An extreme case of epitoky in an Australian Collembolon:

Isotopenola perterrens sp.n. is described from a 40 year old Eucalyptus plantation in Victoria, Australia, and its occurrence in an adjacent site of remnant native vegetation is reported. Fully adult males are armed with numerous strong spine-like macrochaetae on lateral parts of head and body tergites and with fields of long bristles on latero-ventral and ventral areas of abdomen. Antennae of epitokous males are of normal shape but bear thickened chaetae. This is the second and most extreme case of epitoky recorded in the genus. The occurrence of sexual dimorphism, of which epitoky is a subset, is summarised for Australian Collembola. Environmental factors that appear to facilitate successful recolonisation of native fauna onto reveg-etated sites in Australia are proposed.> Key words Sexual dimorphism, revegetation, cyclomorphosis, ecomorphosis, reproductive cycle