Field relevance of a synergistic effect observed in the laboratory between an EBI fungicide and a chloronicotinyl insecticide in the honeybee (Apis mellifera L,Hymenoptera)

It had been found earlier that the chloronicotinyl insecticide thiacloprid (as the 480 g litre(-1) SC Calypso) poses a favourably low toxicity hazard to the honeybee, Apis mellifera L. As with pyrethroids, the metabolization of chloronicotinyl compounds involves monooxygenases, which are known to be inhibited by some ergosterol biosynthesis inhibitor (EBI) fungicides potentially co-applied with these insecticides. The potential synergistic enhancement of the toxicity of thiacloprid to honeybees when co-applied with such fungicides was therefore studied under laboratory and semi-field conditions. Fungicides of other chemical classes were also examined for synergistic potential to reveal other metabolic interactions. In the laboratory, only a slight synergistic effect was observed with the anilinopyrimidine fungicide examined, while a significant enhancement of thiacloprid toxicity to honeybees was found with EBI fungicides. In three tunnel tests conducted under different environmental conditions to simulate field exposure, no increased mortality was observed when honeybees were directly sprayed with thiacloprid (Calypso) alone or in combination with the EBI fungicide tebuconazole (250 g litre(-1) EW, Folicur). There was also no synergized reduction in the foraging intensity on the treated crop. In general, the foraging intensity decreased after thiacloprid treatment but was restored within 24-48 h. The hive vitality was not affected by either thiacloprid or its tank mix with tebuconazole. Our results suggest that, at the recommended use rates, thiacloprid poses a negligible lethal risk to honeybees when applied either alone or in tank mixes with fungicides of various chemical classes.     

1%噻虫啉微胶囊颗粒剂防治松褐天牛

在松材线虫病疫区,利用背负式机动喷雾喷粉机喷施1%噻虫啉微胶囊颗粒剂防治松褐天牛,能够取得因松褐天牛羽化期长、防治难度大等原因常规药剂难以达到的防治效果。施药后30d,防效效果在75%以上,该药剂能将不断羽化出来的松褐天牛杀死,药剂持效期长。     

Effects of six selected orchard insecticides on Neoseiulus fallacis (Acari: Phytoseiidae) in the laboratory

BACKGROUND: Neoseiulus fallacis (Garman) is a key predator of tetranychid mites in integrated pest management (IPM) programs across Canada. This study identified compounds that would be recommended for tier‐II field evaluations in an IPM program. RESULTS: The overall egg mortality caused by the six insecticides was negligible as it extended from 0 to 12.1%. Imidacloprid was classified as toxic to adults. The label rate was 7.73‐fold the LC₅₀. Thiamethoxam was classified as moderately toxic to adults, and its label rate was 2.87‐fold the LC₅₀. Acetamiprid and spinosad were classified as marginally toxic, and their label rates were respectively 0.99‐ and 0.45‐fold the LC₅₀ for adults. Thiacloprid and methoxyfenozide were virtually innocuous to adults. CONCLUSION: Methoxyfenozide was totally harmless to all stages of N. fallacis, and it would be included in IPM programs immediately. Acetamiprid, spinosad and thiacloprid had varying degrees of mild toxicity to at least one growth stage of the predator. Therefore, they were recommended for tier‐II field testing according to their label claims. Imidacloprid and thiamethoxam were toxic to moderately toxic to adults and had significant adverse effects on fecundity. Therefore, they would be field evaluated only if alternatives were unavailable. Copyright 2010 Crown in the right of Canada. Published by JohnWiley & Sons, Ltd     

噻虫啉对杨树天牛成虫的毒力测定及林间防治

噻虫啉(天润)对粒肩天牛和橙斑白条天牛成虫均具有较强的毒力,稀释浓度在3 000倍液以下,对粒肩天牛成虫的校正死亡率达91.00％以上,对橙斑白条天牛成虫的校正死亡率达76.67％以上.应用噻虫啉(天润)林间喷雾防治时,以2000-3000倍液的防治效果较好;应用2％噻虫啉(天保)粉剂林间防治橙斑白条天牛成虫,以2 2...