for S E P T E M B E R Bald-faced "hornet" PROPER NAME: Order Hymenoptera, Family Vespidae, Dolichovespula maculata. WHEN MOST PREVALENT: August and September. SIZE RANGE: Upwards of 15 mm in length. [View magnified Insect] WARNINGS: Like all yellowjackets, bald-face "hornets" can sting ... but fortunately this wasp's large size is not matched by a strong aggression ... bald-faced "hornets" tend to be quite passive, tolerating disturbance around the nest much more than many smaller wasps will ... add to this their tendency to build their nests high in trees, and humans and bald-faced hornets are not likely to come into contact or conflict very often ... GEOGRAPHIC LOCATION: Widely distributed throughout Canada. SOUNDS: Buzzing Bald-faced "hornets" are not true hornets, but rather yellowjackets in disguise. They are boldly patterned in black and white, rather than in black and yellow like most yellowjackets. Their noticeable presence (many gardeners will be quite familiar with them) and their large size have contributed to them incorrectly being named hornets. There is only one true hornet in North America, a large brown and yellow species know as the European Hornet, Vespa crabro. Nests are built in vegetation ... from ground level in shrubs to great heights in trees. Nests are almost always in exposed areas, rather than subterranean or hidden. Nests of the bald-faced "hornet" are some of the largest built by any wasp ... they may reach 35 mm in diameter and 60 mm in length! These large nests actually have only a small number of cells ... 2,000-3,500 (average size wasps' nests have 4,000 cells). Queens emerge from their overwintering hiding spots in April or May and begin building new nests in which several eggs are laid. Workers produced from these eggs take over from the queen the duties of enlarging the nest, cleaning the nest, and carrying for the developing larvae. Nest building is complete by late May or early June. A mature colony has 100-400 workers. Reproductives are produced in late July and throughout August. They mate, the male reproductives die, and the fertilized female reproductives (new queens) find a place safe place to overwinter until spring, when they can start colonies of their own. Workers in the original colony begin to die off as the weather turns colder, usually mid to late September. Bald-faced "hornets" forage mainly for live prey in the form of other insects, including other yellowjacket wasps. However, they will occasionally scavenge their protein from dead insects carcasses. FAMILY RELATIONS a) Order Hymenoptera, Family Vespidae, Dolichovespula and Vespula - the yellowjacket wasps. b) Close cousins: Order Hymenoptera, Family Vespidae, Vespa crabro - the European hornet. [TO TOP] [HOME]