Published January, 2014

Horse owners recognize that fire prevention is critical on the farm, but might overlook threats from insect infestation on surrounding trees. The emerald ash borer (EAB), Agrilus planipennis Fairmarie, is a beetle first discovered in 2002 in Michigan and Windsor, Ontario, and has killed ash trees by the tens of millions in North America. According to the USDA Animal and Plant Health Inspection Service, the beetle has been confirmed in 20 states (see sidebar) as of Aug. 5, 2013. While the threat of wildfires is unfortunately common in the western United States, states with EAB infestation could have an ever increasing threat of larger wildfires.

The EAB has no natural predators and the use of insecticides is expensive and has variable results, depending on the product. As a result, the continued threat of this pest moving across the country is very real. During the EAB life cycle, the adult beetle will feed on the foliage of the as tree and lay eggs on the bark of the tree. The resulting larvae hatch from the eggs and then bore into the bark of the tree where they remain until spring, feeding on the critical inner bark and thus interfering with the tree's ability to utilize nutrients and water. This ultimately leads to the death of the tree. In the spring the adults emerge from the tree and fly a short distance to continue the life cycle.

The dead ash trees resulting from EAB infestation constitute a potential fire hazard, and should be removed from farms to protect horses and property. Check with a cooperative Extension agent on the legal ways to dispose of trees, as transporting them to a secondary location can also spread the pest. Fire risk increases during times of drought and when abundant fuel sources are available, such as the case when dead trees and shrubs are present.

In an effort to mitigate the hazard of wildfire on the farm, owners should establish a defensible space by removing flammable vegetation from around houses, barns, machinery, and horses. The incorporation of fuel breaks, strategic grazing, and landscaping with non-combustible materials and fire resistive plants can help reduce the risk of disaster.

Fire can spread by hot embers dispersing to new fuel sources including buildings, hay, bedding, and manure. Research from the Institute for Business and Home Safety and others has indicated that buildings located less than 15 feet apart are vulnerable to this type of fire spread. Proper planning of new construction including the use of fire resistant materials can reduce this threat.

The likelihood of a wildfire increase dramatically when the fire danger is moderate to hight combined with a large number of dead trees in forested areas. As devastating as the 2013 U.S. summer wildfire have so dramatically shown, wildfires can be started by lightning strikes, humans (deliberately or accidentally), and sparks from vehicles or machinery. Having a plan and implementing fire prevention practices are critical to limiting losses of human and animal life, buildings, and land.

This is an excerpt from Equine Disease Quarterly, funded by underwriters at Lloyd's, London, brokers, and their Kentucky agents.