BIOLOGY AND BEHAVIOR
WASPS, HORNETS AND BEES
Several different wasps, hornets, and bees are found in Utah and the majority are highly beneficial. Bees, such as the honeybee and leafcutter bee are essential to the pollination of many crops and native plants. Most wasps and hornets are predators of pests insects, feeding them to their developing young. Problems with these insects occur when nests are located near high traffic areas or in buildings. Late summer foraging by yellow jacket wasps can be a serious nuisance problem for outdoor restaurants and other areas where food is served outdoors. Also, wasps and hornets may enter homes and buildings during fall in search of overwintering shelter.
SOCIAL WASPS AND HORNETS
Almost all nuisance problems involve social wasps within or adjacent to structures. Social wasps include yellow jackets, European paper wasps, and others. These insects produce new paper colonies or nests each year. Those produced by yellow jackets and European paper wasps are usually located under eaves of structures, in holes, or in wall voids. Bald faced hornets make large paper nests among tree branches. Fertilized females overwinter in protected areas, including buildings, and begin to build nests in the spring. As the season progresses, more workers are present to help with colony development, and nests rapidly increase in size. By late summer colonies may house hundreds of insects. At this time, the colony starts to break up and many of the large females leave.
Following several hard frosts the nests are completely abandoned. Nests are not reused the following year. Social wasps feed their young protein rich foods, mainly insects. Late in the season, food preferences switch to include more sugary materials and they are attracted to soft drinks, syrup, and other materials. During this period, they can be extremely annoying. Almost all stings involve social wasps and hornets.
Several wasps do not produce a social colony and instead individually rear their young in nests of mud or in tunnels underground. These are hunting wasps that collect spiders, cicadas, caterpillars, and other prey for their young. Many are highly beneficial. Although the solitary wasps sometimes appear rather fearsome, they rarely sting, and their sting is less painful than social wasps.
Unlike the social wasps and hornets, honeybees form a semi-permanent colony. Nests are constructed of wax and most colonies are maintained by beekeepers. Honeybees feed on nectar and pollen, which they feed their young and use to produce products such as honey and beeswax. Honeybees may also collect water to cool the hive and plant sap to help seal cracks. Periodically, overcrowded colonies form swarms that leave the hive. The swarms rest temporarily on a tree or shrub while scout bees search for a nesting cavity. Although the swarms are very striking, the bees are very docile at this time.