Seasonal flight activity of scarab beetles (Coleoptera : Scarabaeidae) associated with sugarcane in southern Queensland

Light traps were run at six sites for up to 5 years to determine the season al flight activity of 14 scarab beetles associated with sugarcane in the Bu ndaberg, Queensland, district. Four patterns of seasonal activity were dete cted: brief spring activity by Antitrogus consanguineus and Lepidiota noxia ; brief summer activity by Antitrogus parvulus, Lepidiota crinita, Lepidiot a frenchi and Lepidiota negatoria; prolonged summer activity by Anoplognath us boisduvalii, Anoplognathus pallidicollis, Anoplognathus porosus, Dasygna thus trituberculatus, Repsimus aeneus and Xylotrupes gideon; and prolonged spring-autumn activity by Metanastes vulgivagus and Neodon pecuarius. The d ifferent flight patterns reflect different life cycle strategies to cope wi th environmental adversity. Females of Antitrogus spp. and L. crinita were rarely caught in traps, while in Anop. boisduvalii, Anop. pallidicollis, An op. porosus, D. trituberculatus and X. gideon females outnumbered males. Di fferences between years in numbers of some species with 2-year life cycles point to large differences in sizes of the two allochronic populations of t hese species. Differences in species composition between sites reflect diff erences in soil type.