Molecular characterization and distribution of the needle nematode Longidorus laevicapitatus Williams, 1959 (Nematoda: Longidoridae) in Costa Rica

Correct identification of Longidorus species in Costa Rica is essential to establish appropriate control strategies for preventing the spread of these nematodes. Nematode surveys conducted in the rainy seasons from 2013 to 2015 in areas arbitrarily chosen and widely distributed in the whole territory of Costa Rica, resulted in an overall prevalence of Longidorus spp. infesting soils both cultivated, ornamental and wild plants of 40.26 %. Integrative morphometric and molecular data for Longidorus populations were obtained using D2-D3 expansion segments of 28S rRNA, ITS1-rRNA, and the partial 18S-rRNA, identifying a solely species identified as Longidorus laevicapitatus. Morphology and morphometrical traits analysis of these populations of L. laevicapitatus were in agreement with those of the original and posterior descriptions of the species, except for some minor differences, which may be a result of intraspecific variability. The phylogenetic relationships of this species with other representatives of Longidorus spp. using D2-D3 expansion segments and the partial 18S indicated that L. laevicapitatus clustered clearly separately in a basal position in both phylogenetic trees.