Life history of the leaf‐feeding beetle Calomela intemerata, a potential biocontrol agent against Acacia auriculiformis

Abstract

AbstractWe examined the biology and life history of Calomela intemerata Lea (Coleoptera: Chrysomelidae), to determine its potential as a biocontrol agent of Acacia auriculiformis A.Cunn. ex Benth. (Fabaceae), an environmental weed in Florida, USA. We analysed data from field surveys in northern Australia and determined life‐history parameters and larval feeding under controlled laboratory conditions. In the field, both larvae and adults of C. intemerata fed throughout the year on young shoots of A. auriculiformis. Two geographically isolated populations of C. intemerata were collected from Northern Territory and north Queensland, Australia. We examined developmental time, survival, and size of immature stages in the laboratory at 25 °C. Following development through four instars, larvae move to the soil for pupation. Egg‐to‐adult development was approximately 23 days. Adults were long‐lived – several individuals survived >8 months. Females began ovipositing about 8 days after emergence and laid on average >1000 eggs each. On the invasive Florida A. auriculiformis, larvae of the Northern Territory population performed better than the north Queensland population regarding leaf consumption and developmental rate. The biological attributes of C. intemerata such as short generation time, high fecundity, and a long adult life, combined with the extensive damage larvae and adults inflict to young vegetative growth when feeding, make it a promising candidate biocontrol agent for management of A. auriculiformis in Florida. Formal host specificity testing is currently underway in Florida.