Miss Eloïse Ansermin1

1University Of Melbourne, Parkville, Australia

Biography:

Eloise Ansermin is a PhD candidate in the Pest and Environmental adaptations research group at the University of Melbourne. She completed her Masters at the Evolutionary Entomology group at the University of Neuchatel in Switzerland, where she studied the Meso-American pest Diabrotica balteata and its capacity to sequester plants toxins from cucumber.

She is currently studying how aphids' endosymbionts modify trophic interactions with a focus on pest behaviour. She works mainly on Myzus persicae and its secondary endosymbiont Rickettsiella. Their association could change how aphids are approached by predators such as ladybirds. She has also conducted field work in China, in collaboration with the Sichuan Academy of Agricultural sciences. She is exploring how landscape and environment impact endosymbionts' frequencies in Rhopalosiphum padi and Sitobion avenae.

Abstract:

The green peach aphid, Myzus persicae (Sulzer) (Hemiptera, Aphididae), is a widespread insect pest that causes important economic losses in the agricultural sector, as it attacks more than 400 plant varieties. Due to the increasing pesticide resistance, there is the need for a more integrated approach to pest control. Behavioural traits such as microhabitat selection could provide useful insights on how to reduce the damage to important crops and ornamental plants. When selecting an appropriate microhabitat, herbivores face the trade-off between fitness and predation. If the insects choose to avoid predation at all costs, biocontrol with natural enemies could be ineffective, unless there is a way to change microhabitat selection. The bacterial endosymbiont Rickettsiella is responsible for colour change and reduced fecundity in Myzus persicae. We show using population cage experiments that aphids with Rickettsiella lack the characteristic preference for the abaxial surface of bok choy leaves. We are now performing whole plant experiments and behavioural assays to determine the fitness implications of this modified preference and how it entangles with predation by ladybirds. The upcoming results have important implications for the use of endosymbionts as biocontrol agents.