Identification of Australian canegrubs (Coleoptera : Scarabaeidae : Melolonthini)

Abstract

Larvae of Melolonthini are commonly known as whitegrubs or, in the Australian sugar industry, as canegrubs. In Australia, there are 119 recognised species of Melolonthini, of which 75 are found in Queensland. Of the 75 species, this study examines 19 species that are recognised sugarcane pests. These belong to the genera Antitrogus Burmeister, Dermolepida Arrow, Lepidiota Kirby and Rhopaea Erichson. Descriptions of adults and larvae of the 19 species are provided in this paper, as well as species identification keys for both adults and larvae and a key to the tribes, as a premise for introducing more effective management strategies. Identification of canegrubs is pertinent because the various species have different ecologies, behaviours and insecticide susceptibilities, and their control requires different methods and rates of application of insecticides. We have separated larvae of the species on the basis of their raster pattern, locality and, where necessary, head width. Larvae of some species are difficult to identify and we suggest use of molecular tools for their identification.