ISOPTERA, Brulle, 1832

Herhold, Hollister W, Davis, Steven R, Degrey, Samuel P & Grimaldi, David A, 2023, COMPARATIVE ANATOMY OF THE INSECT TRACHEAL SYSTEM PART 1: INTRODUCTION, APTERYGOTES, PALEOPTERA, POLYNEOPTERA, Bulletin of the American Museum of Natural History 459 (1), pp. 1-184 : 1-184

INFRAORDER ISOPTERA

Although the respiratory physiology of termites (especially as it relates to their digestive system) has been studied for decades, micro-CT scans of respiratory architectures have been absent. The tracheal scans of the reproductive caste Reticulatermes flavipes and soldier caster Zootermopsis angusticollis shown here detail the remarkable intricacy of tracheal branches, especially in the abdomen, well known for its adaptations for digesting cellulose. Although both specimens were scanned at approximately 5 µm resolution, the worker Reticulitermes possesses notably smaller tracheae than the soldier Zootermopsis . Although the two specimens feature many similarities, notably a T1-DLT prothoracic “loop,” the differences are sufficient to describe both in detail.

Wing-leg branching patterns, referred to here as Chapman’s Triangle (see Discussion section), are evident in both termites, albeit with some minor modifications ( Chapman, 1918). In Zootermopsis , T2-AWL branches from T2-DB rather than directly from T2-S (as in Dermaptera and others), T3-AWL is off T3-S. In Reticulitermes , T2-VL branches from T2-VB, rather than T2-VLT, and T3-VL branches off T3-VB. (These could be Tn-Cx and not Tn-VL.)