Revision of Laryngodus Herrich-Schaeffer, an Allocasuarina feeder, with comments on its biology and the classification of the family (Heteroptera:Lygaeoidea:Rhyparochromidae)

Abstract

Laryngodus Herrich-Schaeffer, 1850, is redescribed, including, for the first time, nymphal morphology. Three species are recognised based on qualitative morphology, a principle components analysis of morphometric data, and the study of sequence data from the mitochondrial genes COI and 16S. They are: L. australiae Herrich-Schaeffer from the south-western coastal area of Western Australia, L. cervantes, sp. nov., from southern Western Australia, and L. luteomaculatus, sp. nov., from western Victoria and adjacent South Australia. Sexual dimorphism in all species and variation in males of L. luteomaculatus, sp. nov. is documented and discussed. All species and their hosts are illustrated with colour digital images; scanning electron micrographs are used to illustrate male prosternal spines, antennnae, abdominal trichobothria, and other structures. Male genitalic morphology is illustrated with line drawings. Authoritative host identifications indicate that Laryngodus is restricted to feeding on several species of Allocasuarina (Casuarinaceae); nymphs and adults are known to live on the plants and to be strongly associated with the cone-like fruits. The tribal placement of Laryngodus is discussed.