Bald Faced Hornet Control
Bald-faced hornet is a colloquial name for Dolichovesoula maculata. It is a eusocial wasp which belongs to the Vespidae cosmopolitan family. Its hornet, genus vespa, is not a true hornet, but a yellowjacket wasp species. It has about 400 to 700 workers in its colonies, which is recorded as the largest size of colony in Dolichovespula, its species. The characteristic hanging paper nest it builds is large, around 58 centimeters in length. In a bid to defend their nests, workers aggressively sting invaders.
The distribution of Dolichovespula maculata occurs throughout Southern Canada and the United States, but it is more commonly found in the southeastern United States. Females in the species are diploid, while males are haploid. It therefore becomes possible for worker females to lay eggs that develop into males. After raising enough workers and laying enough queen-destined eggs, matricide may occur. This is in order for workers to have a reproductive advantage.
The bald-faced hornet has characteristic white markings on its face from where it acquires its name. The white and black and white coloring which it has makes it different from its genus mates which are mostly black and yellow. Its black and white coloring differentiates them from other yellowjackets. Its head is “baldface” or white. Three white stripes are located at the end of these wasps’ bodies. They have a larger size than other Dolichovespula species. For an adult, its average length is about 19 millimeters (0.75 in). The morphologies of worker and queen wasps are similar, however, the queens are hairless, while small hairs cover workers. The sizes of queens are larger than those of workers in their colonies, though there are varying distributions across nests, making workers in a colony to probably have equal sizes as those of queens in a different one.
The nests created by D. maculata are paper and egg-shaped with diameter up to 360 millimeters (14 in) and length up to 580 millimeters (23 in). Layered hexagonal combs are their nests with a mottled gray paper envelope as cover. This paper envelope is created by bald-faced hornet by chewing and collecting fibers that naturally occur. A mixture occurs between the wood fiber and their saliva which becomes a pulpy substance which they are now able to create into place.
Dolichovespula maculata is seen in vegetation in urban regions and in forested areas. Generally, the location of nests is in bushes and trees, however, occasionally they are found in building sides and beneath rock overhangs. There has been a record of vertical distribution of nests to be from 1.1 to 20m in heights above ground level.
Bald-faced hornets have a predation of caterpillars, spiders, and flies; as a result, they are considered beneficial. They are omnivorous. Despite being beneficial, they are a threat to humans who move extremely near their nest or in a case where the construction of their nest is extremely close to the habitation of humans. This is as a result of their aggressively defensive nature. A common habit among social bees and wasps is a repeated series of stinging by workers in an attempt to vigorously defend the nests. However, there is a unique defense that the bald-faced hornet has; it is able to squirt venom into the nest intruders’ eyes from the stinger. Through this venom, the eyes begin to water immediately and temporary blindness occurs.
A colony’s life cycle can be divided into three stages: the founding, ergonomic, and reproductive. The cycling of colonies is annually shown. The founding of new nests generally occur during early summer and spring by a single queen, although there are varying temporal specifics depending upon location. Nest initiation happens at mid-May in Washington State, and emergence of workers occurs at mid-June. The starting of large cell buildings happens at mid-July, and the emergence of first queens happens at mid-August. Termination of the colony occurs in mid-September, for a four-month (122 days) life cycle. There is a correlation between longer life cycles and lower altitudes. In Indiana, there was an observation that colonies start in early May and are terminated in late September. This is a five-month (153 days) life cycle. In Central California, the initiation of nests occurs as promptly as the latter part of March. The survival of these nests is within 155 and 170 days. In central Pennsylvania, there has been an observation of active colonies as late as the middle of October.
One overwintered inseminated queen is responsible for the founding of the colony. The rearing of the initial generation of workers is done all by herself alone until they become functional. The foundation stage which colonies pass through ranges between 23 to 24 days. Six days are required for hatching to occur after laying of eggs by the queen. They spend eight days growing as larva and there is an added 9 to 10 days for maturity into adult workers to occur.
During the ergonomic stage, the activities of the colony deal with the building of cell and worker production. While the queen is focused on laying eggs, the workers focus on all other important tasks of housekeeping. There is a division of a colony into female workers, the queen, and sterile males. Reproductive capacities come with the females during birth. Larval feeding regime determines the caste system.
Moisture diffusion encounter a barrier from Cuticular hydrocarbons, and thus dehydration in wasps is prevented. Profiles of cuticular hydrocarbon vary over nests and species, and so they are an intended mechanism for the recognition of nest mates. Cuticular lipids of queens and workers have components that are similar, but there is a dramatic difference in their distribution, which implies that cuticular hydrocarbons also have impacts in caste differentiation.
The mating of queens occurs with only a single male in D. maculata. This leads to a 0.75 worker relatedness. However, there is only 0.5 relatedness between the worker and the queen. Gynes in dolichovesoula maculata are able to discriminate between foreign comb and natal comb fragments. Recognition is not dependent upon the viable brood presence in the fragment of the comb.
Low paternity, queen-worker conflict, and worker production characterize D. maculata. There are disperse genetic interests between the workers and their queen which lead to contention for control inside the nest, and destabilize social organization. Workers do not have the ability to mate as a result of haplodiploidy. Eggs from them which are unfertilized turn into males.
There is a varying diet in D. maculata which is dependent upon both the geographic location and an individual’s life cycle stage. Adult hornets are carnivores and would usually prey upon many insect types. There has been an observation of them consuming spiders, fruit, insects and meat. Adults also consume flower nectar and feed their larvae with it.
Every spring, new colonies are begun by all of the queens that were given birth to and fertilized at the previous season’s end. A queen chooses its nest’s location, starts building it, produces an initial group of eggs, and feeds this initial batch of larvae. These turn into workers and they take over the activity of the nest expansion. They chew wood, and this combines with a starch found in their saliva. Then they disperse it around their legs and mandibles, and it becomes free of moistures and forms into a papery unit.