The Asian ladybug (Harmonia axyridis) is an invasive species that was brought to Europe from Central and Eastern Asia. Effectively fights aphids and other small insects, but displaces our native seven-point ladybugs. Seewhat the Asian ladybug looks likeand how to distinguish it from the Polish seven-dots. We explainwhether the Asian ladybug is dangerousand how to fight it.
Asian ladybug
Fig. pixabay.com
The Asian ladybugis an insect from the order of the beetle (Coleoptera) and belongs to the ladybug family (Coccinellidae).Its native area of distribution is eastern and central Asia, from the Altai to the coasts of the Pacific Ocean and from southern Siberia to southern China. This insect first appeared in Poland in 2006.
How did the Asian ladybug end up in Poland?
The Asian ladybug, also known as the harlequin , has been introduced to various parts of the world to control crops more effectively. In the 1960s, this species was used in Ukraine and Belarus. France was the first country in Western Europe to import the harlequin. For experimental purposes only at first. However, it soon turned out that harlequins meet the expectations of producers as perfect ladybugs for aphids and other countries such as: Portugal, Greece, Germany, Spain, Italy, Switzerland and the Netherlands brought these useful insects.
In 2003, the Asiatic ladybug was introduced in the Czech Republic for the last time, and a few years later its presence was recorded in countries that did not import it at all.In Poland, the presence of the harlequin was officially noticed in 2006 in Greater Poland. Within 2 yearsthe Asian ladybug spread throughout the countryMassively occurring insects aroused sensation and fear, fueled by articles and press reports about their harmfulness.
What does an Asian ladybug look like?
The adult Asian ladybug is 5-8mm longand has an oval shape. It shows great variability in terms of color and pattern on the covers. We can meet yellow and red individuals covered with black dots of various sizes, but also black beetles with 2-4 yellow-orange spots. The precoculum of the Asian ladybug is light in color (white, yellowish or orange) with a black drawing resembling the letter M or a black stripe with light spots on the sides.
Asian ladybug
Fig. pixabay.com
Asiatic ladybug larvaehave distinctive outgrowths on the sides and back. At first they are uniformly black, but with time individual abdominal segments turn orange.
Asian ladybug and Polish seven dots - differences
Both ladybugs are similar in shape and size, but it is easy to recognize them by their color, number of dots and drawings on the pre-knitting needle. Typicaldifferences between the Asian ladybug and our Polish seven-dot ladybugare presented in the table.
Asian ladybug and Polish seven dots
Fig. pixabay.com
Asian ladybug - is it dangerous
The Asian ladybug is dangerousto other species of this genus. It colonizes the areas where it appears, eating eggs, larvae and adults of native species of ladybugs. Only the biggest Polish ladybug - midge (Anatis ocellata), not only cannot be eaten, but also eats Asian ladybugs.
Harlequin can pose a threat to horticultural crops , especially fruit orchards.Although it feeds on pollen and flower nectar, it also does not disdain plant juices and tissues. By feeding on fruit, it can do great damage, especially in vineyards. Once the Asian ladybug has appeared on ripe clusters, there is really no way to get rid of it. Getting on the production line along with the fruit spoils the taste of the wine and makes it unfit for consumption.
Asian ladybug is rarely dangerous to people , most often it is simply a nuisance. Contrary to popular belief, it bites people no more often than native species of ladybugs. Sensitive people may be allergic to substances secreted by the ladybug. Allergens can enter the human body through direct contact with an insect or by droplets, causing an asthma attack, swelling or rash.
Asian ladybug eats aphids
Fig. pixabay.com
Asian ladybug - biology
This predatory beetle is extremely voracious and feeds on small insects: aphids, red beetles, butterflies and mites. An adult Asian ladybug can eat 15 to 65 aphids a day , and a larva of 90 - 370 aphids during its development. The ladybug eats both eggs, pupae and adult aphids. The expansive beetle reproduces very quickly - one female can lay up to 80 eggs a day. Asian ladybugs do not live long, usually 1-3 months, although some adults may survive for several years.
In the period preceding wintering, the Asian ladybug migrates even long distances. Unlike domestic species , the Asian ladybug hibernates in large groupsIt gets into gaps between stones and into the nooks and crannies of tall buildings, and hibernates near windows, doors or roofs. It is quite resistant to low temperatures and can survive even a short-term drop down to -15 ° C.
Asian ladybug - fighting
Toprotect buildings against the Asian ladybugall gaps should be sealed and the windows fitted with nets.Natural fragrances, e.g. menthol, camphor, citrus, cloves, effectively repel this insect. Therefore, it is worth placing fragrance bags near the windows and doors, and sprinkling the frames with essential oils. You can also place traps with a sticky insert on the windows, and in dark rooms and attics setinsecticidal lamps emitting UV radiation
MSc Eng. Anna Błaszczak
