Insects in the order Hymenoptera include more than 150,000 documented species of ants, wasps, and bees that can be found in various parts of the world. Many Hymenoptera insects are considered medically significant due to their ability to inflict venomous stings to humans, which kill more people in the US each year than any other group of insects. Most ant species that are pests of homes in the US do not possess stingers, and those that do are largely absent from Massachusetts, except for the European fire ant (Myrica rubra). This ant species has been known to inflict painful stings that cause anaphylaxis in a small minority of sensitive individuals. However, a surprisingly large number of bees and wasps that nest on residential and commercial properties in Massachusetts are defensive pests that readily inflict venomous stings to humans and animals.

Most people know wasps and bees as nest-dwelling social insects that form colonies, but the majority of wasp and bee species are solitary insects. Although most solitary wasps and bees possess venomous stingers, social wasp and bee species are responsible for nearly all medically significant human envenomation incidents. This is because most individuals within a social wasp or bee colony are always ready to attack anyone or anything that is perceived as a threat to their queen. A mere accidental bump against a social wasp or bee nest that is obscured within a bush is enough to prompt the numerous nest inhabitants to emerge and attack nearby humans and animals.

In Massachusetts, some solitary wasp and bee species are considered nuisance pests on properties, but these species are not generally considered medically significant pests because they have no colony to defend, and therefore, they are highly unlikely to sting humans. Most sweat bees are solitary species that sometimes pester humans due to their attraction to perspiration, and solitary mud dauber wasps often build mud nests on the exterior walls of homes and buildings. Carpenter bees are the most commonly managed solitary bee pests, as females excavate nests in wood siding, and the stingless males defensively dart into people’s faces. Other solitary Hymenoptera species are considered pests due to their natural habitat of excavating ground burrows in well maintained turf-grass lawns. These burrowing pests include mining bees, sweat bees, sand wasps, digger wasps, and cicada killers.

Have you ever sustained a sting from a solitary bee or wasp species?