Laboratory evaluation of alternative insecticides to replace persistent organochlorines in leaf-cutting ant baits is described, based on tests of 40 candidate compounds which were bioassayed with Atta cephalotes (L.) and Acromyrmex octospinosus (Reich). Insecticides having a suitable delayed killing action are listed, together with others which, although highly toxic to ants, had too rapid an action, but could feasibly be modified by using a controlled-release formulation.A search was also made for alternative bait matrices to replace the expensive and often inadequate materials in current use. Horticultural grade vermiculite with sorbed orange juice as an arrestant was the best matrix tested, being at least as attractive as dried citrus pulp, which was the best previously known matrix.Treatment of dried citrus pulp bait with propionic acid gave considerable protection against moulds, which spoil stored baits and baits placed in the field, and did not alter the attractiveness of these baits to ants.
When applied in the soil at the time potato tubers were planted, phorate and disulfoton were more effective than dimethoate and menazon in controlling aphids on the foliage of the crop in dry years, but all four were equally effective in wet years. The reason was sought by comparing the ability of the roots of wheat seedlings to absorb these systemic insecticides from air and from water. When absorbed from solution in water, all four
SUMMARYElectrostatic sprayers charged to 30kV and placed 20 cm above the crop increased the chemical deposition of permethrin in field beans and improved control of the pea and bean weevil, Sitona lineatus. Control of the black bean aphid, Aphis fabae, was improved by electrostatic sprayers only when a systemic chemical, demeton‐S‐methyl, was used. In spring barley, sprays applied electrostatically or hydraulically gave similar control of barley mildew, Erisyphe graminis.
Ten non-organochlorine insecticides which had shown promise in laboratory tests as formicides, because of their delayed toxic action, were field-tested in Brazil in experimental leaf-cutting ant baits and were compared with a mirex bait. Seven of these gave good control (similar to mirex) against Atta sexdens (L.) colonies. Several showed some success, at the concentrations used, against the larger Atta cephalotes (L.) colonies, but were not as good as mirex.By microencapsulating some quick-acting and very potent insecticides it was shown that useful formicides could be produced, presumably because encapsulation delayed the toxic action.Substituting vermiculite plus orange juice in place of dried citrus pulp as an attractive bait matrix gave successful results.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.