• Michael Perrino

The Startling Size of Murder Hornets


Murder hornet, the name alone is pretty fear-inducing. It's no wonder why after its first sighting in 2019 in Washington State, authorities and scientists alike have since embarked on a full-scale hunt to eradicate these pests due to its threat to the bee populations and potentially to humans.


How big can the murder hornets get? Also called the Asian giant hornet (Vespa mandarinia), it’s typically more aggressive and larger than the average hornet. This species can grow nearly two inches in length. Its size can be one of your first indications when you chance upon a terrifying stinger.


How Big Can Murder Hornets Get?


Regarded as the world's largest hornet, the murderous hornet's size alone indicates its quite a ferocious and intimidating creature. Asian giant hornet queen can grow up to 5 centimeters (2 inches) long, about the length of an average-sized woman's thumb. Wingspans can exceed 7 centimeters (2.8 inches), not quite the entire width of a woman's palm. Asian giant hornet workers and males, on the other hand, are smaller.


Beyond its size, the murder hornet has a distinctive look, with a cartoonishly fierce face featuring teardrop eyes, orange and black stripes that extend down its body like a tiger, and broad, wispy wings like a small dragonfly. It has two sets of eyes, one compound and one ocelli, both brown in color and their legs.


Some other insects look identical, but most are quite smaller than the murder hornet. You can differentiate larger lookalikes like the western cicada killer and the eastern cicada killer wasp by their smaller heads, lighter thoraxes, and large eyes. The bands on their abdomens look different as well.


The most common type of hornet in the United States, the bald faced hornet (dolichovespula maculata) on the hand, greatly differs in size and appearance. Baldfaced hornets range in length from three quarters of an inch to just over an inch and have black coloration with a mostly white face.


Due to similarities in their name, many confused Asian giant hornet as the Asian hornet (Vespa velutina), a wasp species also native to many Asian countries. These species are typically smaller, having a body length of 3 centimeters (1.2 inch). It features distinctive yellow legs and velvety brown thorax.


Moreover, while it isn’t a hornet, another insect that is usually mistaken as the Asian giant hornet is the Elm Sawfly, the largest sawfly in North America, growing up to 2 inches. Its body is light yellow to light green in color, sometimes even pink. While it’s size is equally intimidating as the Asian giant hornet, it lacks a stinger and is considered harmless to humans.


How Do Murder Hornets Spread?


It's still unknown how exactly murder hornets arrived in the United States. Many scientists speculate that a few of these ground-nesting insects immigrated through international cargo. The first North American appearance was in British Columbia in August 2019. Four months later, Washington state announced two murder hornet reports. Studies suggest the Canadian and U.S. murder hornets represent separate, unrelated introductions.


Almost a year later, these native wasps were again confirmed in British Columbia and Washington state, verifying these pests can live through North American winters. Although earlier Washington sightings included nonreproductive worker hornets, the recent specimen was a murder hornet queen. This implies a reproductive hive existed the previous year.


Murder hornets, like yellow jacket wasps, establish new nests yearly. A single reproductive hive produces about 200 to 300 new queens every year. Queen hornets overwinter in soil or sheltered hollows, then disband during spring to create their own subterranean colonies. There is no data yet on how far murder hornet queens disperse, but related species travel up to 20 miles. Aside from murder hornets, two other hornet species are present in the country, namely the baldfaced hornet and European hornet.


Are Murder Hornets Harmful?


The presence of murder hornets threatens the environment, native ecosystems, agricultural economies, and public health. During early summer, murder hornet workers start hunting to feed their colonies. All large insects are potential targets, from beetles to caterpillars, but the bee population suffers the worst fate.


At first, workers murder hornets attack honey bee colony sporadically, killing a few adult bees for food. But in late summer, the murder hornet behavior changes. The workers attack and slaughter entire honeybee hives in just a few hours. Bees are lured from the hive and decapitated, their bodies left piled on the ground. Then the murder hornets move in and plunder honeybee eggs, larvae, and pupae to feed their growing hornet colonies.


Asian native honeybees have natural defenses against murder hornets. But the honeybee species responsible for pollinating U.S. crops is a European native. Roughly the size of a murder hornet's thorax, a European honeybee is defenseless against these predators. With U.S. honeybee colony struggling, murder hornet attacks could be devastating. Scientists believe native insects are also at risk.


Moreover, murder hornet stings pose another danger. When threatened, these social wasps sting to defend their nest and honeybee hive they have recently seized. Murder hornet delivers a substantial dose of potent and toxic venom, usually up to 1,100 micrograms (dry weight). That is more than seven times as much as a little honey bee delivers.


It's estimated that the murder hornet's painful sting is comparable to three to 10 yellow jackets stinging at once. Researchers have also likened the sensation to having a hot nail driven into one's flesh. It's also worthy to note that unlike other species of wasp, and indeed bees, the stinger of the murder hornet is not barbed and therefore remains attached to its body once used. This means that murder hornets can sting their victims multiple times. Beekeeper's clothing often cannot defend against the murder hornets’ stings.


What To Do When Stung By A Murder Hornet?



If you're stung by a murder hornet, immediately perform these first aid measures:

  • Wash carefully with water and soap.

  • Apply ice on the sting to slow down the spread of venom.

  • Apply hydrocortisone cream to relieve redness or itching.

  • Take an antihistamine pill or cream to reduce swelling.

  • See a doctor quickly if you have multiple stings or an allergic reaction.

  • If you have not had a tetanus booster in the past ten years, consider getting one over the next couple of days.

If difficulties arise, such as shortness of breath, difficulty to swallow, tightness in the throat,swelling, and lightheadedness or dizziness, you might be experiencing an anaphylactic reaction. Anaphylaxis can occur quickly and can be lethal in just a short period of time. In this case, contact a medical professional for help.


To prevent venom allergy, make sure to always bring a packet of antihistamines in your pocket, wear protective clothing, and use insect repellent if you plan to stay outdoors.


In Japan, 30 to 50 people die from Asian giant hornets each year. Most of the death are due to allergic anaphylactic reactions rather than acute toxicity,


It's important to remember that a giant hornet generally will not attack unless disturbed. Especially when the stinging insect is out foraging, it is likely to shun humans. Most casualties from stings occur because people bother the Asian giant hornet nest. Scientists perceive that giant hornets do give a warning sign before they sting: They fly back and forth snapping their mandibles.


How Can I Keep My Family Safe Against Murder Hornets?



One of your first line of defense against murder hornets is staying informed about this pest's status in the United States. It's also important that you learn how to identify one based on its size and physical features. If you suspect a murder hornet nest anywhere near your home, keep a distance of at least 10 feet. If a murder hornet circles you around, walk away slowly and calmly. Do not swat, as this might provoke it to sting you.


Furthermore, regularly cleaning the indoor and outdoor areas of your property can prevent these invasive species from building their nests in your dwelling. By maintaining a tidy space, you can significantly reduce the insect population, so murder hornets won't have any pesky pests to prey on. If there is no prey, they won't linger around.


Other effective ways to deter hornets from establishing themselves on your property are to eliminate conducive conditions and potential lures.

  • Trim back tree branches and bushes to minimize the amount of cover their nests can have.

  • Pick up yard debris. Ground hornets, like the murder, favor wood or piled debris as nesting sites.

  • Keep garbage bins away from home and ensure that the lid closes tightly.

  • Keep your house clean of trash, food, dog droppings, and fruit fallen from trees.

  • Repair any opening in the house. Crevices, cracks and the like should be sealed with caulk, but screens and weather stripping around doors will need to be patched or replaced.

  • Avoid perfume and fragrance, as well as grooming products with sweet scents. These pests use their senses of smell to detect flowers, and this tricks them into thinking that you might be one.

If you see a dead murder hornet, don't approach it or attempt to remove it. Immediately contact your state department of agriculture or entomologist so they can collect the specimen and study it further. Asian giant hornet sightings must always be reported to authorities to prevent them from breeding.


Seek The Help Of An Expert


Murder hornets are disturbing. They threaten your property and your family's health. Their agonizing stings can cause serious reactions and in extreme cases, can be fatal. It's not smart, safe, and easy to deal with these pests alone. Let our knowledgeable technicians at Midway Pest Management help you exterminate these stingers and stave off pest infestations in your home effectively. Contact us today for a free inspection.


Learn more: Hornet vs Yellow Jacket: How to Tell the Difference

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