Species-specific patterns of shelter exploitation in Chagas disease vectors of the genus Rhodnius

Abstract

Triatomines are insect vectors of Trypanosoma cruzi the etiological agent of Chagas disease. Several species belonging to the genus Rhodnius (Hemiptera: Reduviidae) have been reported inhabiting domestic and peridomestic environments in different regions of Latin America. However, behavioral and sensory ecology aspects related to their use of shelters have been poorly studied. The objective of the present study was to characterize how bug density, illumination and thigmotactic information affect the use of shelters by three species belonging to the Rhodnius prolixus species complex. We evaluated whether exposure to different insect densities affects the proportion of R. prolixus, Rhodnius robustus and Rhodnius neglectus that choose to stay inside a refuge. Besides, we evaluated whether absence of an illumination regime affects their tendency to hide in shelters. Our results showed that the proportion of individuals that remained outside the shelter increased with rising insect densities. Nevertheless, while R. prolixus only reacted by augmenting this proportion with the highest density tested, the other species showed significant increases already at lower densities. On the other hand, a significantly higher number of R. robustus stayed outside the shelter in the absence of a light cycle, while no change was induced for the other species. Thus, this study determined species-specific profiles of refuge exploitation defined by factors such as thigmotaxis and negative phototaxis. The differences observed among these Rhodnius species may impact their house colonization abilities, which seem to be critically affected by bug hiding performance during health service detection processes.

Trypanosoma cruzi-infected Rhodnius prolixus endure increased predation facilitating parasite transmission to mammal hosts

“…To decrease the risk of predation during foraging excursions, these insects take large and sparse blood meals through relatively short interactions, and present most of their activity during the night. Indeed, triatomines stay hidden inside shelters during most of their life, due to accentuated thigmotaxis and negative phototaxis [ 1 ]. Several endogenous events, such as the developmental maturation of host-related behavior [ 2 ], which includes the regulation of the expression of olfactory receptors [ 3 ], and nutritional status [ 4 ], trigger coming out of shelters as a response to the detection of host cues [ 5 ].…”

Shelter selection in the kissing bugs Triatoma infestans and Rhodnius prolixus: Intra‐ and inter‐specific interactions and quality evaluation

“…Recent reports about three members of the R. prolixus species complex, R. prolixus , Rhodnius robustus (Larrousse 1927) and Rhodnius neglectus (Lent 1954), showed different shelter exploitation profiles according to density variations (Mosquera & Lorenzo, 2020). These authors show that with equal density levels, these three species are found inside the shelter in different proportions, probably related to each species' biology, for example, R. robustus hardly colonizes domestic environments, thus showing the poorest use of shelter under laboratory conditions.…”