Boring beetles are back – warm spring hastens emergence
Record-setting warmth in parts of the state has adult emerald ash borer beetles chomping away to emerge from their ash tree homes.
Since June 3, beetles have been caught on traps in Victory and Newburg, areas previously known to be infested with the tree-killing insect. Additionally, larvae and adult beetles have been observed in the city of West Bend, in a tree located in Old Settler’s Park, a location less than 10 miles from Newburg.
“Adult beetles trapped in Newburg were found 16 days earlier than last year,” said Jennifer Statz, the coordinator of the Wisconsin Department of Agriculture, Trade and Consumer Protection’s emerald ash borer survey program. “The beetle needs a certain amount of warmth before it emerges and this year we’re hitting those marks really early. The traps in Newburg, Victory, Oak Creek, and Franklin were set up earlier than any other traps in the state as a way to determine when beetles would begin to emerge.”
Surveyors are wrapping up statewide trap placement this week and will begin checking those traps next week.
In West Bend, Wisconsin’s latest known infested city, park workers were removing a 25-foot tall green ash last Thursday when they observed the tell-tale exit hole of the adult emerald ash borer (EAB) beetle, shaped like a capital “D.”
According to West Bend Park Superintendent Mike Jentsch (yench), staff observed 15 adult beetles on, or in the process of emerging from, the tree. They also found one EAB larva. The tree has been destroyed except for one peeled section that the city plans to put on display. Another tree nearby is also showing signs of infestation and Jentsch says the city will remove that tree in a few weeks after the public has had a chance to take a look at the subtle signs of infestation.
Because West Bend is already located within a county under quarantine for EAB, there will be no additional restrictions or regulations on ash products or hardwood firewood from the city. Residents there remain obligated to follow the quarantine guidelines as they have been since 2008, when the beetle was discovered near Newburg.
In addition to the quarantine in Washington County, the following counties also remain regulated for EAB: Brown, Crawford, Fond du Lac, Kenosha, Ozaukee, Milwaukee, Racine, Sheboygan, Vernon, and Waukesha.
Materials regulated under Wisconsin’s EAB quarantine include all hardwood firewood; ash products such as timber, pallets, mulch and trimmings; and ash nursery stock. Businesses that deal with these products can apply for a variety of certificates or exemptions that are not available to the general public.
The emerald ash borer was discovered near Detroit in 2002, likely arriving in North America accidentally transported in wooden shipping crates from China. They’ve destroyed millions of trees already and have been found in 13 other states and in two Canadian provinces.
It’s the beetle’s larvae that actually kill the host ash tree by tunneling through the soft wood that supplies the tree with food and water. Large, healthy trees can succumb to EAB usually within three to five years. The signs of an infestation in a tree can be very subtle at first, and it’s usually too late to save the tree once its determined that EAB is the cause of the problem.
Wisconsin residents concerned about the health of their ash trees should consult with professionals. There are a variety of treatments available for homeowners, though none are guaranteed to prevent or reverse an infestation.
The beetle only attacks true ash trees. The mountain ash is not a true ash tree and is not susceptible to EAB. Other common occurrences such as drought and disease can make ash trees appear to be infested with EAB.
For additional information about emerald ash borer – including pictures of the common signs and symptoms of infestation, the beetle, and commonly mistaken beetles –visit the Wisconsin EAB Web site at www.emeraldashborer.wi.gov.
