THE IMMATURE STAGES OF SEXTIUS VIRESCENS (FAIRMAIRE) (HOMOPTER A: MEMBRACIDAE)

Abstract

The immature stages of the common Australian membracid, Sextius virescens, are described. The nymphal instars are separated on details of the morphology of the head, prothorax and wing‐pads. A rapid method of separation using only the head‐width and extent of the wing‐pads is described. The course of development is shown to involve progressive distortion of the thorax and a consequent downward movement in the position of the head, and this process is exemplified by changes in the ‘frontal ratio’, which is defined and illustrated. Certain generalisations made in the literature about the morphology of the nymphal instars of the Membracidae do not hold for this species. Copyright © 1974, Wiley Blackwell. All rights reserved