Cooperative Gypsy Moth Suppression Program Policy

Major Components

Gypsy Moth Treatment Site Selection Criteria
Private And Locally Owned Lands

Three primary parameters are used to formulate an overall rating for each potential treatment site for the purpose of selection and final inclusion in the Gypsy Moth Cooperative Suppression Program. The three parameters and the relative weight given each are as follows:

  1. Land use value/human resident population density (40%)
  2. Gypsy moth population density (50%)
  3. Habitat susceptible to gypsy moth (10%)

A rating of 1 (low), 2 (medium) or 3 (high) is given for each parameter based on field observations. The composite rating prioritizes a given area based on the severity of the gypsy moth problem, the potential for economic damage, and the socio-economic importance of the area. The value assigned each category/situation observed is as follows:


A. Land Use Value - (40%)
Category / Situation Rating
1. High density residential areas (< 4 Ac./Domicile): 3
2. Public summertime recreation areas: 3
3. Historic, landmark or unusually scenic areas: 3
4. Forested communities (4-10 Ac./Domicile): 2
5. Publicly owned/managed forested areas-forest products: 2
6. Privately-managed, public use summertime recreational areas: 2
7. Sparsely inhabited forested areas (10-25 Ac./Domicile): 1
8. Publicly owned/managed forested areas, wildlife, game, water quality: 1
9. Registered tree farms and other privately-managed forested areas: 1
10. Bay Critical Area, within 100 feet of the Bay: 1

B. Gypsy Moth Population Density (egg masses/acre) - (50%)
Category / Situation Rating
>1,000 egg masses/acre 3
500 – 900 egg masses/acre 2
250 – 499 egg masses/acre 1
100 – 249 egg masses/acre 0.5

C. Habitat Susceptibility - (10%)
Category/Situation Rating
>75% favored host trees: 3
50 - 75% favored host trees majority of remainder intermediately favored host trees: 2
50 - 75% favored host trees majority of remainder non-preferred host trees: 1

In addition, an area which experienced visible defoliation of the previous year will receive an additional +0.2 to the composite rating value.

Areas having any of the following characteristics are generally not considered for treatment:

  1. Less than 50% preferred host trees (based on a sample count of co-dominant trees in the site).
  2. Less than 50% canopy.
  3. No human habitation, use, or planned management.
  4. Property owners requesting exclusion.
  5. Size clearly less than 25 acres.
  6. Any reason to preclude the use of a particular action or activity (i.e. pesticides or aircraft).

Special circumstances such as proximity to selected treatment areas, or areas where high gypsy moth populations threaten nearby property where protection is greatly desired, may extend consideration of treatment to additional areas. Also, consolidation or expansion of proposed treatment areas may be attempted in the interests of program efficacy and efficiency.

Circumstances may warrant the consideration of areas with egg mass counts below 250 e.m./ac, on a lower priority basis, when Habitat Susceptibility and Land use factors are high and there is clear indication that the gypsy moth populations, though low, are increasing and are healthy. Generally, areas that in the past had experienced high and rapidly rising outbreak levels of gypsy moth would be candidate for such consideration to achieve effective and more efficient long term Pest Management.

In some years, priority may be given to blocks with five or more domiciles in certain areas of the State.

FPM No. 1
December, 1988
Revised November, 1989
Revised October, 1992
Revised October, 1993

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Community Requests for Insecticide Choice

Under the present suppression program decision-making process, it is not feasible for the Maryland Department of Agriculture to allow residents in each treatment site, or affected community, to select the insecticide for that site. The Department must retain the ability to select (propose) the most appropriate insecticide for a treatment site, under the following guidelines:

The Department's Forest Pest Management Section staff will recommend the appropriate insecticide to be used for each proposed treatment site, based on:

  1. egg mass counts (gypsy moth population);
  2. environmental factors (presence of water sources, critical areas, or threatened and endangered species);
  3. operational factors (logistics of application);
  4. biological and economic efficiency of each insecticide; and,
  5. suppression program objectives.

After making a technical/environmental recommendation, the Department will take into consideration a reasonable community-based request to use an alternative insecticide. If the request is operationally and financially feasible, and does not violate label directions, the Forest Pest Management staff will attempt use of an alternative insecticide on a second-priority basis, i.e., once the required treatment sites for that insecticide have been sprayed, then the Department will attempt to spray the sites proposed to receive a community-requested insecticide. The staff will make every reasonable effort to conduct the application within the biological time frame for the insecticide to be effective.

The Secretary of Agriculture will review staff recommendations from the standpoint of appropriate use of each insecticide. In addition, he will review the selection of areas to be treated on a priority basis and will make changes deemed necessary in the context of Statewide needs for resource protection from damage by the gypsy moth. In so doing, lower priority treatments in one area of the State or county (city) may be superseded by treatments in another area where resource protection is more essential or of a higher priority.

The final determinations of insecticide for a treatment site and priority for a treatment site to be sprayed will be made by the Secretary.

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County Cost-Share

Options and Guidelines for Participation by Municipalities, Forestry Boards and Certain Other Groups

A. Each county may consider whether to provide cost-share funding to pay for survey activities (gypsy moth population census) and/or suppression activities (landowner notification, and all activities to plan for, support and accomplish spraying) by the department.

County representatives may decide to cost-share only for survey activities, for survey and limited suppression activities up to budgetary limitations, or for the complete survey and suppression activities, as agreed to by both the state and the county. The state will conduct suppression activities only for areas that have been surveyed by MDA personnel or other approved personnel.

B. In order to deal with reduced or limited county funding, the MDA and the county may agree to limit or to redirect survey and suppression activities by one of the following ways:

  1. By utilizing priority guidelines for site selection, as expressed in FPM No. 1 (see Gypsy Moth Treatment Site Selection Criteria above) to prioritize site consideration for both survey and treatment;
  2. By targeting those areas within a county that represent a funding source towards the county cost-share of the activities; or,
  3. By targeting other areas the county wishes to prioritize, in agreement with MDA and for which the county expressly commits to cost-sharing based on estimated costs provided by MDA.

In each case above, the county must agree to:

  1. Respond to all inquiries from landowners outside selected treatment areas;
  2. Make public notice of selected treatment areas and include a deadline by which other areas may be included, along with a description of minimum requirements for an area to be included; and,
  3. All included treatment areas must meet State minimum criteria for size, percent tree canopy and presence of favorable host tree types.

C. MDA may cooperate directly with county forestry boards or certain county agencies (e.g., parks and recreation or watershed agencies), in agreement with the participating county jurisdiction, or in the absence of written disagreement from a non-participating county jurisdiction. Cooperation may include information, technical advice and assistance as well as survey and suppression services.

D. MDA may cooperate directly with incorporated municipalities in those areas where the county is not a cost-share participant in either suppression or in survey and suppression activities. MDA will not cooperate directly with community associations to other landowner groups, unless there is county cooperation and participation.

If you need further information, please call 410-841-5922.

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Use of Bacillus thuringiensis

It is the Department's policy to give first consideration to the use of Bacillus thuringiensis (Bt) in the gypsy moth cooperative suppression program under the following circumstances:

  1. In a treatment site location within 1,000 feet of the high-tide line in the Critical Area;
  2. In a treatment site containing a body of water or water source visible from the air;
  3. In a treatment site containing certain endangered or threatened species that could be adversely impacted by another insecticide; and
  4. For logistical reasons to increase the efficiency of the suppression program.

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Use of Dimilin

It is the Maryland Department of Agriculture's policy to give first consideration to the use of the insecticide Dimilin in the gypsy moth cooperative suppression program under the following circumstances:

  1. When there is no body of water or area where surface water is present, in the designated spray area boundary;
  2. When the treatment site is at least 1,000 feet from the high tide line in the Critical Area or at least 150 feet from any other bodies of water such as lakes, reservoirs, permanent streams, natural ponds, marshes or estuaries;
  3. When gypsy moth populations are increasing at a rapid rate;
  4. Unless physical or environmental conditions preclude its use;
  5. For logistical reasons to increase the efficiency of the suppression program; and
  6. In an effort to reduce the number and frequency of insecticide applications made aerially to urban or densely populated areas.

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Objection to Suppression Program

Policy for Requesting Withdrawal from a Suppression Treatment Area

  1. Any property owner(s) within a proposed gypsy moth treatment area may request that their property be removed from the treatment area. When this request is confirmed by returning the Withdrawal Request Form to the Department, signed by all legal owners, then the property plus (normally) a buffer of approximately 250 feet, is excluded from the proposed treatment area.

  2. Each property owner submitting a written Withdrawal Request Form is sent a written letter by the Department acknowledging receipt of the Form and confirming the Department's actions to exclude that property from the suppression program.

  3. If the resulting property exclusion is sufficient to make it impractical or logistically impossible to conduct an effective, safe aerial insecticide application, sections of, or the entire, proposed treatment area may be removed from the program.

  4. When the Department is again considering treatment of the same area more than 2 years after receipt of the withdrawal request, the Department will contact the withdrawing property owners prior to delivery of public notifications and require that a new withdrawal request be filed, if the property owners wish to withdraw the property.

  5. Property owners can write at any time to the Department to rescind their request.

  6. A property owner whose property is near to, but lies completely outside, a proposed treatment area may also file a withdrawal request. In these situations, the Department may, at its discretion, leave the original treatment boundaries unchanged. The Department will take specific precautions during the pesticide application to minimize drift onto the landowner's property.

    Property withdrawals usually result in incomplete or ineffective pest suppression in the area around excluded properties. Adjacent property owners may elect to privately conduct gypsy moth control, normally by hiring a licensed pest control firm. The Department encourages all property owners who are contemplating withdrawal to consider alternatives to property withdrawal.

FPM No. 4 Revised January, 2002

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Notification and Contact of Schools in and near Proposed Gypsy Moth Treatment Areas

  1. This policy pertains to all schools up through grade 12, whether public, private, or institutional, and also pertains to registered day care centers. Private schools and Day Care centers are notified through the official notification mailing as for all landowners.
  2. In the case of public schools, a separate letter will be sent to the County IPM Coordinator with a copy of the insecticide label, the MSDS and designation of the two week time frame in which application is expected to occur. Official notices are mailed to the County Board of Education.
  3. All public schools in or within at least 250' of the boundary of a proposed treatment area will be visited by the Regional Entomologist within one month of the planned beginning of aerial application. Contact is made with the school principal (or designee) to explain details of our program and provide and gather certain information including:
    1. Provide copies of the official notification, with insecticide information and Map & Information Sheet; insecticide labels (required), Material Safety Data Sheet (required); and other insecticide information from the National Pesticide Information Center and EXTOXNET (such as Fact Sheet and Pesticide Information Profiles).
    2. Provide details of the planned application and procedures including at least: expected 2- week time frame for application, aircraft type and size, time of day for application, weather restrictions, application altitude and flight patterns, and ground monitoring.
    3. Learn about school activities including: times of school operation, when children arrive, where they congregate prior to school opening, when the school is first open, what activities occur on school grounds outside of times when the school is in session.
    4. Provide information on how the Regional Field Office and headquarters can be contacted by the principal or concerned parents. Highlight our web site and toll free # and information about other web sites and other reliable information sources.
  4. In so far as is practical and feasible, spray time and date will be scheduled to accommodate scheduled school and school-related activities, but changes may not always be possible.
  5. Public schools between 250' and 1000' from the borders of proposed spray areas will be sent a courtesy letter with instructions on how to obtain more information about the proposed application and insecticide.
  6. Notification and visitation to private schools and private registered day care centers within proposed treatment areas and up to 1000' beyond treatment boundaries will be at the discretion of the regional entomologist, and as information is available to identify these facilities.

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