Forest & Shade Tree - Insect & Disease Conditions for Maine
August 28, 2008

Mainers Urged To Sign Up For Free Disposal of Banned, Unusable Pesticides

Hundreds of Maine citizens live unaware of a quiet crisis lurking in or near their homes. In barns, basements, sheds, or garages throughout the state reside tons of banned and unusable pesticides: old chemicals with infamous names like DDT, lead arsenate, 2,4,5-T, and chlordane. Often, new owners of older homes or farms discover they have inherited hazardous waste. When they do, citizens face a dilemma: hire an expensive hazardous waste disposal service or dump the chemicals illegally, inviting harm to the environment and public health.

Fortunately, there’s a third option that’s both legal and responsible. Even better, it’s free simply by contacting the Maine Board of Pesticides Control (BPC). This fall, the state regulatory agency will dispose of banned pesticides or pesticides that have become caked, frozen, or otherwise rendered unusable. And, again, there is no cost to homeowners.

“We urge people holding these chemicals to contact us immediately to register,” says Paul Schlein, BPC Public Information Officer. “There will be four sites throughout the state where folks will be able to bring their obsolete pesticides.” The collected chemicals go to out-of-state disposal facilities licensed by the US EPA, where they are incinerated or reprocessed. “While offering free obsolete pesticide disposal is expensive for us,” notes Schlein, “it’s a bargain, compared to the cost of cleaning up contaminated soil or water. However, it’s worth noting that future funding is not guaranteed, so be sure to take advantage of this year’s collection while you can.”

Preregistration is required by September 15, 2008. To register, find out collection dates and locations, and learn important information about the temporary storage and transportation of obsolete pesticides, go to the BPC Web site at, or call the BPC at 287-2731.


Asian Longhorned Beetle (Anoplophora glabripennis) – The Asian long-horned beetle (ALB) was detected in Worcester Massachusetts earlier this month(Mass Dept. Ag. FAQSheet ).  Experts believe ALB has been in the Worcester area for 5-7 years.  Local, state and federal authorities are cooperating to delimit the extent of the infestation and develop a plan for eradication.  The beetle itself and possible host materials from infested areas are quarantined.  Regulated items include: firewood from all hardwood species, and living, dead, cut or fallen host species material including nursery stock, logs, green lumber, stumps, roots and branches or debris of half an inch or more.

Preferred hosts of ALB include maples, birches, willows, horsechestnut and elms.  Infestations have been found in many other hardwood species (A complete list is available on the APHIS Website). 

Although this insect is not known from Maine, please be alert for its presence (images).  The ¾” to 1½” ALB is shiny black (patent-leather black) with white spots on its back.  The antennae (horns) are longer than the body.  Each of the 11 antennal segments has a white to bluish base, which gives a banded appearance to the antennae.  Similar native borers do not have the patent-leather black appearance of the ALB (image).  More information can be found on our Website

Fall Webworm (Hyphantria cunea) – Populations of this native insect are heavy in spots, but down from their high levels of a couple of years ago.  The webs are conspicuous this time of year and are generally found at the ends of branches.  As the season progresses the webs can enlarge and encompass small trees (photo).  Feeding occurs within the webs; except some late stage larvae may migrate from the webs to feed.  Feeding does not threaten the health of the tree unless the tree is already under stress.  If webs are an aesthetic problem you can remove them by winding them around a forked stick.  If there are caterpillars in the webs, dunk the whole thing in a bucket of soapy water to prevent re-establishment of the larvae.  Mark your 2009 calendars to start looking for developing webs mid-July of next year.  With this and most pests early treatment is best!

Hemlock Woolly Adelgid (Adelges tsugae) – Three new detections of HWA have been confirmed since our last Conditions Report.  Homeowners in Eliot and Kennebunkport correctly identified HWA on native trees growing around their properties.  Additionally, a homeowner in South Portland reported HWA on landscape trees that had been planted about ten years ago.  Initial surveys in South Portland have not revealed additional infested properties.  The infested landscape trees will be treated to eradicate adelgid.  Delimitation surveys are planned for the Eliot and Kennebunkport sites.  A workshop on Identification and Detection of Hemlock Woolly Adelgid to be held in Saco will be offered in late-September or early-October.  More details should be known in early September.  Contact Allison Kanoti at (207) 287-3147 for more information.

Foresters, loggers, landowners, arborists and others planning to harvest and move hemlock roundwood products (such as logs and pulp) from the quarantine area should plan to move them before the end of February.  During this period shipments do not need to be certified before being moved from the quarantine area.  Between March 1st and July 31st, inspections and certifications are required.  All hemlock material leaving the quarantine area must go to a facility that maintains a compliance agreement with the Maine Forest Service.  Questions about the quarantine can be directed to Allison Kanoti at (207) 287-3147.

Insects in Firewood – With the high price of heating oil, more homeowners are turning to firewood to heat their homes.  That’s not really news anymore; it has been said so many times.  If you plan to store firewood in your home be forewarned that you may end up bringing in some unwanted guests with that firewood.  Green, seasoned and even kiln-dried firewood may harbor insects and other organisms.  Plan to burn firewood you bring into your home within one to two weeks.  Otherwise, be prepared to live with the insects, fungi and other organisms that may come with it.  Most will not cause damage to your home or health, but some, including carpenter ants, powderpost beetles and mold, can be harmful.  

Diseases and Injuries

White Pine Blister Rust (Cronartium ribicola) - White pines damaged by white pine blister rust are very conspicuous now, with foliage of affected trees appearing as light yellow in color (image).  Aerial reconnaissance in the western Maine region has revealed a localized area of significant recent cankering and mortality in Magalloway Plantation, just west of Upper Richardson Lake.  Individual tree damage has also been observed in the Downeast areas of Washington and Hancock Counties.

Tar Leaf Spot of Maples (Rhytisma acerinum, R. americanum, and R. punctatum) - The foliage of maples in many towns in central and southern Maine have been damaged by a common leaf disease called tar leaf spot (image).  The disease, caused by one of several closely related fungi, can infect leaves from early spring through summer, whenever periods of wet weather occur. Until this past week, Maine has experienced an exceptionally wet growing season.  Damage from tar spot disease has been found to be most serious in coastal communities, with Blue Hill and Northeast Harbor reporting significant early defoliation, particularly on the Norway maples.  Sugar and red maples are usually much less affected.  While premature loss of foliage is never beneficial to tree health, loss of foliage this late in the season is seldom seriously damaging.  Even severely affected trees are expected to recover fully next spring.  Cornell fact sheet

Marssonina Leaf Spot of Aspen (Marssonina populi) - This disease of aspen has been reported from Islesford, where considerable leaf damage has occurred this season.  Like the tar spot disease of maples, occurrence of this is common and widespread throughout Maine.  Heavy infection levels in coastal areas this year are likely the result of extended periods of rain, fog, and high humidity.  Again, because most of the injury occurs late in the season, affected trees will not be measurably damaged.  No control is recommended or required. site

Sirococcus Tip Blight on Spruces (Sirococcus spp.) - Samples of branch tip dieback of white, Blue, and Siberian spruce were received here at the Lab during July and early August.  The damage was attributed to Sirococcus conigenus, a shoot-blight disease of pines, spruces, and other conifers.  Recent taxonomic research has shown that there are three distinct species in what was earlier recognized as a single species (S. conigenus) (Forest Pathology 37:47-60, 2008). Damage is most severe on current year’s shoots.  Symptoms may appear similar to winter injury or frost damage, but affected shoots are often scattered randomly throughout the tree, unlike environmentally-caused damage.   When shoot infection occurs early in the season, growth of the elongating tip is arrested, and often the shoots appear slightly curled or twisted (image).  Spores are spread by rain splash, and infection occurs when shoots and needles are wet.  It is too late to apply chemical control this year.  Current fungicide recommendations are the same as for other needle diseases of spruce; copper hydroxide (Bordeaux mixture or Kocide) or chlorothalonil (Bravo) applied just after bud break (late April to early June) and again ten days  to two weeks later should provide protection to new shoots from infection. USFS site

Conditions Report No. 5, 2008

Maine Forest Service

Forest Health and Monitoring Division