Behavioral Cost & Overdominance in Anopheles gambiae

Abstract

In response to the widespread use of control strategies such as Insecticide Treated Nets (ITN), Anopheles mosquitoes have evolved various resistance mechanisms. Kdr is a mutation that provides physiological resistance to the pyrethroid insecticides family (PYR). In the present study, we investigated the effect of the Kdr mutation on the ability of female An. gambiae to locate and penetrate a 1cm-diameter hole in a piece of netting, either treated with insecticide or untreated, to reach a bait in a wind tunnel. Kdr homozygous, PYR-resistant mosquitoes were the least efficient at penetrating an untreated damaged net, with about 51% [39-63] success rate compared to 80% [70-90] and 78% [65-91] for homozygous susceptible and heterozygous respectively. This reduced efficiency, likely due to reduced host-seeking activity, as revealed by mosquito video-tracking, is evidence of a recessive behavioral cost of the mutation. Kdr heterozygous mosquitoes were the most efficient at penetrating nets treated with PYR insecticide, thus providing evidence for overdominance, the rarely-described case of heterozygote advantage conveyed by a single locus. The study also highlights the remarkable capacity of female mosquitoes, whether PYR-resistant or not, to locate holes in bed-nets.

High level of resistance in Anopheles arabiensis mosquito to pyrethroid insecticides from low malaria transmission zone of Moroto district, Karamoja region, Uganda: Implication for malaria vector control

“…This appears to re ect the need to monitor malaria vector resistance. As demonstrated in other studies on the host feeding and insecticide resistance, the tness costs associated with insecticide resistance can have in uence on malaria transmission directly by altering host seeking feeding and mating behaviours [67][68][69] or fecundity [70] and reducing mosquito life span [71,72] It can also indirectly in uence malaria transmission by impairing parasite development inside the mosquitoes [70,73,74].…”

Empirical and theoretical investigation into the potential impacts of insecticide resistance on the effectiveness of insecticide‐treated bed nets

“…In both cases, the majority of contact occurred during the first 10 min, with very little active search behavior after 30 min. Other observational studies suggest contact times of up to 7 min on an LLIN (Siegert, Walker, & Miller, ) and up to 50 min on an untreated net (Diop et al., ). These patterns potentially explain why we saw higher mortality when mosquitoes interacted with an LLIN naturally than in 3‐min WHO cone tests.…”

Fitness costs of key point mutations that underlie acaricide target‐site resistance in the two‐spotted spider miteTetranychus urticae

“…Moreover, these mutations also appear to affect nerve functioning and behavior in insect species. For example, a pyrethroid‐resistant strain of Musca domestica responds differently to changes in temperature (Foster et al., 2003) and pyrethroid resistance in A. gambiae and A. aegypti is associated with a lowered ability of host seeking and an increased locomotor activity, respectively (Brito et al., 2013; Diop et al., 2015). It is therefore possible that we have missed a potential pleiotropic effect of the L1024V mutation on the behavior of T. urticae .…”

“…Excluding a number of studies that have focused on mosquitoes [ Culex pipiens quinquefasciatus (Berticat, Boquien, Raymond, & Chevillon, 2002; Berticat et al., 2008; Gazave, Chevillon, Lenormand, Marquine, & Raymond, 2001), Aedes aegypti (Brito et al., 2013), and Anopheles gambiae (Diop et al., 2015)], the Australian blow fly L. cuprina (McKenzie, 1990, 1994), and the peach aphid Myzus persicae (Foster, Denholm, & Devonshire, 2000), the majority of previous work that assesses pesticide resistance‐related fitness costs in arthropods suffers from multiple design weaknesses [see also reviews by ffrench‐Constant and Bass (2017) and Kliot and Ghanim (2012)]. A common design flaw is the evaluation of genetically unrelated populations in the experimental setup.…”