The various species of wasp fall into one of two main categories. These are solitary wasps and social wasps. Adult solitary wasps generally live and operate alone and most do not construct nests, and all adult solitary wasps are fertile. By contrast, social wasps exist in colonies numbering up to several thousand strong, build a nest, and in some cases not all of the colony can reproduce. Generally just the queen and male wasps can mate, whilst the majority of the colonies are made up of sterile female workers.
Generally wasps are parasites as larvae, and feed only on nectar as adults. Some wasps are omnivorous but this is relatively uncommon, they feed on a variety of fallen fruit, nectar and carrion. Many wasps are predatory, preying on other insects. Certain social wasp species, such as yellowjackets, scavenge for dead insects to provide for their young. In turn the brood provides sweet secretions for the adults. In parasitic species the first meals are almost always provided from the animal the adult wasp used as a host for its young. Adult male wasps sometimes visit flowers to obtain nectar to feed on in much the same manner as honey bees. Occasionally, some species, such as yellowjackets, invade honeybee nests and steal honey and/or brood. Wasps do not reproduce via mating flights like bees. Instead social wasps reproduce between a fertile queen and male wasp, in some cases queens may be fertilized by the sperm of several males. After successfully mating, the male's sperm cells are stored in a tightly packed ball inside the queen. The sperm cells are kept stored in a dormant state until they're needed the following spring. At a certain time of year (often around autumn) the bulk of the wasp colony dies away, leaving only the young mated queens alive. During this time they leave the nest and find a suitable area to hibernate for the winter. Early spring After emerging from hibernation during early spring, the young queens search for a suitable nesting site. Upon finding an area for their future colony, the queen constructs a basic paper fiber nest roughly the size of a walnut into which she will begin to lay eggs. Late spring, early summer The sperm that were stored earlier and kept dormant over winter is now used to fertilize the eggs being laid. The storage of sperm inside the female queen allows her to lay a considerable number of fertilized eggs without the need for repeated mating with a male wasp. For this reason a single female queen is capable of building an entire colony from only herself. The queen initially raises the first several sets of wasp eggs until enough sterile female workers exist to maintain the offspring without her assistance. All of the eggs produced at this time are sterile female workers who will begin to construct a more elaborate nest around their queen as they grow in number. End of summer and winter By this time the nest size has expanded considerably and now numbers between several hundred and several thousand wasps. Towards the end of the summer, the queen begins to run out of stored sperm to fertilize more eggs. These eggs develop into fertile males and fertile female queens. The male drones then fly out of the nest and find a mate thus perpetuating the wasp reproductive cycle. In most species of social wasp the young queens mate in the vicinity of their home nest and do not travel like their male counterparts do. The young queens will then leave the colony to hibernate for the winter once the other worker wasps and founder queen have started to die off. After successfully mating with a young queen, the male drones die off as well. Generally, young queens and drones from the same nest do not mate with each other; this ensures more genetic variation within wasp populations, especially considering that all members of the colony are theoretically the direct genetic descendants of the founder queen and a single male drone. In practice, however, colonies can sometimes consist of the offspring of several male drones. Wasp queens generally (but not always) create new nests each year, this is probably because the weak construction of most nests render them uninhabitable after the winter. Unlike most honey bee queens, wasp queens typically only live for one year (although exceptions are possible). Also, contrary to popular belief queen wasps do not organize their colony or have any raised status and hierarchical power within the social structure. They are more simply the reproductive element of the colony and the initial builder of the nest in those species which construct nests.