Adaptive diurnal timing of predation by a mosquito-specialist predator (#125)
Evarcha culicivora is an East Africa salticid spider that feeds indirectly on vertebrate blood by actively choosing blood-carrying mosquitoes as preferred prey and actively chooses Anopheles, the genus to which all human malaria vectors belong, as preferred mosquitoes. An. gambiae s.s., the most important malaria vector in East Africa, is attracted to human odour (anthropophily), feeds late at night and then, while digesting blood, spends the morning quiescent on the walls of houses. E. cuilicivora is also attracted to human odour and, by using sight and olfaction, this spider is highly proficient at finding quiescent mosquitoes. The hypothesis we consider here is that E. culicivora is innately predisposed to time predatory activity in a way that makes it proficient at preying on night-feeding anthropophilic mosquitoes. During the night, E. culicivora rests in a silk nest. When kept under a natural-light regime, E. culicivora came out of its nest and fed primarily in the morning. Lures made from prey were used when testing for vision-based prey choice and a Y-shaped olfactometer was used olfactory prey choice. E. culicivora was consistently more strongly motivated to choose prey when the experiments were carried out in the morning.
Predation, spider, mosquito, Evarcha culicivora, Anopheles gambiae