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Friday, March 24, 2017

EAB discovered in Goodhue County

Jeffrey Hahn, Extension Entomologist

The following is based on a recent news release by the Minnesota Department of Agriculture.

The Minnesota Department of Agriculture (MDA) has placed Goodhue County under an emergency quarantine after emerald ash borer (EAB) was found in the city of Red Wing earlier this month.

An MDA employee noticed an ash tree with significant woodpecker damage, a tell-tale sign of possible EAB infestation, during a hike over the weekend at Barn Bluff. She took photos of the tree and noted the location. After further investigation, the MDA found EAB larvae in the tree. Today the USDA officially confirmed the insect to be emerald ash borer.

There are several things residents should look for when checking for emerald ash borer.

• Be sure you’ve identified an ash tree. This is an important first step since EAB only feeds on ash trees. Ash have opposite branching – meaning branches come off the trunk directly across from each other. On older trees, the bark is in a tight, diamond-shaped pattern. Younger trees have a relatively smooth bark.

Now is a good time to look for woodpecker
pecking on an ash as this often indicates an
EAB infestation.  Photo: Jeff Hahn, U of M
• Look for woodpecker damage. Woodpeckers like EAB larvae and woodpecker holes may indicate the presence of EAB.

• Check for bark cracks. EAB larvae tunneling under the bark can cause the bark to split open, revealing the larval (S-shaped) tunnels underneath.

• Contact a professional. If you feel your ash tree may be infested with EAB, contact a tree care professional, your city forester, or the MDA at or 888-545-6684 (voicemail).

Minnesotans can also help stop the spread of EAB by burning firewood where you buy it and don’t transport it. Look for wood that is MDA certified as heat-treated to ensure it is pest-free.

Because this is the first time EAB has been identified in Goodhue County, the MDA is enacting an emergency quarantine to limit the movement of firewood and ash material out of the county. This will reduce the risk of further spreading the tree-killing insect. Currently 14 other Minnesota counties are under quarantine to prevent the spread of the emerald ash borer.

Emerald ash borer larvae kill ash trees by tunneling under the bark and feeding on the part of the tree that moves nutrients up and down the trunk. The invasive insect was first discovered in Minnesota in 2009 and is now found in 30 states.

For more information on EAB, see the University of Minnesota Extension fact sheet Emerald ash borer in Minnesota

Go here to see the original MDA news release.

Monday, February 6, 2017

Forest Pest First Detector workshop registration now open

Jeffrey Hahn, Extension Entomologist

Consider registering for a 2017 Forest Pest First Detector (FPFD workshop. Anyone interested in forests, trees and invasive pests, including foresters, arborists and master volunteers (who are comfortable with tree identification), are welcome to attend a FPFD workshop and become FPFD volunteers if they wish.
Velvet longhorned beetle, one of the invasive pests that are
covered in FPFD workshops. Photo: WikiMedia Commons

New this year, we're going to incorporate more of a flipped classroom approach for our face-to-face workshops with significant technical and species specific content provided before the workshop through the University of Minnesota's online learning platform, Moodle. This will allow workshop participants more hands-on time with pest displays, time to talk and brainstorm with content specialists and more peer-to-peer learning during the workshop. So whether you are new to Forest Pest First Detectors or have previously attended a workshop, there will be something new and fresh for everyone.

This year’s workshops are at:

Cloquet Forestry Center, 175 University Rd, Cloquet, MN 55720 (Thursday, March 2, 2017, 8 AM - 3 PM)

Oakdale Discovery Center, 4444 Hadley Ave N, St Paul, MN 55128 (Wednesday, March 8, 2017, 8:30 AM - 3:30 PM)

Workshop registration is $50, payable online. To register for either of these workshops and for the online Moodle modules, go here [Be sure to "Add to Cart" to continue with the online registration. For registration questions contact UMN Extension Forestry Program Coordinator, Emily Dombeck:].

For additional information on the Forest Pest First Detector program, visit our FPFD website.

Hope to see you in March,

Angela Gupta and the Forest Pest First Detector team

Friday, January 27, 2017

Boxelder bugs inside homes during winter

Jeffrey Hahn, Extension Entomologist

With the recent mild weather we have experienced, some residents have been finding boxelder bugs and lady beetles in their homes. This is actually not unusual in the middle of the winter. These insects remain inactive as long as their hiding places in various wall voids, attics, and other nooks and crannies in and around buildings remain cold. However, if we receive mild, sunny temperatures, this can cause these overwintering insects to break their dormancy and become active. They then move towards the warmth inside the building where residents find them crawling around. Once active, they do not live much more than a few days to about a week.
Boxelder bugs do not damage property but can be very
annoying when found indoors.  Photo: Jeff Hahn, U of M

Despite the circumstantial evidence; these insects are not laying eggs and reproducing indoors. All of the boxelder bugs or lady beetles that are seen indoors now entered buildings last fall. Unfortunately, there are not many good options for dealing with boxelder bugs and lady beetles at this time of year. It is not possible to prevent them from emerging from wall voids and other spaces. And once they become active in your home, they only realistic option is to physically remove them, e.g. with a vacuum cleaner.

The best time to deal with boxelder bugs and other insects that seek harborage for the winter is in late summer or fall before they start to move into buildings. The best methods for reducing these insects are seal up cracks and spaces that may allow them into your home combined with a timely treatment of an appropriate residual insecticide. Some insects will still get inside but you should be able to reduce the number that would otherwise get inside.

For more information, see the University of Minnesota Extension publication Boxelder bugs.

Thursday, January 26, 2017

Plight of the bumble bee: MN's threatened and endangered bumble bees

Elaine Evans, Extension Educator, Entomology/Pollinators/Bee Lab

Bumble bees are a common site in most Minnesota gardens, but some species have become increasingly uncommon, particularly over the last 20 years. Historically, Minnesota is home to 23 of North America’s 48 bumble bee species. Five species out of these 23 are in serious decline with severe loss of range as well as declines in numbers of bees. Another 3 species are in decline, though the losses are not as dramatic. This means that over one in three bumble bee species in Minnesota are vulnerable to decline. Although bumble bees may still be a common site in gardens, prairies, meadows, and fields, the bumble bee community you are seeing today is most likely a less diverse
group of bumble bees.
The rusty-patched bumble bee is now on
the endangered species list.  Photo:
Heather Holm

On December 11th, 2016, one of Minnesota’s declining bumble bee species, Bombus affinis, the rusty-patched bumble bee, was listed as an endangered species by the U.S. Fish and Wildlife Service. This is the first bumble bee to be given this status and the first bee in the continental U.S. In the United States, endangered species are protected by the Endangered Species Act of 1973, which as amended, is one of the most far-reaching wildlife conservation laws ever enacted by any nation. The listing focuses conservation planning and funding, raises awareness, and by regulation protects listed species from intentional and unintentional harm.

Historically, the rusty-patched bumble bee was commonly seen throughout its range which spread from Minnesota to the east coast, north into southern parts of Canada and south through the Appalachian mountains. Declines were first noticed in the late 1990s. Through the efforts of both professional and citizen scientists, evidence shows that rusty-patched bumble bee populations have declined by about 87%. In addition, their geographic distribution has decreased. They are only found in about 13% of their former range. While evidence of the decline is clear, the cause or causes of the decline are not fully understood. The probable causes include disease (possibly transmitted by managed bumble bees), habitat loss, climate change, and pesticides.

The greater Twin Cities area is one of a handful of areas where the rusty-patched bumble bee is found with regularity. As Minnesotans, we have an opportunity before us to prevent the extinction of a species! Bee-friendly gardening could be a key step in preserving this species. Plant flowers, including flowering trees and shrubs preferred by bees. Aim to have something blooming at all times between mid-April and September. Native plants are a great choice for supporting bumble bees, as well as other native wildlife. Avoid pesticides. If you can’t avoid pesticide use, apply them only where needed and avoid drift into non-target areas. Join efforts to document the rusty-patched and other declining bumble bees. Get out your camera this summer and join Bumble Bee Watch. Strap on your boots and volunteer for bumble bee surveys in the Twin Cities with the Minnesota Bumble Bee Survey or state-wide with the Minnesota Bee Atlas. Together, we can help the recovery of the rusty-patched bumble bee.

Monday, January 23, 2017

Caring for your amaryllis

Julie Weisenhorn, Extension Educator

'Picotee' - note the thin red
margins on the white petals
Whether the first bulb or the fiftieth, there is high anticipation for the plant owner when the large, bright green bud emerges from a beefy amaryllis bulb! Amaryllis may be purchased as bare or planted bulbs, and are prized for their exotic trumpet-shaped flowers born on 1 to 2 foot leafless stalks or “scapes.” They add dramatic color to homes and gardens, and make wonderful gifts to gardeners from beginners to experts. Read more on the new Extension publication Growing and Caring for Amaryllis

Tuesday, December 27, 2016

Caring for Your Norfolk Island Pine

By Beth Berlin, University of Minnesota Extension

Many people will receive a Norfolk Island Pine for the holidays. These beautiful evergreen trees can become a wonderful houseplant with the right care for many years to come.

Norfolk Island Pines, Araucaria heterophylla, is not actually a pine tree. It is a coniferous evergreen native to Norfolk Island in the South Pacific near Australia.  They have short dark green needle-like leaves with broad spanning branches that give it a tiered appearance.  In its native climate they can reach 200 feet tall with a ten foot diameter trunk.  As a houseplant it is very slow growing, only growing about 3-6 inches per year, but can reach a height of 5-8 feet.

To care for a Norfolk Island Pine, place it in a bright, sunny location. Be sure to spin your plant each week so that it doesn’t start to lean or grow towards the window and light. In general Norfolk Island Pines can be kept at 65-72°F, but it is important not to expose them to extremes, both hot and cold.  The minimum night time temperature this plant will tolerate is 50-55°F. The plant will perform best where night time temperatures are about 10°F cooler than the day temperatures.

Humidity is important for nearly all houseplants. The Norfolk Island Pines prefer higher humidity than what most of our homes are in the winter time, preferably around 50% humidity.  Placing a humidifier nearby may help alleviate dry air. Fertilize when plants begin to put on new growth, typically March through September. However the plant will tolerate very little fertilizer which will minimize growth and keep the plant shorter and grow slower. The plant prefers moist roots but doesn’t like to be wet so be sure to have a well drained soil and container.  Water thoroughly once the top one-inch of the soil is dry.

Norfolk Island Pines that experience wet soil and low light conditions may have lower limbs drop off. Some may experience needle drop which could be caused by dry conditions, including soil moisture, lack of humidity, or either cold or hot drafts or airflow. However in general this is a fairly pest free plant and can be enjoyed for decades if well kept.

Thursday, December 1, 2016

Weeds in the Turf Lawn: Invasive Nuisances or Sources of Forage?

By James Wolfin, Graduate Research Assistant

The turf lawn accounts for nearly 2% of the continental United States land cover, and has become engrained in the architecture of many United States neighborhoods and landscapes.  As urban and suburban areas continue to expand, we can expect this number to increase as many yards, store fronts, and commercial buildings are installed to accompany properties.

While the planting of turf lawns alongside most properties is a standard practice, the management practices and personal perceptions of those managing lawns are variable.  Lawns differ in the level of input that is imparted by the landowner.  Input generally refers to the effort that is directed towards maintaining the aesthetics of the lawn, normally in the form of mowing, watering, weeding, and fertilizing.  While each of these practices are generally required to ensure proper turf health, how frequently inputs are applied can vary greatly.  Practicing responsible lawn maintenance practices may be obvious in certain situations.  For example, mowing too frequently can be hazardous due to the fossil fuel emissions let off from a motorized lawn mower and excessive watering or fertilizing can cause harm in the form of runoff, leading to algal blooms in bodies of water.  What may be less obvious are the impacts of weed management practices.  Many land managers differ in the way they perceive weeds, which can have a great impact on the biodiversity that is supported by a lawn.

A weed is generally considered a plant that is undesirable in a lawn for any reason, often due to aesthetics.  Many land managers place a premium on maintaining a uniform, green turf, and believe weeds are a disruption or a nuisance.  What may go unnoticed, however, is the benefit that weedy flowers can have in terms of supporting biodiversity, especially for pollinators.  Weedy flowers often produce nectar and pollen which are collected by pollinators, including honey bees and wild (native) bees.  These floral rewards are essential to the diet of bees, as nectar serves as the main source of carbohydrates in a bee’s diet, while pollen serves as the main source of protein.  While it is impossible to discuss every weedy flower that may exist in a lawn, specific flowers that are popular in lawns or are especially beneficial to pollinators are important to consider.

White CloverWhite Clover
White clover (Trifolium repens) is one of the most common lawn weeds that land managers may encounter.  White clover is often indicative of soils that have low fertility or a situation where lawns are mowed to a very low height.  This plant spreads through a stoloniferous growth habit, where lateral stems grow at or just above the soil surface.   White clover is easily recognizable due to its distinctive leaves, which appear in the form of a three-leaf trifoliate.  Once established in a lawn, white clover will bloom from mid-spring through the fall, generally peaking in May and June.  The blooms of white clover appear in the form of a white flower head that is attractive to a great diversity of bees.   The medium sized blooms provide an adequate landing pad for larger bees, including bumble bees and honey bees, but are also visited by smaller bees.  White clover is a significant source of both nectar and pollen for bees, making it a great addition to a home lawn or garden in terms of supporting biodiversity.  White clover can also benefit overall lawn health due to its ability to fix and add nitrogen to the soil, supporting healthy plant growth.  White clover will bloom at low heights, which will allow a landowner to maintain a normal lawn height (~3.0”) while still supporting bees.

Self-heal (Prunella vulgaris) is a forb from the mint family, Lamiaceae, that receives its name from its history in folk medicine.  A sub-species of this flower, Prunella vulgaris ssp. Lanceolata, is native to Minnesota, making self-heal a useful addition for landowners that want to attract native pollinators.  This flower will grow in home lawns, especially moist areas that receive partial shade.  The central stem of a self-heal flower is distinctive due to its spiked, hairy vegetation that stands upright.  The striking flowers have a violet color and a whorled bloom, giving a tubular shape to the flower.  The tubular shape of self-heal flowers make the nectaries difficult to reach for short-tongued bees.  As a result, self-heal is most frequently visited by long tongued bees, like bumble bees and honey bees (tongue size is strongly correlated with body size).  Self-heal is able to withstand regular mowing, blooming at heights as low as two inches.

Creeping thyme
Creeping thyme (Thymus serpyllum) is another flower from the mint family (Lamiaceae) that is most commonly found in sandy soil areas, but has the ability to establish in a variety of habitats.  Creeping thyme grows by spreading lateral stems in the form of above ground stems (stolons) or below ground stems (rhizomes).  Closely related to the culinary species of thyme, Thymus vulgaris, this species also retains a strong, herbal scent.  The leaves of this plant grow low to the ground in opposite pairs, with flowers that will bloom at heights as low as one inch.  The flowers are pink-purple in color, and form small, open blooms.  The size of these blooms makes the rewards accessible to smaller bees, like mining bees, but may also be visited by honey bees.  In addition to supporting bees, this plant also serves as important habitat for butterflies.  Two species of butterflies, the small blue butterfly and the large blue butterfly, will lay eggs on the vegetation of creeping thyme.  Their larvae will then feed on the leaves before maturing into adult butterflies.  Creeping thyme is also useful as a border plant for gardens, as it acts as a natural deer deterrent.  

Dandelion (Taraxacum officinale) is a common perennial lawn weed not only throughout the Unites states, where it is present in every state, but globally.  Dandelion is native to Europe and Asia, but is now present on all continents except Antarctica.  This herbaceous forb is able to establish in a wide variety of conditions and will bloom in full sun, part sun, or full shade.  Dandelion is found frequently in disturbed soils, especially those that are high in potassium content.  The leaves of dandelion vary in size based on the age of the plant, but are easily recognized by their unique, lobed shape.  Dandelion has conspicuous yellow flower heads, containing many individual ray flowers.  This species spreads easily once established in the soil due to dandelion’s prolific seed production and the ability of these seeds to be distributed widely by the wind.  Dandelion does not require pollination and is able to reproduce via apomixes, a form of asexual reproduction in plants.  Despite this, dandelion still produces nutritious pollen that is moderately high in crude protein content.  Although it is often considered a nuisance in residential and recreational lawns, a wide range of insects use dandelion as a source of forage, including many types of bees.  Honey bees, bumble bees, and a variety of solitary bee species will use this plant as a source of both nectar and pollen.  Dandelion can survive and bloom despite mowing at low heights, making it an ideal candidate for a bee-friendly lawn.

Creeping CharlieCreeping Charlie
Creeping Charlie (Glechoma hederacea, aka ground ivy) is an aggressive lawn weed species that is found in every state in the United States, except for certain parts of the Southwest (NV, AZ, NM).  This plant is considered an invasive species in some habitats, and tends to thrive in disturbed sites that are shady and poorly drained.  Once established in a soil, creeping Charlie will spread quickly through aggressive stolons, forming mats that provide dense ground cover.  The flowers of creeping Charlie are easily recognizable, with small, purple, tubular flowers arising from upright, square stems.  Creeping Charlie has been the subject of heavy debate as to whether or not it should be used as a forage source for bees and other pollinators.  While it has many desirable qualities, including ease of establishment and a low-growing nature, recent research suggests that creeping Charlie is not an ideal forage source due to its unique pattern of nectar production.  Creeping Charlie exhibits wide ranges in both the quantity of nectar that it produces, and in the quality of the nectar (sugar concentration).  While some flowers of creeping Charlie will produce great amounts of nectar high in sugar concentration, the average flower from this plant produces less than half the nectar quantity seen in comparable flowers like white clover.  On average, nectar from creeping Charlie is higher in sugar concentration than that of white clover; however the range in sugar concentration is much more extreme.  Because of this, creeping Charlie is considered an inconsistent source of nectar for visiting pollinators, and should be omitted for more reliable alternatives like dandelion and white clover. 

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