GYPSY MOTH MANAGEMENT PLAN

Transcription

1 CONSERVATION PLAN APPENDIX I-1 GYPSY MOTH MANAGEMENT PLAN CREATED: 26 OCTOBER 2006 UPDATED: 6 OCTOBER OCTOBER JUNE 2009

2 GYPSY MOTH MANAGEMENT PLAN A. GENERAL The inevitability of gypsy moth infestation on the Blue Ridge Scout Reservation is an acknowledged fact. This plan is promulgated in an effort to mitigate damage to the Reservation s forest environment and to reduce risks to user safety and enjoyment. The plan is designed to take full advantage of federal, state and local government activities aimed at monitoring and suppressing the gypsy moth. Since there are no know measures that are economically or environmentally feasible to stop or eliminate the gypsy moth, the primary purpose of this plan is to establish policies and procedures to: 1. Protect critical camp and program areas from excessive defoliation and tree mortality that would materially alter the camp/program area environment or detract significantly from user experiences and enjoyment of the area. 2. Protect sensitive species that may be adversely affected or eliminated from the Reservation s ecosystems. 3. Reduce risks to user safety, and 4. Reduce risks of artificial spread of the gypsy moth to uninfected areas in and outside the Reservation. B. RESPONSIBILITY 1. The Council Conservation Committee is responsible for the development and implementation of this plan and to evaluate its effectiveness. 2. The Property Superintendent of the Blue Ridge Scout Reservation is designated as the Reservation Gypsy Moth Coordinator and is granted authority, within budgetary limitations, to authorize and/or initiate gypsy moth suppression activities on the Blue Ridge Scout Reservation, to monitor gypsy moth activity, and to evaluate their effectiveness. C. VULNERABLITY The Blue Ridge Scout Reservation is considered to be extremely vulnerable to gypsy moth damage due to its hardwood forests with a predominance of oak species.

3 D. CRITICAL AREAS Critical areas are those deemed to be of significant value or sensitivity to justify extraordinary measures to protect from gypsy moth damage. Critical Areas designated within the Blue Ridge Scout Reservation include: E. MONITORING 1. Camp Powhatan 2. Camp Ottari 3. King Ranch area 4. Huff Farm area 1. The Blue Ridge Mountains Council shall cooperate with the STS (Slow the Spread) Program under the Virginia Department of Agriculture and Consumer Services to install and inspect traps to monitor for the presence and abundance of any gypsy moths on the Reservation. 2. Following designation of Pulaski County as a Quarantine Area, the County s Gypsy Moth Coordinator is responsible, in cooperation with the Blue Ridge Mountains Council BSA, to establish and monitor the egg mass survey. F. TREATMENTS 1. Until such time as the gypsy moth infestation reaches the Quarantine Stage in Pulaski County, the STS Program under the Virginia Department of Agriculture and Consumer Services shall provide treatments to suppress the moth. 2. After Pulaski County is designated as a Quarantine Area, the Blue Ridge Mountains Council BSA, in cooperation with the County, shall be responsible for treatment efforts (taking advantage of any federal, state or local government assistance available). 3. Treatments to suppress the gypsy moth shall focus on the Critical Areas of the Reservation as established by this plan. 4. Treatment options include: a. Bacillus thuringiensis (B,t.) -- a bacterial agent b. Nucleopolyhedrosis virus (NPV, aka Gypcheck) a viral agent c. Diflubenzuron (Dimilin) a chemical agent d. Mating Disruption Disrup ii

4 G. MANAGEMENT ACTIONS 1. The Blue Ridge Mountains Council BSA shall fully cooperate with the Virginia Department of Agriculture and Consumer Services to monitor and treat gypsy moth activities on the Blue Ridge Scout Reservation. 2. When Pulaski County is designated as the lead agency for the Gypsy Moth Program, the Council shall fully cooperate with the County s Gypsy Moth Coordinator and any efforts to monitor and suppress gypsy moth damage on the Blue Ridge Scout Reservation. 3. All vehicles entering the Blue Ridge Scout Reservation originating from a Gypsy Moth Quarantine Area shall be inspected for gypsy moth egg masses and moths prior to entry into the Reservation. a. Unit or group leaders and individual visitors shall be responsible to inspect each vehicle used for travel to or from the Reservation and all equipment to be used while on the Reservation (including any firewood brought to the Reservation) during the period of potential gypsy moth spread (primarily fall, winter and early spring see Appendix A) to assure no gypsy moth egg masses or moths are present. b. When deemed appropriate, camp rangers and staff shall spot check vehicles (including Reservation and user vehicles) present on the Reservation for gypsy moth egg masses or moths as often as the opportunity arises. c. Whenever appropriate, all Reservation vehicles shall be inspected each day to assure no egg masses or moths are present that may be carried to uninfected areas of the Reservation due to normal travel. d. Any moths or egg masses located during a gypsy moth inspection shall be removed from the vehicle or equipment and killed or placed in a sealed container for disposal (see Section G.7.). 4. Whenever the Reservation Gypsy Moth Coordinator determines a treatment measure is required, the GM Coordinator shall develop a treatment plan (may be written or oral). The plan shall be coordinated with the Chairman of the Council Conservation Committee and the Reservation Director for administrative support. a. Treatment measures that are within previously authorized budget allocations shall be implemented as soon as practicable. b. Treatment measures that exceed previously authorized budget allocations shall be approved by the Reservation Director prior to implementation. c. The Council Conservation Committee shall assist in evaluating the effectiveness of treatments to suppress the gypsy moth on the Reservation. 5. Individual trees within the Reservation deemed by the Gypsy Moth

5 Coordinator to be of high value that are infested with gypsy moths shall be wrapped with burlap bands and inspected each day to remove collected larvae (other means useful in trapping larvae --sticky or Teflon-coated bands -- may also be used as appropriate). 6. An education program for campers and other users of the Reservation shall be implemented to assure all are aware of the presence of gypsy moths on the Reservation and the measures that are or may be taken to reduce their impact. 7. Live gypsy moth adults, larvae or pupa, removed from vehicles, trees, or other locations shall be killed by mechanical means. Egg masses should be initially sprayed/coated with a biodegradable vegetable oil, then physically removed by scraping into a container of soapy water. The container should be tightly sealed and placed in the trash for disposal. 8. The Forest Management Task Group of the Council Conservation Committee shall investigate the efficacy of initiating silvicultural measures to mitigate the impact of gypsy moth defoliation on the Reservation forest to complement or augment other control measures. 9. Whenever the Gypsy Moth Coordinator determines a need for the salvage of trees killed or severely weakened due to gypsy moth defoliation, the Coordinator shall recommend the Forest Management Task Group of the Council Conservation Committee initiate the timber harvest process under the Reservation Conservation Plan. Recommend Approval: Date: Chairman, Council Conservation Committee Approved: Scout Executive Date:

6 APPENDICES A. GYPSY MOTH LIFE STAGE CALENDAR B. COMPARISON OF INSECTICIDES FOR GM CONTROL C. AGENCY LIST D. GYPSY MOTH IN THE FOREST

7 APPENDIX A

8 APPENDIX B Comparison of Insecticides for GM Control Common Name Trade Name(s) Bacillus thuringiensis var. kurstaki (Btk) DiPel Bacillus thuringiensis var. kurstaki (Btk) Thuricide Diflubenzuron (not available for homeowner use) Dimilin Carbaryl Sevin Phosmet Imidan Tebufenozide Description and General Effects Naturallyoccuring microorganism that is a stomach poison to moths and butterflies. Feeding ceases and then death occurs. Stops insect growth and development Stomach and contact insecticide. Neurological poison cholinesterase inhibitor When to Apply When eggs have hatched and leaves are expanded. Apply when young caterpillars are present. Timing is very important (see Duration). When eggs have hatched and leaves are expanded. Apply when young caterpillars are present. When eggs have hatched and leaves are expanded. Apply when young caterpillars are present. Whenever caterpillars are present. Duration of Effect No more than 1 week 3 months on foliage 2-3 weeks 1-2 weeks Other Considerations Will kill some other butterflies and moths. Cannot be applied over water courses or ponds. Will affect any animals that produce chitin (e.g., crawfish and insects) Highly toxic to honey bees. Also toxic to many other insects and aquatic organisms. Toxic to some domestic animals, birds, aquatic life, and honey bees. Mimic

9 Chlorpyrifos (not available for homeowner use) Lorsban Chlorpyrifos (not available for homeowner use) Do not allow livestock to graze in treated area. Dursban Azadirachtin Neemix Methoxychlor Cyfluthrin Growth regulator First sign of caterpillars Avoid contamination of water. Tempo Golden Oil Acephate Orthene Stomach poison. Broad spectrum insecticide. cholinesterase inhibitor When eggs have hatched and leaves are expanded. Apply when young caterpillars are present weeks Toxic to birds, bees. Do not apply over water.

10 APPENDIX C AGENCY LIST GYPSY MOTH STS PROGRAM VIRGINIA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES JAMES R. ZINCK OFFICE OF PLANT AND PEST SERVICES CHRISTIANSBURG, VA WORK: FAX: VA DEPARTMENT OF FORESTRY JAMES C. CLARK AREA FORESTER CHRISTIANSBURG, VA 540/ FAX 540/ PULASKI COUNTY GYPSY MOTH STS COORDINATOR TBA COUNCIL CONSERVATION COMMITTEE DR. BILL SHINER, CHAIR Appendix D

11 Gypsy Moth in the Forest Northern Hardwood Notes (Gypsy Moth and Oak Silviculture in the North Central Region) Gypsy moth is a recent addition to the long list of insects that defoliate oak, aspen, and other hardwood species in the North Central United States. This exotic pest did not occur in North America until it was accidentally introduced into Massachusetts in Since then, gypsy moth populations have spread west through Pennsylvania and Michigan, and south to North Carolina. As the infestation spreads, the gypsy moth is likely to move into other North Central States besides Michigan. Like those of other defoliators, gypsy moth outbreaks can last 1 to 5 years. Outbreak populations then decline because of the buildup of disease, natural enemies, and starvation. Low gypsy moth populations may be held in check by birds, insect predators, and small mammals for several years, before the next outbreak occurs. In oak-dominated stands, gypsy moth outbreaks usually persist 2 to 5 years, before collapsing. Populations then remain low for 4 to 12 years before increasing again. Outbreaks may build and decline faster in aspen dominated stands than in oak stands, according to recent observations in Michigan. Effects of gypsy moth defoliation are usually most severe during the initial outbreak in a newly infested area. If more than 60 percent of the canopy is consumed by gypsy moth caterpillars, trees typically "refoliate," producing a second flush of leaves later in summer. Low rates of diameter growth are common during years of heavy defoliation and often for one or more years after defoliation ceases. The amount of tree mortality and topkill sustained during a gypsy moth outbreak depends on the severity and frequency of defoliation, and on tree health. Vigorous trees can often withstand severe defoliation for a few years. However, each refoliation stresses the tree, reducing its energy reserves. Subsequent stress, including additional defoliation, drought, or frost injury, may kill the tree. Defoliated oak trees often become more susceptible to attack by the two-lined chestnut borer or Armillaria root rot. Suppressed, diseased, or low vigor trees may be killed after 1 year of heavy defoliation. Gypsy moth defoliation can reduce seed production and root-sprouting, resulting in poor regeneration. Diversity or species composition of native insects, birds and other animals may be altered during outbreaks. Severe gypsy moth defoliation, accompanied by an abundance of large hairy caterpillars and frass (fecal pellets), can be unsightly and may reduce the enjoyment of visitors at recreational areas. Risk and Harzard Rating Forest health specialists often evaluate hardwood stands to estimate the chance of severe defoliation and the likelihood that mortality will occur. Risk and hazard rating systems can be used to rank stands and to determine where pest problems are likely to occur.

12 RISK refers to the chance that a stand will be severely defoliated. Risk of gypsy moth defoliation is primarily based on tree species composition. Stands dominated by oaks, aspen, birch, basswood, willow, or other species preferred by gypsy moth will be at high risk of defoliation. On the other hand, risk will be lower in stands dominated by tree species that are less preferred by gypsy moth, such as maples, ash, and most conifers. Risk of defoliation may also be higher where many dead branches, bark flaps, and stem wounds are present, because these areas provide good hiding places for gypsy moth caterpillars and pupae. HAZARD refers to the chance that stands will be damaged (mortality, topkill, dieback) if defoliation occurs. Hazard depends primarily on the vigor of trees growing in the stand before defoliation. Stand hazard is increased by factors that reduce stand vigor such as overmature trees, suppressed or diseased trees, compacted soil, or severe competition. Hazard also increases when drought, late spring frosts, flooding or other stressful environmental conditions occur. Trees growing off-site are especially vulnerable. In Michigan, tree mortality has been observed primarily in oak-dominated stands where gypsy moth defoliation coincided with drought or late spring frosts. Management Options Appropriate strategies for gypsy moth management depend on: 1. The specific management objectives for each stand 2. The quality of the site. Consider the following strategies when managing for timber, wildlife, or recreation/ornamental tree objectives. Timber Pre-Salvage In high hazard stands nearing economic or pathological rotation age, you may choose to log harvestable trees or stands before gypsy moth defoliation occurs. Pre-salvage harvesting can secure economic benefits while reducing stand susceptibility and vulnerability to gypsy moth defoliation. Regeneration (root- and stump-sprouting) is often high following pre-salvage harvesting. Remove suppressed and low-vigor trees that will be highly vulnerable to damage by gypsy moth and other pests. Leave healthy trees with large crowns that are likely to survive defoliation. If you plan to leave mature residual trees, be sure to allow trees 1 to 2 years to recover from defoliation, severe drought, or other stress before beginning pre-salvage operations. Residual trees will require that much time to recover from stress and adjust to increased exposure. Consider conducting pre-salvage operations during winter, when frozen soils will limit soil compaction and root damage. Carefully consider methods of stand regeneration following pre-salvage. Root and stump sprouting can be high after harvest of relatively vigorous trees, but subsequent timber stand improvement (TSI) may

13 be needed to adjust stocking. Residual trees from shelterwood or seed tree cuts may be repeatedly defoliated during a gypsy moth outbreak, reducing seed production. In understocked stands, consider underplanting, especially with tree species that are less preferred by gypsy moth. However, be aware that white pine and hemlock growing under overstories dominated by oak, aspen, or birch can be severely defoliated and even killed during gypsy moth outbreaks. Timber Stand Improvement (TSI) Thinning to reduce stand density can increase vigor of residual trees and reduce stand risk and hazard. Thinning is most appropriate on medium- and high-quality sites, where costs are economically justified. Increased exposure to sun and wind may cause residual trees to be stressed for a year or two after thinning. Allow trees 1 to 2 years to recover from defoliation, severe drought, or other stress before beginning TSI activities. To reduce stand hazard, cut suppressed, wounded, diseased, or low vigor trees with poor canopies. Thin to stocking levels appropriate for the species and the quality of the site. Consult stocking guides to determine residual stocking level. Prevent soil compaction, wounds, and other injuries to residual trees. Anything that reduces vigor of the residual trees can increase stand hazard. Consider conducting TSI during winter, when soils are frozen. Also, consider removing cattle from woodlots managed primarily for timber production. Cattle grazing will cause compacted soil and stress trees. Thinning or partial cuts are rarely practical on poor quality sites. Consider managing for conifers or non-preferred hardwood species after harvest or salvage operations on poor sites. Convert to Less Preferred Species Selecting against tree species that are preferred hosts of gypsy moth will reduce long-term risk of defoliation. On poor sites, consider converting stand cover type to conifers after harvest or salvage. On fertile, mesic sites, altering the species mix can result in stands of high-quality hardwoods. Favoring ash, tulip poplar, maples, or conifers in northern or mixed hardwood stands can help increase stand diversity while reducing the risk of defoliation. Increasing species diversity within stands may also reduce the long-term risks of damage by other forest pests. Apply Bt High-value oak-dominated stands approaching economic or pathological rotation age can be protected with an aerial application of Bt (Bacillus thuringiensis var. kurstaki), a short-lived microbial insecticide that causes a bacterial disease in foliage-feeding caterpillars. Bt is not toxic to other insects, or to fish, birds, humans, or other animals. It is commonly used in recreational areas to prevent gypsy moth caterpillars from consuming more than 50 to 60 percent of the canopy, the threshold for tree refoliation. Timing of Bt application is critical and is determined by caterpillar age, canopy

14 development, weather, and other factors. Cost of Bt application varies widely; seek estimates from experienced aerial applicators. Do Nothing Sometimes, taking no action is the best alternative. Young, vigorously growing stands are likely to tolerate even severe defoliation for 2 to 3 years or longer. Gypsy moth, like other defoliators, may act to "thin from below," eliminating suppressed and other low vigor trees that would have eventually died or required removal. Stands with a mixture of species are less likely to sustain severe, repeated defoliation than are stands of nearly pure oak or aspen. No action may also be the best option when stands are at or near optimal stocking levels, especially if vigorous non-host species are present. Carefully consider the cost effectiveness of Bt sprays, TSI, or other management actions in stands with low to moderate risk or hazard. Salvage You may choose to salvage stands damaged during gypsy moth outbreaks. Salvage logging should occur within 6 to 12 months of tree death, before economic value is substantially reduced by stain or decay. It can be used to modify species composition, reducing long-term stand risk and hazard. Salvaging oak after a gypsy moth outbreak may reduce the cost of species conversion on poor quality sites. Avoid damage to residual trees and advance regeneration. Wildlife Managing stands to provide wildlife habitat may result in greater numbers of natural enemies that feed on gypsy moth. Understory plants and shrubs, trees with cavities, and fallen trees are important for maintaining populations of predatory and parasitic insects, insectivorous birds, rodents, and other small mammals. In low vigor stands, severe defoliation may reduce acorn production. Consider planting or favoring other food plants for wildlife, such as serviceberry (Amelanchier sp.), hazel (Corylus sp.), American beech (Fagus grandifolia), and hickories (Carya sp.). When leaving trees for wildlife, consider selecting species that are not preferred by gypsy moth. Avoid using Bt to protect foliage in stands managed primarily for wildlife. Bt can kill caterpillars of "non-target" butterfly and moth species that are present during spraying. However, high gypsy moth populations may also temporarily reduce diversity and abundance of some native insect species. Recent research in some Eastem States indicates that closed-canopy bird species may leave severely defoliated areas, while open-canopy bird species typically increase in abundance. Recreational/Ornamental Trees Recreational areas experiencing a gypsy moth outbreak can be unpleasant places for camping or picnics. The swarms of large caterpillars and frass are distasteful, and the hair on the caterpillars may trigger allergic reactions in some people. Defoliation of ornamental and shade trees in late June and

15 July contributes to the annoyance that this pest can cause. Consider applying Bt in high-use recreational areas during outbreaks to reduce the defoliation and nuisance caused by an abundance of gypsy moth caterpillars. Consider using burlap, sticky or Teflon-coated bands on the lower trunk of gypsy moth host trees in recreation areas. Use burlap and sticky bands to trap or destroy caterpillars as they move up and down tree stems. Use Teflon-coated bands to prevent caterpillars from crawling up into tree canopies to feed. Banding is economically viable only for high-value ornamental or shade trees. More information on banding for gypsy moth management is available from the Michigan State University Extension Service. Where practical, water defoliated trees during warm dry periods. Prevent soil compaction and wounds to gypsy moth host trees. Additional Readings Anonymous Gypsy moth in Michigan: homeowner's guide. Ext. Bull. E East Lansing, Ml: Michigan State University. 8 p. Bauer, L.S.; McCullough, D.G.; DuBois, N.R Using Bt to control gypsy moth. Ext. Bull. E East Lansing, Ml: Michigan State University. 2 p. Gottschalk, K.W Silvicultural guidelines for forest stands threatened by the gypsy moth. Gen. Tech. Rep. NE-171. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 50 p. Hall, D.J Silvicultural guidelines for oak stands threatened by gypsy moth In tine Lake States. Madison, Wl: Wisconsin Department of Natural Resources. 4 p. Haack, R.A.; Acciavatti, R.E Twolined chestnut boron For. Insect 8 Dis. Leafl.168. Washington, DC: U.S. Department of Agriculture, Forest Service. 12 p. Katovich, S.; Haack, R Gypsy moth in the northern hardwood forest. Northern Hardwood Notes St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station. 6 p. McManus, M.; Schneeberger, N.; Reardon, R.; Mason, G Gypsy moth. For. Insect & Dis. Leafl Washington, DC: U.S. Department of Agriculture, Forest Service. 13 p.