Aerial treatment of forests with pyrethroids.
A description is given of experiments in which oak [Quercus] and pine [Pinus] forests infested by various leaf- and needle-feeding Lepidoptera and tenthredinids in areas of the European part of the USSR were sprayed with pyrethroids from fixed-wing aircraft or helicopters. The chief pests included the gypsy moth [Lymantria dispar], brown-tail moth [Euproctis chrysorrhoea], green oak tortrix [Tortrix viridana], fruit-tree tortrix [Archips crataeganus], and winter moth [Operophtera brumata] and other geometrids on oak, and the pine moth [Dendrolimus pini], nun moth [L. monacha], pine noctuid [Panolis flammea], fox-coloured sawfly [Neodiprion sertifer] and the stellate pamphiliid [?Acantholyda sp.] on pine. Preparations based on permethrin, cypermethrin and deltamethrin were tested. The majority of the formulations in each of these groups (which included ones for ULV application) was in general fairly effective, and up to 100% control was achieved in many instances. The pyrethroids were found to be ineffective against Acantholyda sp. and E. chrysorrhoea under unfavourable weather conditions.