Photo By Malcom Manners / CC BY 2.0

A Bug Very Appropriately Named


The thorn bug gets its name from the fact that it looks exactly like a thorn from a bush. Found in the United States only in southern Florida, the thorn bug is mostly found on fruit trees. The thorn bug flies onto these trees, and can cause a lot of damage to the limbs and life supporting structures of the tree. The damage to these trees is caused by the thorn bug making cuts in the plant in order to lay its eggs inside the tree.  When the bugs cut these holes in the tree limbs it can cause the tree to lose much of its foliage, and in some cases even cause the tree to die. On top of just creating holes in the branches to lay their eggs, they also use these small crevices to eat. They feast on the sap from any tree they can get their hands on, thus giving them more reason to cut into more trees, and unfortunately cause more damage to crops. Most of the bugs we have discussed are not treated with pest control, but this bug is an exception. Because it causes so much damage to fruit trees in South Florida, farmers are forced to use insecticides to keep these bugs away. Another interesting fact about the thorn bug is that it secrets honeydew from its body! Because it secrets honeydew as it sits and lays its eggs, many times mold will form around the areas where they lay their eggs. On occasion, thorn bugs have been known to try to lay eggs on cars, causing large amounts of honeydew to appear on the tops of peoples cars. 

The thorn bug is part of the same family as the treehopper, which is a bug we have written about before that can be checked out here. The part of their body that looks like a thorn has no purpose but to serve as camouflage. It is actually completely hollow! When the thorn bug crouches down on a branch, it can be almost impossible to distinguish it from an actual thorn. Although it looks hard and sharp, it is actually very soft, and cannot be used as a defense from predators. It only serves as camouflage. When thorn bugs are born they are not very colorful. They are mostly brown or grey, with a few small hints of color. As they grow older however, they begin to turn very lime green and yellow. Many times in the wild these bright colors signify to other animals that they are dangerous to eat.


Source: “Thorn Bug - Umbonia Crassicornis.” Africanized Honey Bee - Apis Mellifera Scutellata Lepeletier,