Description of external cuticular setae of head, thorax, legs, abdomen and genitalia of four Triatominae species

Abstract

Introduction: The classification of the cuticular extensions of insects has been proposed as a taxonomic tool; however, the internal and external processes of the cuticular extensions of the Triatominae subfamily have not been fully analyzed and categorized. Objective: To describe the setae from different regions of the outer cuticle of several triatomine species by scanning electron microscopy. Materials and methods: Triatomines were washed and dried, after which different regions of the body from Eratyrus mucronatus, Triatoma maculata, Panstrongylus geniculatus and Belminus ferroae specimens were dissected, mounted on graphite double-sided adhesive tape over metal supports, metalized with gold and micrographed for further analysis. Results: We described nine types of cuticular setae. We found five types of setae in B. ferroae and T. maculata, four in P. geniculatus and only one in E. mucronatus. According to the proposed typology, type 3 seta was the most common in T. maculata, P. geniculatus and E. mucronatus, whereas type 1a predominated in B. ferroae. Conclusion: Type 3 seta was the most common in the Triatomini tribe (T. maculata, E mucronatus and P. geniculatus), whereas type 1a seta was specific to B. ferroae (tribe Bolboderini), suggesting that the surface morphology of the setae may have taxonomic value at tribe taxonomic level.