Gypsy moth suppression
There will be a 2009 Gypsy Moth Informational Meeting presented by the Frederick County Forestry Board and Gypsy Moth Task Force.
Where: The Community Room at C. Burr Artz Regional Library, 110 East Patrick Street, Frederick, MD 21701
When: Thursday, December 4, 2008 from 6:30 pm until 8:30 pm
See the Spotlight section of our Home FCFB page for more details.
In 2008, gypsy moth infestations in many forested areas of Frederick County were severe enough to potentially defoliate thousands of acres of forest. High tree mortality can result from gypsy moth defoliation two or more years in a row or when other stresses to the forests are present such as drought. In 2008, thousands of acres of Frederick Forest are expected to be defoliated, unless treated. With an estimated one million acres devastation since 1980 state lawmakers have been studying the problem. "It literally looks like a war zone once they come through," said American Joe Miedusiewski, a lobbyist for the Maryland Arborist Association (Washington Post, Moths Munch Trees, 3/21/2008).
Gypsy moths, native to parts of Europe, Asia and Africa, were brought to the U.S. for a breeding experiment to produce a more robust silk worm. After their accidental release in the United States in the 1860’s they have proliferated in the absence of the natural controls present in their native habitat. Gypsy moth larvae (caterpillars) have voracious appetites and thrive on the hardwood forests of our area, with oaks being their preferred diet.
Pictured below are Gypsy moth larvae emerging from the egg mass (left) and an older Gypsy moth larvae showing five pairs of raised blue spots and six pairs of raised brick-red spots (right).
On November 3, 2007 the Frederick County Forestry Board conducted a workshop at Cunningham Falls to educate property owners of the anticipated spring time infestation of gypsy moths and the potential defoliation of Frederick forests. The workshop resulted in a follow-up meeting where concerned property owners discussed alternative actions to combat the problem. Six attendees have offered to serve as a 'task force' to act as an interface with spray applicators and the property owners. The Frederick County MD Gypsy Moth Task Force has also been successful in securing governmental support for the suppression program.
Spraying for Gypsy moth in northern Frederick County
Monday May 5, 2008
Day one saw us tweaking the Ag-Nav system and the relative humidity plummeted from a reading of 75 to 35 right about 9:00 am. As such we had to cut our day short . ( We can not spray once the Rh goes below 60 because the spray will evaporate before it reaches the leaves.) The navigation system is working perfectly now and Tuesday promises to be a good spray day so that we anticipate spraying for most of the day. Wednesday should be a good day as well along with most of Thursday. Rain is expected for late Thursday and most of Friday.
Below are photos of from the first day of spraying showing the insecticide 'Confirm' and the helicopter ready for flight. The photos were taken at the Macintosh property over on Ira Sears Road.
Pictures from the first round of spraying
Pictures from the second round of spraying
Officials wait to gauge damage from gypsy moths
Monday June 2, 2008
To learn more news on the status of Gypsy moth suppression in Frederick County see the article entitled Officials wait to gauge damage from gypsy moths in the Frederick News-Post.
Gypsy Moth Update for June 19, 2008
Forecasts for 2008, based on fall 2007 egg mass counts, predicated a severe outbreak of gypsy moth in Frederick County affecting nearly 43,000 acres of forests. This represents nearly 30% of our forest land base in the county! With this in mind the Maryland Department of Agriculture ramped up its yearly suppression program spraying nearly 23,000 acres of forest in the county. A private “supplemental” program was also launched where private landowners paid 60% of the cost of suppression and 40% was cost shared from funds earmarked by the Frederick County Commissioners. This supplemental program resulted in the spraying of nearly 9,000 acres. The supplemental program was developed and administered by a diverse group of partners known as the Frederick County Gypsy Moth Task Force. In addition, the Federal Government sprayed much of their susceptible forest land in Catoctin National Park and along the C&O Canal and Monocacy National Battlefields.
Most gypsy moth populations are entering into the final stages of their larval development. The larvae are entering a transformational “pupal” state for a few weeks then they will emerge as adults, mate, lay their eggs then die. Once the larval stage is past the threat of defoliation is over since adult gypsy moth does not feed.
A section of forest near Thurmont defoliated by gypsy moth 6-16-08.
A nearby property that was spayed with Confirm during the supplemental program.
By late summer we will be better able to assess the damage inflicted on our forests when the Maryland Department of Agriculture conducts its aerial surveys; and, determine the gypsy moth threat for 2009 by counting newly laid egg masses. From my general observations it appears that the widespread spraying initiative combined with environmental factors has helped us avoid widespread destruction by this damaging insect. I have recently seen signs that naturally occurring disease pathogens are impacting gypsy moth such as the NPV virus and the bacterium Entomophaga maimaiga. These pathogens are more active when we experience cool, wet weather during the spring and the gypsy moth populations are high which certainly the case was during 2008.
A late season larvae getting ready to pupate right, next to a gypsy moth that has died from the NPV Virus left.
The Gypsy Moth Task Force will be meeting in Mid-July to critique the supplemental program and to develop a report that will be distributed to the County Commissioners and other State and Federal officials. Our hope is that we can maintain the necessary resources to enable gypsy moth control should a damaging population arise again.
Gypsy Moth Update for July 18, 2008
The Maryland Department of Agriculture has finished its 2008 aerial surveys to assess defoliation across Frederick County and they have determined that 4,494.22 acres of Moderate Defoliation i.e. (30% - 60%) occurred and 3,709.325 acres of Heavy Defoliation i.e. (> 60% defoliation) occurred during 2008. The total acres defoliated equals 8,203.545 acres. So, to sum up the 2008 season, we expected 43,000 acres of heavy defoliation based on 2007 egg mass counts, nearly 32,000 acres were sprayed throughout the county during the spring of 2008; and, we witnessed 8,203.545 acres of moderate to heavy defoliation. Please refer to the accompanying maps that shows were defoliation took place along with the spray blocks of the supplemental program.
At present the adult gypsy moth are mating and laying eggs that will hatch during the spring of 2009. The adults do not feed, so trees will not be further damaged during 2008. The adults will die after egg laying is complete. It has been noticed that the naturally occurring virus and bacterium have affected the later stage caterpillars; and, the adult females are being found in lesser numbers than males. (Female gypsy moth goes through an additional larval stage so they are more prone to be affected by the naturally occurring diseases.) In addition, some of the new egg masses are smaller than normal which is a sign of a population under stress. All of these observations point out that the overall populations may be in a state of decline. However, it is too early to predict the 2009 populations. The Maryland Department of Agriculture will soon embark on their 2009 egg mass surveys to ascertain what the 2009 season will bring.
Pictured above: Male gypsy moth (left) and female laying eggs
The Frederick County Gypsy Moth Task Force recently met to evaluate the 2008 Supplemental program using the insecticide Confirm for suppression. By talking to various landowners, looking at spray blocks, and evaluating the defoliation surveys we concluded that the Confirm spray was very effective; however, in some cases it did not prevent migration and moderate defoliation from untreated areas onto the edges of spray blocks. We concluded that making future spray blocks as large and rectangular as possible would reduce this “edge effect”. The task force also generated recommendations on how to make future spray programs more cohesive and concluded that we need to conduct more regional trainings and public information meetings to get public feedback and educate people on their options for gypsy moth control. The Gypsy Moth Task Force wishes to thank the Frederick County Commissioners for their support of our program allowing us to offer landowners 40% cost share. We would also like to thank our State and National officials who increased their appropriations for the Maryland Suppression program. Working together we were able to prevent the defoliation of 43,000 acres of forest (1/3 of the forest in the county) by this destructive insect.
Use the links below to download an image of the 2008 spray block map for the central Frederick County, Thurmont, or Urbana areas.
Gypsy Moth Update for September 11, 2008
On September 11, 2008 Frederick County Forestry Board member Mike Kay presented a report on the 2008 Gypsy Moth Suppression Program to the Frederick County Commissioners since they provided funding for cost share. The 2008 Supplemental Gypsy Moth Control Program report is available to download as a PDF file. The report includes the three maps made of the spray blocks overlaying areas that were defoliated during the summer of 2008.
