jex2007_climateariditythelastomatoidsdistribcockroachaustralia

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Local climate aridity influences the distribution of

thelastomatoid nematodes of the Australian giant

burrowing cockroach

A. R. JE X1*, M. A. SCHNEIDER2, H. A. ROSE3 andT. H. CRIBB1

1 School of Molecular and Microbial Sciences, The University of Queensland, St Lucia, Queensland, Australia2 School of Integrative Biology, The University of Queensland, St Lucia, Queensland, Australia3 School of Land, Water and Crop Sciences, The University of Sydney, Camperdown, New South Wales, Australia

(Received 23 January 2007; revised 25 February 2007; accepted 25 February 2007)

S U M M A R Y

In this study, we examined the effects of local climate aridity on the richness and composition of the thelastomatoid

(Nematoda: Oxyurida) guild parasitizing the Australian giant burrowing cockroach, Macropanesthia rhinoceros (Blattodea:

Geoscapheinae). In total, 9 thelastomatoid species parasitized this cockroach in north-eastern Australia (Queensland).

Local observed richness ranged from 3 species (in Cooktown, Magnetic Island, Maiden Springs and Whitsunday Island) to

7 species (in Rochford Scrub). The lowest richness occurred in both relatively wet and dry climates, and the highest

richness was in moderate climates. Three species, Cordonicola gibsoni, Leidynemella fusiformis and Travassosinema jaidenae,

were found at all 13 collection sites. One species, Geoscaphenema megaovum, was found exclusively in dry to moderate

climates. The remaining species, Blattophila sphaerolaima, Coronostoma australiae, Desmicola ornata, Hammerschmidtiella

hochi and Jaidenema rhinoceratum, were found in moderate climates only. We hypothesize that the egg is the stage in the

thelastomatoid life-cycle most vulnerable to the effects of adverse climate and that the geographical distribution for each

species is, in part, bound by environments that are too dry, resulting in egg desiccation, and by environments that are too

wet, resulting in decreased oxygen uptake across the egg-shell and in osmotic lysing.

Key words: Nematoda, Thelastomatidae, guild, distribution, species-richness, climate.

I N T R O D U C T I O N

For as long as parasite systems have been studied,

parasitologists have sought to explain variation in

the assemblage of species parasitizing different in-

dividuals within and among host species. Variation in

parasitic guild structure among host species is surely

influenced by a range of factors, such as host speci-

ficity and host ecology. Within a species, however,

discerning patterns beyond random variation among

individuals has been as fascinating as it has been

perplexing. Overarching patterns governing faunal

variation are rare and universal laws difficult to

determine (Guegan et al. 2005). Perhaps the most

consistent patterns, when patterns exist, governing a

host individuals parasite fauna have been linked to

the distance decay hypothesis (Poulin and Morand,

1999; Morand and Guegan, 2000; Poulin, 2003) and

the latitudinal gradient hypothesis (Rohde, 1993;

Poulin, 1998b). The distance decay hypothesis,

in relation to parasite systems, predicts that the

similarity in the make-up of the parasite fauna

of conspecific host populations will decrease with an

increase in the geographical distance between them

(Poulin and Morand, 1999). The latitudinal gradient

hypothesis is directed more specifically at overallspecies richness of the assemblage parasitizing a

given host and is based on the observation, both in

parasite and non-parasite systems, that species rich-

ness is higher in ecosystems closer to the equator than

in those closer to the poles (Hawkins et al. 2003).

However, these patterns do not necessarily apply

to all systems (Kennedy et al. 1991; Brown, 1995;

Rosenzweig, 1995) and, although they have been

used successfully in some systems occurring over

large geographical areas, the utility of distance decay

and latitudinal gradients across smaller geographical

ranges or, in the case of the latitudinal gradienthypothesis, longitudinally broad rather than lati-

tudinally long ranges, is perhaps somewhat limited.

A major obstacle in defining non-random patterns in

parasite systems is the remarkable array of parasitic

behaviours and life-cycles. Perhaps a more targeted

approach of searching for non-random patterns in

more specific systems in which there are fewer con-

founding obstacles, such as intermediate hosts, will

provide a simpler system for investigations leading to

additional discernment of useful patterns in the

variation of parasite assemblages.

For any parasite, one of the most dangerous

periods of its life-cycle is the time during which it

must exist outside of its host. Multi-host life-cycles,

* Corresponding author: Department of VeterinaryScience, The University of Melbourne, Werribee,Victoria, Australia. E-mail: [email protected]

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Parasitology, Page 1 of 8. f 2007 Cambridge University Press

doi:10.1017/S0031182007002727 Printed in the United Kingdom


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such as those found in many platyhelminths and

protists, represent a common adaptation which

helps overcome this danger by allowing life-cycle

stages to shelter in intermediate hosts. Many para-

sites, such as the oxyurid nematodes (pinworms),

do not have intermediate hosts, and thus have direct

modes of transmission.

In pinworm systems, females produce eggs whichare shed in the hosts faeces and must survive in

the external environment long enough to be ingested

by a new host (Adamson, 1984). Numerous studies

have suggested that oxyurid eggs are sensitive to

environmental conditions, particularly moisture

(Geller, 1944; Anya, 1966; Adamson, 1989; Grice

and Prociv, 1993). Geller (1944) showed that eggs

of the human pinworm, Enterobius vermicularis, re-

quired humidity levels ofy100% to develop. Similar

requirements were observed by Skrjabin et al. (1960)

for the horse pinworm, Oxyuris equi. Grice and

Prociv (1993) demonstrated that eggs of the rat pin-worm, Syphacia obvelata, collapsed if exposed to

conditions that were too dry and ruptured or opened

prematurely in excessive moisture. However, these

responses are not universal; levels of susceptibility

vary among species (McSorley, 2003), suggesting

that some species are more or less suited than

others to the external environment across a range of

climates. From these findings, it can be predicted

that the pinworm fauna of widely distributed hosts

varies in response to different local climatic con-

ditions. There is presently little information avail-

able to test this hypothesis.

Macropanesthia rhinoceros (Blattodea : Geosca-pheinae) has an unusually wide geographical distri-

bution relative to the other burrowing cockroaches

(Roth, 1977; Walker et al. 1994). Jex et al. (2006)

reported the thelastomatoid fauna of this species

from a number of localities across Queensland,

Australia. Here, we extend this previous study and

examine in detail the relationship between local

climate and the observed and estimated richness and

overall composition of the thelastomatoid guilds

parasitizing this host species. We test for patterns in

thelastomatoid distribution both at the individual

species and the guild levels. Additionally, we exam-ine ecological and physiological characteristics which

may explain these distribution patterns.

M A T E R I A L S A N D M E T H O D S

Data collection

Specimens of Macropanesthia rhinoceros (n=114)

were collected from 13 localities across Queensland,

Australia, over y20 years. All cockroach specimens

were preserved in 70% ethanol, where they remained

until recent dissection. A transverse incision was

made along the posterior end of the abdomen. The

hindgut was then teased out and severed at the point

immediately anterior to the origin of the Malpighian

tubules. The excised hindgut was dissected, and all

nematodes found were extracted and preserved in

fresh 70% ethanol. Preserved nematodes were placed

in a (v/v) solution of 100% glycerol in 100% ethanol

to a final concentration of 5% glycerol and 95%

ethanol. These were left uncovered for 48 h to allow

the ethanol to evaporate, thereby leaving thespecimens in 100% glycerol. This was done to limit

any damage to the worms caused by rapid transfer to

pure glycerol. The nematodes were mounted in

glycerol using the wax-ring method described by

Hunt (2002). All nematodes were identified using a

morphological character database compiled from the

literature as described by Jex et al. (2005).

Climate comparisons

Relative aridity was calculated using Budykos

Aridity Index (h) (Budyko, 1974). We used theequation as defined by Arora (2002): h=P/PE, where

P is annual precipitation and PE is annual potential

evapotranspiration. We employed areal potential

evapotranspiration, which is defined as the evapo-

transpiration that would take place, if there is un-

limited water supply, from an area large enough such

that the effects of any upwind boundary transitions

are negligible, and local variations are integrated to

an areal average. This was done to limit the impact

of micro-climate variation at individual localities.

All climate and potential evapotranspiration data

were provided by the Bureau of Meteorology,Victoria, Australia ([email protected]).

Estimation of species richness and non-linear

regression analysis

Species richness estimates were calculated using

the software package EstimateS v.7.0 (available at

http://viceroy.eeb.uconn.edu/estimates). Although

this software package provides many species richness

estimators, only Bootstrap (Smith and van Belle,

1984), Chao2 (Chao, 1987) and Jack1 (Burnham

and Overton, 1978, 1979; Heltshe and Forrester,

1983; Smith and van Belle, 1984) were used, as

recommended by Walther and Morand (1998) and

Poulin (1998 a). Richness estimation values were

calculated over 1000 runs, using a randomized

dataset for each run. Trend analysis was performed

using the software package Statistica Kernel release

5.1 (available at www.statsoft.com). Trend lines were

fitted using the least squares method.

Egg morphometrics

The eggs were measured (at 400r magnification)

using an ocular micrometre employing an Olympus

BH-2 light compound microscope. Egg length

A. R. Jex and others 2


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and width were measured from the longest and

widest portion of each egg. Egg volume was esti-mated by calculating the volume of an ellipsoid of

the same dimensions (=4/3p* polar radius * equa-

torial radius2 ; where polar radius is one half of the

total egg length, and equatorial radius is one half of

the total egg width). Egg surface area was estimated

as the surface area of an ellipsoid of the same

dimensions (=2p* equatorial radius2

* (1+(polar

radius/equatorial radius)* arcsin(e)/e), where e=

eccentricity and is calculated as e=(1x(polar

radius2/equatorial radius2))1/2).

R E S U L T S

We examined 114 adult M. rhinoceros from 13

localities in Queensland, Australia (Fig. 1). These

localities represent the known distribution for

M. rhinoceros (see Roth, 1977 and Walker etal. 1994).

We identified 9 species of Thelastomatoidea. The

prevalences of infection for the species at each site

ranged from 9 to 100%, with the lower figure rep-

resenting a single infection (Table 1). Abundance

and intensity values were not considered here.

Observed species richness ranged from 3 species,

at Cooktown, Magnetic Island, Maiden Springs and

Whitsunday Islands, to 7 species at Rochford Scrub

(Table 2). Estimated species richness ranged from 3

species at Cooktown, Magnetic Island, Maiden

Springs and Whitsunday Islands, to 8, 12 and 10 at

Rochford Scrub for the estimators Bootstrap, Chao2

and Jack1, respectively. All 9 species were never

found at a single locality.

Localities were ranked by Budykos aridity index

(Table 2). The aridity index ranged from 0.29

for Maiden Springs (driest locality) to 0.94 forCooktown (wettest locality). Trend analysis using

the least squares fitting method suggested a strong

curvilinear relationship between species richness

and climate aridity (Fig. 2). Only the comparison

between observed richness and aridity is shown.

However, comparisons between estimated richness

and aridity revealed a similar trend, regardless of the

estimation method used.

Overall fecundity, as measured by number of

eggs in utero, ranged from a mean of 90 per female

for Hammerschmidtiella hochi to just 1 per female

for Geoscaphenema megaovum (Table 3). Egg volumeranged from 0.19 pl (L. fusiformis) to 2.23 pl

(G. megaovum). Egg surface area ranged from 6 nm2

(T. jaidenae) to 24 nm2 (G. megaovum). Egg shell

thickness ranged from 0.95 mm (B. sphaerolaima) to

4.37 mm (G. megaovum). We compared the climate

range, as indicated by Budykos aridity index, for

each thelastomatoid species with these 3 parameters

(Fig. 3); the findings of which are discussed in detail

in the following section on egg morphology.

D I S C U S S I O N

Species richness

For all localities examined, except Rochford Scrub

and Mount Garnet, estimated richness was within

2 species of observed richness, suggesting that a

high proportion of the thelastomatoid species in-

fecting M. rhinoceros at these localities have been

found. Rochford Scrub and Mount Garnet had ob-

served species richness levels of 6 and 7, respectively

(Bootstrap=8 and 7, Chao2=11 and 12, and

Jack1=10 and 10, respectively). These localities

were highly species rich and all included several

species found in only a single cockroach individual;C. australiae, G. megaovum and J. rhinoceratum

at Rochford Scrub and L. fusiformis, C. australiae,

G. megaovum and D. ornata at Mt. Garnet. It is

rare species (particularly singletons or doubletons)

which relate to estimated richness levels that are

greater than observed species richness. This effect is

exacerbated for smaller sample sizes. Walther and

Morand (1998) indicated that the Chao2 and Jack1

estimation methods performed best and should be

used in studies of parasite species richness. The

present data appear to agree with this observation. In

most localities for which estimated richness differed

from the observed richness, the Bootstrap based

richness estimates were consistently lower than those

3

4

5

11

102

7 9

128

13

16

Fig. 1. Map of the sampling sites for Macropanesthia

rhinoceros in Queensland, Australia. Alpha (1),

Boonderoo (2), Coen (3), Cooktown (4), Dimbulah (5),

Duaringa (6), Gumlu (7), Granite Gorge (8), Magnetic

Island (9), Maiden Springs (10), Mt Garnet (11),

Rochford Scrub (12), Whitsunday Island (13).

Climate aridity effects on thelastomatoid nematode distribution 3


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predicted by Chao2 or Jack1, with the exceptionof the dataset for the locality Duaringa, where

Bootstrap was slightly higher than Chao2 (4.42 vs.

4.33). In addition, in most of these localities, the

differences between Chao2- and Jack1-based rich-

ness estimates were less than the differences between

the values calculated via either of these estimators

as well as those calculated using the Bootstrap

method. The exceptions to this apparent trend were

Rochford Scrub and Mount Garnet, the 2 localities

with the highest richness levels or, perhaps more

importantly, the greatest number of singletons. It

may be that in systems with a high number of

singletons, the Chao2 method overestimates richness

levels. We take the view here that there may be

species that we have not detected in some localitiesand, therefore, all subsequent analyses of the data

were repeated for observed richness and the 3 rich-

ness estimators. In either case, Coen, Mt. Garnet and

Rochford Scrub are clearly the most species-rich of

the sites surveyed; any uncertainty about their true

richness is unlikely to have a negative impact/effect

on the subsequent analysis.

Distribution of thelastomatoids by local climate

Macropanesthia rhinoceros is found in some of

the driest to some of the wettest areas of Australia.

There appears to be a clear relationship between

thelastomatoid guild richness and local climate

Table 2. Observed and estimated thelastomatoid species richness, climate variables, Budykos aridity

index by locality for Macropanesthia rhinoceros in Queensland, Australia

(Precipitation (Prec), average areal potential evapotranspiration (AAPE), Budykos aridity (BA), observed species richness(Obs), bootstrap based richness estimation (Boot), Chao2 based richness estimation (Chao2) and Jack1 based richnessestimation (Jack1).)

LocalityPrec(mm)

AAPE(mm) BA Obs Boot Chao2 Jack1

Maiden Springs 475 1635 0.29 3 3 3 3Boonderoo 491 1617 0.31 4 5 6 6

Alpha 498 1549 0.32 4 4 4 4Dimbulah 723 1694 0.43 5 6 7 7Coen 900 1906 0.47 6 7 7 8Rochford 825 1715 0.48 7 8 12 10Mount Garnet 900 1758 0.51 6 7 11 10Duaringa 820 1500 0.55 4 4 4 4Granite Gorge 860 1500 0.57 5 6 7 7Gumlu 1058 1835 0.58 4 4 5 5Magnetic Island 1169 1800 0.65 3 3 3 3Whitsunday Island 1776 1988 0.89 3 3 3 3Cooktown 1809 1919 0.94 3 3 3 3

Table 1. Prevalence of infection for each thelastomatoid species parasitizing Macropanesthia rhinoceros in

Queensland, Australia

(Localities ranked by decreasing aridity. Cordonicola gibsoni (Cg), Leidynemella fusiformis (Lf), Travassosinema jaidenae(Tj), Geoscaphenema megaovum (Gm), Coronostoma australiae (Ca), Jaidenema rhinoceratum (Jr), Desmicola ornata (Do),Blattophila sphaerolaima (Bs) and Hammerschmidtiella hochi (Hh).)

Locality n Cg Lf Tj Gm Ca Jr Do Bs Hh

Maiden Springs 7 86 43 57 Boonderoo 9 56 33 11 11 Alpha 8 100 75 63 50 Dimbulah 10 100 80 50 10 10 Coen 6 67 100 33 83 17 17Rochford Scrub 11 100 73 64 9 9 9 27 Mt. Garnet 10 90 10 20 10 10 10 Duaringa 6 100 33 100 17 Granite Gorge 10 90 30 90 10 10 Gumlu 6 83 83 50 17 Magnetic Island 10 100 30 100 Whitsunday

Island10 100 60 70

Cooktown 11 73 64 55



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aridity. Wet localities, such as Cooktown (observed

species: 3), Whitsunday Island (3) and Magnetic

Island (3) and dry localities, such as Alpha (4),

Boonderoo (4) and Maiden Springs (3) have lower

species richnesses than mid-range localities, such

as Coen (6), Mt. Garnet (6) and Rochford Scrub (7).

Importantly, the relationships between guild

richness and climate aridity correspond to realspecies not just numerical variations in richness

statistics. Three species of thelastomatoid, C. gibsoni,

L. fusiformis and T. jaidenae, were found at all

localities. Geoscaphenema megaovum was found

in all localities with a dry climate, except Maiden

Springs, and was not found in the 6 wettest sites.

The other 5 species were all found only in mid-range

aridity sites; none was found in any of the 3 wettest

or the 3 driest sites.

Egg morphology

The survival of any parasite species depends upon itsability to successfully infect new hosts. Successful

infection is certainly improved by maximizing the

number of host encounters. In parasites with direct

life-cycles, the number of encounters can be in-

creased by increasing egg longevity, maximizing the

time over which an encounter may occur or, by in-

creasing fecundity, allowing greater frequency of

host encounters by weight of numbers. Clearly, cli-

mate may have an effect on egg longevity when eggs

are shed into the environment. Conversely, it seems

unlikely that climate directly impacts fecundity.

Certainly, any impact that climate may have on

fecundity will be indirect and exceedingly difficult to

predict.

We propose that egg longevity varies from site to

site, largely due to the climatic conditions en-

countered. Based on previous studies (Geller, 1944;

Anya, 1966; Adamson, 1989; Grice and Prociv,

1993), we predict that in dry climates desiccation is

the greatest threat to egg longevity and that in wet

climates it is threatened by osmotic lysing and egg

suffocation in water-logged soils. We hypothesizethat, under these circumstances, the most likely

indicators of egg longevity in response to environ-

mental stress will be egg surface-area to volume

ratios and egg-shell thickness. Presumably, eggs with

lower surface area to volume ratios (i.e. large eggs)

will be less susceptible to desiccation. Also, we pre-

dict that eggs with thick shells will be less susceptible

to desiccation and, hence, more successful in dry

environments.

A comparison of the egg characteristics from the

9 species examined suggests that there is some

correlation with the climate-related distributionsof these species. Three species, Cordonicola gibsoni,

Leidynemella fusiformis and Travassosinema jaidenae,

were reported from all localities surveyed and had

by far the broadest climate ranges. An examination

of the egg characteristics of these 3 species relative to

all others showed that they were in the mid-range in

most respects. The mean numbers of eggs in utero

for these species were 8 (L. fusiformis), 11 (C. gibsoni)

and 13 (T. jaidenae). Two species, G. megaovum

(1 egg) and J. rhinoceratum (5), had fewer eggs

in utero, and the other 4 species, D. ornata (15),

C. australiae (24), B. sphaerolaima (40) and H. hochi

(90) had more. Egg surface area to volume ratioswere 14.2 nm2/pl for C. gibsoni, 16.7 nm2/pl for

T. jaidenae and 55.1 nm2/pl for L. fusiformis. With the

exception of L. fusiformis, these had also mid-range

levels. Three species, G. megaovum (10.8 nm2/pl),

Jaidenema rhinoceratum (11.8 nm2/pl) and C. aus-

traliae (12.5 nm2/pl), had lower surface area to

volume ratios and 3 other species, Desmicola ornata

(17.4 nm2/pl), B. sphaerolaima (33.4 nm2/pl) and

H. hochi (37.2 nm2/pl) had higher ratios. All 3

common species had an approximately mid-range

shell thickness; 1.56 mm, 1.78 mm and 2.62 mm thick

for C. gibsoni, L. fusiformis and T. jaidenae eggs,respectively. Two species, H. hochi (1.25 mm) and

B. sphaerolaima (0.95 mm), had thinner shells,

1 species, J. rhinoceratum (1.64 mm) had similar

shell thickness and 3 species, D. ornata (2.76 mm),

C. australiae (3.10 mm) and G. megaovum (4.37 mm),

had thicker shells.

Overall, the eggs of the 3 dominant species are

unremarkable in comparison with the other 6

species examined here. We suspect that the un-

remarkable morphology and morphometrics of the

eggs for these dominant species is precisely what

permits them to be so widespread. By producing eggs

of moderate size (with the exception of L. fusiformis),

shell thickness and number, the 3 dominant species

75

65

55

45

35

25

02 03 04 05 06 07 08 09 10

CKWI

GG

Du Gu

MGCo

RS

Di

BoAI

MS MIObservedspeciesrichness

Budyko's aridity

Fig. 2. Non-linear regression analysis of observed species

richness versus relative aridity for Macropanesthia

rhinoceros by locality in Queensland, Australia. Locality

(2); Alpha (Al), Boonderoo (Bo), Coen (Co), Cooktown

(Ck), Dimbulah (Di), Duaringa (Du), Granite Gorge

(GG), Gumlu (Gu), Magnetic Island (MI), Maiden

Springs (MS), Mount Garnet (MG), Rochford Scrub(RS), Whitsunday Island (WI). (Note: Although not

included here, analysis using estimated richness,

regardless of the estimation method used, produces a

similar trend.)

Climate aridity effects on thelastomatoid nematode distribution 5


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may represent a generalist compromise that allows

them to survive in a broad range of climatic con-

ditions.Eggs of Geoscaphenema megaovum are the largest

and have the thickest shells of any of the thelasto-

matoids reported here. In addition, this species

never had more than 1 egg in utero. This species was

found in all of the dry localities, except Maiden

Springs. Conversely, it was not found in any of

the wet localities. In fact, although we found a

number of cockroach species harbouring this para-

site across large geographical areas within Australia,

we have yet to find it in a wet locality (Jex etal. 2007).

These distributional data and the combination of

large egg size and thick shell for this species suggest

that G. megaovum is an arid climate specialist.Coronostoma australiae and J. rhinoceratum also

have large, thick-shelled eggs and broad distri-

butions across most arid localities and no wet

localities for M. rhinoceros. Jaidenema rhinoceratum

may also be an arid climate specialist as it has also

been found in many cockroach species in Australia

but not in wet localities (Jex et al. 2007). However,

although not found in any wet climates in this study,

C. australiae has been reported previously from

another cockroach species, Panesthia tryoni tryoni,

from a particularly wet locality, Lamington National

Park, Queensland (Jex et al. 2005). Therefore, wecannot consider this species to be an arid specialist,

although it is apparently more successful in arid

regions. None of the species reported here could be

considered a wet climate specialist based on the

present data.

Overall, we showed that the thelastomatoid fauna

of M. rhinoceros, across its entire range, is hetero-

geneous. The variation in the fauna appears to be

correlated to local climate aridity and some of this

variation appears to be ascribable to egg morphology.

However, inconsistencies between egg surface area to

volume ratio, thickness of egg-shell and width of

climate range presented by the 3 dominant thelasto-

matoids, C. gibsoni, L. fusiformis and T. jaidenae,

Table 3. Mean number of eggs in utero and egg morphometrics for each thelastomatoid species

parasitizing Macropanesthia rhinoceros

Parasite speciesEggsin utero

Egglength(mm)

Eggwidth(mm)

Shellthickness(mm)

Surfacearea( nm2)

Volume(pl)

Surfacearea:Volume

Cordonicola gibsoni 11 82 50 1.56 12 0.86 14 200

Leidynemella fusiformis 8 71 25 1.78 10 0.19 55 100Travassosinema jaidenae 13 57 38 2.62 6 0.34 16 700Geoscaphenema megaovum 1 115 68 4.37 24 2.23 10 800Coronostoma australiae 24 100 59 3.1 18 1.46 12 500

Jaidenema rhinoceratum 5 84 55 1.64 13 1.06 11 800Desmicola ornata 15 83 46 2.76 13 0.74 17 400Blattophila sphaerolaima 40 91 36 0.95 16 0.49 33 400Hammerschmidtiella hochi 90 67 29 1.25 9 0.24 37 200

A

0

10

20

30

40

50

60

70

80

90

0.2 0.4 0.6 0.8 1

Budyko's aridity

Eggsinutero

C. gibsoni

L. fusiformis

T. jaidenae

G. megaovum

C. australiae

J. rhinocerata

D. ornata

B. sphaerolaima

H. hochi

B

9500

14500

19500

24500

29500

34500

39500

44500

4950054500

0.2 0.4 0.6 0.8 1

Budyko's aridity

Eggsurfaceareatovolum

e C. gibsoni

L. fusiformis

T. jaidenae

G. megaovum

C. australiae

J. rhinocerata

D. ornata

B. sphaerolaima

H. hochi

C

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

0.2 0.4 0.6 0.8 1

Budyko's aridity

Eggshellthickness

C. gibsoni

L. fusiformis

T. jaidenae

G. megaovum

C. australiae

J. rhinocerata

D. ornata

B. sphaerolaima

H. hochi

Fig. 3. Comparison of climate range with egg

characteristics for each Thelastomatoidea species

parasitizingMacropanesthia rhinoceros

acrossQueensland, Australia; eggs in utero. (A) Egg surface area

to volume ratio; (B) egg-shell thickness (C).



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Poulin, R. and Morand, S. (1999). Geographical

distances and the similarity among parasite communities

of conspecific host populations. Parasitology 119,

369374.

Rohde, K. (1993). Ecology of Marine Parasites, CAB

International, Wallingford, UK.

Rosenzweig, M. L. (1995). Species Diversity in Space and

Time, Cambridge University Press, Cambridge.

Roth, L. M. (1977). A taxonomic revision of the

Panesthiinae of the world I : The Panesthiinae of

Australia (Dictyoptera: Blattodea: Blaberidae).

Australian Journal of Zoology (Supplementary Series

No.) 48, 1112.

Skrjabin, K. I., Schikhobalova, N. P. and

Lagodovskaya, E. A. (1960). Oxyurata of Animals and

Man; Part 1, Translated from Russian by the Israel

Program of Scientific Translations, Jerusalem.

Smith, E. P. and van Belle, G. (1984). Nonparametric

estimation of species richness. Biometrics 40, 119129.

Walker, J. A., Rugg, D. and Rose, H. A. (1994). Nine

new species of Geoscapheinae (Blattodea: Blaberidae)

from Australia. Memoirs of the Queensland Museum 35,

263284.

Walther, B. A. and Morand, S. (1998). Comparative

performance of species richness estimation methods.

Parasitology 116, 395405.


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