Kiss Your Ash Goodbye (Emerald Ash Borer Update)

Attached at the bottom of this message is the text of an email that’s been circulating in invasive species circles, originally from the Maryland Extension Office. For those of you not sure what to make of the update, let me help: it’s bad news. To put it another way, USDA-NRCS is collecting and freezing ash seeds so the species doesn’t go extinct (read about this initiative). Get it now?

Emerald Ash Borer or EAB (Agrilus planipennis Fairmaire) is a beetle of the Buprestidae family, commonly known as the metallic wood boring beetles. Generally, the adult beetle lays eggs in or under the bark of trees and the larvae feed on the sapwood under the bark. They pupate in galleries in the wood and emerge through holes in the bark. Obviously, they can be severely injurious to the tree.

People who collect insects to look at (as opposed to those who collect them for scientific purposes) think Buprestidae are the bomb because they are (especially in the tropics) shiny, colorful, and sometimes have funky tufts. Also, they are mostly diurnal (active in the day), which means they tend to be wary and fast (hard to collect) and hence less well represented in collections (perceived as rare).

Emerald Ash Borer is native tonortheastern China and Japan. It was first detected in the U.S. in Michigan in 2002. It probably entered the country in wooden packaging (pallets, etc.). It is shiny green and about 1/2 inch long. Adults leave a distinctive “D”-shaped hole in the bark when they emerge in June. It only attacks trees in the ash genus (Fraxinus). Ash is an economically, culturally, and aesthetically important tree. It is an important component of hardwood forests (upland and wetland) throughout eastern North America.The wood is useful for handles, baskets, furniture, and other stuff. This is a tough street tree and has been planted widely in cities, especially in the mid-west (doh!).

EAB is not known from Rhode Island, and although I hope it stays that way, I’m not counting on it. DEM monitors for EAB periodically, paying particular attention to Providence and the Port of Providence. Neighboring states (CT, MA, VT, NH) monitor extensively so presumably we’ll get a heads-up from them as EAB spreads into our area.

Here’s a great link with all the info on EAB that you could possible want, including info on identification: www.emeraldashborer.info

Official info can also be had from the U.S. Forest Service (USFS)

Original Message —–
Sent: 10/29/2007 3:53:11 PM
Subject: [ma-eppc] Emerald Ash Borer (EAB) Update

The following note is from the Maryland Extension office’s current IPM report.

Emerald Ash Borer (EAB) Update
I attended the Emerald Ash Borer (EAB) Research Conference in Pittsburgh, PA this week and thought you would appreciate some of the information that was presented. Philip Bell, USDA APHIS, reported that EAB has been found in Michigan, Maryland, Virginia, Ohio, Indiana, Illinois, Pennsylvania and West Virginia. The find in West Virginia is very recent(2007). Gina Davis, Michigan Department of Agriculture, also confirmed EAB in the Upper Peninsula of Michigan near the Canadian border in Mackinac County, Brevort Township. This is a new area of spread in Michigan. In Pennsylvania, researchers believe the EAB has been in PA for at least 7 years. S. E. Spichiger, PA Department of Agriculture, is working with Greg Hoover, PA State University, in developing an educational outreach program. PA Department of Agriculture has hired 35 people for sampling in the state. Fifteen billboards have also been posted in PA on Emerald ash borer to increase public awareness.

Ken Marchant, Canadian Food Inspection Agency, reported on the EAB situation in Ontario. In Canada they created a firebreak to try to stop the spread of EAB, but unfortunately it failed. The problem was that by the time they found infested areas, the emerald ash borer had already been present for several years. Canada stopped cutting infested trees because they found it not to be cost effective. Marchant said that once an ash tree is dead it will fall within 18 months, which creates a liability problem for municipalities. Ash trees make up about 50% of the street trees in most cities in Ontario. Merchant also noted that, with millions of street trees in Ontario, the potential for spread and damage from EAB is very high. In Canada they are registering all wood mills, pallet makers, and saw mills to prevent EAB from getting into processed wood.

A.A. Cosse, USDA, reported on the biology and behavior of the emerald ash borer. Cosse noted that male EAB seem to locate females more readily when they are located in the sun, and do not do well in shade. There are long-chained, heavy pheromone compounds on the cuticle of the female. In the sun the pheromone volatilizes more and attracts the males. Once the male is close to the female, he finds her visually. The shape of the beetle is what attracts the male to the female.

Heat Treating Firewood to Kill EAB Larvae
Scott Myers, the Brighton Institute, has been doing work on investigating methods to kill emerald ash borer larvae in firewood. He tested multiple temperatures, 50 °C 65 °C (122 °F to 149 °F) at 15, 30, 45 and 60 minute intervals. He reports that heating firewood to 65 °C (149 °F) for 30 minutes provides a safe starting point that resulted in 100 % mortality in his studies. Scott feels that firewood processors with large kilns and temperature probes could meet this required temperature and treatment time fairly efficiently. This might have practical use for firewood suppliers that are shipping to other states, but more research is needed. Small firewood processors may find it impossible to accurately treat their firewood at a responsible cost. Kelli Hoover, PA State University, will be presenting at the January USDA Interagency Research Forum on Gypsy Moth and other Invasive Species in Annapolis on alternative methods of treating firewood.

Notes on Ash
Plant breeders are looking for variation in ash seedlings. Since ash produce male and female trees, there should be some variability out there. They are sampling seedlings from various parts of the US to see if they can find genes for EAB resistance. White ash is considered an upland species and the green ash is considered a lowland species. The black ash performs best in wetland areas.

Chemical Control Research
Phillip Lewis, USDA APHIS, looked at aerial application of spinosad and found that it lasts about 7 days before the spore count drops down to very low levels. Dow Agro Chemical has developed a synthetic form of spinosad called XDE-175. This synthetic spinosad lasts longer and is more toxic to pests. In a trial that Lewis et. al conducted, they found that synthetic spinosad was slightly more toxic to EAB. A mix of regular spinosad and synthetic spinosad XDE-175 extends efficacy for up to 2 months. Lewis feels that spinosad has the potential to control EAB adults when it is applied during their feeding stage. Deb McCullough, Michigan State University, reported that trunk sprays and trunk injections of emamectin benzoate (Syngenta Company) gave 100% mortality. This product is not registered with EPA. More work needs to be done with this product, and hopefully it will receive EPA registration in a couple of years. In their trials, Safari applications worked well and Safari with Pentra Bark was slightly better. Nate Royalty, Bayer Company, and Dave Smitley, Michigan State University, are doing work on rates of imidacloprid soil applications for different sized trees. They found that imidacloprid worked on small trees, but did not give good control on large trees. They found that larger trees require 8 to 12 weeks uptake the imidacloprid. Weakened trees do not uptake imidacloprid as well.

This entry was posted in Invasives, News, Plants. Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *