Discovery of a remarkable new species of black fungus gnat (Diptera, Sciaridae) from termite nests in Malaysia

A remarkable new species of black fungus gnat Pnyxiopalpus roslii sp. nov., was discovered from nests of the termite Nasutitermes proatripennis in Ulu Gombak, Malaysia, and is described based on the female morphology and DNA barcodes. This is the first record of a termitophilous black fungus gnat from South-east Asia. The new species is easily distinguished from its known congeners by the degeneration of all thoracic setae into tiny setulae. This species is described as a symbiont of the host termite based on field observations and the examination of specimens. The “wing stump” structure of the new species indicates that this species has wings after eclosion and later loses them, an adaptation to a cryptic life. A second still undescribed termitophilous species of Pnyxiopalpus was observed walking in amarching column of the termite Longipeditermes longipes in Ulu Gombak.