Adaptations to Granivory

Seed feeding is a specialized process and entomophagous arthropods that consume seeds possess a series of adaptations that allow them to exploit this unique food resource. On one level, arthropod populations coincide spatially and temporally with their seed food source. For example, ants are well adapted to living with booms and busts in the abundance of seed resources (Brown et al., 1979). These population characteristics are important in allowing the seed predator to encounter the seeds of choice, and will be discussed in more detail in subsequent chapters. But inevitably the insect that comes in contact with the food needs to know what to do with it, and this is where the present chapter will focus.

A host of morphological and physiological adaptations in the insect are necessary for them to identify, collect, and consume a seed. Anatomically, mandibular shape and other external morphological variations, as well as the structure of the alimentary canal, influence the dietary range of an arthropod. Moreover, the size and morphology of the arthropod will ultimately influence the techniques that are used to consume seeds. Analyses of seed feeding techniques grant an understanding of how the different anatomical adaptations function together to attain the intended outcome: a digested seed.