Residual Toxicity of Insecticides to Neoseiulus fallacis (Acari: Phytoseiidae) in Apples

Neoseiulus fallacis (Garman) is a predatory mite that is common in apple orchards and distributed throughout North America. However, N. fallacis may be susceptible to pesticides used for the management of crop pests. This study aimed to evaluate the temporal effects of commonly used insecticides on N. fallacis survival. Neoseiulus fallacis adults were exposed to field-aged residues, and mortality and lethal time were measured over 96 h of exposure. Carbaryl caused high mortality to N. fallacis and the shortest lethal time values (LT50), followed by spinetoram, with moderate lethal time values. Esfenvalerate, acetamiprid, chlorantraniliprole, and novaluron showed little to no lethality to N. fallacis following exposure to dry field-aged residues. The results of this study provide important field-relevant knowledge that is often void from laboratory-based studies, which can aid integrated pest management (IPM) decision-makers in apple production systems.

Lethal time of insecticides on the predator mite Neoseiulus fallacis (Acari: Phytoseiidae) following topical exposure

Neoseiulus fallacis (Garman) (Acari: Phytoseiidae) is an efficient predator of the European red mite (ERM) (Panonychus ulmi (Koch); Acari: Tetranychidae) in Michigan, United States of America apple orchards and an important part of integrated pest management. Four reduced-risk insecticides (acetamiprid, spinetoram, chlorantraniliprole, and novaluron) and two conventional insecticides (esfenvalerate and carbaryl) were tested against N. fallacis for topical toxicity effects. Bioassays using a Potter spray tower were conducted to measure the topical toxicity of compounds when applied at field rate concentrations to N. fallacis. Lethal time was measured for adult N. fallacis at 4, 24, 48, 72, and 96 hours after treatment. Carbaryl and esfenvalerate showed the highest levels of toxicity to adult N. fallacis with shortest lethal time values (LT50) whereas the reduced risk insecticides novaluron, acetamiprid, spinetoram, and chlorantraniliprole were nontoxic. This study provides important information to apple growers regarding direct lethal effect of insecticides on predator mites and its implications to integrated mite management.

Predatory mite fauna associated with agri-horticultural crops and weeds from the Gangetic Plains ofWest Begal, India*

Astudy was conducted in 2008–2009 to explore the predatory mite fauna from different agri-horticultural crops and weeds in the Gangetic plains ofWest Bengal. A total of 31 species belonging to nine genera, seven families and two orders were identified; they are listed along with their prey, period of occurrence and the plant habitats in which they were recorded. The most frequently collected specieswere the phytoseiids Amblyseius largoensis (Muma) and Neoseiulus longispinosus (Evans), the stigmaeids Agistemus spp. and the anystidWalzia indiana Smith-Meyer&Ueckermann.Given the frequencywithwhich these mites were found, they can be considered potentially useful in suppressing the associated prey mites. The phytoseiids Paraphytoseius multidentatus Swirski & Schechter, Euseius ovalis (Evans), Euseius coccineae (Gupta), Neoseiulus fallacis (Garman) and the cheyletid Cheletogenes ornatus (Canestrini&Fanzago) were less frequently found and less abundant, implying that their impact on prey population is less important. The remaining species were rare.