The definition of an insect is an animal in the classification insecta having a well-defined head, thorax, and abdomen. They have three pairs of legs and may have wings spiders and other arachnids (class arachnida) aren’t insects because they don’t fit the physical profile and are in their own biological classification. Given the definition, Washington state doesn’t have many dangerous insects. However, some species pose risks to humans, and some humans are more prone to health problems if and when they come into contact with a dangerous insect.

Regarding yellowjackets, wasps, and hornets: While these creatures have different names, they are all part of the vespidae family. Fun fact: The world is home to about 100,000 types of wasps, but Washington state has only a few. The state varieties of the vespidae family include yellowjackets, paper wasps, mud daubers, and bald-faced hornets. A non-native variant called the northern giant hornet has been found in this area, as well

Common Aerial Yellowjacket (Dolichovespula Arenaria)

Yellow jackets are the most common wasp found in Washington State. These animals are about one half of an inch long with abdominal black and yellow stripes. They build round paper aerial hideaways in trees, on the ground. The common aerial varieties are aggressive wasps and spit venom to alert their fellow jackets to intruders. These creatures defending their territory can cause serious allergic reactions to their stings.

Bald-Faced Hornets (Dolichovespula Maculata)

Bald-faced hornets are not true hornets but are still in the wasp family. Their coloring is black and white. These hornets are usually not aggressive but will defend their territory if provoked. The bald-faced hornet sting is very painful. They have smooth stingers, allowing them to sting repeatedly with venom that can cause life-threatening allergic reactions.

Northern Giant Hornet: ‘Murder Hornets’ (Vespa Mandarinia)

Northern giant hornets were called Asian giant hornets, but scientists changed the name to avoid using language that may appear to be discriminatory. The northern giant hornet is the largest in the world, typically about 1.75 inches. This hornet is not native to Washington, but northern hornet sightings have been reported in the state, although not for a few years now. The hornets are very aggressive and will flock to sting multiple times. They inject a larger amount of venom than other wasps, leading to severe reactions. People should not approach these hornets. They should report sightings to Washington’s Department of Agriculture.

UPDATE: As of December 19, 2024, Washington State’s Department of Agriculture has declared the Northern Giant Hornet eradicated from the State.

Honeybees And Bumblebees (Family: Apidae)

Bumblebees and honeybees are vital to agriculture, the human food supply making all life possible. Some species in Washington state are the endangered western bumblebee (bombus occidentalis) and the dainty fairy bee (perdita). They are not aggressive creatures, preferring to float among their flowers to keep the world healthy and green. However, like any creature bothered in its home, bumblebees and honeybees will attack to defend their territory. This defense poses a risk to people with allergies

Mosquitoes (Family: Culicidae)

Mosquitoes, those buzzing and annoying creatures that plague summer picnics, are of various species. One species is the western treehole mosquito (Aedes sierrensis). While this animal is unlikely to cause West Nile virus, it can cause heartworm disease in dogs. Two mosquito species that can cause West Nile virus are Culex tarsalis and Culex pipiens. Their enemies are dragonflies, which kill mosquito larvae. Fun fact: In some cultures, including China, dragonflies aren considered sacred; some people think it’s bad luck to kill one.

Blister Beetles (Family: Meloidae)

Blister beetles do exactly as their name suggests. These elongated beetles release a chemical called cantharidin when crushed. Contact with the chemical can cause skin blistering and irritation. Like any wild animal, leave these creatures peacefully to themselves. The largest group of blister beetles, called epicauta, includes many species that are dangerous to horses. Eating just a few of these beetles in alfalfa hay can be deadly. A common practice called hay conditioning, where machines crush the stalks to help them dry faster, can also crush beetles. This releases cantharidin into the hay.

Assassin Bugs (Genus: Pselliopus)

Assassin bugs are useful in keeping pests like leafhoppers, beetles, and caterpillars in check, these bugs pose risks to humans. The bite from their needle-like beak may be painful and cause allergic reactions. They may transmit the deadly Chagas disease from the parasite trypanosoma cruzi. Assassin Bugs are known as “kissing bugs” because their preferred bite area is the mouth. Assassin bugs are 0.5 inches to 2 inches long and may be brown, red, yellow, black, or multicolored. When they catch other insects with their sticky or spiny front legs, they use their mouth to poke the insect and suck out its insides.

Carpenter Ants (Genus: Camponotus)

Carpenter ants do not pose a direct threat to human life. Instead, they cause damage to buildings. Carpenter ants eat through wood, creating big holes, intricate tunnels, and colony routes throughout buildings. The creation of these holes, tunnels, and routes can weaken a building’s framework and make structures unsafe. Carpenter ant bites are not as toxic as many other dangerous Washington state insects. Part of this has to do with their mouth structure. Their bites are painful because carpenter ants can also spray formic acid onto their victims when they bite. Washing off the bite area gets rid of the formic acid.

Conclusion

When encountering dangerous insects, remember these are not “bad” animals, but organisms merely defending themselves or their territories. Whether the encounter is with a blister beetle disturbed from its haven, a mosquito rising from a lake, or a delicate bee ambling in the breeze, these small entities are part of Washington state’s environment and nature. Remember, too, that these meetings can cause life-threatening emergencies for some people, requiring immediate medical attention. Learning to live safely with the eight most dangerous insects in Washington is important for everyone — residents and visitors alike. So get out and enjoy the great outdoors.