What’s the first thing that comes to mind when you think of ladybugs? I think of sweet little red beetles who munch on aphids in rose beds? We’ve had swarms of them all over our garden beds. I’m noticing something odd — their color is different than they were in past years. The red color is dull and their little spots are more frequent.
In my biology and ecology classes, the topic of microevolution came up as part of the adaptive skills of nature. The first time I heard about this phenomenon was in reference to the Peppered Moths in England. Their wings became darker in response to increased soot in the air from industrialization. Because they had darker wings, they were no longer easily visible to the birds who fed on them. As years passed, the moths wing have become lighter. This may be attributed to stronger clean air laws.
As climate change impacts so much of our world, now even the sweet little ladybug is impacted. The coast of the Netherlands is home to another microevolution. If you picked up a two-spot ladybug on the coast thirty years ago, you’d most likely find a beetle with black spots on a red shell. But inland, a two-spot ladybug would have red spots on a black shell. The coastal areas have more sun and are therefore warmer, so the ladybugs don’t need the black shell to reflect the heat of the sun.
Three decades later, researchers are finding more red shelled ladybugs inland. The University of Cambridge’s ecological geneticist, Paul Brakefield has studied the two-spotted ladybugs. And while they don’t yet know the exact change in temperature that causes the ladybugs spots to change, it is clear that there is only one genetic protein that is responsible for the coloration of their spots. In 1980, 10% of the ladybugs near the coast had black with red spots, and 90% were red with black spots. But in the last 25 years of sampling, Brakefield and his associates found more and more red with black spotted ladybugs, even further inland. When Brakefield first started to do his research, he was able to catch hundreds of the ladybugs for his data counts, now he can hardly gather enough for a sample.
The moths in London and the ladybugs in the Netherlands rely on their coloration to survive — one needs it to hide from predators, and one warns predators to stay away. As the climate changes and the spots on these insects evolve, they will have to adapt their locations or eventually disappear. As we work to save the future of our planet, let’s not leave the tiniest creatures of our beautiful Earth behind.