Many people encounter ladybugs, also known as ladybirds, and often feel a sense of benign curiosity. However, when these familiar insects appear with a black coloration, questions regarding their safety frequently arise. This exploration addresses common concerns about black ladybugs, aiming to clarify whether they pose any danger to humans or pets.
Understanding “Poisonous” in Insects
The terms “poisonous” and “venomous” are often used interchangeably, but they describe different ways toxins are delivered. An organism is considered poisonous if its toxins are harmful when ingested, inhaled, or absorbed through skin contact. In contrast, a venomous organism actively injects toxins into another creature, typically through a bite or sting.
Insects employ various defense mechanisms, including producing irritating substances. Some insects, like certain beetles, can release defensive fluids that cause discomfort upon contact, a behavior known as reflex bleeding. Ladybugs, for instance, are known to exhibit this behavior, exuding hemolymph from their leg joints. This defense deters predators.
Identifying the Black Ladybug
Many observed black forms are not native ladybugs but rather Asian lady beetles (Harmonia axyridis). True black ladybugs, such as melanic forms of native species like the twice-stabbed lady beetle (Chilocorus stigma), typically have two red spots on their shiny black bodies. These native black ladybugs are generally rounder and smaller than their orange or red counterparts.
The Asian lady beetle, an invasive species, can appear entirely black or with varying numbers of red spots. A distinguishing feature of the Asian lady beetle is the “M” or “W” shaped marking found directly behind its head, on the white section of its pronotum. Their body shape is also more oval than native ladybugs.
Are They Harmful?
True black ladybugs, which are native species, are not considered harmful to humans or pets. While they may engage in reflex bleeding when disturbed, releasing a yellowish fluid that can stain surfaces and has a mild odor, this substance is not toxic to humans.
Asian lady beetles can exhibit bothersome behaviors, though they are not truly poisonous. They can deliver a minor bite, which might cause slight irritation or a small red mark. These beetles also emit a foul-smelling, yellowish fluid when threatened or crushed, which can stain light-colored surfaces and fabrics. In rare instances, prolonged exposure can lead to allergic reactions in sensitive individuals, manifesting as skin irritation or respiratory issues. If ingested in large quantities by pets, Asian lady beetles can cause mild gastrointestinal upset.
What to Do After Contact
If you have had skin contact with a black ladybug or Asian lady beetle, wash the affected area with soap and water. This will remove any irritating fluids and reduce the chance of mild skin reactions. For a minor bite, cleaning the area with soap and water is also sufficient.
If a pet ingests a few Asian lady beetles, monitor them for any signs of discomfort, such as vomiting or lethargy. If a pet consumes a large number of beetles or shows concerning symptoms, consult a veterinarian. To remove these beetles from your home without causing stains, gently sweep them into a dustpan or use a vacuum with a stocking placed over the nozzle, then release them outdoors.