Ugly Duckling Orangedog Caterpillars

By University of Arkansas

First posted on 09-14-2009

Disguised as bird droppings, the orangedog caterpillar is the classic case of the ugly duckling that eventually turns into a swan.

These caterpillars are native to Arkansas and range from Michigan in the north to western Connecticut in the east, all the way to Florida and Texas. They have a remarkable appetite for cultivated citrus.

Daniel Beasley, Jefferson County extension agent for the University of Arkansas Division of Agriculture, and county extension Staff Chair Don Plunkett spotted orangedogs of various sizes and ages in a homeowner’s lemon tree.

A second homeowner with the same infestation in her citrus told Plunkett that she had taken to using the “smooshing them” method of pest control.

“They look like bird droppings on the lemon tree leaves,” said Don Plunkett, Jefferson County extension staff chair for the U of A Division of Agriculture. “The larger ones actually took on a tree bark look and those could in some cases blend onto the tree trunk.”

Plunkett said it was larvae that “neither of us had ever seen before.” The two shot photos and video of the caterpillars.

Gentle prodding by the agents agitated caterpillar.

“What came next was a shock,” Plunkett said. “The creatures began to stick out what appeared to be a red, forked tongue and this pretty well scared these two county Extension agents into not wanting to handle the larvae!”

The sight was immediately followed by a foul odor.

The two consulted with John Hopkins, extension urban entomologist for the division of agriculture, to solve the mystery of the bizarre-looking creature.

“The caterpillar is the larval form of the Giant Swallowtail butterfly,” Hopkins said. “They’re usually seen from July to October, and produce at least two generations a year in Arkansas.”

The forked tongue Beasley and Plunkett saw was a scent gland, which all swallowtail larvae possess. The caterpillar emits the odor as a defense when disturbed.

“The orangedogs feed on cultivated citrus, hoptree, prickly ash, torchwood, wild lime and other plants in the citrus family,” Hopkins said.

The odd name – orangedog – refers to their habit of showing up in orange and other trees.

Once the second homeowner learned what the orangedog caterpillar would become, she quit the smooshing.


thank you for the information. I have these little critters on my grapefruit tree. now I know why all the butterflies where landing on it. why doesn’t my 2 different neighbors have them on their grapefruit trees?

By marie rogers on October 31, 2014 – 8:10 pm

I know this is an old article but this is my fistt citrus tree.  I think these things are hideous.  They were eating all my leaves!  I understand the butterfly is beautiful but not the larva state.  Besides stepping on them, how do I get rid of them?

By Bobbie Brady on December 23, 2013 – 12:01 pm

Well, in Sept my orngedogs turned to cacoon stage. after about two weeks they hatch out right before my eyes! I was so excited…how beautiful they were…. I hatched them in a screened container and turned them loose afteward. I see them flying all around now. I live in southeren California.

By Emily on October 05, 2012 – 9:57 am

Just pulled five of them off of my lemon tree here in TEXAS.  Hideous!

By Robyn on October 05, 2012 – 9:32 am

Why didn’t this article show a picture of the butterfly it becomes?

By Chris Belker on September 19, 2012 – 8:37 am

I found and killed one of these caterpillers.  My poor tree was losing leaves like crazy.  Why is it in Arizona?

By Jackie on September 19, 2012 – 2:41 am

I have found several orangedog caterpillers on the ornge tree.. I am thrilled. they are turning into the cacoon stage. Can I move them to a safe place to hatch by dislodging their cacoon and moveing it to a encloser or screened porch? Will they be able to reatach themselves or will they be ok ? does their head need to point downward? would love to have them hatch…or at least one to observe in captivity…..I have found no imformation on relocating them…only on how to overwinter them….

By emily on August 26, 2012 – 9:37 am

I just smashed 5 ugly creatures that looked like a prehistoric animal that did stick out a red forked tongue and emitted a foul odor.  I thought it was my dog.  I then came in the house, got on the computer and found your article.  Thanks.  I did put some “Sevin 7” on my lemon and lime trees because the leaves were being eaten.  Now that I know they will turn into butterflies, I will not do it again.

By Celia on April 10, 2012 – 6:35 pm


By Mary Cohoon on October 07, 2011 – 9:43 am

I captured this catipiller when it was a small larve, feeding it only one leaf a day it grew very fast and is now huge, will this creature cacoon and turn into a butterfly in captivity? whitch end is the head?

By Barbara Howe on July 31, 2010 – 12:18 pm

What does the finished product look like?

By Chris on October 06, 2009 – 3:22 pm