Molecular Phylogeny of Thelastomatoidea (Nematoda) with the Description of a New Genus and Two New Species of Hystrignathidae Associated with Bess Beetles (Coleoptera: Passalidae) from Oaxaca, Mexico

Redescription of three pinworms of the genus Cephalobellus Cobb, 1920 (Nematoda: Oxyuridomorpha: Thelastomatidae) from scarab beetle grubs from Hungary

Larvae of European rose chafer Cetonia aurata (Linnaeus, 1758) and cockchafer Melolontha sp. beetles were collected in Hungary for parasitological study. Intestinal examination revealed the presence of three well-known thelastomatid nematodes belonging to the genus Cephalobellus Cobb, 1920. We report for the first-time Cephalobellus cuspidatum (Rudolphi, 1814) Leibersperger, 1960, C. osmodermae Leibersperger, 1960, and C. potosiae Leibersperger, 1960 in Hungary, all found in scarab beetle larvae. Due to incomplete original descriptions, a comprehensive redescription with detailed morphological data is presented. Additionally, an identification key for closely related Cephalobellus, Thelastoma and Severianoia species infesting scarab beetles worldwide is provided. Newly generated 18S and 28S rDNA gene sequences of C. osmodermae place it as one of the early branches within Thelastomatidae.