ISSN 1911-2173


Westwood 1846

Diagnosis (Adapted from Webb et al., 1975): Wings with background color clear, crossveins margined. Apical band dark brown, broad anteriorly and narrow posteriorly, sometimes interrupted with clear spots. Pterostigmal band brown, continuous. Marginal spots absent. Male terminalia pale to dark yellow. Ninth tergum deeply emarginate. Hypovalve broad and rounded apically, ending before base of dististyle. Ventral paramere elongate, narrow, unbranched and barbed; reaching well between dististyle. Basistyle with a large tubercule near the base of dististyle, with a tuft of setae. Dististyle smaller than basistyle.

P. debilis is common and widespread in southern Ontario, with adults occurring from June and August but usually emerging in late summer. This species is widespread in the northeast and occurs in a variety of habitats. P. debilis can be easily confused with P. claripennis because the apical tubercle on the base of the dististyle is not always conspicuous. In addition to the presence of a tubercle, the ventral parameres are long and straight in P. debilis, while in P. claripennis the ventral parameres are curved and short, not reaching very far beyond the base of the dististyle.