Maine's Report to the Eastern Plant Board, a Summary of Plant Protection Activities in 2010

April 2011 - Worcester, Massachusetts

Introduction

The Division of Animal and Plant Health within the Maine Department of Agriculture, Food and Rural Resources (MDA) includes Maine's plant regulatory agency,responsible for protecting the state's plant resources from theintroduction and spread of regulated insects and diseases. TheDivision provides technical information and support toagricultural producers and issues a number of licenses and permits for individuals to conduct certain business. The Division carries out its mission through the work of various programs including: nursery program, integrated pest management program, apiary program, cooperative agricultural pest survey (CAPS), seed potato certification and the Board of Pesticides Control. The Division also works closely with the Department of Conservation, Maine Forest Service, Division of Forest Health and Monitoring which is charged with protecting Maine’s forest, shade and ornamental tree resources from significant insect and disease damage.

Nursery Program

Licensing and Inspection

All businesses or individuals selling nursery stock in Maine must have a license. Nursery stock is defined as: woody plants, including ornamental and fruiting trees, shrubs, vines and all viable parts of these plants; herbaceous plants, including florist stock plants, annuals, perennials, vegetable seedlings, herbs, potted plants and all viable parts of these plants; and any other plant or plant part designated by the commissioner. 1386 nursery stock licenses were issued in 2010. Inspectors performed 673 inspections at nurseries, greenhouses and plant dealers. A variety of pests were observed during inspections, but most were minor or common pests. One pest new to Maine, basil downy mildew was identified on basil plants at a greenhouse in July. This destructive disease, first found in the northeast in 2008, produces an abundance of spores and spreads quickly. Maine growers were advised to look for symptoms including purplish gray spores on the undersides of leaves of yellowing basil plants.

Late Blight of Tomato and Potato

In 2009, Maine experienced an increase in outbreaks of late blight (Phytopthora infestans) on tomato and potato crops. Though late blight is not a new pest to the area and the weather conditions were favorable for it, infected tomato seedlings sold at retail stores contributed to the increased incidence of the disease across the state. The Maine Legislature directed the MDA to require notification of any tomato seedling shipments sent to businesses in the state during 2010. Of the 359 shipments (586,636 tomato plants) reported, 97 lots representing 50 percent of the imported seedlings were examined during 44 routine inspections at plant businesses. No signs of late blight were seen during these inspections. Minimal outbreaks of late blight were reported from Maine’s public and farming communities. Notification of shipments and monitoring for this pest on imported stock will continue through 2011.

Inspections of Imported Hemlock

In 2010, MDA collected information on hemlocks that were imported into the state through the nursery trade in order to inspect for the state quarantined pest hemlock woolly adelgid (HWA). 7 businesses from the states of New York, Ohio, and Tennessee supplied hemlock trees to 17 nurseries or landscapers in Maine. 35 shipments were imported, with a total of 822 hemlock plants. 29 of these shipments (666 plants) were inspected and found free of HWA, and 5 shipments (146 plants) were cleared by inspecting other recipients of the same truck load.

Hemlock Woolly Adelgid (HWA) Infestation Spreading

Courtesy of the Forest Health & Monitoring Division, Maine Forest Service (MFS)

HWA was first detected in Maine forests in 2003 and for several years was found only in 6 towns in York County, on Maine’s southern coast. During 2008, HWA was found in 2 additional towns also in York County. However, the situation began to change in 2010 and a significant increase in range of HWA from previous years was recorded. Scattered populations of HWA were detected in at least 26 towns from Maine’s southern coast to the mid-coast region. The MFS suspects the warm winter of 2009-2010 allowed populations to build enough to reach detectable levels in areas where populations had previously been established but at sub-detectable levels. Maine’s HWA quarantine remains in effect with the 6 originally infested towns listed as quarantined. MDA hosted a meeting at the end of March 2011 to begin discussing how the quarantine should be changed to reflect the evolving HWA situation in Maine.

Phytosanitary Inspection and Shipping Certification

482 lots of plant materials were inspected and certified for shipment using phytosanitary certificate forms. 9 federal certificates and 8 state certificates were for nursery/forest materials, 465 federal certificates were for potatoes, feed barley and wheat. 21 businesses received Nursery Stock Certificates to ship nursery stock to other states. 4 businesses had firewood kilns certified to operat under compliance agreement meeting the requirements of New York’s firewood regulations.

Nursery Survey

Surveys were conducted by MDA for seven exotic tree pests as part of the CAPS Bundled Nursery Survey. Ten nurseries in five counties were surveyed between June 1 and August 25 for summer fruit tortix (Adoxophyes orana), variegated golden tortrix (Archips xylosteanus), pine tree lappet (Dendrolimus pini), Siberian silk moth (Dendrolimus superans), old world bollworm (Helicoverpa armigera), and pink gypsy moth (Lymantria mathura). Appropriate pheromone traps were used for each pest. While visiting the participating nurseries, MDA staff visually inspected hemlock trees for hemlock woolly adelgid (Adelges tsugae) and distributed an information sheet about target pests. None of the target species were detected.

Seed Potato Certification

Seed potatoes are certified to control the level of pests in Maine’s potato industry. Certification is a three step process: inspection of seed potatoes during the summer, disease evaluation of samples submitted for testing in Florida and inspection during shipping to ensure the potatoes meet grade standards.

Summer Field Inspection

In 2010, 10,848 acres from 94 growers met disease tolerances for regulated diseases and pests during the summer field inspection. A directory of producers whose seed lots passed the summer inspection program is compiled at the conclusion of the field inspection season and posted at www.maine.gov/agriculture/pi/potato

Post-Harvest Testing

Maine statutes require that in order for a seed lot to receive certification, a sample must be submitted for post-harvest disease evaluation at a state-owned farm in Homestead, Florida. In November 2010, 1048 samples, representing approximately 10,755 acres of potatoes were planted, and then evaluated for disease in January 2011. 47.7% met the certification requirements for foundation seed (total virus <0.55%), 43.5% met the requirements of certified seed (total virus 0.56-5%) and 8.7 % did not meet the seed certification standards (>5% total virus). 2010 saw a significant increase in potato lots not meeting the seed certification standards (up from 2.9% in 2009 and 1% in 2008). Florida test results are also posted at www.maine.gov/agriculture/pi/potato

Potato Cyst Nematode National Survey

The Seed Potato Certification Program participated in the Potato Cyst Nematode (PCN) National Survey for the fourth year in a row. No seed potatoes could be shipped out of Maine unless they came from fields that have been sampled and tested for PCN (Globodera pallida) and Golden nematode (GN) (Globodera rostochiensis). MDA staff used specialized mechanical samplers to survey all seed potato fields in Aroostook County that grow seed for export. Each acre was sampled according to protocol to collect a 5lb sample, resulting in 4166 samples. All soil samples were shipped to the USDA APHIS Nematode Laboratory in Avoca, NY. No PCN or GN was found.

Cooperative Agricultural Pest Survey (CAPS)

MDA participated in the Cooperative Agricultural Pest Survey (CAPS) Program, a cooperative effort between the USDA APHIS PPQ, state departments of agriculture and state universities.

The Maine CAPS Program consisted of the following in 2010:

Surveys were conducted by MDA for seven exotic tree pests as part of the Bundled Nursery Survey,
MDA contracted with the Maine Forest Service (MFS) on a trapping survey for certain exotic pine commodity pests as part of the Pine Commodity Survey,
MDA contracted with The University of Maine Pest Management Office on a trapping survey for exotic Lepidoptera pests of apple,

In addition several other surveys were administered through the CAPS program including:

Potato Cyst Nematode (PCN) national survey,
Forest Pest Outreach and Survey Project (FPOSP),
a delimiting and transition zone survey to detect the spread of gypsy moth,
surveys related to the current regulated area in Maine to prevent spread of European larch canker (ELC),
surveys for pine shoot beetle (PSB).

Details of these surveys can be found in this section as well as throughout other parts of this report.

Lepidopteran Pests of Apple Survey

The MDA contracted with The University of Maine Pest Management Office on a trapping survey for exotic Lepidoptera pests of apple - summer fruit tortix (Adoxophyes orana), variegated golden tortrix (Archips xylosteanus), and red-belted clearwing (Synanthedon myopaeformis). Pherocon 1C traps with pheromone lures were deployed on edges of 22 monitored commercial apple orchards, in nine counties between June and August. Traps were checked biweekly. No target moths were found.

Forest Pest Outreach and Survey Project (FPOSP)

MDA staff coordinated the Forest Pest Outreach and Survey Project (FPOSP), a continuation of the successful Northeast Forest Pest project, a region-wide effort to build an awareness program aimed at early detection of Asian longhorned beetle (ALB), emerald ash borer (EAB), and other invasive forest pests. A part-time coordinator was hired to manage the volunteer program. A large number of state and federal agencies cooperated on this project, including: The Nature Conservancy, USDA APHIS PPQ, USDA NRCS, Maine Department of Conservation, University of Southern Maine, University of Maine Cooperative Extension, Master Gardeners, Small Woodlot Owners of Maine (SWOAM), various soil and water conservation districts, Acadia National Park, Penobscot Nation Department of Natural Resources, etc. For 2010, 57 new volunteers were trained (59 in 2009) to conduct outreach on ALB and EAB, which resulted in over 215 outreach efforts. The governor signed a proclamation proclaiming August Asian longhorned beetle awareness month. There was numerous TV and print media coverage throughout the summer season. Two high-risk surveys were conducted – one at Sebago Lake State Park and one in Lewiston. No ALB or EAB have been found in Maine, although there is definitely increased awareness about these beetles.

Apiary Program

Registration and Interstate Movement

In 2010, 621 Maine beekeepers registered 6,975 hives. Approximately 52,000 hives managed by 36 commercial beekeepers entered Maine for blueberry and apple pollination. Hives were also rented to cranberry, small fruit and vegetable growers for pollination and were situated on canola and buckwheat acreage for honey production. The majority of migratory hives left Maine after blueberry bloom for crop pollination and honey production in other states. 14,176 hives were issued Maine health certificates for interstate movement.

Inspection and Disease Detection

Throughout the year 4,137 colonies were surveyed at random and 1,416 opened, sampled and inspected for disease and parasites. American foulbrood (Paenibacillus larvae) (2.05% of inspected hives), European foulbrood (Melissococcus pluton) (0.91%) and Sacbrood virus (2.47 %) were found. The frequency of sacbrood detected in 2010 was the highest since 1986 (2.5%). Many colonies were found with mild to acute infections of Chalkbrood disease (Ascosphaera apis). South African small hive beetle (Aethina tumida, SHB) infestations were common in migratory beekeeping operations, package bees and nucs shipped to Maine from the south. Over wintered populations of the SHB have been documented in the 10 southern Maine counties.

Like 2009, commercial beekeeping operations were not surveyed for Africanized honey bees. 41 hives were sampled and microscopically examined for honey bee tracheal mite (Acarapis woodi). 11 hives from 10 beekeeping operations were positive. Nosema was detected in 80.41% of the 291 hives sampled from the brood area and examined microscopically.

The mild winter, early spring and ample early honey flow of 2010 contributed to elevated Varroa populations. The excessive mite loads, associated viral complex and poor nectar production during late summer/fall resulted in colony losses due to robbery, Varroa collapse, and colony collapse disorder (CCD) like symptoms during the fall. In mid-late October several beekeepers reported collapse of hives that were populous and had consumed and stored sugar syrup fed for wintering purposes. Unlike previous accounts of CCD, the collapsing and dead hives were being robbed of stored honey and sugar syrup on warm days when bees were able to fly.

2010 was the first year that CCD-like symptoms were documented in Maine since the fall of 1994 when apiaries collapsed in a similar fashion. Samples of honey bees and brood sent to the USDA in 1994 resulted in the detection of several bee viruses. It is probable that the collapse of hives during the fall of 2010 was due to the excessive Varroa infestations and associated viral/pathogen complex.

Outreach

There was an increase in bee, wasp and hornet inquiries from the public in 2010. The most common requests for assistance pertained to: bees in swimming pools, swarms, bees in chimneys and wall voids, clusters of bees at truck stops, on fuel pumps and at rest areas. A few individuals with allergies to bees called the department about regulations pertaining to the location of their neighbor’s hives.

During 2010 the state apiarist presented 30 lectures, workshops and field sessions to various bee associations, farm organizations and the general public. There is an increased awareness about bees and farming practices among the general public and an interest in bee culture.

Board of Pesticides Control

Pesticide Use and Applicator Licensing

The Board of Pesticides Control (BPC) licenses applicators (Private and Commercial) and dealers (limited/restricted and general use products). As of March 2010, there are 1113 active private licensees, 1433 active commercial licensees, 208 spray contracting firm (business) licenses, 51 limited/restricted use dealers, and 830 general use dealers.

Legislation

Currently there are four bills in the Legislature to amend or repeal the aerial and air blast notification registry that was established by the Legislature in 2010. There are also bills to change the composition of the Board of Pesticides Control (replace one of the public members with a new member who has horticulture experience), ban almost all pesticide applications at schools and day care facilities and to require all agricultural commodity growers that sell over $1000 of produce to be minimally certified to use any pesticide.

FOREST INSECT AND DISEASE CONDITIONS

Courtesy of the Forest Health & Monitoring Division, Maine Forest Service, Maine Department of Conservation (MFS). Once it is published the more detailed summary report “2010 Forest and Shade Tree Insect and Disease Conditions for Maine” will be available on the MFS website www.maine.gov/doc/mfs/AnnSummIndex.htm

Firewood Regulation

In April 2010, the Legislature passed LD 1607, An Act to Regulate the Transportation of Firewood, which banned import of untreated firewood into Maine. An Emergency Order was signed enacting regulations to implement the ban on firewood. Details of the Emergency order can be found at http://www.maine.gov/doc/mfs/fhm/pages/firewood_out_of_state_ban.html. Heat treatment certification and labeling protocols are being finalized to ensure that commercial dealers and campers have ways to acquire treated firewood. In 2011, MFS will be conducting formal Rule Making for the final firewood rules.

As part of the transition to new regulation in 2010, the (MFS) worked with partners in the private and public sector to escalate public education and outreach efforts, and inform the visiting public about the new ban. An initial effort was a firewood exchange for incoming tourists conducted by MFS forest rangers over Labor Day weekend.

Elongate Hemlock Scale

Elongate hemlock scale (Fiorinia externa, EHS) was first detected in Maine in August 2009, in a planted hedge in Kennebunkport, on the southern Maine coast. In 2010, EHS was detected on eastern hemlock in the forest in Kittery, also on the southern Maine coast. This is the same part of Maine where hemlock woolly adelgid is also found. EHS range expansion is expected to follow that of hemlock woolly adelgid. The most vulnerable areas of the state are likely within 20 miles of the coast. It is most likely to be found in the southern- and mid-coast areas, but along with hemlock woolly adelgid it is quite conceivable it could be found in downeast coastal regions as well. In addition to being a serious forest pest, elongate hemlock scale eventually may become a significant problem for Christmas tree growers in Maine.

Browntail Moth

Towns where browntail moth was most prevalent in 2009 again saw high populations in 2010. Towns most affected were Bath, West Bath, Bowdoinham Brunswick, and Topsham. In 2009 a dry May and cool June led to a moth population explosion. The mild winter weather of 2009-2010 followed by an early, warm spring allowed for high larvae survival rate and early spring emergence causing the newly emerging foliage to be stripped from trees. The populations were high enough that it caused considerable stress to residents. The early emergence of larvae in 2010 may prove to be a benefit in 2011 as many larvae may have had a difficult time finding food and starved to death.

Pine Commodity Survey

The MDA contracted with the MFS on a trapping survey for certain exotic pine commodity pests as part of the CAPS Pine Commodity Survey. This program built upon earlier CAPS-supported exotic bark beetle and pine shoot beetle surveys using a subsample of the previously monitored sites, with additional investigation and trapping at new sites. Specifically, five previously sampled import/manufacturing sites (those with a high pine component) were surveyed for pine beetles (Hylurgops palliates, Hylurgus ligniperda, Ips subelongatus, Orthotomicus erosus), and eleven pine plantations/stands were surveyed for moths and woodwasps (Dendrolimus pini, Dendrolimus superans, Sirex noctilio). Three lindgren funnel traps with the recommended combination of lures were deployed for surveying bark beetles, and tetratraps, milk carton traps, and lindgren funnel traps were used to survey for Dendrolimus moths and Sirex, respectively. Brown spruce longhorned beetle (Tetropium fuscum) was surveyed for at ten sites around lumber mills and in adjacent parks and campsites using a single Colossus cross-vane trap baited with a spruce-blend lure. None of the target specimens were found, although a non-target exotic bark beetle (Xyleborus seriatus), found only in Massachusetts and Maine, was again recovered.

European Gypsy Moth

The MFS received PPQ funding through MDA to conduct a delimiting and transition zone survey to detect spread of gypsy moth into unregulated towns in northern Maine in order to maintain the current quarantine boundary. No defoliation of hardwoods resulting from gypsy moth larval feeding was recorded in 2010. The 2010 fall egg mass survey indicates that the population will remain at endemic levels next season.

European Larch Canker

The MFS received PPQ funding through MDA to conduct surveys related to the current regulated area in Maine to prevent the spread of European larch canker (ELC). No new locations were found or reported in 2010 for this disease. A re-inspection of the Brunswick (Cumberland County) site at which a small eradication effort was completed in 2008 revealed one additional infected tree, which was sanitized by removal of the branch bearing a single canker. Re-inspections of the site will continue for at least another three years.

MFS assistance was again provided to the larch canker intensification project in Washington County being conducted by Dr. David Houston (Retired, USDA Forest Service). The project entered its final phase, as sample trees in three of the study stands were harvested for detailed analysis. A final report of findings will be available when data analysis is complete.

Pine Shoot Beetle

The MFS received PPQ funding through MDA to conduct surveys for pine shoot beetle (PSB) which has been trapped previously in two Maine counties. Fourteen of Maine’s 16 counties are regulated. MFS and PPQ shared trapping responsibilities in the two unregulated counties. No PSB were recovered.

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