I was always very fond of ladybugs as a child. They were pretty and bright, didn’t bite, and I was always told that they were ‘good insects’, that ate aphids and therefore protected gardens. I remember picking them up and trying to keep them alive in various terrariums of my own design — one of the worst was when I placed a few ladybugs inside one of my Polly Pockets, crammed a few leaves inside, and expected them to live. They died, very quickly. In fact, not one of my ladybugs ever managed to survive.
Ladybugs are more correctly called ladybirds, as they are beetles, not bugs. To be fair, they are also not birds, so the most correct term is ladybird beetles, or lady beetles. There are over 5,000 species of ladybird beetles that can be found across the globe.
Ladybird beetles range in size from 0.8 to 18 mm, depending on the species. Though the lady beetles we are most familiar with are the common black-spots-on-red variety, there are many other colours of lady beetle. The background colour can be red, orange, brown or yellow, and the spots can be white instead of black. Some species have stripes, and some have no markings. With 5,000 species in one family, there’s bound to be a bit of variation.
Though they are often touted as wonderful pest controllers, not all ladybirds eat aphids and other nasty bugs. The prey ladybird beetles consume ranges from mites to caterpillars to eggs of moths and other beetles. They will also eat various other materials, like sap, nectar, and fungi. Other species like to eat plants, and are themselves considered to be pests.
As small little beetles, ladybirds have a number of predators, including birds, wasps, spiders, dragonflies and frogs. Ladybird beetles have two main defences against these terrible creatures. First, their distinct colouration makes some predators avoid them. After all, brightly coloured animals often taste pretty terrible. The second defence occurs when a predator attacks; the ladybird secretes a toxin from its joints that makes eating them seem like less of a good idea. It sounds nasty.
Ladybird beetles put little effort into raising their young, other than strategically laying their eggs. Often the beetles will lay eggs near their prey, so the larvae can find their first meals with ease. Other species lay extra, unfertilized eggs with their clutch, so the little ones have something to eat when they hatch. When resources are scarce, the mother beetle will lay a higher proportion of these unfertilized eggs, and fewer viable eggs.
Overall, ladybird beetles are a pretty decent group of insects. They do like to come into houses before winter, which can be a bit unsettling. This year we had a late start to winter, and there were ladybirds everywhere. My friend and I counted at least ten on one window of the YMCA alone. Still, they’re pretty harmless, so I don’t mind them all that much.
Cover image credit: Gilles San Martin via Wikipedia