Search bioRxiv⌕ Search

bioRxiv · 10.1101/653980

Sub-lethal insecticide exposure affects host biting efficiency of Kdr-resistant Anopheles gambiae

Abstract

AO_SCPLOWBSTRACTC_SCPLOWThe massive use of insecticide-treated nets (ITNs) has drastically changed the environment for malaria vector mosquitoes, challenging their host-seeking behaviour and biting success. Here, we investigated the effect of a brief exposure to an ITN on the biting behaviour of Anopheles mambiae mosquitoes and the interaction between such behaviour and the kdr mutation that confers resistance to pyrethroids. To this aim, we developed a video assay to study the biting behaviour of mosquitoes with similar genetic background, but different kdr locus genotypes (SS i.e. homozygous susceptible, RS i.e. heterozygous and RR i.e. homozygous resistant), after a brief exposure to either control untreated nets or one of two types of pyrethroid-treated nets (deltamethrin or permethrin). In presence of untreated nets, the kdr mutation did not influence mosquito blood feeding success but caused differences in feeding and prediuresis durations and blood meal size. Exposure to deltamethrin ITN decreased the blood feeding success rate of RR and RS mosquitoes, whereas in presence of permethrin ITN, the kdr mutation increased the blood-feeding success of mosquitoes. Exposure to the two types of pyrethroid-treated nets reduced feeding duration, prediuresis duration and blood meal size of all three genotypes. Our study demonstrates a complex interaction between insecticide exposure and the kdr mutation on the biting behavior of mosquitoes, which may substantially impact malaria vector fitness and disease transmission.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Diop, M. M., Chandre, F., Rossignol, M., Porciani, A., Chateau, M., Moiroux, N., Pennetier, C.. 2019-05-29. Sub-lethal insecticide exposure affects host biting efficiency of Kdr-resistant Anopheles gambiae. https://doi.org/10.1101/653980

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Can a Tiny Brain Plan? Reconstructing a Predatory Detour inthe Jumping Spider Portia labiata

Planning is the process of evaluating alternative futures to predict outcomes and guide action. Evidence for this process exists in several vertebrates, but remains contested in in-vertebrates. Jumping spiders in the genus Portia show planning-like behavior in lab studies, but how this translates to the wild is unclear, where hunts of potentially lethal spider prey occur over durations of more than an hour in dense foliage. We present the first fully video-recorded wild hunt of any Portia species, with a 3D reconstruction of its forty-two minute long route to attack an orb-weaving spider. The reconstruction suggests P. labiata may have planned its approach, avoiding a route half as long but potentially more conspicuous to the prey's sensory systems.

animal behavior and cognition↗

Assessing Enclosure Modifications to Enhance Accessibility for Zoo-Housed Meerkats (Suricata suricatta)

Scientific advancements have contributed to increased longevity of animals in zoos and aquariums, creating a growing need for environments that remain accessible to geriatric animals and animals with disabilities. However, few empirical studies have evaluated whether accessibility-focused enclosure modifications impact species-appropriate behavior. We evaluated the effects of accessibility modifications on a group of four adult zoo-housed meerkats (Suricata suricatta), including one individual with a forelimb amputation and one geriatric individual. Low-level logs and steps were added to the enclosure to provide intermediate heights and facilitate access to elevated areas. Following the introduction of these enclosure modifications, sentry behavior increased, with all individuals engaging in this behavior compared with only one individual during baseline. The meerkats also increased their overall use of low-elevated areas following modification, although individual responses varied. Posture differed between study phases, with meerkats more frequently adopting tri/quadrupedal postures following modification. Together, these findings suggest that relatively simple accessibility-focused modifications can expand opportunities for geriatric animals and animals with disabilities to engage in species-appropriate behavior. More broadly, this case study highlights the importance of empirically evaluating accessibility interventions and incorporating universal design principles into animal spaces to accommodate individuals with diverse physical abilities and promote positive animal welfare.

animal behavior and cognition↗

Moving Heads, Moving Sounds: Systematic Errors in Auditory Motion Perception

The movement of moving objects seen during self-motion is incorrectly perceived as a result of errors in parsing the visual motion arising from the retina and from information about the movement of the head and eyes in space1. The perception of motion of auditory targets may be even more challenging as previous research suggests that the auditory system lacks dedicated low-level speed processing mechanisms. This study investigates how the perception of a moving auditory sound source is influenced by concurrent head movements, drawing comparisons with established visual motion perception findings and illusions, such as the Filehne Illusion. Participants were asked to move their heads at a fixed speed, either horizontally (left to right or right to left) or vertically (up to down or down to up), while indicating the perceived direction of a moving sound source by using a joystick. A physical sound source was moved silently at a constant speed in fronto-parallel 2D space using a 3x3x3m cable robot. Results showed that head movements created a perceptual bias of the perceived direction of the moving sound source in the opposite direction to the head movement. Responses were less precise during horizontal than vertical head movement, whereas overall directional accuracy did not differ reliably between movement planes. The magnitude of the directional error also depended on the direction of head movement, consistent with the different cues available for horizontal and vertical localization (binaural vs. spectral cues). These findings suggest that similarly to how visual motion perception is distorted by extraretinal signals and the movement of the eyes, so too is auditory motion perception influenced by movement of the ears, revealing errors in the integration of proprioceptive, vestibular and auditory cues that distort the perceived direction of a moving sound source.

animal behavior and cognition↗