Cereal Leaf Beetle11 Instars and Sex, Denned by Larval Head Capsule Widths2

Abstract

Four instars of the cereal leaf beetle, Oulema mclanopus (L.), were determined from the frequency distributions of head capsule widths of field- and laboratory-reared larvae. Linear regressions and geometric progressions inadequately described the larval growth because of the smaller ratio of growth of the 3rd-4th instar. When the width of the 4th instar head capsule and the length of the adult elytra were correlated to sex, the male had a narrower head capsule and shorter elytra than the female.