Beetles are an incredibly diverse group of insects found in nearly every environment. While most are harmless to humans, a few species can inflict a defensive bite. This typically occurs during accidental encounters or when a beetle feels threatened.
Why Beetles Might Bite
Beetles typically bite as a defensive measure, not out of aggression. A bite might occur if a beetle feels cornered, is handled roughly, or is accidentally pressed against skin. This action serves as a warning or a means of escape when the insect perceives a threat. Their mouthparts, known as mandibles, are primarily used for feeding, but in some species, they are robust enough to deliver a pinch or a bite.
The strength and structure of these mandibles vary significantly among different beetle species, determining their capacity to inflict a noticeable bite on human skin. Most beetles lack the jaw strength to break skin, and even those that can rarely do so without provocation.
Beetles Known to Bite
While most beetles are harmless, certain species are more likely to react defensively with a bite or a chemical irritant. Blister beetles, for instance, do not bite with their mandibles, but they secrete a substance called cantharidin when disturbed. Contact with this chemical can cause painful blistering and irritation on the skin.
Stag beetles, known for their large mandibles, can deliver a painful pinch or bite if provoked. Female stag beetles possess robust jaws capable of inflicting a noticeable bite. These bites are generally not medically serious. Longhorned beetles also have mandibles strong enough to cause a painful bite that may result in discomfort lasting up to a day or two. Ground beetles might deliver a pinch if mishandled, but their mandibles typically do not break human skin.
Responding to a Beetle Bite and Prevention
Should a beetle bite occur, basic first aid measures can help manage discomfort. Begin by gently washing the affected area with soap and water to clean the wound and reduce the risk of infection. Applying a cold compress can help reduce swelling and alleviate pain. For minor irritation or itching, over-the-counter topical creams containing hydrocortisone or oral antihistamines may provide relief.
Seek medical attention if symptoms are severe, such as widespread swelling, difficulty breathing, dizziness, or signs of an allergic reaction. If the bite area shows signs of infection, like increasing redness, warmth, pus, or persistent pain, consulting a healthcare professional is recommended. Preventing beetle bites involves simple precautions. Wear gloves when gardening or handling wood, shake out clothing or shoes left outdoors, and avoid direct contact with unfamiliar beetles. If a beetle lands on you, gently brush it off rather than crushing it, especially blister beetles, to prevent chemical exposure.