Development, larval voracity, and greenhouse releases of Stethorus punctillum (Coleoptera : Coccinellidae)

摘要

Stethorus punctillum Weise (Coleoptera: Coccinellidae) is a Palearctic species first found in North America in the 1940s (Putman 1955). Commercial mass-rearing methods were developed in the late 1990s (Agriculture and Agri-Food Canada, London, Ontario, and Applied Bio-nomics Ltd, Saanich, British Columbia). The beetle is now released in North America to control two-spotted spider mites, Tetranychus urticae Koch (Acari: Tetranychidae). Knowledge of the life-history traits of S. punctillum is necessary for effective use of the predator in greenhouses. Putman (1955) provides useful information, but his results cannot be readily interpreted with respect to larval voracity, lower developmental temperature threshold, and developmental time in degreedays (~d), traits that affect efficacy. In this note I report new results relating to these life-history traits and to beetle releases in greenhouse vegetable crops.