CONTROL OF DASYSTOMA SALICELLUM, A NEW PEST OF BLUEBERRIES IN BRITISH COLUMBIA
A leafroller, Dasystoma salicellum Hbn. (Lepidoptera:Oecophoridae), recorded on this continent only from Lulu Island, B.C., in 1955, became a pest m 1962 when the larvae were found infesting the early berries, and mechanical pickers dislodged large numbers into the crates. This univoltine, phytophagous, photopositive insect overwinters as the pupa in the litter under the bushes. Flightless females emerge in mid-March, mate, and lay eggs under the blossom scales and loose bark of the canes. The eggs hatch in 2 weeks beginning in mid-May and the larvae destroy flower buds, invade or scar the berries, and sometimes defoliate the bushes.Preblossom sprays were not effective because plots were reinfested by first-instar larvae blown in from wild hosts nearby. Single postblossom sprays of phosphamidon, TDE, mevinphos, malathion, carbaryl, and Perthane and three sprays of Thuricide (Bacillus thuringiensis Berliner) were all effective. Malathion is recommended. Several non-chemical methods of control are discussed.