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Ladybugs are red with black spots, right? Well, not always. There's a lot of genetic and evolutionary reasons that they can be different colors with wacky patterns.

Hosted by: Savannah Geary (they/them)
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Savannah: When I say the word "ladybug," you probably think of a small, round beetle with red wings and black spots. But the truth is ladybugs don't have to look like that. When they're young, they can be caterpillar-like creatures with long, pointy tails and lots of hairy spikes across their body - not at all what you might think of as ladybug-looking, but very punk rock of them.

And as they age, they can end up being almost every shade on the color wheel, not just red and black. The 22-spot yellow ladybird still has those typical black spots but set to a bright yellow background instead of a red one. Even within the same species, ladybugs like Harmonia axyridis can come in a variety of colors. And don't even get me started on the Steelblue ladybug or the 10-spot ladybird with crescent-shaped spots. So, buckle up, because your idea of a ladybug is about to get a whole lot wackier.


Now, plenty of ladybugs do have that traditional look that you might associate with them. For example, the seven-spot ladybird is a ladybug with lots of red and accents of black. And red is a great color, but it's no wear-it-everyday color. Unless, say, you're poisonous. Some ladybirds are flaunting their red to say, "Hey, if you eat me, we'll both lose," and this isn't just an empty threat. Asian ladybirds really do produce a chemical called "harmonine," which is essentially an alkaloid poison.

A 2007 study found that proportionally redder ladybirds pack a larger amount of the poison. So from an ecological perspective, it makes sense that plenty of the ladybugs you see are red; they're the ones that have managed to scare away their predators and attract mates. But this is where the story gets a little more complicated, because just like red hair in humans, that red color in ladybugs? It's recessive.

Experiments from the early 20the century investigated warmer hues versus black dominance in Asian ladybird species. They started where many scientists do, mating some bugs because they wanted to see what would happen when a ladybug with black on a part of the wing was mated with a ladybug with color on that same part of the wing. You know, let the two colors duke it out to see which was dominant. And they had a clear winner; anywhere either parent had black, the offspring would also have black - clear evidence that the black coloration was the dominant trait. Essentially, even though we see red ladybugs pretty frequently, they need several recessive alleles to have so much colorful real estate.

But even when most of a ladybug is red, they can still have black spots; the color depends on how many of the ladybug's genes are recessive. To study that fine balance, another team of scientists grouped the same kind of ladybugs into those that were black with red spots and those that were red with black spots. Then they compared these ladybugs' entire genomes, looking for any differences they could find. The most likely suspect turned out to be a transcription factor called "Pannier." That's a protein that controls when specific parts of DNA are used.

So, they put Pannier to the test with special genetically modified ladybugs that couldn't make it. The result was majorly naked ladybugs, all reddish-orange with no black spots. This means that ladybugs can't make spots without this transcription factor. So the spot inheritance that those 20th century researchers saw in their cross-breeding experiments seems to have been parents passing their spots down through Pannier expression, which means pannier is behind the ladybug you know and love. But we can also thank it for some pretty wacky looking offspring.

See, ladybugs reproduce like us, with two parents coming together to make offspring. But in ladybugs, the offspring take all of the black color patterns from both parents. It's as if you had freckles everywhere both of your parents have them, and that means that a red ladybug with black spots can reproduce with a black ladybug with red spots, but the sections of the red spots donated by one parent can get covered up by the black patterning on the other. So that black coloring in an offspring wherever the parent has it can lead to overlapping and lopsided spots, to the horror of any perfectionists out there. But there's nothing wrong with those wonky-spotted ladybugs. If you see them out and about, now you know that their transcription factors are working just as plann-iered.

And what about those beetles that are mainly black with only a few red spots? For them, we must consider an age-old question: "Are zebras white with black stripes or black with white stripes?" Before you Google it, zebras are black with white stripes. And the answer for ladybugs lies in their DNA.

When the Pannier scientists were doing their whole genome sequencing, they couldn't ignore the fact that a small section of DNA looked different when comparing the mostly-red to the mostly-black ladybugs. It turned out that it was backwards. This means that, unlike zebras, ladybugs can be red with black spots or black with red spots depending on whether this small section of DNA is forwards or backwards, which gives a whole new meaning to Missy Elliot's idea of flipping and reversing it.

But you'd think that black ladybugs with red spots would be more common if more melanated ladybugs have the dominant traits. I mean, evolutionarily, they're on a relatively even playing field. While the red pigment is busy scaring off predators, the black pigment is equally busy with a different job - thermal regulation. See, ladybugs with more melanin can retain heat better, so bugs with more black on their wings suck up as much heat as they can in the cold.

In a 1997 study, scientists raised ladybugs from larvae in different temperatures to see if this would affect their spots. And sure enough, for most populations, the colder the temperature, the larger their spots. These spots can be helpful in the cooler spring months when they are trying to find someone to pass on their spots with, if you know what I'm saying.

But in warmer temperatures, this becomes a disadvantage because it still keeps heat in, and that's a problem because, well... climate crisis. Some studies have already found evidence for this with fewer dark ladybugs observed in certain parts of the world as temperatures steadily increase, but those results vary depending on where you live. So primarily red and primarily black ladybugs are each suited for their own environments. And even if a mainly-black ladybug finds themself in warmer weather, they're not totally doomed, because researchers think melanin provides advantages to insects like being better equipped to fight off pathogens thanks to melanin-based immune responses.

Really, red ladybugs and black ladybugs each have their advantages whether ecological, genetic, or physiological, even if it makes them a little more difficult to identify as a ladybug in passing. Ultimately, genetics and the environment can have a huge effect on what they look like, and that image you had a red beetle with some perfect, circular black spots isn't has comprehensive as you might've thought five minutes ago. So, the next time you go for a walk, consider whether that black beetle or creepy, spiky, caterpillar-like thing you come across might actually be a ladybug in disguise.

And if you have a young person joining you on that walk, you can get them involved in these discoveries about the world we live in. You can even conduct an experiment with them that we explained over on the SciShow Kids channel. It's designed to help people understand some of the effects that color can have on the bug's survival. And we have plenty more videos for kids where that came from, so you can keep learning with SciShow and the young people in your life every week.