Abrolophus from Australasia, and the mysterious Mypongia (Trombidiformes: Parasitengona: Erythraeidae)

An undetermined species of Abrolophus Berlese was intercepted in quarantine by Australian biosecurity on kiwifruit imported from New Zealand. Here, we show that these are the Australian species Abrolophus ripicola (Womersley, 1934), a species known from the post-larval stages only. We present evidence that the larva of A. ripicola is probably the taxon Mypongia brevipes Southcott, 1961, which belongs to a monotypic genus with unique morphology that is placed in a different subfamily to Abrolophus. The larval and post-larval stages we examined share a similar morphology, most notably a reduction of the prodorsal shield and much reduced leg setation. Three M. brevipes larvae were intercepted on kiwifruit imported from New Zealand, and with an additional larval specimen from South Australia, these four specimens represent the first collections of this taxon since its description. Further circumstantial evidence supporting the conspecificity of the two taxa includes a female specimen of A. ripicola collected from Myponga, the type locality of M. brevipes, , and larval stages of an undescribed Mypongia collected together with the post-larval stages of an undescribed Abrolophus, , from the same locality in South Africa. Keys are provided for the post-larval stages of Abrolophus species in Australia (6 spp.), Papua New Guinea ( Abrolophus novaeguinensis (Gunther, 1941)) and New Zealand ( Abrolophus zelandicus Luxton, 1989).