The subgenus Persicargas (Ixodoidea: Argasidae: Argas). 36. structure and postembryonic development of the neurohemal organ in A. (P.) arboreus.

The structure and postembryonic development of the paraesophageal neurohemal organ lying posteriad to the central nerve mass of Argas (Persicargas) arboreus are described and compared with other arthropod neurohemal-endocrine organs. During postembryonic development, a few large cells differentiate in the larval esophageal epithelium and gradually multiply to form a compact cell mass. In the first nymphal instar, cell mass evagination forms the dorsal lobe of the neurohemal organ which develops in the second instar and attains its final lobular structure in the third instar. These observations provide evidence for homology to the insect corpora cardiaca and related organs in other arthropods.