Control of larvae of the western corn rootworm /WCR/

(Diabrotica virgifera virgifera LeConte, 1868)

József, TAKÁCS –Miklós, NÁDASY – Péter, BALOGH

University of Veszprém, Georgikon Faculty of Agriculture, Institute of Plant Protection, Department of Agricultural

Entomology

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Female adult

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Damages on leaves and tassels

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Damages on silk and ears

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Larvae of WCR

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Root damage and plant lodging

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Life cycle of WCR

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Biology of the pest Diabrotica

• Overwinter in egg state (about 8 to 10 months in soil)

• Prolonged hatching of eggs (longer than a month)

• Three larval instars (Root damages under a two month period)

• Oviposition from July to October

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• Continuous hatching of eggs• Problems of soil insecticides:

High doses, risk of soil pollution Expensive

Period of effectiveness• Problems of seed coating:

Period of effectiveness(less than a month)

• Need longer effectiveness period• No need soil pollution

Problems of WCR

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MAVICELL pearl

• Microporous build• Able to bind over triple dose of insecticide

agents• Prolonged transmittance of the agents even

under two months• 100 % cellulose• Disorganize under three months in soil

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Porous body of

MAVICELL pearl

Large absorptive surface to bind chemical and biological agents

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Test object:

Tanymecus dilaticollis GILLENHAL

Greenhouse screening

Mortality: Over 95 % even after the 60th day.

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Seeding machines: - Kuhn Planter Junior - Monosem NG Pus - JohnDeere Maxemerge

Plough land applications

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Problems of sowers

• Monosem: Its micro-granule adaptor not able to sow the large pearls (necessary to change the adaptor for sowing micro-granules)

• JohnDeere: Its not able to sow the complete dose of the pearl (only half dose)

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Observations and dataprocessing

• Inspection of regularity of sowing• Estimation of the number of early stage pests

(Corn Weevils – Tanymecus dilaticollis GILLENHAL)

• Measuring of larval damages with IOWA or Oleson-Tollefson scales

• Estimation of lodging after growth of ears• Statistical analysis

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IOWA scale

0,0

2,0

4,0

6,0

8,0

10,0

12,0

14,0

16,0

18,0

20,0

1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 6

Scale levels

[pcs

]

Gaucho 0.26

Talstar

Mospilan

Furadan K.

Absz. K.

Results of MAVICELL and differences between treatments

Average damages in:

Control: IOWA value 5

Soil treatment (Furadan): IOWA value 4

MAVICELL treatments: Under economical

threshold (IOWA value 3,5)

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Treatment Average* Sd Multiple comparison**

Gaucho 0.26 [M] 3,14 0,92 a

Talstar [M] 3,44 1,01 a

Furadan K. 3,96 0,71 b

Mospilan [M] 4,11 1,00 b

Absz. K. 4,51 1,05 c

*: IOWA values, n=80**: No significance between data marked with the same character on α = 0,5 (Data processed with SPSS for Windows 9.0)

Statistical analysis of damaging on roots after washing

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Results

• After three years of investigation we can say: MAVICELL is able to protect maize against WCR!

• Are there any losses of quality of pearl or agents? Checking with greenhouse screening!

• Costs of a hectare are much cheaper than the same with soil insecticides!

• We need to find a reliable method or seeding-machine to sow the pearls under the rows of corn!!!

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