Excerpt from Proceedings of the Entomological Society of Washington, Vol. 89: January, 1987 Earwigs exhibit sexual dimorphism in both the number of abdominal segments and the Shape of the forceps. Males have ten abdominal segments, whereas females have only eight apparent segments due to the fu sion of the eighth and ninth segments with the tenth (giles, The forceps of males are generally curved and widely separated at the base, and many Species have one or more prominent teeth on the inner margins (figs. 11 Female forceps are more or less straight, usually closer together basally than those of the male and lack prominent teeth on their inner margins (figs. 26 - 3 Both sexes possess a divided plate called the pygidium, which is located between the bas es of the forceps (fig. The pygidium is thought to be derived from the epiproct and is useful taxonomically, especially in males. Immature earwigs undergo five to six in stars before reaching adulthood. Antenna] segments are added at each molt, and wing pads begin to develop in the second or third instar. Immatures are lighter in color than adults and possess conspicuous ecdysial lines on the head and thoracic terga. Immatures have male-like, ten-segmented abdomens, but have female-like, straight forceps. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.