Prospects for malaria control through manipulation of mosquito larval habitats and olfactory-mediated behavioural responses using plant-derived compounds

Abstract

Malaria presents an overwhelming public health challenge, particularly in sub-Saharan Africa where vector favourable conditions and poverty prevail, potentiating the disease burden. Behavioural variability of malaria vectors poses a great challenge to existing vector control programmes with insecticide resistance already acquired to nearly all available chemical compounds. Thus, approaches incorporating plant-derived compounds to manipulate semiochemical-mediated behaviours through disruption of mosquito olfactory sensory system have considerably gained interests to interrupt malaria transmission cycle. The combination of push-pull methods and larval control have the potential to reduce malaria vector populations, thus minimising the risk of contracting malaria especially in resource-constrained communities where access to synthetic insecticides is a challenge. In this review, we have compiled information regarding the current status of knowledge on manipulation of larval ecology and chemical-mediated behaviour of adult mosquitoes with plant-derived compounds for controlling mosquito populations. Further, an update on the current advancements in technologies to improve longevity and efficiency of these compounds for field applications has been provided.

Keywords: Anopheline mosquitoes; Integrated vector management; Larval habitat manipulation; Malaria; Mosquito functional ecology; Plant-derived compounds; Vector control.

Fig. 1

Mosquito olfactory-driven behavioral responses. Physiological status such as circadian-regulated appetitive stimulus or gonotrophic status activates olfaction in search of nutritional sources, mates and oviposition sites. On binding to odorant chemoreceptors and subsequent flight orientation, mosquitoes follow the source of the chemical cues for behavioral response depending on brain odor coding. Reproduced with permission of Wageningen Academic Publishers. Citation: Bohbot JD, et al. (2010) Molecular regulation of olfaction in mosquitoes. In: Takken W, Knols BGJ, editors. Olfaction in vector-host interactions. Wageningen, Netherlands: Wageningen Academic Publishers 2010; p. 17–38 [38]

Fig. 2

Plant-derived insect repellent compounds: a Citral, b Geraniol, c Citronellal, d Citronellol e Myrcene, f α-pinene, g β-pinene, h p-menthane-3,8-diol (PMD), i linalool, j Thymol, k Eugenol, l Carvacrol, and m Caryophyllene

Fig. 3

Plant-based insect growth regulators with potential for control of mosquito larvae. The structural similarity of the above compounds with endogenous insect hormones dysregulate normal physiology and development culminating to death or impaired morphology