Unveiling the morphology of the Oriental rare monotypic ant genus Opamyrma YAMANE, BUI & EGUCHI, 2008 (Hymenoptera: Formicidae: Leptanillinae) and its evolutionary implications, with first descriptions of the male, larva, tentorium, and sting apparatus

Abstract

The monotypic genus Opamyrma Yamane, Bui & Eguchi, 2008 (Hymenoptera, Formicidae, Leptanillinae) is an extremely rare relictual lineage of apparently subterranean ants, so far known only from a few specimens of the worker and queen from Ha Tinh in Vietnam and Hainan in China. The phylogenetic position of the genus had been uncertain until recent molecular phylogenetic studies strongly supported the genus to be the most basal lineage in the cryptic subterranean subfamily Leptanillinae. In the present study, we examine the morphology of the worker, queen, male, and larva of the only species in the genus, Opamyrma hungvuong Yamane, Bui & Eguchi, 2008, based on colonies newly collected from Guangxi in China and Son La in Vietnam, and provide descriptions and illustrations of the male, larva, and some body parts of the worker and queen (including mouthparts, tentorium, and sting apparatus) for the first time. The novel morphological data, particularly from the male, larva, and sting apparatus, support the current phylogenetic position of the genus as the most basal leptanilline lineage. Moreover, we suggest that the loss of lancet valves in the fully functional sting apparatus with accompanying shift of the venom ejecting mechanism may be a non-homoplastic synapomorphy for the Leptanillinae within the Formicidae.Open access, licensed under CC BY 4.0. © 2020 The Author(s).DOI: 10.25849/myrmecol.news_030:027Pages: 27-52Volume: 30Year: 2020Journal: Myrmecol. News