Australian Journal of Entomology (2007) 46, 7–16 © 2007 The Authors Journal compilation © 2007 Australian Entomological Society doi:10.1111/j.1440-6055.2007.00579.x Blackwell Publishing AsiaMelbourne, AustraliaAENAustralian Journal of Entomology1326-6756© 2006 The Authors; Journal compilation © 2006 Australian Entomological Society? 2007461716original articleScarabs of the southern tablelands of New South Wales M J Steinbauer and T A Weir *martin.steinbauer@daff.gov.au †Present address: Australian Plague Locust Commission, Australian Government – Department of Agriculture, Fisheries and Forestry, GPO Box 858, Canberra, ACT 2601, Australia. Summer activity patterns of nocturnal Scarabaeoidea (Coleoptera) of the southern tablelands of New South Wales Martin J Steinbauer 1 *† and Tom A Weir 2 1 University of Tasmania and CRC for Sustainable Production Forestry, c/– CSIRO Entomology, GPO Box 1700, Canberra, ACT 2601, Australia 2 CSIRO Entomology, Australian National Insect Collection, GPO Box 1700, Canberra, ACT 2601, Australia Abstract Australia has a rich diversity of Scarabaeoidea; however, little is known about the majority of them. Because adults of Anoplognathus, Automolius, Heteronychus, Heteronyx and Liparetrus in particular are reliant upon eucalypts, a number of bluegum plantation companies supported the commencement of research into the biology and ecology of scarabs of economic significance to them. Consequently, it was decided that the occurrences of species endemic to this area would be studied and it was assumed that information on the nocturnal species in the aforementioned genera would be obtained. From late November 2003 until late February 2004, the abundances of Scarabaeoidea caught in two light traps that partition insects caught on a given night into seven time periods each of 1.75 h duration were recorded. A total of 48 263 scarabs representing 21 genera were caught. Within the 14 species caught most often, six types of summer activity pattern were apparent: late spring to early summer (Austral- obolbus gayndahensis), early to mid-summer (Scitala sericans), mid-summer only (Sericesthis ignota), mid- to late summer (Acrossidius tasmaniae, Aphodius lividus, Heteronyx chlorotica, Het. praecox and Antitrogus morbillosus), late summer only (Ataenius picinus) and all summer (Anoplognathus pallidicollis, Phyllotocus macleayi, Sericesthis geminata, Ser. micans and Ser. nigrolineata). Abundances of nine species peaked between 21:30 and 23:15 h (Aph. lividus, Phy. macleayi, Het. chlorotica, Sci. sericans, Ser. geminata, Ser. micans, Ser. nigrolineata and possi- bly also Ant. morbillosus), three were most abundant between 19:45 and 21:30 h (Ano. pallidicollis, Ser. ignota and possibly also Ata. picinus), another two were most abundant from 19:45 to 23:15 h (Acr. tasmaniae and Het. praecox) and Aus. gayndahensis was most abundant between 23:15 and 01:00 h. Of course, it is not just a knowledge of the identity of the species and the timing of their occurrence that are important when making insect management decisions, but also the size of popu- lation needed to inflict economically significant loss. It is now beholden upon bluegum plantation companies to support further research to determine the relationships between light trap catches of eucalypt-feeding scarabs, tree age and/or size and level of defoliation in order to improve their confidence in this method of monitoring over ground surveys. Key words Bolboceratidae, Christmas beetles, cockchafers, pasture scarabs, Scarabaeidae, Trogidae. INTRODUCTION Scarabaeoidea are a very characteristic and often abundant element of the insect fauna of Australian summers (e.g. Carne et al. 1974, 1981; Roberts et al. 1982a). Nevertheless, detailed information relating to the seasonal phenologies of these insects is rather scarce. Of the published information, Allsopp and Logan (1999) recognised four patterns of seasonal activity in the 14 species of scarab they monitored, i.e. brief spring activity, brief summer activity, prolonged summer activity and prolonged spring to autumn activity. Only the nocturnal activ- ity patterns of some Australian dung beetles have been rela- tively well documented. Within species of Australian and exotic dung beetle there is an array of activity patterns that encompass the spectrum from entirely diurnal to entirely nocturnal (Houston & McIntyre 1985; Howden et al. 1991; Caveney et al. 1995; Davis 1999). Seasonal and daily activity patterns of any organism are so fundamental to understanding any organism that they are usu- ally the first aspects of a species’ biology that needs to be studied if not already known. The expansion of eucalypt plan- tations in parts of temperate Australia has increased the need to improve the level of knowledge of the basic biology of many eucalypt-feeding insects. The often sudden need to gain an understanding of the biology of insects of concern to human activities is not new; for example, the study of species of