Thousands of lepidopterous larvae representing a wide range of species are collected every year in Ontario by the Forest Insect Survey. Many of these require microscopic examination for identification. During a 10-year period I have only found one specimen with an extra pedal appendage.

In June 1963, a larva with an extra anal proleg on the right side was collected by H. G. McPhee near Thessalon, Ont., on the north shore of Lake Huron. The species was Epinotia solandriana Linn., a leaf roller on white birch, Betula papyrifera Marsh. A subsequent large collection from the same area contained only normal specimens.