Wasps & Hornets
Why Are They a Problem?
Left alone, wasps and hornets do not go out of their way to sting humans, but wasps will vehemently protect themselves and their nests, making them undesirable occupants of our homes and gardens. In addition to the pain of being stung, some people are allergic to wasp venom and can have life-threatening allergic reactions if stung. Wasps can sting repeatedly — and they can send a signal to the rest of the colony when they are threatened. A swarm of wasps or hornet scan be very dangerous to people and poses a more serious threat to small children and pets.
Wasps and hornets can also be major pests away from home by making nests at campgrounds and picnic areas, and by persistently crawling on food and into beverage cans.
Wasp & Hornet Biology
In the early spring, the hibernating queen emerges to look for a new nesting site. Once this is found, she builds the first few paper cells and lays a single egg in each cell. These new workers and future workers will tend to the colony. In the fall, the colony can house from 1,000 to 30,000 individuals. As the weather turns cooler in the fall, the queen usually abandons the nest to hibernate. The workers also abandon the nest and eventually die.
Wasps and hornets are members of the group of bugs known as the Family Vespidae. They’re easily differentiated from bees by the fact that a wasp’s body appears to be hairless and their hind legs are thinner. Bees, in contrast, have obvious body hair and wide parts on their hind legs to store pollen.
All wasps can sting: Their stingers are connected to venom-producing glands. Unlike honeybees, wasps can sting repeatedly because their stingers do not have barbs that stick in the skin.
How to Prevent Invasions & Infestations
- Seal cracks around windows and doors.
- Make sure that all garbage containers are sealed and that recycling materials are rinsed out before putting them into the bin — wasps particularly like sweet drinks such as soda pop.
- Avoid camping or picnicking near garbage containers where wasps and hornets tend to congregate.
- To avoid repeated stings, don’t squish a wasp! When a wasp stings what it perceives to be a threat to the colony, or when it’s crushed, it releases a pheromone (a chemical signal) that the other wasps in the colony can detect. The wasps follow this chemical signal and sting the intruder. This signal causes colonies to swarm around an intruder and sting it repeatedly.
Recommended Treatment
If the location of the nest does not present a health hazard, it’s best to leave the nest until November or December when it has been abandoned. The nest can then be removed with minimal risk.
If you choose an insect control product, only use a federally registered wasp and hornet product. If the nest must be controlled when the wasps are active, the control of wasp colonies in their nests should be attempted only at dusk or after dark when they’re least active. At these times, nearly all members of the colony will have returned to the nest, and they will be less likely to leave.