Rhabditis rainai n. sp. (Nematoda: Rhabditida) associated with the Formosan subterranean termite, Coptotermes formosanus (Isoptera: Rhinotermitidae)

Abstract

AbstractRhabditis rainai n. sp. is described from the gut and head of sick Formosan subterranean termites (Coptotermes formosanus) collected in New Orleans, LA, USA (isolate LKC20). Rhabditis rainai n. sp. is a hermaphroditic species with an unusual prerectum, four denticles per glottoid swelling, enlarged posterior stoma, three paired lip sectors, protruding posterior anal lip, and five ridges in the hermaphrodite lateral field. Males generated from starved bacterial cultures have three lateral field ridges and a notched peloderan bursa with only eight rays. Male spicules are distinctive with a round but truncated head, constricted neck, narrow shoulders, nearly straight blade with distal tenth upturned, and rounded tips supporting a curved ventral arch. Males of LKC20 were mated successfully with hermaphrodites cultured from a Fiji Islands soil (isolate PS1191). In subsequent crosses, male progeny were fertile as expected for conspecific populations. Differences in morphometrics of cultured specimens that were heat-killed or fixed is demonstrated. Rhabditis rainai n. sp. was compared to R. blumi and R. adenobia, but does not fit clearly within the current subgenera of Rhabditis or genera of Rhabditidae. Nematode-termite relationships and possible origin of R. rainai n. sp. with Formosan subterranean termites from Southeast Asia are discussed.