Origin: There are many species of Vespula in North America, including several species introduced from Europe. Two of these, Vespula germanica and Vespula vulgaris, are among the serious scavenger pests in this group.
Biology: Yellowjackets are social wasps, with a Queen that initiated the colony and female workers that build the nest, care for the young, forage for food, and defend the colony. Colonies typically begin each spring and die off each fall in cooler climates, but may survive over the winter in warmer climates. The population of the colony easily grows to many thousands of workers by the end of the summer, at which time males are produced, mating with new queens takes place, and these fertilized queens then over-winter in protected locations. Adults feed on sweet liquids such as honeydew, nectar, fruit juices, or human foods such as sodas. They also relish a sugary material exuded by the larvae. The larvae are fed meat, and natural sources are insect larvae or bits of flesh from dead animals. As scavengers the workers also gather human foods at outdoor eating areas. The workers are all able to sting repeatedly, and very aggressively defend their colony from perceived intruders. Nests are placed either in aerial locations, including trees, shrubs, wall voids, or attics, as well as in the ground, where workers enlarge holes they find to accommodate the growing colony. The nest is created from cellulose gathered from tree bark, dried plant materials, or other sources, mixed with saliva, and formed as the hexagonal cells for the larvae.
Identification: Yellowjackets are very similar to the other social paper wasps called Umbrella Wasps, but differ by having no narrow waist between their thorax and abdomen. Colors are yellow and black, and specific identification of each species is done with differences in the patterns of the black patches around the eyes and head as well as on the abdomen. Yellowjackets, as wasps, have 2 pairs of wings that are dissimilar in size and shape. This separates them from many species of flies that mimic wasps, where there is only 1 pair of wings.
Origin: A number of species of wasps in this family are
native to North America, with the Black and Yellow Mud Dauber and the Blue Mud
Dauber most often nesting on structures.
Biology: Mud daubers are solitary wasps that provide a nest and food for their larvae but do not further care for them. The nest is created from blobs of mud gathered by the female and formed into hollow cells, often with many cells arranged next to each other in columns. The female then gathers food, in the form of insect larvae or spiders, stings it to paralyze it, and then places this immobilized prey in the cell. She lays an egg in each cell, seals the cell with mud, and never returns. While the female mud daubers can sting it is a rare occurrence. They do not defend their nests and will sting only when they feel directly threatened. Nests are commonly placed in the eaves or attics of houses, but will often show up in other odd locations where the nest could be placed securely.
Identification: The most common mud daubers around structures are the large black and yellow species and the metallic blue species. These are long wasps with very long, thin waists and small abdomens. The black and yellow species may be an inch long, while the blue species is slightly smaller. The antennae are often somewhat curled.
Origin: A number of native species of these bees occur in North America.
Biology: Carpenter bees are solitary bees that get their common name from their habit of boring chambers in solid wood in order to create living quarters for their larvae. Softer woods such as redwood may be preferred, and the wood is not eaten, but instead is reduced to sawdust (“frass”) which is ejected from the tunnels. The female bee does the excavating, and several females may be working in the same section of wood and using the same entrance hole, but creating separate galleries. Males and females over-winter in old galleries and emerge in the spring to mate. They will both die before the end of the summer and it is their offspring which begin the next year’s activity. The galleries may be used repeatedly, with each new female lengthening the tunnel, which often can be over 10 feet in length. She creates an average of 6 or 7 cells, each separated by a plug, and places an egg and a food supply of pollen and nectar in each cell. Once this is completed she never returns to care for the larvae.
Identification: There are several species of carpenter bees that are fairly small, but the common Xylocopa species that may invade structural wood are some of the largest bees in North America, with some of the largest over an inch long. Coloring normally is shiny metallic blue-green to black, although the male of the Valley Carpenter Bee is light tan. They may be separated from bumblebees by the relative lack of hairs on the abdomen, as well as by their more rapid, erratic flight habits Damage from these bees is hidden within the wood, often with only the round entrance hole visible. Within the wood the galleries extend with the grain of the wood, and are almost perfectly round, ending with the cells in which the larvae develop.