Developmental changes in the caudal and lateral processes of larvae of Aspidomorpha deusta (Fabricius) (Coleoptera : Chrysomelidae : Cassidinae)

Caudal and lateral processes of larvae of the Australian tortoise beetle As pidomorpha deusta (Fabricius) were examined using scanning electron microsc opy. The caudal process holds a movable faecal shield thought to be importa nt in larval defence. First-instar larvae have barbs on the caudal processe s, whereas older larvae (second, third and fourth instar) lack barbs. Simil arly, young larvae (first instar and second instal) have barbs on lateral p rocesses. Bal bs may help in the retention of the shield material. The late ral processes of first-instar and second-instar larvae carry spinules that terminate in complex structures thought to be touch sensitive.