Cuticular lesions: a non-infectious integumental disease of Glossina species

Abstract

Purified suspensions of macerated cuticular lesions from the insectary-reared tsetse Glossina morsitans morsitans were applied on laboratory-reared newly emerged teneral tsetse by three pathways: topical application on the ventral abdominal integument, oral microfeeding, or microinjection into the haemocoel. A second group of flies were subjected to teratological wounding pin-stabs, forcep-pinch and shallow blade-slits, all in attempt to induce cuticular lesions. Samples of tsetse were examined every week for 11 weeks. Application of cuticular lesion suspensions did not result in lesion formation, but three types of lesions were formed due to physical damage induced artificially on the integument.

Total haemocyte counts (THCs) and differential haemocyte counts (DHCs) were also determined for tsetse with, and without, lesions. THCs were significantly higher (P < 0.01) in tsetse with cuticular lesions than in those without lesions. DHCs showed a high number of large spindle-shaped cells and thrombocytoids in the flies with lesions (P < 0.05).