Acute Sublethal Heat Stress Impairs Blood Feeding and Trypanosome Infection in the Kissing Bug, <i>Rhodnius prolixus</i>

Kissing bugs are the primary vectors of <i>Trypanosoma cruzi</i> , the causative agent of Chagas disease. Kissing bugs are exposed to thermal variability, including short periods of heat stress, which can induce mortality or exert sublethal effects. This study investigated <i>Rhodnius prolixus</i> following brief periods of high thermal stress with respect to survival, blood feeding, developmental processes, and <i>T. cruzi</i> infection, with a focus on sublethal effects. Our results demonstrated a significant decrease in survival for <i>R. prolixus</i> at 42 °C for 8 hours. When exposed to sub-lethal thermal stress (40°C for 8 hours), blood ingestion (amount and proportion) was reduced after 24 hours of recovery from thermal stress. Among the bugs that fed after 24 hours, molting was not impacted by temperature exposure. The infection rate decreased after heat exposure, likely due to reduced blood volume ingested when feeding 24 hours after heat stress. A week of recovery after exposure to higher temperatures improved feeding and increased infection rates to levels comparable to those of kissing bugs not exposed to thermal stress. Our findings offer insights into how extreme temperature events may influence Chagas disease. Specifically, these studies highlight the need to clarify how temperature, particularly at sublethal levels, interacts with vector biology to alter parasite transmission.