Khapra beetle diagnostics

Poster

Abstract

The khapra beetle, Trogoderma granarium Everts, is a serious pest of grains and stored dry food stuffs and is the subject of strict quarantine measures in many countries including Australia. Morphologically the khapra beetle can only be reliably identified by dissection by a limited number of skilled taxonomists. Suspect specimens found in grain products are usually the larvae or larval skins which are difficult to diagnose morphologically. Adult specimens are usually scarce and damaged. Due to their similarity, warehouse beetle (Trogoderma variabile) and other native Trogoderma spp. could be mistakenly identified as T. granarium with market access implicatons or could mask an incursion. Molecular diagnostic protocols have been developed for khapra beetle, but remain largely untested against other species of Trogoderma, some also capable of being pests. Western Australia has a broad large, poorly studied native Trogoderma fauna, many of which are still undescribed; their estimated number is possibly over 100 species. Occasionally native Australian species can occur in stored commodities. Their identification and at least separation from the pestiferous exotic Trogoderma presents a serious problem. The work in this paper has been undertaken in an attempt to distinguish T. granarium from Australian native Trogoderma and related Dermestid species by both morphological and molecular methods. Dermestid specimens were sourced mainly from a targeted survey around grain silos throughout Australia, using two trap types, inside and outside facilities. Khapra beetle specimens were sourced from different geographical locations around the world.