Ecological notes on Achthosus westwoodi （Coleoptera: Tenebrionidae） from King Island and a successional relationship with Toxeutes arctuatus (Coleoptera: Cerambycidae) in Pinus radiata logs

摘要

Achthosus westwoodi Pascoe, 1863 (Plate 1) is a medium-sized (15-25 mm body length) saproxylic tenebrionid beetle that occurs in eastern Australia from the high tropics of Queensland to southern Victoria, and in a wide variety of climate and habitat types (Atlas of Living Australia (ALA) 2019a; Hawkeswood 2009). Both genders have a distinctive prothorax that is slightly broader than long and strongly excavated anteriorly; this is particularly prominent on the largest males. Achthosus westwoodi is stout, nearly cylindrical in crosssection, and has relatively small legs. The distinctive prothorax may be used by males to compete for access to females, defend favoured oviposition sites from rival males or both, as its shape allows two opposing males to meet face to face (one at 180° to the other), and interlock within the narrow galleries in rotten wood.