Unicorn caterpillar

May 20, 2006 10:56 PM

A wee horned caterpillar turned up in my backyard yesterday. Can you identify it?

It's about 12cm long. When I nudged it with a broom it swung around and tried to horn the bristles. This is Sydney, Australia.

posted by tellurian to science & nature (12 comments total)

I have absolutely no clue, but the good people at What's That Bug might know.
posted by bshort at 11:01 PM on May 20, 2006

That's a tomato hornworm.

Common, pesky things. I pick them off my tomato plants in the summer and squash them.
posted by Ostara at 11:04 PM on May 20, 2006

I was just at What's That Bug and my best guess from similar caterpillars there is that it is a caterpillar of a sphinx moth. I don't know what sphinx moth, but googling "sphinx caterpillar" came up with this guy who looks pretty similar. I'll keep looking to see if I can narrow it down...
posted by lemuria at 11:05 PM on May 20, 2006

I second the tomato worm. I used to see those on my parents tomatos all the time. Cut of the horn with scissors and it dies.
posted by zgott300 at 11:48 PM on May 20, 2006

Yepper - it looks like Manduca sexta, tobacco hornworm. Could also be a tomato hornworm, although the common/latin names can be a bit confused. Also, I'm not sure which species are found in Australia.

Anyway, I used to do neurobiology on the cute little things. I'm not sure they'll die if you just cut off their tails (as they'll sometimes bite off their own tails in lab - stupid little things) but I suppose if you cut low enough they'd bleed to death. Might as well cut them in half if you're going to go to the trouble.

The tail is otherwise quite harmless - it's there to make it look like a thorn, presumably, but it's soft and bendy.

Keep him! They are absolutely incapable of biting humans, and will turn into a barely pretty moth if allowed to pupate. Since this guy looks pretty old, he might be about ready. You can put him in a little tin with some dirt and some leaves to eat, and when he's ready he'll burrow under the dirt to make a cucoon type thing. (It looks a little like something from Alien, with a big"handle" that's actually its developing tongue. Then, after a week or so, he'll come out as a moth, and climb up the nearest surface to inflate his wings, and ultimately fly away. It's quite neat to watch.

Also, they have hexagonal poop!
posted by metaculpa at 12:24 AM on May 21, 2006 [1 favorite]

Here's a whole site called The Manduca Project that will tell you more than you ever wanted to know about your little friend.

Now I've revealed my inner dork and will go to bed.
posted by metaculpa at 12:30 AM on May 21, 2006

Oh, also - the horned end is the tail end, if that wasn't clear.

Goingtobednow.
posted by metaculpa at 12:32 AM on May 21, 2006

The tobacco hornworm is closely related to, and often confused with the tomato hornworm. The adults are hawk moths aka sphinx moths. So lemuria is also correct.
posted by weapons-grade pandemonium at 12:37 AM on May 21, 2006

Hawk moths are strong, powerful fliers frequently mistaken for hummingbirds. They play an important role in pollination: in Australia, they're vital to papaya crops. If you ever have the opportuntity to (gently) catch and examine an adult hawk moth, they're quite beautiful.

Although what you have there looks very similar to a Tobacco Hornworm—at home in Colorado, BTW—I think your Australian variety is the larva of the Grapevine Hawk Moth, aka Hippotion celerio.

And the official lingo for caterpillar poop is frass, itself a valuable commodity.
posted by cenoxo at 10:14 AM on May 21, 2006

...make that Tomato Hornworm in Colorado.
posted by cenoxo at 10:17 AM on May 21, 2006

It's probably a tomacco hornworm, then.
posted by speedo at 10:19 AM on May 21, 2006

Wow! there are a lot of hornworms. It's hard to tell which one it is but it seems pretty certain it's going to turn into a Sphinx Moth of some sort. Thanks, all.
posted by tellurian at 6:09 PM on May 22, 2006