Effect of (2-Chloroethyl) Trimethylammonium Chloride on the Eriophyid Gall Mite Cecidophyopsis ribis Nal., and Three Fungus Diseases of Black Currant

Abstract

THE eriophyid gall mite, Cecidophyopsis ribis NaL, the vector of the reversion virus, is the most important pest of black currants. The mites migrate to new buds during a period lasting 3–4 months, but individuals are rarely exposed, while on the plant, to contact acaricides for more than a few days, and no non-phytotoxic systemic compound has yet been found which kills mites within the tissues of the host plant. Preliminary experiments at Long Ashton have shown that quaternary ammonium compounds and herbicides can cause sufficient interference with host and parasite relationships to exert some control. (2-Chloroethyl) trimethylammonium chloride, ‘Cycocel’, a plant growth retardant, has been shown to reduce tho reproductive rate of the aphid Brevicoryne brassicae (L.) on brassicas¹, and to give some control of Verticillium wilt of tomato². The effect of this compound on the black currant gall mite and the fungi most common on currants was therefore investigated.