Respiration of Corixidae (Hemiptera-Heteroptera)

Abstract

PTERYGOTE insects originally evolved as terrestrial animals, but various families of Hemiptera have since colonized aquatic habitats. Corixids live on the bottom, feeding mainly on algae and detritus. Air carried on the hydrophobe body surface functions as a ‘physical gill’1–4. The thoracic tracheal system is well developed. The ventrally situated anterior thoracic spiracles occur between the pro- and ptero-thorax. The dorsally placed posterior thoracic spiracles occur laterally to the wing bases. The anterior abdominal spiracles occur dorsally, just posterior to the thorax. On each side these spiracles are joined by a wide, lateral, longitudinal tracheal trunk, which supplies tracheae to the flight and leg muscles. The tracheae from each of the ventrally placed abdominal spiracles supply gonads and gut, but, except for the dorsally placed vestigial longitudinal tracheal trunks, are unconnected with other tracheae of the same or adjacent segments. The passage of gas anteriorly through the thorax (a centre of high oxygen consumption) is largely independent of that through the abdomen where the consumption of oxygen is relatively low.