While surfing the Internet in 2020, you’ve likely seen all kinds of articles about COVID-19, toilet paper shortages, and, most recently, “murder hornets.” The Asian giant hornet, Vespa mandarinia, was discovered in Washington state in December 2019, and two new workers were found in August 2020. Many in North Carolina are worried about the invasive hornet, which is the largest hornet ever discovered. However, the North Carolina Department of Agriculture and Consumer Services is monitoring for these “murder hornets,” and they have not been discovered in our state. We have several large wasps and hornets (and even some flies) in North Carolina that may fool North Carolinians, but don’t be alarmed! You can easily tell these look-alikes apart with a few defining characteristics. The Asian giant hornet is the world’s largest hornet, measuring up to two inches in length. These hornets are bright orange or yellow in color with a dark brown thorax (the portion where the wings and legs connect). They have notched eyes that are far from the back of the head, and their abdomen is covered in continuous brown and orange stripes. There are a few native wasp species in North Carolina that are comparably large. One example is the cicada killer wasp (Sphecius speciosus), which can reach up to almost two inches in length. But size does not indicate danger - unless you are a cicada (a large, noisy insect in North Carolina), the cicada killer wasp will not harm you! Likewise, there are several other insects, such as the introduced European hornet (Vespa crabro), that are commonly mistaken for “murder hornets.” Even a fly species, the red-footed cannibal fly (Promachus rufipes), deceives people! Still, with a careful eye and a few resources, it is possible to tell the difference. So, why does the Asian giant hornet elicit so much alarm? Besides its large size, many are worried about the hornet because it threatens other insect populations, such as the European honey bee. The European honey bee is not native to the United States, but it is an important pollinator for our agriculture. Asian giant hornets are predators of honey bees, and they are capable of destroying entire hives in just a few hours. These predators send out pheromones, or chemical messages, to other Asian giant hornets, signaling them to attack and rapidly kill honey bees. Japanese honey bees have evolved to fend off Asian giant hornets and respond to these pheromones, but European honey bees haven’t. Without any strong defenses, European honey bees can’t withstand the wrath of Asian giant hornets. It is unknown exactly how the Asian giant hornet would affect other insect populations in the U.S., but it is likely that it would prey upon our native bees, and its impact on European honey bees is enough to worry beekeepers! No one knows for sure how the Asian giant hornet got to Washington state, but some suggest it could have ended up in packing material or been brought illegally for food or medicinal purposes (the nutritious larvae and pupae of the hornet are often eaten in Asia). Researchers in Washington created a model to predict whether the Asian giant hornet could establish itself in the United States. They suggest that the hornet is most likely to occur in areas with low to warm annual temperatures and high precipitation, which exist in most of the eastern part of the country. Since Asian giant hornets are so concerning to beekeepers, professionals across the country are monitoring for these insects. It is understandable that many North Carolinians are worried about the “murder hornet,” but, as of now, these hornets are not in North Carolina. If you see a large wasp, keep in mind that we have several large species in North Carolina, and try to keep your eyes peeled for defining characteristics like colors and patterns. Above all, don’t just kill any large insect you see...most of them are beneficial! Written by Courtney Smith Edited by Dr. Matt Bertone, Director, Plant Disease and Insect Clinic, NCSU References |
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AuthorWe are a group of NC State University students committed to spreading awareness about the invasive species that inhabit or threaten North Carolina. Archives
March 2023
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