MIGRATING MOTHS (LEPIDOPTERA) COLLECTED IN TOWER-MOUNTED LIGHT TRAPS IN NORTHERN NEW-SOUTH-WALES, AUSTRALIA - SPECIES COMPOSITION AND SEASONAL ABUNDANCE

Light traps were operated between September and April for five years o n towers on mountain tops at two locations in northern New South Wales , Australia. The traps were designed so that their lights could only b e seen from above, and therefore only insects engaged in high altitude flight, presumed to be migrants, were captured. The catch consisted m ostly of Noctuidae and Sphingidae. Sweep netting failed to reveal loca l breeding, and for many species there were few host plants close to t he traps. A total of 51,580 moths were trapped at Point Lookout and 10 ,223 at Mt Dowe. Sphingids, mostly Hippotion scrofa (Boisduval), compr ised 26.9% of the catch at Point Lookout, but only 2.6% at Mt Dowe, an d there were more species of noctuids at Point Lookout (44) than at Mt Dowe (15). The most common noctuid species were Agrotis infusa (Boisd uval), Mythimna convecta (Walker), Helicoverpa punctigera (Wallengren) , H. armigera (Hubner), Dasygaster nephelistis Hampson and A. munda Wa lker. Known or suspected migrants comprised 94.6% of the catch at Poin t Lookout and 99.9% at Mt Dowe. However, there were at least 24 specie s not previously suspected as migrants. The seasonal distribution of c atches varied between sites and years. Some species showed peaks in bo th spring and autumn in some years, but only in spring in other years. Many of the less common species were caught only in summer and autumn . Large catches were usually obtained overs short periods (1-2 nights) , separated by long periods when catches were very low. These large ca tches, which were thought to represent major migrations, accounted for 76% of the catch in 3% of the trapping period at Point Lookout, and 8 7% of the catch in 2% of the trapping period at Mt Dowe.