INSECTS
production of offspring. The adult insect is necessarily the reproductive stage, but in most cases it must support itself as well; the immature insect has no other direct object in lire than that of feeding and of preparing itself for its transformation into the adult. The feeding function, however, as we have seen in Chapter IV, involves
Fig. 133. Wasps, or yellow jackets
A, an adult male of Vespula maculata. B, C, D, larva, pupa, and adult worker of Vespula maculifrons. The worker is a non-reproductive female and uses her ovipositor as a sting
most of the activities and structures of the animal, including its adaptation to its environment, its modes of locomotion, its devices for avoiding enemies, its means of obtaining food. Hence, in studying any young insect, we must understand that we are dealing almost exclusively with characters that are adaptive to the feeding function.
When we observe the life of any caterpillar we soon realize that its principal business is that of eating. The caterpillar is one creature, at least, that may openly proclaim it lives to eat. Whatever else it does, except acts
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