Epsilon Archive for Student Projects

Abstract

Lack of food security is a serious problem, worsened by climate change, which impacts both the
crops and their pests, who are responsible for significant yield and quality losses in food crops.
Effective pest control demands knowledge of how the pests respond to environmental change.
Organisms can adjust to change through phenotypic plasticity, within and across generations.
Transgenerational effects have been observed in a variety of organisms, including Spodoptera
littoralis, a generalist herbivorous moth with a wide host range. To investigate possible
transgenerational effects of diet in this moth, two generations were reared on either maize or
cabbage, with matching or mismatching diets between generations. Life history traits were measured
in the offspring generation. A transgenerational effect was found on fecundity in treatments where
the offspring generation was reared on cabbage. A mismatching diet appeared beneficial, indicating
a positive effect on fitness of switching diets between generations. Within-generation plasticity was
found in larval growth rate, mortality, pupal weight and fecundity, with cabbage appearing to be the
superior diet, contrary to what may be expected from previous work regarding preference. These
results make further investigation into mechanisms of transgenerational effects in this species a very
interesting prospect.