The residual contact toxicity to honey bees of insecticides sprayed on to white clover (trifolium repens l.) in the laboratory

Abstract

A spray tower was adapted to enable insecticide sprays to be applied to the flowers of white clover (Trifolium repells L.) held in jars of water. Honey bees were enclosed with the flowers for an hour (3. 18. or 42 hours after application) to determine the residual contact toxicities of the sprays. Comparative tests on artificial flowers made of foil ind'cated that they cannot be used as a substitute for clover flowers.Direct contact toxicity tests appear of little value as guides to residual toxicity.

Laboratory assessment of the speed of action on honey bees of orally dosed insecticides

“…It is therefore necessary to exercise extreme care when interpreting the results of field trials with this compound and others that act as swiftly. Clinch (1965) suggested that, before carrying out field trials, it was essential to determine, by laboratory tests, certain basic facts about the toxicity of a pesticide. Our evidence suggests that it would be worth while to include a test to estimate the speed of action of pesticides on honey bees.…”

“…Laboratory tests, using the technique described by Palmer-Jones (1958), had shown that this compound has a very high oral toxicity to honey bees (LD 50 0.2 p.g per bee). Residual contact tests, similar to those developed by Clinch (1967), indicated that if methomyl was applied to a white clover crop in the evening, when the bees had ceased flying, surface residues would not present a hazard to bees working the flowers next day. The compound was therefore applied to the caged area in the evening.…”

“…It appeared that bees affected by phenthoate while on the crop were unable to return to their hives. Later, using the technique described by Clinch (1969), the same compound was applied to a plot of flowering white clover enclosed with a nucleus hive in a cage. Again, after the application, a fall in the number of bees on the crop was observed, and some of the bees collected from the treated flowers died within 24 hr (Clinch, unpublished data).…”

Aplicación y validación de la tecnología de inmunosensores piezoeléctricos de alta frecuencia (HFF-QCM) para la detección de pesticidas y antibióticos en miel

“…A raíz del fenómeno mundial ocurrido con el DDT, la síntesis de pesticidas ha ido evolucionando hacia la obtención de otros menos persistentes que se degraden rápidamente y sean más específicos para minimizar sus efectos sobre el medio ambiente. Entre ellos, destacan los organofosforados y carbamatos, que han reemplazado casi por completo a los pesticidas organoclorados (Porrini et al, 2002 La alta toxicidad del carbaril para las abejas es un hecho conocido desde los años 60 (Clinch, 1967), por ello, aunque su aplicación ha estado permitida durante muchos años, se Los antibióticos se pueden clasificar atendiendo a diferentes criterios:…”