DESCRIPTION AND BIOLOGY OF A NEW SPECIES OF CYBOCEPHALUS ERICHSON (COLEOPTERA, NITIDULIDAE), A PREDATOR OF AUSTRALIAN CITRUS WHITEFLY

Cybocephalus aleyrodiphagus sp.n., a predator of Australian citrus whi tefly, Orchamoplatus citri (Takahashi), is described from adults and l arvae collected from southern New South Wales (where it appears to be the major natural enemy of O. citri and South Australia. Eggs of C. al eyradiphagus are)aid singly near egg circles of O. citri and larvae fe ed on eggs, crawlers and nymphs. Adults feed on all immature stages of O. citri. Reproductive, but not non-reproductive, females contain gre ater quantities of stearic, oleic and linoleic acid than males indicat ing the possible presence of a sex pheromone. In southern New South Wa les, C. aleyrodiphagus sp.n. overwinters as non-reproductive adults an d produces two adult generations during December-January and March-May . The sex ratio is close to 1:1 during October-December (overwintered adults) but male biased (2.2:1) during January-July (new generation ad ults). Trends of abundance for C. aleyrodiphagus correspond well with those for O. citri nymphs/pupae indicating a functional response of th e predator to prey, despite disruption by foraging ants.