Researchers from the Stellenbosch University are undertaking a large-scale study of the invasive Harlequin ladybird (Harmonia axyridis) in South Africa. They are calling upon the public to assist them. The team plan to use molecular genetic techniques to uncover the origins, route of invasion and spread of the Harlequin ladybird in South Africa.
The Harlequin ladybird, also known as the Asian ladybeetle, is native to central and eastern Asia. It is known to be an aggressive invader on at least four other continents. The Harlequin ladybird was discovered in the Western Cape in the early 2000’s but has since spread rapidly to all nine provinces in South Africa. While many countries introduced the Harlequin ladybird as a biological control agent, the nature and origin of its introduction in South Africa is unknown.
In South Africa, the Harlequin ladybird (Harmonia axyridis) is listed as a Category 1b species on the National List of Terrestrial Invasive Invertebrates as per the Alien and Invasive Species (AIS) Regulations (2014) of the National Environmental Management Biodiversity Act (NEMBA) (Act 10 of 2004).
Why is this ladybird a problem?
Multiple studies have shown that the Harlequin ladybird can have detrimental effects on agricultural crops and on native ladybird diversity in other regions of the world. As an agricultural pest, these ladybirds can feed on fruit and taint grapes harvested for wine-making.
The Harlequin ladybird is also predatory and by feeding on native ladybirds, alters or displaces native ladybird species. Moreover, during autumn and winter, the Harlequin ladybirds typically gather in large numbers around urban developments and when disturbed, adults exude a fluid with an unpleasant smell that can also stain fabrics.
The Harlequin ladybird can easily be distinguished from our native South African ladybirds by the distinctive “M” or “W” on its head (see images) and are often found on oak trees, ornamental conifers and garden roses. Adult beetles can vary in colour from deep red to light yellow, and the number and size of the spots on the wing cases can also vary between seasons.
Citizen science project is launched
To tackle pressing questions surrounding the invasion of the Harlequin ladybird in South Africa, the CL.I.M.E lab at the Centre for Invasion Biology, Stellenbosch University has launched a citizen-science project to document the distribution of this species in South Africa. In collaboration with scientists at Stellenbosch University this project will involve the general public to help collect specimens and gather data on the distribution of the Harlequin ladybird in South Africa.
What can you do?
If you encounter a site with high abundance of Harlequin ladybirds (>20 beetles) or a large aggregation such as those typically found around households in window frames and doors, you can contribute to the project by collecting 10-30 ladybirds per site. All that is needed is that you place these ladybirds in a small, clean container or ziplock bag, note the date and site of collection, and freeze them in your home freezer.
Once you have collected them, you can email our researcher, Dr Minette Karsten (), who will contact you with information on how to send your sample. The specimens that you collect will be highly valuable to answer key questions of the invasion biology and be used in a genetic study to uncover the origins, route of invasion and spread of the Harlequin ladybird in South Africa.
In addition, if you spot a Harlequin ladybird, snap a digital photo with your camera or phone, note the date and location of your sighting, upload this information and image to iSpot, a platform for the general public to share sightings of interesting animals. Your uploaded information will be captured by the Harlequin ladybird iSpot project. Even if you only observe a single Harlequin ladybird it still counts and can be extremely valuable information!
* Harlequin Ladybird Fact Sheet
* Science feature on invasive Harlequin Ladybirds: Ladybirds: successful invaders in small packages. In a warming world, can an invasive ladybird take the heat? Susana Clusella-Trullas, Michael Logan and Ingrid A Minnaar ask the question. Quest 11|2 2015.
* For more information on the Citizen Science Harlequin Ladybird, view or download the z-fold pamphlet below.
Image 1: Invasive harlequin ladybirds (Harmonia axyridis) – Photograph © I.A. Minnaar 2016
Image 2: Colour and spot variation in invasive Harlequin ladybirds (Harmonia axyridis) – Photograph © J.L. Allen 2016