New species, synonymies, and life-histories of the Southeast Asian treehopper genus Pyrgauchenia Breddin (Homoptera: Membracidae: Centrotinae)

Taxonomic information and life-history observations are given for Pyrgauchenia treehoppers (Auchenorrhyncha: Membracidae) in South-East Asia. Specimens from field studies in Peninsular Malaysia and Sabah are identified as: P. biuni Stegmann & Webb sp. nov., P. pendleburyi Stegmann & Webb sp. nov., P. tristaniopsis Stegmann & Webb sp. nov., P. ?brevinota Funkhouser and P. colorata Distant. Two nominal species, P. angulata Funkhouser and P. brunnea Funkhouser, are placed as junior synonyms of P. colorata Distant syn. nov. Descriptions and detailed figures of the new species and P. colorata are given, together with type data and some morphological details for P. breddini, P. jugulata Buckton, P. kinabalense Breddin, P. wallacei Breddin, P. fulmeki Schmidt, P. foersteri Breddin and P. recurva Funkhouser. Pyrgauchenia nymphs (P. tristaniopsis) are described for the first time and an unusual morphological variant in adult females of the same species is described. The first study of the male and female genitalia of South-East Asian Centrotinae has revealed considerable similarity among the Pyrgauchenia species studied. Characters found in these structures and in the abdomen of the nymph, which may be useful at a higher level of classification, are discussed. A key and list of all Pyrgauchenia species is given, together with their distribution and life-history data (where known). The record of P. pendleburyi in Peninsular Malaysia is the first of this genus from mainland South-East Asia. Life-history observations, together with published records, demonstrate maternal egg-guarding, and a potential for polyphagy and for specificity in mutualistic ant partners.