Description of the third instar larva of a hypogean ground beetle, Trechus alicantinus (Coleoptera: Carabidae: Trechinae)

Abstract

Description and illustrations are provided for the third instar larva of Trechus alicantinus Español, 1971 obtained from a laboratory breeding. This paper aims to contribute to increase the general knowledge about microendemic hypogean species of the east of the Iberian Peninsula. Besides, it expands the existing knowledge about the preimaginal stages of the genus Trechus and the whole tribe Trechini (Coleoptera, Carabidae). Larvae can give additional information about the life style of the species. Larvae can also express, even more than the imagos, some apomorphic characters, traditionally considered a result of adaptation to the hypogean habitat, such as the regression of ocular structures. The characteristic lack of stemmata is discussed. This type of event, which also appears in other Trechini larvae, is probably more related to phylogenetic lineages than with an adaptive response to hypogean environment.