Caterpillar ID

[Lindsaylew82]

This one is parasitized. My ecology class professor found him out in the woods in Upstate, SC yesterday during our lab. . That yellow bead is on his bum end. I've looked and looked, but can't seem to find anything but hornworms...and I know too well what they look like. Best pic I could get...

[told2b]

Blue horn worms.jpg (19.83 KiB) Viewed 4998 times

It looks like a blue horn worm.

[applestar]

Do you remember this thread? In it I showed photos of parasitized hornworm with grey spots where the wasp larvae are under the skin, coming out. So it's possible those scattered spots are signs of emerging wasp larvae.
Subject: Thought you could eat my tomatoes and get away with it, eh?

But I agree with you, Lindsay, that hornworms have their distinct diagonal marking even when in the younger instars. I think I have seen the caterpillar in your photo before... maybe in Bringing Nature Home by D. Tolmy. Do you have that book? I can look later.

[Lindsaylew82]

I don't have that book... but I'll add it to my "to buy" list.

Definitely not tomato or tobacco hornworm, but it may be closely related. There were no diagonal markings associated with hornworms. I've searched every caterpillar guide I could find.

[Lindsaylew82]

I've been looking around.

Promethia is the closest think I can find. I don't remember there being red horns on its head though... Seems like if remember that.

[applestar]

Hm. The ones I was thinking of in that book were promethia that you mentioned and Dryocampa rubicunda caterpillar. Not quite right I think?

[rainbowgardener]

I did some looking around too. The promethia was the closest one I found, but I wasn't convinced enough to bother suggesting it.

But check this out. https://www.prairiehaven.com/?page_id=8499 They do look quite different in different instars.

[Lindsaylew82]

https://bugguide.net/node/view/60479

Found it!

[rainbowgardener]

Good work!

It's a really interesting one, the different instars are SO different: https://www.silkmoths.bizland.com/Sphinx/sabbotti.htm

It is a relative of hornworm, then, because the hornworms are also sphinx moth caterpillars (just different ones)

[ElizabethB]

It is a shame that these creatures do so much damage to our gardens. They really are amazing to watch.

After my recent battle with horn worms on my heirloom tomatoes I had to resort to dusting with Bt. Unfortunately it will kill the black swallow tail caterpillars on my dill.

This afternoon I planted 6 dill plants in pots away from my SFG boxes. 4 are for me. The other 2 are for the black swallow tails.

I don't mind sharing except for my tomatoes.

[applestar]

https://bugguide.net/node/view/60479

Found it!

Oh cool! It's a grapeleaf eater. Maybe I might come across it here some day.... now I will have to go check the Butterflies and Moths site and see if any sighting has been reported for my area.....

...just checked the link rainbow posted -- really really interesting about the different instar forms, and I WAS wondering about whether they also fed on Virginia creeper... plus the 40 yr old sighting in NJ. Heh. All my questions answered.

[Lindsaylew82]

I saw that they DO feed on Virginia creeper. It's the primary source in my area. Our native grape in muscadine, but we have a lot of virginia creeper!