Evidence of an Aggregating Pheromone in Pissodes approximates and P. strobi1, 2

Preliminary field studies in central New York State indicate that an aggregating pheromone is released by males of the northern pine weevil, Pissodes approximatus Hopkins. Males of the white pine weevil, P. strobi (Peck), may also release a pheromone which attracts P. approximates. These closely related species are extremely similar morphologically. Chemotaxonomy (Peckham 1969), cytotaxonomy (Manna and Smith 1959, Smith 1962), analysis of sonic signals (Harman and Kranzler 1969) and breeding experiments (Godwin and O'Dell 1967) have yielded equivocal evidence that P. strobi and P. approximatus are separate species. Nevertheless, discriminant analysis of several characters has been used to identify individuals to species (Godwin et al. 1959) and differences in host preference and breeding site of the 2 entities are widely recognized (Hopkins 1911, Smith and Sugden 1969, Baker 1972).