Gallery of Pests

 

Gallery of Pests:
Pests & pathogens not too widely spread:

Soapberry borer - Agrilus prionurus Chevrolat

 

• The soapberry borer was introduced from Mexico, probably during the 1990s.  The pathway by which it was introduced is unknown.

• It kills the Western Soapberry tree.

The soapberry borer (Agrilus prionurus) is native to Mexico.  It was first detected in Texas in 2003, but it was probably present for several years before detection.  Some reports of beetle damage are as early as 1998 (Billings and Pase 2009; Anonymous 2007).

By 2009, it was known to be in 33 counties - but it is probably more widespread (Billings and Pase 2009).

The only known host to the beetle is the Western Soapberry (Sapindus saponaria L. var. drummondii (Hook. & Arn.) L.D. Benson).  Soapberry is a medium-sized, drought-hardy native tree that occurs in scattered patterns along creeks, and is occasionally used in native landscapes. (Merchant 2006; Billings and Pase 2009).  Soapberry’s range extends from northern Mexico to Missouri, and west to Arizona (Billings and Pase 2009)

So far, the beetle’s attack kills all sizes of soapberry trees larger than 2 inches in diameter (Billings and Pase 2009).

In order to understand the threat from the soapberry borer, the Texas Forest Service (TFS) has undertaken several initiatives.  To determine where the beetle is established, the Texas Forest Service in 2009 sought input through a volunteer survey questionnaire sent to county extension agents and administrators of state parks and wildlife management areas of the Texas Parks and Wildlife Department and posted on websites managed by the Texas invasive species council, Texas Forest Service, and International Society of Arborists Texas Chapter.  This was supplemented by a full-page advertisement in the September 2009 issue of Texas Parks & Wildlife magazine (Billings and Pase 2009).  Responses to this survey increased the number of counties with known infestations from 18 to 33 (Billings and Pase 2009).

The Texas Forest Service is also testing detection methods.  Initial testing of the purple panel traps used by the emerald ash borer program proved them not to be very effective (Billings and Pase 2009).

The Texas Forest Service has also begun studies on control methods.  They are testing the efficacy of systemic pesticides (emamectin benzoate) injected into trees before infestation (Billings and Pase 2009).  They are also doing emergence studies to determine the number of generations the beetle has per year - so far, the answer appears to be one (Billings and Pase 2009).

 

Sources

Anonymous. 2007. Past Chapter President, Jerry Pulley Credited with New US Record. In the Shade (Newsletter of ISA Texas Chapter, Vol. 30, No. 5 (March 2007)

Billings, R. F. and H. A. Pase III, Texas Forest Service. No Date. Soapberry Borer, Agrilus prionurus (Coleoptera: Buprestidae) An Exotic Pest Recently Detected in Texas

Billings, R. F. and H. A. (Joe) Pase III, Texas Forest Service. 2009. Soapberry Borer Infestations Found in 33 Counties in Texas

Michael Merchant. 2006. TX A&M University fact sheet. Texas A&M University Research and Extension Center, Dallas;