Ever since the dreaded emerald ash borer (EAB) showed up in Arkansas and Louisiana, tree lovers have braced themselves for its inevitable arrival in Texas. Then, in May 2016, the insect was discovered in a single surveillance trap near Caddo Lake in Harrison County in east Texas. In 2017 all was quiet, with no officially reported sightings; but this summer the beetle has been found in possibly three new counties.
The EAB is a small but powerful beetle pest–an enemy of ash trees. Adult beetles feed on ash leaves and deposit eggs on the bark of their ash hosts. The eggs hatch and the tiny larvae penetrate the bark to feed on water conducting tissues inside the tree. Within 2-3 years the tree loses the ability to conduct sap, and succumbs to the infestation. Within 10 years of initial invasion all untreated ash trees in an invaded area are expected to die.
When it comes to ecological destruction, the EAB is practically without peer among exotic insect pests. In areas where established, it wipes out virtually all species of ash trees in the genus Fraxinus. In 2017 scientists at the International Union for the Conservation of Nature declared five major species of ash trees in the U.S. on the brink of extinction due to the borer.
According to Texas A&M Forest Service entomologist Allen Smith, EAB showed up in two new Texas counties this year. As of last week, Marion and Cass counties near the northeastern corner of Texas have detected EAB in traps placed out to monitor for the beetle. In addition, 6-7 additional traps in Harrison county (the initial site of entry into Texas) have detected the beetle.
The beetle spreads naturally from tree to tree, but large jumps in distribution are thought to occur only with the help of man. Foresters caution the public to never move hardwood firewood out of an EAB-infested county to avoid helping the beetle spread. Firewood cut from infested trees is likely to harbor live beetles that later emerge and infest nearby ash trees.
Also, reports of suspected EAB may be submitted through the Sentinel Pest reporting function of the Texas Invasives website.
Experts from USDA there are ready to evaluate samples, but keep in mind some simple guidelines for sending in pictures.
For more information about how to recognize EAB damage, check out this guide.
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