - 12.30 Round Table Discussion12.30 - 14.00 Lunch14.00 - 18.00 Development of Control Strategies

Conclusions and Recommendations.

Thursday, 03 October 1996

08.30 - 12.30 Field Visit14.30 - 15.30 Adoption of the Workshop Report

Closure of the Workshop

30

(Annex III)

Workshop on Citrus Leafminer (Phyllocnistis Citrella)and its Control in the Near East

30 September - 3 October 1996Safita (Tartous), Syria

LIST OF PARTICIPANTS

1) Participating Countries:

Cyprus LebanonAndreas Patsias Aref HelouAgricultural Officer, Plant Protection Section Ministry of AgricultureDepartment of Agriculture BeirutNicosia Tel: 01-455617 - 455618Tel: 02-302254

Egypt LibyaAbdel Fattah Gad Hashem Ali Amin A. KafuResearch Prof. Research EntomologistA.R.C., FPRI Agricultural Research Centre3, El-Monairy St. Hadaik El-kobba P.O.Box 2933, TripoliCairo Tel: 218-21-603865 - 605540Tel: 3556176 - 2850030 Fax: 218-21-605541

Tlx: 20320

Iran MaltaMohammad Ibrahim Jafari David MifsudMinistry of Agriculture EntomologistPlant Pests & Diseases Research Institute Department of Agriculture Tehran Research and DevelopmentTel: 98-21-2401242 Centre,Fax: 98-21-2403691 Ghammieri - Marsa

Tel: 356-224911/312110Fax: 356-440251E-Mail: davemif@keyworld.net

Iraq MoroccoAbdul-Razzak Khattat Ahmed MazihSenior Scientific Researcher Professor of EntomologyGeneral Body for Agr. Research Hassan II - AgadirMinistry of Agriculture Plant Protection DepartmentAbu-Ghraib Agronomy & Veterinary InstituteBaghdad P.O.Box 121 Ait-MelloulTel: 5110470 - 5110465 Tel: 212-8-241006

Fax: 212-8-242243Oman Syria

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Salim Ali Humaid Al-Khatri Wajih Al-MouieEntomology Assistant Researcher Director of Citrus BoardGeneral Directorate of Agricultural Research Ministry of Agriculture & P.O.Box 50, Postal Code 121 Agrarian ReformMuscat TartousTel: 968-893132 / 893917 Tel: 963-34-226041Fax: 968-893097

Pakistan TunisiaAgha Ikram Mohyuddin Brahim ChermitiChief Consultant Professor of Entomology Integrated Pest Management Projects Plant Protection DepartmentHouse No. 16, I/8-3 Ecole Supérieure d’Horticulture Islamabad de Chott MeriemTel: 92-51-446362 4042 SousseFax: 92-51-443461 Tel: 03-248134/459E-mail: ikram@ipm.isb.erum.com.pk Fax: 03-248275

Saudi Arabia TurkeyMajed S. Al-Fehaid Rabia YumruktepeResearch Associate EntomologistNational Agric.& Water Res. Centre Ministry of Agriculture and Rural Riyadh AffairsTel: 4576780 Plant Protection Research Fax: 4584979 Institute

Adana Tel: 90-322-3219581Fax: 90-322-32248

SudanMusa Abdalla AhmedAssociate ProfessorNational Insect CollectionsAgricultural Research CorporationWad Madani

2) Invited Speakers 3) FAO

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Jorge E. PeñaAssociate ProfessorUniversity of Florida, T.R.E.C.. 18905 S.W. 280th Street, Homestead, FL 33031U.S.A.Tel: 305-246-7048Fax: 305-246-7003

John LaSalleInternational Institute of Entomology56 Queen’s GateLondon, U.K.Tel: 44-171-938-9364Fax: 44-171-938-9309

Badar MunirFAO Consultant210 Gilley Road, MT. Juliet, TN 37122, U.S.A.Tel: 615-758-4603Fax: 615-758-4603

Mahmoud TaherSenior Plant Protection OfficerFAO Regional Office for the Near East

P.O.Box 2223Cairo - EgyptTel: 00202-3497184Fax: 00202-349581Tlx: 22155 FAO NE UN

Gerard G.M. SchultenSenior Officer (Entomology)Plant Production and Protection DivisionFAOViale delle Terme di Caracalla00100 RomeItalyTel: 00396-5225-3551Fax: 00396-5225-6347

Mustapha Menouar SinaceurFAO RepresentativeP.O.Box 10709 DamascusSyriaTel: 00963-11-3339152Fax: 00963-11-3330429

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