ABSTRACT
The effect of residues of esfenvalerate on oviposition of the resistant strain 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 applied at the field rate. Furthermore, when given a choice, T. pyri preferred to lay eggs on residue-free surfaces. Of the two prey species, only P. ulmi showed significant avoidance of increasing levels of residues of the field rate concentration of esfenvalerate, as measured by runoff mortality, however both P. ulmi and T urticae, when given a choice, showed a preference for esfenvalerate-free surfaces. As with the predatory mite T. pyri, both prey species showed a significant linear reduction of oviposition with increasing esfenvalerate residues and a preference to lay eggs on esfenvalerate-free surfaces. Esfenvalerate residues as high as 15X field rate were not repellent to pyrethroid-resistant T. pyri. The possible effects of these sublethal effects on predator-prey dynamics and implications for integrated mite control programmes in apple orchards are discussed.
Subject(s)
Fruit/parasitology , Insecticides/pharmacology , Mites/drug effects , Pyrethrins/pharmacology , Animals , Female , Insecticides/pharmacokinetics , Mite Infestations , Mites/physiology , New Zealand , Nitriles , Oviposition/drug effects , Pest Control, Biological/methods , Pesticide Residues , Plant Leaves/parasitology , Predatory Behavior , Pyrethrins/pharmacokineticsABSTRACT
Ethyl nicotinate was found to be a potent attractant forThrips obscuratus in peaches and apricots. The male-to-female ratio in traps was 1â¶8. The chemical was more attractive than ripe fruit, with peak catches at harvest. Season-long trapping showed the efficiency of the chemical compared to unbaited traps. The chemical remained attractive for at least 2 weeks when 50 µl were placed in open 2-ml vial caps. Various pyralids, geometrids (Lepidoptera), and chironomids (Diptera) were also attracted in low numbers to ethyl nicotinate.
