Prelarva and larva of Opilioacarus (Neocarus) texanus (Chamberlin and Mulaik) (Acari : Opilioacarida) with notes on the patterns of setae and lyrifissures

摘要

The prelarva and larva of Opilioacarus (Neocarus) texanus (Chamberlin and Mulaik, 1942) are described based on reared specimens. The larval description focuses on the pattern of setae, lyrifissures, and glands in order to test the hypothesis that these structures carl be homologized among larvae of all suborders of the Parasitiformes. The distribution pattern of lyrifissures and setae on the hysterosoma of opilioacarid larvae appears to be the most complete pattern of these structures in the order Parasiliformes, and strongly suggests an ancestral segmental arrangement of the cuticiular sensillae and glands. Unlike the condition for the post-larval instars, sensillae (setae and lyrifissures) on the palps, hysterosoma, and legs II-III of the larva can be homologized among larvae in all suborders. Homologies among suborders could not be established for the sensillae and glands of the propodosoma and most segments of legs I. [References: 33]