Wasps are members of the order Hymenoptera (skin wings) and come in many types and sizes. The ones that we are concerned with in this text, belong to the families Vespidae and Sphecidae. The family Vespidae has seven subfamilies in North America, containing many common wasp species like yellow jackets and hornets. Their social organizations range from cooperative fertile females paper wasps to the caste system of yellow jackets, in which there is a single fertile queen and a large population of smaller unmated females. Due to their size and colouration these wasps are often mistaken for bees. Bees are not nearly as aggressive and are valued as major pollinators as well as honey producers.
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Description: 12-17.5 mm in length; head, thorax, and abdomen black and yellow or white; body fairly stout; wings smoky.
Range: Throughout North America
Note: They have been noted recently in Chili, South America.
Food: Adults feed on nectar and other insects, larvae are provided with pre-chewed insects and pieces of meat. Adults can become pests around outdoor eating areas by attempting to carry off bits of food. They are very aggressive and will sting repeatedly at the least provocation.
Habitat: Meadows, gardens, hedges, forest edges. Usually nest in the ground or at ground level in fallen logs and tree stumps. In urban settings they can also be found under stairs, in fence posts, brick walls and discarded mattresses, carpets, boxes etc.
Life cycle: In spring the fertilized female builds a small nest and begins laying eggs. She tends to the resulting larvae until the first brood matures into female workers which rear consequent larvae and extend the nest. Males develop from unfertilized eggs toward the end of summer and mate. At the onset of cold weather all the wasps, including the old queen, die except young mated females which overwinter among leaf litter or in soil.
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Description: 16-20 mm in length; body stout with black and yellow white markings on face, thorax, abdomen and first antennal segment; wings smoky
Range: Throughout North America
Food: Adults consume fruit, nectar and other insects; larvae are fed pre-chewed insects
Habitat: Gardens, parkland; meadows and forest edges. Nests are constructed out of wood pulp and saliva and attached to branches in the open. They consist of many layers of cells encased in protective paper with an opening at the bottom. Adults are very protective of the nest and will sting repeatedly when molested.
Life Cycle: In spring females construct small pendant nests with a few cells and begin laying eggs. The first brood matures into female workers which feed the larvae several times a day and continue nest expansion. In late summer males develop out of unfertilized eggs and mate. Only young mated females survive the winter in soil or among litter.
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Description: 16-20 mm in length; body black with bright yellow markings on sides of head, thorax, legs and across each abdominal segment; wings smoky
Range: Canada, northern USA
Food: Adults feed on nectar; larvae eat pre-chewed insects and fruit
Habitat: Sandy country, gardens. Globular "paper" nests are found in shrubbery and hedges close to the ground and roof eaves. If disturbed these wasps sting viciously.
Life cycle: Female constructs small nests in spring. The first generation consists of female workers who take over the rearing of young and the expansion of nest. Males emerge at the end of summer and mate. Only young mated females overwinter.
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Description: 13-25 mm in length; body mostly reddish brown to black with yellow rings and reddish areas on abdomen; wings reddish or amber brown
Range: Throughout North America
Food: Adults feed on nectar and juices, larvae are fed pre-chewed insects
Habitat: Fields, meadows, gardens and near buildings. Nests are free hanging and consist of a single layer of cells constructed out of wood and saliva with openings at the bottom. Paper wasps are not nearly as aggressive as yellow jackets or hornets.
Life Cycle: In spring several females construct a nest together. One of the females becomes the dominant queen and starts laying eggs. The first generation consists of females only which were cared for as larvae by unmated females. In late summer males emerge from unfertilized eggs and mate. Only mated young females overwinter under leaf litter and in stone walls.
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The family Sphecidae is made up of a large variety of solitary hunting wasps. There are about 1200 species in North America, many of which are common. These wasps usually form separate nests in the ground, natural openings or by constructing mud cells like, for instance, the mud daubers. Sphecidae can deliver a painful sting when annoyed.
Description: 25-30 mm in length; long cylindrical one segmented "waist", (pedicel) between thorax and abdomen; body black with large yellow area on prothorax; yellow pattern on thorax, pedicel, 1st segment of abdomen; legs mostly yellow; wings brown -black.
Range: Throughout North America
Food: Adults feed on nectar, larvae on provided spiders
Habitat: Meadows, rock faces; settled areas, where nests are located under rocks, overhanging roofs and other structures.
Life Cycle: Solitary female builds nests out of moist mud containing several parallel cell rows. A paralyzed spider is stuffed into each cell and one egg deposited on each spider. The female then closes the cell opening with mud. Hatching larvae slowly consume the spiders after which they pupate inside the cell. Males are rarely seen before midsummer and feed on nectar.
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The nest is sprayed inside and out with diatomaceous earth (Insecolo®). Insecolo® is a very fine dust which doesn't scatter the insects but dries them out. There is no noxious odour and the material is non-toxic to humans and animals.
To prevent wasps from entering your house and attic, check roof, outside brick walls, window frames, anywhere wood meets brick and under siding for openings. This is best done in late fall or early spring to avoid unpleasant encounters. If wasps have already invaded your house watch for daytime activity and note location of entrance. Do not shine a light on wasp nest found in attic or other dark enclosed places, since the light source will attract them to you and make them aggressive.
Wasps forage actively and widely during the day and will seek out available and suitable food sources, including anything sweet or meaty you might be enjoying. To prevent painful conflicts over a piece of cake, we also supply bait stations.
If the wasps do not bother you, please extend them the same courtesy since they destroy pest insects and play a minor role in pollination.
Under favorable circumstances wasp populations can increase quickly. Conditions needed are mild winters with a high survival rate of mated females; access to suitable nest building materials and sites, an abundance of food i.e. nectar and soft bodied insects as well as certain temperature and humidity levels during the development of the young. The mild winter, locally, plus relative high temperatures of spring '95, provided almost optimal conditions for rapid growth. Some of the nests encountered to date are already about 40 percent bigger than expected. We expect '95 to be a big "wasp year". The local spray of B.T. for the Asian Gypsy Moth has ceased. This allows for normal larva production of all moth and butterfly species. Lots to eat means lots of caterpilars. I am sure your getting the idea!
Tip: Wear light coloured clothing - - even hair cover if needed. Avoid known active areas, particularly during September in the Pacific Northwest region. Do not attempt self-removal of nests unless you are positive that no severe alergic reaction will result from a sting.
We do supply Wasp Traps in Greater Vancouver only. Baited and setup @ $ 45.00 each plus GST.
Prepared by Ursula Dole, Entomologist.
Assisted by David Buchanan, Know-it-all.
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© 1995 David Buchanan