U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 close



Research
                Research Home
                            National Programs
                            Research Projects
                            Scientific Manuscripts
                            International Engagement
                            Scientific Software/Models
                            Databases and Datasets
                            Office of Scientific Quality Review
            Media
                News & Features
                            Multimedia
                            Briefing Room
                            Down on the Farm
                            Press Room
                            Science in Your Shopping Cart
                            Scientific Discoveries
                            Tellus
                            Under the Microscope
            About ARS
                About ARS Home
                            Staff Directory
                            Labs and Research Centers (Map)
                            Headquarter Offices
                            Organizational Chart
                            Employee Services (REE Employees Only)
                            Office of Outreach, Diversity, and Equal Opportunity
            Work With Us
                Work With Us Home
                            ARS Vacancies at USAJOBS
                            Careers at ARS Information
                            Scientific Collaborations
                            Extramural Agreements
                            1890 Faculty Research Sabbatical ProgramSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home News & Events News Articles Research News 2020





- ARS@Work
- Blog
- Down on the Farm
- Image Gallery
- News Archive
- Podcasts
- Press Room
- Science in Your Shopping Cart
- Scientific Discoveries
- Tellus
- Under the Microscope
- YouTube Channel

Xylosandrus germanus
 Scientists Bolt Down the Defenses Against Ambrosia Beetles By Jan Suszkiw January 13, 2020 Exotic ambrosia beetles are costly pests of ornamental and fruit trees nationwide—from front-yard plantings of Japanese maple and oak to commercially grown orchards of cherry, peach, plum and even avocado. Now, however, Agricultural Research Service (ARS) scientists may have found a way to turn the tables on the beetles. Unchecked, the two- to three-millimeter long pests tunnel into the sapwood of host trees and expose them to symbiotic fungi that obstruct the flow of nutrients. The researchers' tactic exploits a key weakness of ambrosia beetles—namely, their attraction to ethanol emitted by stressed, injured or dying trees and a reliance on the alcohol to "farm" gardens of the fungi as food without interference from other competing microbes. Trees severely infested by the beetle-fungus duo cannot be saved, so careful monitoring and preemptive measures must be taken beforehand. These include deploying ethanol-baited traps to monitor the beetles' flight and timing insecticide treatments to deter them from boring into the trees on which they land. However, the traps also tend to capture non-target beetle species, obscuring accurate counts and monitoring. Michael Reding and Christopher Ranger, entomologists with the ARS Application Technology Research Unit in Wooster, Ohio, tried a different approach. Instead of the standard bottle traps, they used ethanol-infused bolts cut from the stems of young host trees—red maple, American elm, sassafras and dogwood among them. In nursery trials, the researchers hung both the traps and bolts (with and without ethanol) about 1.6 feet off the ground using steel rods and compared the number and types of ambrosia and other beetle species that visited them. Among results reported in the November 2019 issue of the *Journal of Economic Entomology*: The bolts worked as well as the traps but with the added benefit of attracting fewer non-target beetle species.
*Xylosandrus germanus*, an exotic species known as the black stem borer, generally preferred the bolts over the traps and was the most common ambrosia species captured.
TBolts cut from red maple tended to be most attractive to the pests—especially *X. crassiusculus*, another exotic species known as the granulate ambrosia beetle.
Bolts began to lose their attractiveness after seven days. By 14 days, few if any beetles could be found in them.
Drilling a hole down the middle of the bolts and filling them with ethanol—a variation to infusing them—also worked. The researchers will further investigate this "drill and fill" variation as a way to extend the bolts' use for monitoring purposes as well as to facilitate screening of different insecticide treatments. Such screening currently involves injecting trees with ethanol to lure the beetles so that the insecticides' effectiveness against them can be evaluated. However, using the bolts may help reduce some of the time, labor and expense that's involved, according to the researchers. *The Agricultural Research Service is the U.S. Department of Agriculture's chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.*


Return to top


Research
                            Media
                            About ARS
                            Work With Us


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov