If you’ve been along the Western Cape coast over the last few days, you may have seen thousands of ladybirds that have washed up.
There have been sightings in Strand, Gordon’s Bay, Lambert’s Bay, and even along the West Coast, with Woodbridge Island being one of those locations.
CapeTalk’s Lester Kiewit asked entomologist and Senior Field Officer at the Endangered Wildlife Trust, Renier Basson, why this has occurred.
Basson said he thinks it’s because of the sudden change in the weather.
“And I really think El Niño has played a role in this event. So, we’ve received a lot of rain suddenly, and then the landscapes were lush and green, and this allowed for aphids to thrive.
“And the ladybirds that washed up, and I’m referring to them as ladybirds; many people call them lady beetles, others call them ladybugs, which they are not; they’re not actually bugs, they’re beetles. So, these specifically feed on aphids.”
Basson said it became really hot and dry all of a sudden, which resulted in plants dying off, and there were fewer aphids. “And the ladybirds then migrated to greener fields, if I could call it that. And with all the winds we’ve been experiencing along the coastline, they probably got swept offshore and into the ocean.
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How do lady beetles end up travelling hundreds of meters above the ground?
“They actually use the higher, warmer air currents to migrate. Ladybirds are very clumsy and bad flyers. So, they have to use wind currents to take them to other places. That’s why they fly vertically, and then they just get swept by the air currents as high up as 500 meters.
“The recent event didn’t really have that many ladybirds, even though people saw thousands of them. That is nothing compared to the actual number of ladybirds out there. And this is only three species out of approximately 300 described species in South Africa.”
Basson said the majority of those species are tiny, dull-looking beetles that look nothing like ladybirds, but they fill the same niche.
“I don’t think it really had a big effect on their numbers and it wouldn’t really have an effect on the beach itself. They would just decompose and become one with the beach sand.”
Is this a regular occurrence or is it a once-in-a-while phenomenon?
“I wouldn’t say it’s a regular occurrence, but it’s not uncommon. It is happening all over the world with different insect groups. And this is just one of those. So, it’s definitely not uncommon, but it’s also not a regular event.”
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Vicky Stark
www.ewn.co.za