Meeting Abstract
Aedes aegypti mosquitoes transmit serious diseases including Zika and Dengue fever, and use their chemosensory system to find appropriate hosts. We have shown that adult Aedes aegypti can readily learn host odors, which may allow them to find appropriate blood-hosts, avoid defensive prey individuals, or even select oviposition sites. However, less is known about learning ability of the larvae. Larval learning could play an important role in predator avoidance, finding food, or avoiding stressful environments. Furthermore, the sensory bases of these behaviors remain unknown. Here we demonstrate a new Pavlovian conditioning protocol tailored for aquatic Aedes aegypti larvae. Using computer vision algorithms to track the larvae, we can quantitatively analyze many facets of larval activity. Our results demonstrate that Aedes aegypti larvae are indeed capable of aversive olfactory conditioning. This learned behavior persists for at least 24 hours and appears to be specific to the learned olfactory stimulus. Further, we tested this same protocol on mosquitoes deficient for the olfactory co-receptor Orco. This obligate co-receptor is required for function of olfactory and gustatory receptors in Aedes aegypti. We expect Orco deficient larvae to exhibit no learned olfactory avoidance behavior, because of their inability to sense olfactory stimuli presented throughout an experiment. The odor-specific learning ability of Aedes aegypti larvae suggests that learning may be crucial for mosquito development and proliferation in the wild. Further research will provide valuable information that may be useful in preventing the spread of mosquito hosts of virulent diseases.
