SPRUCE CONE INSECTS IN BRITISH COLUMBIA AND THEIR CONTROL

Abstract

AbstractInsects cause considerable loss of seed in white spruce, Picea glauca (Moench) Voss, and Engelmann spruce, P. engelmannii Parry, in British Columbia. The most important species are a maggot, Hylemya anthracina (Cz.), and a seed moth, Laspeyresia youngana (Kit.). Other insects are: a seed chalcid, Megastigmus piceae Roh., a cone axis midge, Dasineura rachiphaga Tripp, a gall midge, D. canadensis Felt, a seed midge, Mayetiola carpophaga Tripp, and a scale-feeding midge. These insects also occur in cones of Sitka spruce, P. sitchensis (Bong.) Carr., and black spruce, P. mariana (Mill.) BSP.The systemic insecticides dimethoate and formothion proved to be effective against these insects when applied as sprays following pollination in mid-June.