The subgenus Persicargas (Ixodoidea: Argasidae: Argas). 35. The lateral segmental organs and peritracheal gland in immature and adult A. (P.) arboreus.

Lateral segmental organs and a peritracheal gland in adult and immature Argas (Persicargas) arboreus are described and compared with similar organs in other arthropods. Four pairs of lateral segmental organs containing neuronal cell bodies and innervated by branches of hemal nerves from pedal nerve roots are present in nymphal instars and in the adult; 3 pairs are present in the larva. In each postembryonic developmental stage, the peritracheal gland consists of cell masses with neurosecretory granular activity and is associated with the tracheal plexus in the region of the central nerve mass and adjacent hypodermis. The glandular cells show cyclic changes in size and activity related to the molting process in immature stages and probably to other events in the adult.