Pest Management Science (2014) 70, 1138-1144

Jitka Stara, Marta Nesvorna and Jan Hubert (2014)
Comparison of the effect of insecticides on three strains of Tyrophagus putrescentiae (Acari: Astigmata) using an impregnated filter paper test and a growth test
Pest Management Science 70 (7), 1138-1144
Abstract:
BACKGROUND
In this study, we compared the efficacy of insecticides against three strains of Tyrophagus putrescentiae using an impregnated filter paper test and a growth test. We tested the suppressive activity of commercial insecticides and their analytical standards (pirimiphos-methyl, cypermethrin, deltamethrin, chlorfenapyr, β-cyfluthrin).
METHODS
The strains of T. putrescentiae originated from a laboratory, a field and dog food. The mortality of the mites due to active ingredients and analytical standards was tested using an impregnated filter paper test after 24 h. Lethal doses, LD₅₀, LD₉₅ and LD₉₉ were determined. A growth test was used to observe the suppressive effect of the active ingredients on mites at 21 days after application of the active ingredients to wheat grain. The effective doses ED₅₀, ED₉₅ and ED₉₉ were determined, indicating the concentration at which the population was reduced by 50, 95 and 99% more than control.
RESULTS
Cypermethrin, β-cyfluthrin and a formulation of deltamethrin with piperonylbutoxide in the pesticide K-Othrine showed low toxicity to mites. High toxicity was observed for chlorfenapyr (LD₅₀: 0.1-1 µg cm^-2; ED₅₀: 0.11-1.2 µg g^-1) and pirimiphos-methyl (LD₅₀: 0.01-0.06 µg cm^-2; ED₅₀: 0.2-12 µg g^-1). We did not find significant differences among the compared strains in terms of their sensitivity to highly toxic insecticides.
CONCLUSION
The obtained results showed that a filter paper test is a more sensitive method of identifying differences in pesticide susceptibility among strains, but the efficacy of pesticides against one species should be tested using a growth test.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Jan Hubert, Jitka Stara

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tyrophagus putrescentiae