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Non-target arthropod testing with the predatory mite (Typhlodromus pyri)

The acute toxicity of Typhlodromus pyri nymphs will be measured in the laboratory via contact on treated glass surfaces or treated leaves, respectively, compared to a water treated control and to a reference item. Additionally, an assessment for significant sublethal effects will be made (reproduction assessment). If possible the LR50 value for mortality effects will be calculated.

 

Study Design

Test organisms

The predatory mite Typhlodromus pyri is recommended as one of the most sensitive standard species for non-target arthropod regulatory testing for plant protection products (Candolfi et al. 2001).

Course of the test

Exposure will last for 7 days with assessments on day 3 and 7. At day 7, for the reproduction assessment surviving mites from the control and from all test item groups where the corrected mortality is less than 50 % will be sexed and the number of eggs per female will be recorded on 3 further assessment days within one week.

Tailor-made study designs

The study can also be performed in an aged residue design. For this study type plants will be treated under field conditions and the treated leaves will be transferred to the lab after aging of a determined time period. The course of the test is the same as described above.

Endpoints

Mortality after 7 days of exposure; if possible LR50: lethal rate producing 50 % mortality after exposure over 7 days. Additionally reproductive capacity for survived mites.

Guidelines and Literature

  • Blümel S., Bakker F., Baier B., Brown K., Candolfi M., Goßmann A., Grimm C., Jäckel B., Nienstedt K., Schirra K.J., Ufer A. and Waltersdorfer A. 2000: Laboratory residual contact test with the predatory mite Typhlodromus pyri Scheuten (Acari: Phytoseiidae) for regulatory testing of plant protection products. In M.P. Candolfi, S. Blümel, R. Forster, F.M. Bakker, C. Grimm, S.A. Hassan, U. Heimbach, M.A. Mead-Briggs, B. Reber, R. Schmuck and H. Vogt (eds.) 2000: Guidelines to evaluate side-effects of plant protection products to non-target arthropods. IOBC/WPRS, Gent, pp 121-143
  • Oomen IOBC 1988 (International Organization for biological and integrated control of noxious animals and plants) 1988 Guideline for the evaluation of side effects of pesticides Phytoseiulus persimilis A.-H.