The Egg Masses, Eggs, and First-Instar Larvae of Eastern North American Corydalidae12

A comparative study was made of the egg masses, eggs, and first-instar larvae of the hellgrammite, Corydalus cornutus (L.) ; Nigronia serriconis (Say) ; N. fasciatus (Walker); Chauliodes pectinicornis (L.) ; and Neohermes concolor (Davis). The egg masses were found to differ in regard to presence or absence of a covering and configuration. The eggs of all species were found to possess the characteristic micropylar process. However, differences in size, shape, color, and the presence or absence of minute structures associated with the chorion were evident. Larval characters of diagnostic importance include pigmentation of the head, shape of the labrum, length of the lateral abdominal appendages, location of the spiracles on the 8th abdominal segment, and presence or absence of minute spines on the abdomen.