Biology subjects

Ramos Rodrigues, A.

Publications and source records attributed to Ramos Rodrigues, A..

3 recordsLinked to original sources

bioRxiv2021

Genomic signatures of recent adaptation in a wild bumblebee

Behavioral experiments and analyses of observation records have shown that environmental changes threaten insect pollinators, creating risks for agriculture and ecosystem stability. Despite their importance, we know little about how wild insects or other animals can adapt in response to environmental pressures. To understand the genomic bases of adaptation in an ecologically important pollinator, we analyzed genomes of Bombus terrestris bumblebees collected across Great Britain. We reveal extensive genetic diversity within this population, and strong signatures of recent adaptation throughout the genome. More specifically, we find that selection recently affected key processes underpinning environmental interactions, including neurobiology, wing development, and response to xenobiotics. We also discover unusual features of the genome, including a 53-gene region that lacks genetic diversity in many bee species, and a horizontal gene transfer from a Wolbachia bacteria. The genetic diversity and gene flow we observe for this species could support its resilience to ongoing and future challenges. Overall, we provide important insight on the genetic health of an ecologically and economically important pollinator and reveal mechanisms by which it has recently adapted. The approach we used could help to understand how species differ in their adaptive potential, and to develop conservation strategies for those most at risk.

evolutionary biology↗

bioRxiv2020

Pollen source richness may be a poor predictor of bumblebee colony growth

O_LIAgricultural intensification has drastically altered foraging landscapes for bees, with large-scale crop monocultures associated with floral diversity loss. C_LIO_LIResearch on bumblebees and honeybees has shown individuals feeding on pollen from a low richness of floral sources can experience negative impacts on health and longevity relative to higher pollen source richness of similar protein concentrations. Florally rich landscapes are thus generally assumed to better support social bees. Yet, little is known about whether the effects of reduced pollen source richness can be mitigated by feeding on pollen with higher crude protein concentration, and importantly how variation in diet affects whole colony growth, rearing decisions and sexual production. C_LIO_LIStudying queen-right bumblebee (Bombus terrestris) colonies, we monitored colony development under polyfloral pollen diet or monofloral pollen diet with 1.5-1.8 times higher crude protein concentration. C_LIO_LIOver six weeks, we found monofloral colonies performed better for all measures, with no apparent long-term effects on colony mass or worker production, and a higher number of pupae in monofloral colonies at the end of the experiment. Unexpectedly, polyfloral colonies showed higher mortality, and little evidence of any strategy to counteract the effects of reduced protein; with fewer and lower mass workers being reared, and males showing a similar trend. C_LIO_LIOur findings i) provide well-needed daily growth dynamics of queenright colonies under varied diets, and ii) support the view that pollen protein content in the foraging landscape rather than floral species richness per se is likely a key driver of colony success. C_LI

ecology↗

bioRxiv2018

Pesticide exposure affects flight dynamics and reduces flight endurance in bumblebees

The emergence of agricultural land use change creates a number of challenges that insect pollinators, such as eusocial bees, must overcome. Resultant fragmentation and loss of suitable foraging habitats, combined with pesticide exposure, may increase demands on foraging, specifically the ability to reach resources under such stress. Understanding the effect that pesticides have on flight performance is therefore vital if we are to assess colony success in these changing landscapes. Neonicotinoids are one of the most widely used classes of pesticide across the globe, and exposure to bees has been associated with reduced foraging efficiency and homing ability. One explanation for these effects could be that elements of flight are being affected, but apart from a couple of studies on the honeybee, this has scarcely been tested. Here we used flight mills to investigate how exposure to a field realistic (10ppb) acute dose of imidacloprid affected flight performance of a wild insect pollinator - the bumblebee, Bombus terrestris audax. Intriguingly, intial observations showed exposed workers flew at a significantly higher velocity over the first [3/4] km of flight. This apparent hyperactivity, however, may have a cost as exposed workers showed reduced flight distance and duration to around a third of what control workers were capable of achieving. Given that bumblebees are central place foragers, impairment to flight endurance could translate to a decline in potential forage area, decreasing the abundance, diversity and nutritional quality of available food, whilst potentially diminishing pollination service capabilities.\n\nSummary StatementAcute neonicotinoid exposure impaired flight endurance and affected velocity of Bombus terrestris workers, which may dramatically reduce colony foraging potential and pollination provision in pesticide applied landscapes.

ecology↗