Canadian Forest Service Publications
Coleopterous predators of the Swaine jack pine sawfly, Neodiprion swainei Middleton (Hymenoptera : Diprionidae) 1972. Tostowaryk, W. Can. J. Zool. 50(8): 1139-1146.
Issued by: Laurentian Forestry Centre
Catalog ID: 16128
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Thirty-four species of elaterids were collected in jack-pine stands. Eighty-six percent of the elaterid larvae (wireworms) collected from soil samples belonged to the genus Ctenicera which were effective predators of the Swaine jack-pine sawfly, Neodiprion swainei Middleton. The peak activity of wireworms occurred in late May and June which coincided with a high abundance of sound sawfly cocoons in the soil. Wireworms destroyed a constant proportion of cocoons with increasing cocoon densities indicating a density-independent response. Populations of wireworms also appeared independent of sawfly cocoon populations. It may be concluded that wireworms played only a minor role in the life system of N. swainei. Five of the 15 species of adult carabids, captured in jack-pine stands, were found to prey upon sawfly cocoons. These were Pterostichus punctatissimus Rand, P. adstrictus Esch., P. coracinus Newn., P. pensylvanicus Lec., and Sphaeroderus lecontei Dej. The peak activity of adult carabids coincided with peak abundance of sawfly cocoons in the soil. Adult carabids destroyed an increasing proportion of cocoons at higher cocoon densities indicating that they may be playing an important role in the life system of N. swainei.