DOLICHODORUS COSTARICENSIS N. SP. (TYLENCHIDA: DOLICHODORIDAE): A NEW AWL NEMATODE SPECIES FROM THE CENTRAL PACIFIC REGION OF COSTA RICA

A Esquivel, H Ferris, I Cid del Prado, S A Subbotin

Abstract


A new species, Dolichodorus costaricensis n. sp., was found in soil samples collected from a native tree in the Central Pacific Region of Costa Rica. It is the second species of the genus Dolichodorus, after D. minor, to be reported in our country.  This new species is described and illustrated herein based on light and scanning electron microscopy. Molecular characterization of D. costaricensis n.sp. using the D2-D3 expansion fragments of 28S rRNA gene is provided. The phylogenetic relationships of this species with other representatives of the genus Dolichodorus indicated that D. costaricensis n.sp. has a sister relationship with D. mediterraneus. Dolichodorus costaricensis n.sp. is distinguished from the other 18 species of the genus by combinations of morphological and morphometric characteristics, including total body length (1.9-2.4 mm); body width (32-45 μm); stylet length (74-117 μm); oesophagus length (202-258 μm); and tail length (62-86 μm). Important morphological characters of the species are:  a rounded head flattened distally, lip region with a distinctive flat oral disc, vulva, and vagina without evident sclerotization and gubernaculum clearly bent, lobed, and forked at the distal end, a character not previously described for any Dolichodorus species. An updated key is provided for identification of species of the genus Dolichodorus.

Keywords


awl nematode, Costa Rica, Dolichodorus costaricensis, Inga ruiziana, taxonomy

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