Effects of Larval Competitors and Predators on Oviposition Site Selection of <I>Anopheles gambiae</I> Sensu Stricto

Abstract

We examined whether predators and competitors influence selection of oviposition sites by Anopheles gambiae Giles. Mosquitoes in cages laid significantly fewer eggs in rainwater conditioned with a predator (backswimmers, Notonecta sp.) than in unconditioned rainwater. Rainwater conditioned with a putative competitor (tadpoles, Xenopus sp.) also had fewer eggs than unconditioned rainwater. Similarly, mosquitoes laid significantly fewer eggs in rainwater conditioned with five and 50 An. gambiae larvae than in unconditioned rainwater. When larvae were present, significantly more eggs were laid in containers with five larvae than in containers with higher densities, but the differences in number of eggs laid were not significant among the densities of 40, 70, and 100 larvae. This study demonstrated that caged An. gambiae females avoid oviposition in habitats with supposed competitors and predators.

Landscape Epidemiology Modeling Using an Agent-Based Model and a Geographic Information System

“…The oviposition behavior of An. gambiae mosquitoes can be affected by a variety of factors, as demonstrated by several studies [21][22][23][24][25][26][27][28]. In the core model, all larvae are categorized into different age groups, or cohorts, according to the common age of the cohort.…”

Anopheline Mosquitoes and the Malaria Scourge

“…gambiae to breed in rather clear water bodies. Other factors that may play an important role in habitat selection are volatile compounds that are produced by microbial populations in the breeding site [16], chlorophyll a content in the breeding site [8] or the presence of conspecific larvae or aquatic predators [17]. Some studies reported no effect of turbidity on the occurrence of An.…”

“…funestus which are more dominant species during the dry periods [11,30]. The distance between oviposition site and blood host may affect the oviposition choice [17]. [30] showed that immatures of An.…”

Chemical Cues for Malaria Vectors Oviposition Site Selection: Challenges and Opportunities

“…This occurs through several sensor factors including olfactory [13], tactile, temperature, chemical, and visual cues [6,14]. Chemical cues may be sensed before physical contact with the site, or they may be sensed upon contact [15] and may emanate from a variety of sources, including microorganisms; mosquito eggs, larvae, or pupae; decomposing organic materials; microbes of larval breeding water and predators or competitors, whether vertebrate or invertebrate [5,6,[16][17][18][19][20][21][22][23].…”

“…Attractant and repellent compounds for mosquitoes oviposition, including anopheline, have been identified from several sources such as hay infusion [18,34], water-associated bacteria [21,35,36], mosquito oviposition and larvae holding water, pheromones [6,21,29,37], and exudates from aquatic competitors or predators [13,38]. The different sources of stimuli result in patterns of distribution of immature-stage mosquitoes that reflect differences in the suitability of sites for the development of different species [29,39].…”