Sarah Powell

Arthropod Ecophysiology Group

Climate change, arthropod overwintering and pest outbreaks

Home Research Group Members Publications Collaborators Contact

Thermal acclimation processes in aphids

Sarah Powell

I did my undergraduate degree at the University of Birmingham in Zoology. I did my final year research project on the effects of high energy drinks on human metabolism and endurance.

I am currently doing my PhD on thermal acclimation processes, for example rapid cold hardening, in aphids.

Current research

Most studies on insect cold hardiness have focused on seasonal adaptations occurring within the overwintering stage of an insect’s life cycle, triggered by decreasing temperature and photoperiod from summer through autumn to winter. Recent research has discovered a rapid cold hardening response that can be induced within 1-2h of low temperature exposure and results in highly significant increases in survival.

Sitobion avenae adult and nymphs

Due to their short generation times, an aphid that enters winter is unlikely to be the same individual that survives until spring. For this reason, although aphids are able to cold harden when reared at lower temperatures (10° and 5° C), the ability to rapidly cold harden may be relatively more important than in other longer-lived overwintering insects, where seasonally-induced cold hardening is the dominant response.

This project intends to assess the effect of sub-zero temperatures on the mortality of an anholocyclic clone of Sitobion avenae, characterise the rapid cold hardening response in this species, and investigate the ecological costs of rapid cold hardening in terms of effects on development, longevity and fecundity.

To date, this project provides evidence that S. avenae is capable of rapid cold hardening, supporting the hypothesis that rapid cold hardening can be induced during the cooling phase of natural diurnal temperature cycles. Rapid cold hardening increases survival and extends the lower lethal temperature, allowing aphids to acquire maximum cold hardiness when it is most needed.

Back to Group Members

Home Research Group Members Publications Collaborators Contact