Ladybugs are often seen as harmless, beneficial insects, but many people wonder if they can bite. While most native species are benign, there’s a nuance to this common question. Understanding the differences between various ladybug types clarifies how humans might interact with these familiar beetles.
Can Ladybugs Bite?
While many people consider ladybugs gentle insects, certain species can deliver a sensation often described as a “bite.” This feeling is more accurately a pinch, as these beetles do not possess true biting mouthparts like mosquitoes. Instead, they use their mandibles for grasping.
Most native ladybug species rarely attempt to pinch humans, as their mandibles are primarily adapted for consuming small insects like aphids. However, the Asian Lady Beetle (Harmonia axyridis) is an exception and is more prone to doing so. Their mandibles can apply enough pressure to be felt on human skin, though they are not designed to break the skin or draw blood.
Reasons for a Ladybug Bite
When an Asian Lady Beetle “bites,” it is not an act of aggression but a reaction to conditions. A common reason is a defensive response, particularly if the beetle feels trapped or threatened. If one lands on your skin and gets pressed, it might pinch as self-preservation.
Beetles also pinch when seeking moisture, especially during dry periods or before overwintering. They might mistake salt or moisture on human skin for food or water.
Sometimes, a pinch is an exploratory action, as the beetle investigates its surroundings or attempts to find a resting spot. This behavior is incidental, not intentional harm.
Identifying the Biting Species
Distinguishing the Asian Lady Beetle (Harmonia axyridis) from native ladybugs is important for identifying the species more likely to pinch. Native ladybugs have a dome-shaped body and are bright red with a consistent number of black spots.
The Asian Lady Beetle, however, exhibits a wider range of colors, from pale yellow or orange to deep red, and can appear slightly oval rather than perfectly round. A distinguishing feature is the presence of an “M” or “W” shaped black marking on the white area behind its head, known as the pronotum, which is absent in most native species.
While native ladybugs have a consistent number of spots, Asian Lady Beetles can display significant variation, possessing many spots, few spots, or even no spots at all. Their size can also vary, but they are slightly larger than most native ladybug species, measuring between 5 to 8 millimeters in length. Observing these specific markings and color variations helps differentiate them.
Responding to Ladybug Encounters
If an Asian Lady Beetle does pinch, the sensation is minor and momentary, feeling like a tiny pinprick or a slight scratch. It causes no more than a slight discomfort or a small, red mark. Ladybug bites do not transmit diseases to humans, nor do they inject venom.
To prevent a pinch, gently brush the beetle off your skin rather than trying to crush or swat it, as this can provoke a defensive reaction. To deter them from entering homes, consider sealing cracks around windows and doors, repairing torn screens, and ensuring caulk is intact. They are attracted to light-colored surfaces and warmth, so reducing exterior lighting near entry points helps minimize their presence.