Description of a new and two known species of the insect–associated genus Oigolaimella Paramonov, 1952 (Nematoda: Diplogastridae) with a note on the biology, biogeography and relationship with congeners

Abstract

The present article deals with the description of one new and two known nematode species extracted from insects, as well as from the dwelling places of insects, viz., compost, rotting wood and bark, based on light microscopic and scanning electron microscopic observations. The species were tested for pathogenicity towards insects and found to have the potential to kill insect pests. A detailed morphological characterization of the species along with information on their associations with insects can be utilized to assess their relevance in insect pest management. Oigolaimella winchesi (Goodey, 1929) is reinstated and differentiated from both O. agilis (Skwarra, 1921) and O. longicauda (Claus, 1862) on the basis of number of liplets; shape of spermatozoa in spermatheca; structure of spicules and gubernaculum. Also, the molecular characterization of the cosmopolitan species O. longicauda (Claus, 1862) and Oigolaimella trilineata sp. n. has been done based on D2/D3 segment of LSU 28s rDNA gene and phylogenetic inferences have been made by performing a Bayesian analysis. A biogeographical distribution of species of Oigolaimella is provided and the relationships of its congeners are analyzed and discussed along with a key to identification of species.