Australian Larvae of the Genus Trombella (Acarina, Trombidioidea)

The Australian larvae of the genus Trombella Berlese, 1887 (Acarina : Trombidioidea : Trombellidae) are revised. All six known species are Australian, five new, the larva having been correlated with adult and deutonymphal forms by the earlier rearing to deutonymphs of larvae of Trombella alpha Southcott, 1985 obtained from the field cricket Teleogryllus commodus (Walker) in New South Wales. The five new species of larvae are: T. cucumifera, sp. nov.; T. fusiformis, sp. nov.; T, rugosa, sp. nov.; T. sternutor, sp. nov.; and T. calabyi sp. nov.; they have all been obtained by a systematic survey of the ectoparasitic mites of Australian grasshoppers. T. cucumifera occurs in the northern part of Western Australia, in the Northern Territory, Queensland and New South Wales; T. fusiformls in the northern part of Western Australia, and the northern parts of the Northern Territory and Queensland; T. rugosa and T. sternutor in the south-western part of Western Australia; T. calabyi is recorded from a single specimen in north- western Western Australia. Correlation studies are made on the metric characters of T. cucumifera, T. fusiformis and T. rugosa. In each species there was a significant excess of positive correlations between many of the metric variates used, within and between the groups of variates for scutal, idiosomal setal and leg variates. There appeared to be a tendency for a greater excess of these correlations within character groups than between characters of different groups.