A Technique for Sexing Live White-Pine Weevils, Pissodes strobi

Abstract

A method was devised for determining the sex of live white-pine weevils, Pissodes strobi (Peck), without harming the insect. The weevils were held venter up and observed under a binocular microscope. The last abdominal tergite was pulled down and the anogenital vestibule opened with a mounted minuten insect pin bent at a right angle. Key characters used in sex determination were: (1) the pygidium (8th tergite of the male, 7th tergite of the female), (2) the posterior view of the opened anogenital vestibule, which exposed the displaced eighth abdominal tergite and the apodeme fork of the 8th sternite in the female or a small projection of the 8th abdominal tergite in the male.