Harmonia axyridis Pallas, 1773
Common names: Asian lady beetle, Japanese ladybug, Harlequin ladybird [En], Coccinelle asiatique [Fr], Veelkleurig Aziatisch lieveheersbeestje [Nl], Asiatischer Marienkäfer [De]
Meise, BRABANT ● Belgium
Description: It is a large coccinellid beetle, being domed and having a "smooth" transition between its elytra (wing coverings), pronotum and head. It occurs in three main color forms: red or orange with black spots (known as form succinea); black with four red spots (form spectabilis); and black with two red spots (form conspicua). However, numerous intermediate and divergent forms have also been recorded.
The species is typically large (7–8 mm long) and even more dome-shaped than native European species (these characteristics distinguish H. axyridis from native species in the UK). It often has white markings (typically defining an "M"- or "W"-shaped black area) on its pronotum, and usually brown or reddish legs.
Distribution: It is native to eastern Asia, from central Siberia, Kazakhstan and Uzbekistan in the west, through Russia south to the Himalayas and east to the Pacific coast and Japan, including Korea, Mongolia, China and Taiwan.
It has been introduced to North America and Europe to control aphids and scale insects. Consequently, it has been introduced into greenhouses, crop fields and gardens in many countries, including the United States and parts of Europe. The species is now established in the United States, Canada, Argentina, Brazil, the United Kingdom, Denmark, the Netherlands, Belgium, Luxembourg, France, Germany, Poland and South Africa.
In Europe it is currently increasing to the detriment of indigenous species, its voracious appetite enabling it to out-compete and even eat other ladybirds. Native ladybird species have experienced often dramatic declines in abundance in areas invaded by H. axyridis.
Biology: H. axyridis 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.
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.
H. axyridis, like other lady beetles or ladybirds, 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 such 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.
The Harlequin Ladybird Survey
Mizell R.F., 2007. Impact of Harmonia axyridis on native arthropod predators in pecan and crape myrtle, Florida Entomologist.
Multicolored Asian Ladybeetle (Harmonia axyridis)
Wikipedia, Harmonia axyridis