Creatonotos and the Inflatable Hairy Bits

Image: Juan Manuel Sánchez

Hmmm... I'm not completely sure, but I have a feeling this may be disgusting.

It's a large, southeast Asian moth wowing the ladies with the intoxicating scent of his inflatable, hairy bits.

Yup. Disgusting.

Image: Logan Lai
Creatonotos gangis

Creatonotos is a genus containing about 10 species of moth found in parts of Africa, southeast Asia and Australia. Two species are particularly widespread and well known: C. transiens with their pale, orange abdomen and wings entirely white save for a few carefully-placed, black dots, and the more dramatic C. gangis. Their abdomens are red and they have lovely black stripes on their wings, as if someone was testing a brush before practising some Chinese calligraphy.

They also have a wingspan of some 4 cm (1.6 in), so they're big enough for us to appreciate their spooky beauty. I sure hope they don't do anything to ruin it!

Video: terrabithian2
Pretty sure that's Creatos transiens. Ruining it.

Ah... never mind.

From his nether regions, the male inflates two pairs of hairy, pneumatic organs known as coremata. Each one can be about as long as the rest of his body and they're covered in some 3,000 hairs each.

It's all rather nightmarish. It actually looks like a high-speed eruption of that devilish, zombifying fungus known as Cordyceps. But it's not like that at all. In fact, this marks the start of a really great night/sexy times.

Image: 義欽 黃
Creatos transiens

The coremata release pheromones that attract both males and females. Basically it's a big Facebook invite saying "party at my house". For a while, females have their pick of males to mate with. After a couple hours the males deflate themselves and any females who haven't mated yet continue to release pheromones of their own until they're attended to by a handsome fella.

Females simply release their scent from their abdomen, none of these inflatable body parts for them. Also, not all males have equally enormous or equally hairy coremata. It all depends on how much POISON they ate when they were young.

Image: goldentakin

A lot of plants defend themselves from attack by producing various unappetising chemicals which course through their leafy veins. Some creatures are able to not only feed on such plants, but even take over the plant's failed defences and use them to fend off their own attackers. Among the most famous of these is the monarch butterfly, who feeds on milkweed as a caterpillar and sequesters the milkweed's poison
for their own use.

Creanotos is similar. Their caterpillars aren't nearly as picky eaters as Monarchs are, but what they really want is lots of plants rich in toxins known as pyrrolizidine alkaloids. This stuff will make caterpillars and adults a lot less appetising to predators, but males also need enough of it to develop their coremata. If they don't get enough, the rest of the moth develops perfectly fine but their coremata will be rather small, not very hairy, and won't produce as much scent.

Image: Shipher (士緯) Wu (吳)
Creatonotos transiens caterpillar

Even big, hairy caterpillars need to eat their greens to grow up big and hairy! In all the right places.

.....

My thanks to Dimitri for suggesting this one!