Chemical Defense and Sound Productionin Australlian Tenebrionid Beetles (Adelium Spp.)

Girdled eucalyptus trees, felled to make room for grazing pasture, are a common sight in rural Australia. In the dead and decaying stumps that are strewn through the countryside, many insects flourish. Two of these, the congeneric tenebrionid beetles ddelium percatum and .4. pustulosum (subfamily Adeliinae) possess interesting defense mechanisms that we here describe. Both have eversible abdominal glands such as are commonly found in Tenebrionidae (Roth, I945), but some features of the chemistry and biology of the glands are anomalous. Moreover, .4. pustulosum has a stridulatory apparatus that may function for acoustical reinforcement of the. chemical defense.