Potential new host for emerald ash borer studied and confirmed

On October 14, 2014, the USDA Systematic Entomology Laboratory (SEL) at the Smithsonian confirmed the partial adult and larval specimens recovered from a white fringetree (Chionanthus virginicus) as emerald ash borer (EAB) (Agrilus planipennis Fairmaire). EAB larvae and a partial adult specimen were collected from four white fringetrees up to 20 miles distant from one another in the Dayton, OH area. Also present in the infested material were D-shaped exit holes and fully developed galleries identical to those caused by EAB.

 

Based on these findings, APHIS PPQ is conducting studies to determine the full extent to which EAB is able to complete its lifecycle and utilize white fringetree as a host, which will take several months. APHIS is also revisiting previous research on whether other members of the Olive family can serve as hosts to EAB and whether this is a local phenomenon or occurring across the EAB infested part of white fringetree's range.

 

APHIS will engage national, state, and industry partners as part of the regulatory decision making process should APHIS officially declare white fringetree as an EAB host and the plant and its parts as regulated articles under the EAB regulations and quarantine. Agency experts and leaders will be discussing this issue to determine the implications of this new information to the regulatory and detection aspects of the EAB program.

 

White fringetree is in the olive family, as is the genus Fraxinus (ash). While other members of the olive family, including lilac and privet, were tested for host suitability, those species were not considered suitable hosts for EAB.  Further study and evaluation of white fringetree’s suitability as a host will be undertaken. White fringetree is native to the United States and grows wild from New Jersey south to Florida and west to Oklahoma and Texas. It is a popular ornamental tree that has been planted in other parts of the country.

 

Scott Pfister, Ph.D.

Pest Management Division Director

USDA, APHIS, PPQ, Plant Health Programs