Forest Insect and Disease Newsletter
In 2013, the Minnesota Department of Agriculture (MDA) and partners caught a record number of male gypsy moths. Male moths are surveyed using sticky traps baited with the gypsy moth female sex pheromone. The presence of a high number of male moths suggests a reproducing population. This year, 13,903 traps were placed across the state and picked up 71,258 moths, almost three times the previous record of 28,000 caught in 2009! And almost all of those caught this year were trapped along the North Shore (see map of 2013 Gypsy Moth Trapping Results).
Pockets of heavy moth captures were inspected for signs of alternate life stages, and several egg masses, pupal cases, one adult female moth and one larva were discovered in a total of 17 different sites. The majority of these were found in the area just north of Silver Bay.
The combination of high moth captures and alternate life stages along the North Shore prompted two responses. First, the national gypsy moth Slow-the-Spread program adjusted their action zone boundaries westward to include more of St. Louis County (see Slow-the-Spread Action Zones map). This is the zone in which future treatments designed to disrupt gypsy moth mating are most likely to occur. The second response is a recommendation from MDA that Cook and Lake Counties be quarantined beginning in April 2014.
More details are to be released in January, 2014 and a public comment period will be announced to discuss the need for and the potential impacts of the recommended quarantine.
No new counties were added to the emerald ash borer (EAB) quarantine this year, which is good news. However, surveys within existing infestations indicate that EAB is slowly expanding its range. New finds in the metropolitan area indicate that EAB occurs across a slightly larger area than previously mapped (see EAB Status map). In Winona County, tree mortality as a result of EAB infestation indicates that EAB population numbers are increasing in that area.
The only new infestations found were in New Brighton (in Ramsey County and already under quarantine) and in Superior, Wisconsin. Douglas County in Wisconsin is now under quarantine as a result of that infestation. Preliminary surveys in the Duluth area across the bridge from Superior failed to produce any signs of EAB. A more intensive survey will be conducted later this winter when woodpecker damage may be more noticeable.
A federal grant was received in 2012 to map and prioritize treatments of buckthorn across an area that ranges from Sandstone to Detroit Lakes. South of that area, buckthorn infestations are common and dense, impacting forest sustainability. North of that area, buckthorn is either absent or present in relatively small infestations (although some of these can be quite dense). This project was designed to better understand factors affecting the spread and establishment of buckthorn, and where possible, to slow its spread through local treatment projects.
Each fall, native tree species drop their leaves one to two weeks before buckthorn turns color and drops its leaves. That gives us a short window during which buckthorn infestations can be seen from the air. In early November 2012, just over 300,000 acres of state forest and wildlife management area land were flown and stereo-paired photographs taken. The photographs were then interpreted to locate suspected pockets of buckthorn.
Approximately 100 polygons of suspected buckthorn were mapped. A subset of these polygons was checked on the ground this summer to confirm or disprove the presence of buckthorn. Most of the sites checked were not buckthorn, but lowland alder or understory conifer in stands of mixed hardwoods. Based on those results, 2013 flight plans were adjusted to include a broader set of land and soil types. In November, 2013 another 300,000 acres of state lands were flown and additional photography taken. These photographs will be interpreted during the winter of 2014 and ground-checked in summer. The results will be used to assess factors associated with the presence of buckthorn.
In the meantime, state partners will be looking at areas where treatments may be useful. As funding allows, local treatments will be executed over the next two years. Final project results will be available in 2015.
With a combination of state and federal funds, work on three other invasive plant projects took place in 2013. A grant from the US Forest Service allowed all state lands and selected private lands within the Kettle and St. Croix Scenic River ways to be inventoried and infestations treated. The inventory work was completed in 2010 and 2011. Management projects were carried out in 2012 and 2013. The results of that project will be covered in the next issue of the Forest Insects and Disease Newsletter.
With funding received from the Division of Ecological and Water Resources, two other projects were begun in 2013. In one project, St. Croix state forest land impacted by the 2012 blow-down event will be inventoried. Once mapped, infestations will be prioritized and treated as funding allows. In the other project, buckthorn in the Zumbro Bottoms area of the Richard J. Dorer Memorial Hardwood State Forest will be treated using cut-stump treatment methods. Both projects are scheduled to finish in 2014.
PlayCleanGo: Stop Invasive Species In Your Tracks is an outreach and education program designed to disrupt the link between outdoor recreation and the spread of terrestrial invasive species (those that occur on land). The program was branded in 2011 and launched in 2013. This year the first annual PlayCleanGo Day was held at six park locations on June 8, 2013. The second Saturday of June is National Get Outdoors Day, and the DNR state parks open house day (with free admission), so the parks were full of people. PlayCleanGo (PCG) volunteers were able to talk to over 2000 park visitors about the threat of invasive species and steps they can take to avoid spreading them.
PCG also launched ad campaigns through Facebook and Google. The pop-up ads were seen by over 8 million people, resulting in an average of 6,500 actions (such as "likes," "friends," and "tweets") per month between July and October (29,323 total in 2013).