Emerald Ash Borer


Adults. The Emerald Ash Borer (Agrilus planipennis), is a beetle (Coleoptera) in the family Buprestidae. Adult EAB appear metallic, with emerald green hardened front wings (elytra). Adults are 7.5-13.5 millimeters (0.3-0.5 in) long. After having completed their development under the bark of an ash tree, in the spring new adults chew holes through the bark, producing a characteristic D-shaped exit hole. Newly emerged adults feed for about one week on ash leaves before mating, but cause little defoliation in the process. A typical female can live around six weeks and lay approximately 60–90 eggs, but some females live long enough to lay up to 200 eggs.

Eggs. Eggs are deposited between bark crevices, flakes, or cracks and hatch about two weeks later. Eggs are approximately 1.0 millimeters (0.04 in) long and 0.6 to 1.0 millimeter (0.02 to 0.04 in) in diameter, are initially white, but later turn reddish-brown and hatch in 7-10 days.

Larvae. EAB larvae are white and slightly flattened, with a pair of brown pincher-like appendages on the last abdominal segment. Larvae feed on an ash tree’s vascular cambium (a thin layer under a tree’s bark that produces new wood and conductive tissues). This feeding produces long serpentine galeries that interrupt transport of water and nutrients and kill the tree. Over the course of one or two years, EAB larvae develop through four growth stages (instars), shedding their skin (molting) between each instar. Fully mature fourth-instar larvae are 26 to 32 millimeter (1.0 to 1.3 in) long. In fall, mature fourth-instar larvae excavate chambers about 1.25 centimeters (0.49 in) into the sapwood or outer bark where they fold into a J-shape. Inside the chambers, the J-shaped larvae shorten into prepupae before converting into 10-14 millimeter (0.4-0.6 in) long pupae and then emerging as adults the following spring.

Impact. All species of ash (Fraxinus spp.), including those native to Texas, are vulnerable. EAB infestations in other states have devastated their ash trees. In many Texas cities, ash is an important ornamental tree in landscapes and along streets.

Spread of the pest. EAB populations can spread 20 km (12 mi) a year naturally. However, it is artificially spread much longer distances by transport of firewood and other infested wood products that contain ash bark, which allows EAB to reach new areas and create satellite populations. Prevention of the movement of infested firewood is a critical tool in impeding the spread of this highly destructive pest. Campers are strongly advised not to transport firewood, but to buy it locally, where they plan to use it.



With the goal of containing and managing the infestation, the department has filed emergency quarantine regulations in the Texas Register, to cover areas quarantined on this webpage.

Under provisions in the Texas Administrative Code, Title 4, Chapter 19, Emergency Rule §19.701 (having to do with quarantined areas), the department has designated this page for declarations and descriptions concerning areas in Texas that are quarantined for emerald ash borer. Names and descriptions of quarantined areas are effective and enforceable upon being published online in the “Current Quarantined Areas” section of this page.



       CLICK HERE to view TDA's Emerald Ash Borer Emergency Quarantine regulations, as published in the Texas Register.



    Per Emergency Rule §19.701, the following areas in Texas are subject to the quarantine:


    Harrison County  Emerald Ash Borer Quarantined Area.

      CLICK HERE to view Map of Harrison County Emerald Ash Borer Quarantined Area.

       Legal Description of the Harrison County  Emerald Ash Borer Quarantined Area: All of Harrison County, Texas, is quarantined.



    07/11/2016. The Harrison County  Emerald Ash Borer Quarantined Area (see above), consisting of all of Harrison County, Texas, is hereby added to the quarantined areas in Emergency Rule §19.701.

    06/30/2016. The department filed an Emerald Ash Borer Emergency Quarantine (Title 4, Chapter 19, Subchapter Z, §§19.700-19.708) with the Texas Register; the quarantine became effective upon filing. The emergency quarantine can be found in the Texas Register issue for July 15, 2016 (page: 41-TexReg-5127).