Study of the Salivary Glands in Triatominae (Hemiptera, Reduviidae, Triatominae): Their Color and Application to the Chagas Disease Vector Evolution

Abstract

Chagas disease is caused by and transmitted by feces of a triatomine that has the habit of defecating during blood feeding. The salivary glands of triatomines are important to hematophagy because their saliva is rich in anticoagulant and hemolytic proteins. The salivary glands of some species analyzed are reddish due to the presence of nitrophorins (antihemostatic activity). The present study aimed to analyze the color pattern of the salivary glands of 67 triatomine species to evaluate whether the presence of nitrophorins is a synapomorphy of or the tribe Rhodniini, or if it is shared with triatomines of the tribes Triatomini and Cavernicolini. Since only the species of the tribe Rhoniini present red glands, it is admitted that the presence of nitrophorin proteins is a synapomorphy of the tribe Rhodniini and that this tribe has derived more recently when compared with Triatomini and Cavernicolini.

Microanatomical and secretory characterization of the salivary gland of the Rhodnius prolixus (Hemiptera, Reduviidae, Triatominae), a main vector of Chagas disease

“…Each insect has one pair of SG located in its thorax. Individuals of the genus Rhodnius have two close and independent units forming each SG: (i) a larger and reddish structure called the 'principal unit' and (ii) a smaller, translucent, elongated and rounded structure called the 'accessory unit' [11][12][13][14]. The accessory unit opens at the base of the main excretory duct, which emerges at the medial portion of the principal unit.…”