Why has the harlequin ladybird (Harmonia axyridis; Pallas, 1773) been chosen as the 2023 insect of the year?

• Firstly, to highlight the arrival of invasive species in Latvia and the fact that the introduction of new species is not always beneficial to native ones;

• Secondly, to show that Latvia's fauna continues to expand. This ladybird was not introduced to our country by humans, but arrived here naturally by flight;

• Thirdly, to demonstrate the species' ability to adapt to local conditions outside its natural range.

Ladybirds are well known to us all as dievgosniņas (ladybugs), cute beetles that eat aphids and do good for the garden. There are around 60 different species of them here. However, quite recently, since 2009, the rather voracious harlequin or Asian ladybird has flown into Latvia.

It is not native to our fauna. It was brought into Europe from Asia long ago as an effective exterminator of aphids and scale insects. Once brought in and released into the wild, it was expected to adapt to local conditions. The ladybird is ecologically plastic. It has spread not only in Europe but also elsewhere in the world. By attacking other insects, including local ladybird species, it can affect the local fauna. That is precisely why it is considered invasive – it impacts local insect species. In Latvia too, although the species has not been studied extensively, a detailed profile of this invasive species can be downloaded. It was prepared in 2014 and is based mainly on information from websites.

In 2021, the harlequin ladybird was included in the participant list of the Nature Concert Hall Invasivus. Alongside other truly terrible invasive species, it was also awarded this status.

The name of the harlequin ladybird comes from the fact that adult beetles can be quite different in body colour. The basic upper colouration is orange with characteristic 19-22 or fewer spots, but there can also be black individuals with two orange spots on the elytra.
Image used from Pinterest