The host range and biology of Amniscus perplexus Haldeman (Coleoptera: Cerambycidae), a candidate evaluated for the biological control of Baccharis halimifolia in Australia

Amniscus perplexus is a rare and hence little known cerambycid found in the stems of Baccharis halimifolia in South Carolina, Georgia, Florida, Louisiana and Texas. It was evaluated as a candidate for the biological control of B. halimifolia in Australia. Observations on its life cycle indicated that it was univoltine with adults appearing in late spring. Larvae were found from midsummer onwards and it overwintered as this stage. Multiple choice host specificity tests conducted in Texas and in Brisbane, Australia, indicated that this species was very selective about plants suitable for oviposition and that larvae would not develop on any plant other than Baccharis. However, in cage experiments the adults fed on the green bark of a wide host range and for this reason A. perplexus was not released in Australia.