What is Emerald Ash Borer (EAB)?

Since its accidental introduction from Asia, emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), has killed millions of ash trees in North America. As it continues to spread, it could functionally extirpate ash with devastating economic and ecological impacts. Little was known about EAB when it was first discovered in North America in 2002, but substantial advances in understanding of EAB biology, ecology, and management have occurred since. Ash species indigenous to China are generally resistant to EAB and may eventually provide resistance genes for introgression into North American species.

EAB is characterized by stratified dispersal resulting from natural and human-assisted spread, and substantial effort has been devoted to the development of survey methods. Early eradication efforts were abandoned largely because of the difficulty of detecting and delineating infestations. Our efforts here at Muscle Tree & Landscaping have always focused on biological control, insecticide protection of high-value trees, and integrated efforts to slow ash mortality in and around the Boulder, CO area.

Emerald Ash Borer (EAB) was found in Boulder, CO, in September 2013.

As a non-native insect, EAB lacks predators to keep it in check. EAB only attacks ash trees in the genus Fraxinus (so mountain ash are not susceptible).

Approximately 15% of the trees that make up Colorado's urban forest are ash. There are an estimated 98,000 in the city of Boulder alone. The Denver Metro area has an estimated 1.45 million ash trees. EAB is responsible for the death of millions of ash trees in the United States.

Help protect Colorado's ash trees! Don't move firewood, and consider chemical treatments to protect high-value ash trees within or near the EAB Quarantine area.

Dutch elm disease is caused by the fungus Ophiostroma ulmi and is spread from tree to tree primarily by insects. In the United States, the smaller European bark beetle (Scolytus multistriatus) and the native elm bark beetle (Hylurgopinus rufipes) are the most common vectors.

Common symptoms of Dutch Elm Disease are wilting or discolored leaves, first turning yellow, then brown. Infected branches typically develop dark streaks. If left untreated, the affect trees can die within a few months to a year.

Eradicating Dutch elm disease from newly infected trees.

If a new crown infection of DED is detected early enough, there is opportunity to save a tree through pruning, fungicide injection, or both. Eradicative treatment is not possible on trees that have become infected via root graft transmission.

Tree affected by EAB
Photo credit: www.bouldercounty.org

Tree affected by Dutch Elm Disease
Photo credit: www.apsnet.org