Longhorn Beetle

Summary: There is an insect called the longhorn beetle, but it has nothing to do with cattle or steak restaurants. Check out this article to find out if longhorn beetles pose a threat to the trees in your backyard.

The longhorn beetle, also known as the sawyer beetle and goat beetle, includes several different species. They include the Asian longhorn beetle, the cactus longhorn beetle, and the citrus long-horn beetle. All species of these beetles are classified as longhorns because of their unusually long antennae.

The Asian longhorn beetle made its debut in the United States in 1996 in New York City. It is thought that it was brought to America in ships carrying cargo composed of wooden pallets and crates. The longhorn later appeared in Chicago. These two cities suffered so many infestations that they had to spend nearly $369 million to eliminate the pest and keep it from killing more trees.

The longhorn is black with white specks and is very long for an insect, measuring up to an inch and a half in length. Its namesake antennae can be as long as four inches. This is not a bug you want to find crawling around in your bed.

Asian longhorn

Unfortunately, the Asian longhorn beetle can cause a lot of damage to trees. Its larvae dig deep into trunks in order to feed on the vessels that provide the tree with water and food. The larvae may spend up to nine months living off of the tree as they grow into adult beetles. As the bugs mature they start to burrow back out of the tree leaving noticeable holes in the trees. At this stage, there is not a lot that can be done for the tree. The damage is done.

Its favorite trees include the American Elm, Boxelder, Ohio Buckeye and the Red, Silver and Sugar Maples. Its least favorite trees include the White ash, Green ash, Sycamore, Rose of Sharon and the Hackberry. Good replacement trees include the Crabapple, Cherry, Hawthorn, Black Locust, any Oaks, Pear, Black Walnut, Magnolia and quite a few others.

Because Asian longhorn beetles spend so much time inside trees, they are nearly impossible to kill with insecticides. Spraying pesticides on infected trees is essentially useless. The best course of action to take with an infected tree is to destroy it. Experts note that beetle infestations may spread if people move parts of infected trees. Infested branches should be burned in order to prevent more infestations. Research is ongoing centering upon the introduction of parasitic wasps and nematodes and there has been recent success with tree injections using the insecticide, Imidacloprid.

The Cactus longhorn beetle thrives in the deserts of North America. This bug is noted for its black body and inability to fly. Although it has wings, the wings are hardened together and are not useful to the bug.

Oddly enough, Cactus longhorn beetles feed on cacti, just as Asian longhorn beetles feed on Asians. Only kidding! Asian longhorns feed on trees and Cactus longhorn beetles feed on wannabe trees. Cactus longhorns take what they can get. The adult beetles eat the stems. Larvae eat both the roots and the stems. They tend to favor prickly pear cacti, but they will eat any type of cactus they can find. Adult beetles feed and mate on the top of cacti right around sunset.
The cactus longhorn beetle gnaws through cacti, laying its eggs inside the plant. The eggs mature into larvae and feed off of the cacti. They eventually leave the plants as full-grown beetles.

Again, there are not too many cures to eliminating Cactus long-horn beetles. If you have infected cacti, it is best to get rid of them. Be sure not to spread the infestation, though, or your neighbors may have some words for you.

Insect exit holes

The Citrus longhorn beetle is a native of China. The first recorded sighting of the bug in the United States occurred in Washington in 2001. However, the Citrus longhorn was immediately eliminated and is most likely gone from North America. However, some Americans worry that the bug may reappear due to the large number of Chinese imports.

The Citrus longhorn beetle tends to feed on healthy trees, not dead trees. This can cause mass destruction. Just like the Asian longhorn beetle, this Citrus will bore into trees, lay its eggs and allow its offspring to feed on trees in order to grow. Citrus trees are the primary targets for these pests.

This species of beetle is intimidating for a number of reasons. First, the bug can attack trees in forests and well-populated areas. The beetle will go to town on most any tree it can find. Secondly, the Citrus longhorn beetle does not have many known predators. Lastly, these beetles can lay up to 200 eggs at a time. The fact that they reproduce exponentially means they would be extremely hard to eradicate in the United States if left uncontrolled.

All in all, the many different species of longhorn beetles have many unique traits, but they are all ultimately destructive tree pests.