The fitness of African malaria vectors in the presence and limitation of host behaviour

Malaria Journal

Research

Richard Reeve¹  Heather M Ferguson¹  Daniel T Haydon¹  Edgar M Mbehela²  Ally A Daraja²  Kasian F Mbina²  Issa N Lyimo³ 

[1] Boyd Orr Centre for Population and Ecosystem Health, College of Medicine, Veterinary and Life Sciences, University of Glasgow, G12, 8QQ, Glasgow, UK;Environmental Sciences Thematic Group, Ifakara Health Institute, PO.BOX 53, Ifakara, Tanzania;Environmental Sciences Thematic Group, Ifakara Health Institute, PO.BOX 53, Ifakara, Tanzania;Boyd Orr Centre for Population and Ecosystem Health, College of Medicine, Veterinary and Life Sciences, University of Glasgow, G12, 8QQ, Glasgow, UK;

关键词: Malaria vectors;    Fitness;    Feeding success;    Host species range;    Host behaviour;    Natural selection;   

DOI  :  10.1186/1475-2875-11-425

 received in 2012-08-09, accepted in 2012-12-13,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundHost responses are important sources of selection upon the host species range of ectoparasites and phytophagous insects. However little is known about the role of host responses in defining the host species range of malaria vectors. This study aimed to estimate the relative importance of host behaviour to the feeding success and fitness of African malaria vectors, and assess its ability to predict their known host species preferences in nature.MethodsPaired evaluations of the feeding success and fitness of African vectors Anopheles arabiensis and Anopheles gambiae sensu stricto in the presence and limitation of host behaviour were conducted in a semi-field system (SFS) at Ifakara Health Institute, Tanzania. In one set of trials, mosquitoes were released within the SFS and allowed to forage overnight on a host that was free to exhibit a natural behaviour in response to insect biting. In the other, mosquitoes were allowed to feed directly on from the skin surface of immobile hosts. The feeding success and subsequent fitness of vectors under these conditions were investigated on six host types (humans, calves, chickens, cows, dogs and goats) to assess whether physical movements of preferred host species (cattle for An. arabiensis, humans for An. gambiae s. s.) were less effective at preventing mosquito bites than those of common alternatives.ResultsAnopheles arabiensis generally had greater feeding success when applied directly to host skin than when foraging on unrestricted hosts (in five of six host species). However, An. gambiae s.s. obtained blood meals from free and restrained hosts with similar success from most host types (four out of six). Overall, the blood meal size, oviposition rate, fecundity and post-feeding survival of mosquito vectors were significantly higher after feeding on hosts free to exhibit behaviour, than those who were immobilized during feeding trials.ConclusionsAllowing hosts to move freely during exposure to mosquitoes was associated with moderate reductions in mosquito feeding success, but no detrimental impact to the subsequent fitness of mosquitoes that were able to feed upon them. This suggests that physical defensive behaviours exhibited by common host species including humans do not impose substantial fitness costs on African malaria vectors.

【 授权许可】

CC BY   
© Lyimo et al.; licensee BioMed Central Ltd. 2012