Meeting Abstract
Environmental conditions may affect offspring quality and quantity, which are important fitness components. Here I ask, what are the effects of variable environments on egg composition (offspring quality) in a holometabolous insect species? Using Speyeria mormonia (Lepidoptera: Nymphalidae), I focus on triglycerides, which as a group are important energy stores and cryoprotectants for overwintering larvae, which in this species do not feed before entering diapause. Using data from both the field and the lab, I show that triglycerides in eggs increase with the temperature under which the eggs were matured, as well as with larval rearing temperature for the mothers. Neither the larval nor adult food availability to the mother significantly affected the investment of triglycerides in her eggs. However, there was a non-linear trans-generational effect of adult food availability on investment: a female’s investment was highest if her own mother experienced intermediate food availability. Any resulting selection pressures will be blunted by the fact that the population as a whole experiences the same conditions, which should lead to smaller effects on relative fitness than on absolute fitness. Nonetheless, which triglycerides are altered, their effects on absolute fitness, and the impacts on the butterfly’s life history and population dynamics remain to be explored.
