Tropical Cactus Borers

Subject: orange caterpillar
Location: Lakeland, FL
February 10, 2014 12:53 pm
We found several of these crawling around on rocks. They’re very fast movers, but curl up if you touch them. They’re about 1 to 1 1/4″ long. We didn’t see them on any plants, just the rocks. We’re in Central Florida, inland and found them on 2/10/14. I’ve never seen anything like this before and after trudging through the interweb, don’t see any pics that match. As you can see in the 2nd fuzzy pic, they have black heads. He was on the move and hard to catch.
thanks for any help.
Signature: Cindy & Jim

Dear Cindy & Jim,
We are very rushed this morning and our initial attempts at identification did not produce any results.  We are posting your photos as unidentified and we hope to return to this later when we have more time.  Meanwhile, perhaps one of our readers wants to take up the challenge.  We are not certain if these are caterpillars or Sawfly Larvae.

Thanks for your quick reply. We’ve never seen anything like it.

Considering your Florida location, this could easily be a new exotic import from a faraway land.

I was afraid of that. I feel like we should go hunt them down and hold on to them until we know what they are. We have too many exotics here.
thanks

Update:  August 13, 2018
Carpenter Moth Caterpillar
Because of a new query we just received that we are researching, we now believe both this and an additional posting in our archives are Carpenter Moth larvae in the family Cossidae, but we are uncertain of the species since the larvae do not look like any posted to BugGuide., but they do resemble what has tentatively been identified as the Carpenter Moth Caterpillar Macrocassus toluminus from South Africa.

Update:  Tropical Cactus Borers
Ed. Note:  The following is a comment from Cesar Crash.
Those look like Lepidoptera. Found on a cactus garden, may be the cactus moth: https://www.ipmimages.org/browse/detail.cfm?imgnum=5015058 aka Tropical Cactus Borer https://bugguide.net/node/view/78959/bgpage

Thanks so much Cesar.  The mystery is finally solved.  Here is a nice BugGuide image of the caterpillar.  According to BugGuide:  “Imported to the Caribbean to control prickly pear cacti; arrived in the U.S. naturally or in cargo imported from the Caribbean (Johnson and Stiling 1998). Widely dist. in southern FL, spreading east along the Gulf Coast to New Orleans and north along the Atlantic Coast to SC.”  BugGuide also has this interesting statement:  “The moth has become a pest in se US.   This South American moth was introduced into Australia to control cacti, which are not native to that continent and which were becoming a very serious pest. It was so successful that memorials and monuments to it have been erected by grateful citizens there.”