Thousands of ladybugs were found on the beaches of the West Cape, with a significant number being dead and others alive along the tide line. The mass gathering was observed on Strand beach over the weekend, and similar incidents have been recorded in Gordon's Bay and Lambert's Bay on the West Coast recently.
Beetle experts identified three species among those found on Strand: two local species and an exotic ladybug species that has been present in South Africa for many decades. These species were identified as Lioadalia flavomaculata, the common southern African species, the local Lunate Lady Beetle (Cheilomenes lunata), and the variegated beetle Hippodamia variegata.
The latter species is exotic and found in several countries; it is believed to have arrived in South Africa from Europe around 1967. Specialists did not find signs of the harmful invasive alien species Harlequin Ladybird, which originates from Asia.
Despite the unusual scale of the gathering on Strand, mass wash-ups of ladybugs have been recorded in other parts of the world. The exact cause of such phenomena is not always clear, but it is known that insects undertake large migratory flights in search of new feeding grounds or to escape colder conditions.
During these migrations, they can fly at altitudes of 150 to 500 meters, using warm air currents and winds to cover long distances. One explanation for the wash-ups on the coast is that migrating ladybugs are affected by changes in wind or thermal currents and carried out to sea, from where they eventually fall into the water. Insects can remain afloat for several days, allowing some of them to be alive when currents bring them back to shore.
Observations in three locations in the West Cape within a short period have raised questions about whether these wash-ups are related to the same weather or wind conditions. One of the largest recorded instances of ladybug wash-ups occurred in Egypt in 1939, when approximately 4.5 billion beetles were recorded along a coastline of about 21 kilometers.