Sublethal effects of esfenvalerate residues on pyrethroid resistant Typhlodromus pyri (Acari : Phytoseiidae) and its prey Panonychus ulmi and Tetranychus urticae (Acari : Tetranychidae)
Mh. Bowie et al., Sublethal effects of esfenvalerate residues on pyrethroid resistant Typhlodromus pyri (Acari : Phytoseiidae) and its prey Panonychus ulmi and Tetranychus urticae (Acari : Tetranychidae), EXP APPL AC, 25(4), 2001, pp. 311-319
The effect of residues of esfenvalerate on oviposition of the resistant str
ain of the predatory mite Typhlodromus pyri and its main prey, European red
mite Panonychus ulmi and two-spotted spider mite Tetranychus urticae, were
investigated. T. pyri showed a significant linear reduction in oviposition
after 24 h in the presence of increasing levels of esfenvalerate residue a
pplied at the field rate. Furthermore, when given a choice, T. pyri preferr
ed to lay eggs on residue-free surfaces. Of the two prey species, only P. u
lmi showed significant avoidance of increasing levels of residues of the fi
eld rate concentration of esfenvalerate, as measured by runoff mortality, h
owever both P. ulmi and T. urticae, when given a choice, showed a preferenc
e for esfenvalerate-free surfaces. As with the predatory mite T. pyri, both
prey species showed a significant linear reduction of oviposition with inc
reasing esfenvalerate residues and a preference to lay eggs on esfenvalerat
e-free surfaces. Esfenvalerate residues as high as 15X field rate were not
repellent to pyrethroid-resistant T. pyri. The possible effects of these su
blethal effects on predator-prey dynamics and implications for integrated m
ite control programmes in apple orchards are discussed.