Asian Beetle or Lady bugs
Harmonia axyridis is a large coccinellid beetle originally native to eastern Asia, but which has been introduced to North America and Europe to control aphids and scale insects. It is now common, well known and spreading in those regions.It is commonly known as Asian lady beetle, or Japanese ladybug, in North America, and Harlequin ladybird in the United Kingdom (the latter name because it occurs in numerous color forms).
It is also known as the multicolored Asian lady beetle, and Halloween lady beetle (because it invades homes in October in preparation for hibernation).
Biology and behavior
Life cycle: mating, eggs, five larval stages, pupa and newly-emerged adult Asian lady beetles hibernate in cooler months, though they will wake up and move around whenever the temperature reaches about 10 °C (50 °F). Because the beetles will use crevices and other cool, dry, confined spaces to hibernate, significant numbers may congregate inside walls if given a large enough opening. These beetles use pheromones to “call” each other, allowing for the large gatherings that are often seen in the Autumn. This is exploited by the makers of Asian ladybug traps. They often congregate in sunlit areas because of the heat available, so even on fairly cold winter days, some of the hibernating beetles will “wake up” because of solar heating. These large populations can be problematic because they can form swarms and linger in an area for a long time. These beetles can form groups that tend to stay in upper corners of windows. This beetle has been also found to be attracted to dark screening material for its warmth. This beetle has good eyesight, and will come back from where it was removed, and is known to produce a small bite if provoked. The Asian lady beetle, like other lady beetles, uses isopropyl methoxy pyrazine as a defensive chemical to deter predation, but also contains this chemical in its hemolymph at much higher concentrations than many other lady beetle species. These insects will “reflex bleed” when agitated, releasing hemolymph from their legs. The liquid has a foul odor (similar to that of dead leaves) and can cause stains. Some people have allergic reactions, including allergic rhinoconjunctivitis when exposed to these beetles. Sometimes, the beetles will bite humans, presumably in an attempt to acquire salt, although many people feel a pricking sensation as a lady beetle walks across the skin. Bites normally do no more harm than cause irritation although a small number of people are allergic to bites.