Meeting Abstract
Across taxa, males use sexually selected weapons in competition for access to a mate. A sub-optimal diet can cause a reduction in the size of these weapons, and lead to lower fitness. As well as size, the structural properties of the weapon should be important in its effectiveness. For example, if the cuticle is too thin, it might be more likely to be damaged during combat. However, not much attention has been given to how diet affects the structural properties of the weapon, especially in invertebrates. We investigated this question using the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae) which uses its hind leg as a weapon in competition for access to females and also has a diet that can change in quality throughout the year. We measured the amount of force it takes to puncture the surface of the weapon in individuals on high and low quality diets and found that a high quality diet leads to significantly better puncture resistance, while those on the low quality diet punctured more easily. Variation in fighting behaviours throughout the year could possibly be explained by cuticle properties, something that has received very little attention. More generally, these results could provide insights into the effects of environmental stresses on skeletal properties in invertebrates.
