Review of the biology, distribution and taxonomic history of Gnoma biosduvali Plavilstshikov, a longicorn beetle from the rainforests of Papua New Guinea and Irian Jaya (Insecta, Coleoptera, Cerambycidae, Lamiinae)

Biological and morphomertric details provided on the tropical longicorn bettle Gnoma boisduvali Plavilstshikov (Cerambycidae, Lamiinae, Gnomini) based on collections made during 1989 by the senior author in the East Sepik Province, Papua New Guinea. The taxonomic history and distribution records for the beetle are also reviewed and a distribution map provided. The species inhabits tropical rainforests and flies into clearings or around human habitation, where they mate and feed on bark and sap flows from certain trees, e.g. Citrus grandis Osbeck (Rutaceae), Ficus sp. (Moraceae), Spathodea campanulata Beauv. (Bignoniaceae) and Intsia bijuga (Colebr.) Kuntze (Caesalpiniaceae), although at this stage, there is no evidence that any of these plants are larval hosts for Gnoma boisduvali. The only recorded larval host is Theobroma cacao L. (Sterculiaceae). Morphometric data indicates that there is marked sexual dimorphism in the length of the antennae, in the length of the protibia and profemur, and generally, in the length of the pronotum. The sexes are also clearly distinguished on the basis of elytral pattern. From the recent collection of Gnoma boisduvali from Papua New Guinea, the males can be divided into two groups based on body size--it is possible that "major" and "minor" males exist in this species, as they do in other beetle groups such as the Scarabaeidae and the Geotrupidae.