Site of the Frederick County Forest Conservancy District Board
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FCFB site navigator: Gypsy moth suppression Stronghold's demonstration forest Ecological communities and woodland wildlife habitats Related Gypsy moth links: Invasive Species of concern in Maryland Garrett County Gypsy Moth Workshop 2/9/2008 Combating Gypsy Moths - Advice for Landowners
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Gypsy moth suppressionThe cool damp conditions we are experiencing in 2011 should promote the growth of various diseases that will affect trees, but it should not encourage insect outbreaks, especially in the lepidopterous "moth and butterfly" group (of which gypsy moth is a prominent member).
Gypsy moth numbers saw a steep decline after 2009, and if they behave like historical models, there should be eight to 10 down years following the three up years we experienced in 2007, 2008 and 2009.
There were very few viable egg masses deposited in Frederick County last summer, and gypsy moth egg mass counts are low. As a result, there will not be much gypsy moth presence this spring. Although no counting of Eastern tent caterpillars, forest tent caterpillars or oak span worms are taken, these insects should be on the low side also, based on the weather conditions.
A review of the 2009 Supplemental Gypsy Moth Program The Frederick County Gypsy Moth task force met during the fall of 2008 and determined that a supplemental gypsy moth suppression program would again be needed in 2009 given the expected levels of infestation throughout the county. Parkton Woodland Services was once again retained to provide administrative support and, the task force submitted bid requests to numerous spray contractors. Helicopter Applicators provided the successful bid and were chosen as the spray contractor. To publicize this program the Task Force sent out individual mailings to previous year’s participants, submitted articles to local newspapers, and held a gypsy moth informational meeting at the C. Burr Artz Library in Frederick City on December 4, 2008. The failing economy of 2008 – 2009 had a fairly significant impact on this program. Given budget constraints Frederick County was unable to offer monetary assistance to provide cost sharing. In addition, the State of Maryland had to drop some of their anticipated spray blocks due to reduced funding levels thereby increasing participation in the supplemental program in some cases. In addition, many private individuals cited poor economic conditions as reason for not participating in the 2009 program. Spraying for the Supplemental Program began on May 12, and concluded on June 1, 2009. In total, nearly 300 landowners participated in this program treating some 5,400 acres. All of these properties were sprayed with the insecticide Confirm at 3.5 oz/acre. The spring and summer of 2009 was characterized by cool, rainy weather. These environmental conditions benefit the naturally occurring virus and fungus that suppress gypsy moth numbers. The result of the public and private spray programs along with the prevailing climatic conditions is that that gypsy moth populations had declined significantly without causing much defoliation. These ground observations were confirmed after The Maryland Department of Agriculture, Forest Pest Management Section conducted its summer flight to determine levels of defoliation and noted no significant defoliation in any section of the county. In addition, the Forest Pest Management Section is in the midst of their gypsy moth egg mass surveys and reports that no significant populations exist to warrant developing a spray block in 2010. This survey is not yet complete so this might change. For now it appears that the gypsy moth populations have crashed and it looks like no significant spaying will be necessary in 2010 or the foreseeable future. Special thanks go out to those private citizens who assisted with this effort especially members of the Gypsy Moth Task force many of which spent significant time and effort on this project with no monetary gain. Also thanks go out to the local jurisdictions who assisted with this program especially Frederick County, legislators who helped acquire diminishing funds for this work, and those individuals in the MD Department of Agriculture, MD Department of Natural Resources, Parkton Woodland Services, and Helicopter Applicators that assisted with the spray effort. Mike Kay
Maryland plans spraying to combat gypsy moth damage The Associated Press The Maryland Department of Agriculture says it is beginning an aerial spraying program to combat gypsy moth caterpillars that will total 33,000 acres across the state. The forest pests defoliated about 19,000 acres of trees last year. Agriculture Secretary Roger Richardson said Thursday that this year's campaign will focus largely on central and western Maryland, including more than 11,000 acres in Frederick County and about 7,200 in Washington County. The cyclical infestations are on a downswing. Defoliation damage last peaked in 2007 at 68,000 acres statewide.
2009 Gypsy Moth Informational Meeting
The maps below show the results of spraying on defoliation in 2008 for Frederick County. Note the lack of overlap between the spray areas and deloiation areas (maps courtesy of Frederick County Geographic Information Systems (GIS)).
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 CountyMonday 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 mothsMonday 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 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.
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.
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. |










