Aspects of the life history of Chauliognathus lugubris, a predator of eggs and early stage larvae of the Eucalyptus leafbeetle, Chrysophtharta bimaculata, were studied in southern Tasmania. In the laboratory (ambient temperature 15-25 "C and artificial diet), the egg to adult period was about 10 months with seven larval stages. Advanced larvae (5th-7th instar) were collected in the field from soil litter during mid-winter. Adults were most common in the spring and early summer, with regular field collections suggesting adult longevity of 2-3 months. Based on the pattern of ovarian development of field-caught adults, in combination with the long larval development times, it appeared that C. lugubris has only one generation a year.
Chrysophtharta bimaculata is a serious pest of eucalypt forests in Tasmania. The beetle overwinters as a diapausing adult, but it is poorly documented whether it forms overwintering aggregations or where it shelters. During winter 1992, we searched 386 possible overwintering sites for C. bimaculata in Eucalyptus obliqua forests. Fourteen types of habitat were identi®ed, of which clumps of Gahnia grandis sheltered the greatest mean number of insects (3.31 0.72 insects/plant, n 65 plants), while bracken fern litter sheltered the least (0.14 0.14 insects/sample, n 7, 1 m 2 quadrat samples). Of the 14 habitat types, all except two (under the bark of eucalypt stags and in G. grandis clumps) were more often unoccupied. Beetles were more commonly found on mature forest edges or in logged and regenerating forests; few were found within mature forests. Our results show that C. bimaculata rarely forms overwintering aggregations of greater than 20 individuals per site, nor does it appear to have a signi®cant pre-diapause dispersal.
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