Effects of Temperature on Blood Feeding and Activity Levels in the Tiger Mosquito, Aedes albopictus

SIMPLE SUMMARY: Mosquito populations experience variations in temperature across space and time as well as temperature rises associated with climate change. Our understanding of how temperature affects blood feeding behavior and activity levels in adult mosquitoes is currently limited, particularly in Aedes albopictus, the tiger mosquito. Aedes albopictus is a successful invasive mosquito around the globe that vectors several arboviruses important to human health. We evaluated the impacts of temperature on the behavior of adult females of Aedes albopictus from a population from St. Louis, MO. The mosquitoes were reared from hatch to adult across three temperature treatments (26 °C, 29 °C, and 32 °C) and we compared the propensity to blood feed in adults and the size of the blood meal ingested. We also measured the general activity patterns of adults that were raised for their entire life cycle across these three temperature treatments. At the highest temperature tested, female adult Ae. albopictus were less likely to blood feed yet moved more actively around the cage. These behavioral responses to higher temperatures suggest these conditions may be stressful to the adults, at which point they reduce normal behaviors associated with disease transmission and may seek out refugia to buffer the heat stress. These responses may negatively impact their population growth and also reduce biting and transmission rates during periods of relatively high temperatures. ABSTRACT: Temperature has been shown to have profound effects on mosquito population dynamics and life history. Understanding these effects can provide insight into how mosquito populations and the diseases they transmit may vary across space and time and under the changes imposed by climate change. In this study, we evaluated how temperature affects the blood feeding and general activity patterns in the globally invasive mosquito species Aedes albopictus. We reared cohorts of Ae. albopictus from hatch through adulthood across three temperatures (26 °C, 29 °C, and 32 °C). The propensity of adult females to take a blood meal and the size of the blood meal were compared across temperatures. We also observed the overall activity levels of adult females over a 13.5 h period. At the highest temperature tested (32 °C), females were less likely to take a blood meal and were most active, as measured through frequency of movement. We postulate that our highest-temperature treatment imposes heat stress on adult female Ae. albopictus, where many abstain from blood feeding and increase movement in an attempt to escape the heat stress and find a more favorable resting location.