Variation in host preferences of malaria mosquitoes is mediated by skin bacterial volatiles

Abstract

Abstract. The host preferences of the anthropophilic mosquito species in the Anopheles gambiae complex (Diptera: Culicidae) are mediated by skin bacterial volatiles. However, it is not known whether these mosquitoes respond differentially to skin bacterial volatiles from non-human host species. In this study, the responses of two malaria mosquito species in the An. gambiae complex, Anopheles gambiae s.s. (hereafter, An. gambiae) and Anopheles arabiensis, with different host preferences, to volatiles released from skin bacteria were tested. Skin bacteria collected from human, cow and chicken skin significantly increased trap catches; traps containing bacteria collected from human skin caught the highest proportions of An. gambiae and An. arabiensis. Traps with bacteria of human origin caught a significantly higher proportion of An. gambiae than of An. arabiensis, whereas bacterial volatiles from the chicken attracted significantly higher numbers of An. arabiensis than of An. gambiae. Additionally, An. gambiae showed a specialized response to volatiles from four specific bacteria, whereas An. arabiensis responded equally to all species of bacteria tested. Skin bacterial volatiles may therefore play important roles in guiding mosquitoes with different host preferences. The identification of these bacterial volatiles can contribute to the development of an odour blend that attracts mosquitoes with different host preferences.

Nectar-dwelling microbes of common tansy are attractive to its mosquito pollinator,Culex pipiensL

“…Microbe-derived semiochemicals have been shown to guide foraging behavior of mosquitoes in a variety of contexts. Semiochemicals emitted from human skin microbiota, including S. epidermidis, Corynebacterium minutissimum and Brevibacterium epidermidis, attract mosquitoes to human hosts [37,39,48,49]. Moreover, semiochemicals from Psychrobacter immobilis, Sphingobacterium multivorum, Bacillus spp., Pseudomonas spp., Klebsiella spp., and others help mosquitoes locate suitable oviposition sites [42,44].…”

“…The odor profiles of inflorescences differ not only between plant species [50] but also within the same species due, in part, to microbe-specific semiochemicals [17]. These semiochemicals may enable mosquitoes to discern nectar-rich and -poor inflorescences analogously to mosquitoes selecting human hosts based, in part, on their skin microbiota [38,39]. Emission of microbe-semiochemicals from nectaries could inform mosquitoes about the presence of nectardwelling microbes which, in turn, would signal sugar or amino acid metabolism and thus the availability of sugar or amino acids.…”

“…For example, the odor bouquet of microbe-inoculated or infested aphid honeydew is more attractive to the yellow fever mosquito, Aedes aegypti, than the odor bouquet of sterilized honeydew [36]. The volatile semiochemicals emitted by human skin microbes help attract host-seeking mosquitoes [37][38][39]. Carbon dioxide is another important vertebrate-and plant-host cue for mosquitoes [27,40], which originates not only from potential hosts but also from their symbiotic microbes [41].…”

Experimentally broken faecal sacs affect nest bacterial environment, development and survival of spotless starling nestlings

“…Recent works have stressed the importance of considering the role of bacteria and other microorganisms in evolutionary and ecological frameworks (Archie and Theis 2011, Ezenwa et al 2012, McFall-Ngai et al 2013. For instance, it was demonstrated that chemicals from bacterial metabolism play important roles in animal communication (Leclaire et al 2017), and that some parasites cue on such volatiles to find and select hosts (Verhulst et al 2011, Busula et al 2017. Bacteria may also have positive (Møller et al 2012) or negative (Polin et al 2015) effects on the probability of being captured by predators, or even deter parasitoids from using infected hosts (Costopoulos et al 2014).…”

Attraction of Female <em>Aedes aegypti </em>(L.) to Aphid Honeydew

“…Aphid honeydew and floral nectar contain sugars and amino acids [1,22,23] that exogenous microbes metabolize, producing odorants in the process [24][25][26][27]. Mosquitoes respond to microbial 3 of odorants when they forage for hosts [28][29][30][31], and seek oviposition sites [32]. Microbial odorants emanating from aphid honeydew attract aphidophagous hoverfly predators [25] and may also attract mosquitoes.…”