Knowledge Bank

The abilities of many insects to learn have been well documented. However, a limited number of studies have been conducted to determine associative learning capabilities in medically important insects. To date, no studies of this sort have been carried out with the malaria vector Anopheles gambiae. This research study used Culex pipiens to investigate methods used in a previous study that looked at the learning abilities of Cx. quinquefasciatus to associate an odor (conditioned stimulus) with a sugar-meal (unconditioned stimulus) by individual training and testing. Those methods were then adapted and used to examine associative learning capabilities in An. gambiae by both individual training, and testing with a dual-port olfactometer. Vanilla and almond extracts were used for individual training and testing of Cx. pipiens, but were found to be unsuitable. In order to determine compounds more appropriate than extracts to train and test An. gambiae, two sets of experiments were carried out with chemicals found in honey to determine An. gambiae mosquitoes’ innate responses to them. From those results, phenylacetaldehyde and geranylacetone were chosen to be used for the dual-port olfactometer trials, and linalool oxide and (Z)-β-ocimene were chosen to be used for the individual training and testing of An. gambiae. The results indicate the possibility that An. gambiae mosquitoes can associatively learn and illustrate the need to ensure that all the parameters that may affect the learning abilities and behaviors of mosquitoes are taken into account in the experimental design so that definitive conclusions about their learning abilities can be made.