Ag Day visitors can do the ‘waggle dance’ at beehive exhibit

April 27, 2012 under CANR News

There’s something for almost everyone at Ag Day, this Saturday, April 28, at the University of Delaware. There’ll be pony rides, farm tours, the UD Botanic Gardens plant sale, sheep-shearing demos and free-flight bird shows. And, at one of the most popular attractions, a chance to see an open beehive and learn how to do the “waggle dance.”

Debbie Delaney, a UD assistant professor of entomology and wildlife ecology, is responsible for the Ag Day bee exhibit, which is staffed by her graduate and undergraduate students.

“Visitors do seem to like the bee exhibit,” acknowledges Delaney. “In recent years, I think people have become more aware of the critical role that bees play in pollinating crops – here in North America they’re responsible for pollinating some 90 crops.”

Beyond that, notes Delaney, “bees are fascinating social insects. People want to learn more about them. Take the ‘waggle dance,’ performed by honeybees. With this figure-eight dance, honeybees are able to tell their hive mates where to find patches of flowers, water, new housing locations and more. The direction of the dance demonstrates the angle other bees should fly to find the nectar source.  And the speed of the movements indicates the value of the source.”

At Ag Day, waggle dances and open beehive demonstrations (by veiled beekeepers in a cage) get the most attention. But visitors who check out the rest of the exhibit will discover that UD’s bee program is abuzz with activity.

“It’s an exciting time to be a bee researcher at UD,” says Delaney. “We have lots of going on, from the addition of a second apiary to several innovative research projects.”

Delaney is starting the second year of a research study to see if bumblebees improve crop productivity. Before this project, bumblebee research hadn’t been conducted in Delaware since the 1940s. But Delaney and her co-researcher, Gordon Johnson, a Cooperative Extension fruit and vegetable specialist, see potential in bumblebees.

“Over the past decade, managed honeybee populations have been in decline due to colony collapse disorder and other factors,” says Delaney. “In response, growers and researchers have started to pay a lot of attention to native pollinators, and in particular, to bumblebees.”

Delaney also is excited that the University will soon be home to two apiaries — the existing 22-hive teaching apiary and a new research apiary operated in collaboration with Penn State University and supported by the Environmental Protection Agency. Delaney and other researchers will use this apiary to study non-chemical ways to manage parasites in colonies.

The teaching apiary, tucked below mature black locust and tulip poplar trees, is the hands-on classroom for Delaney’s beekeeping class. Her students steward their own hives and learn bee biology and beekeeping skills. Plus, the honey that these students collect can now be purchased. “Dare to Bee Honey” is sold exclusively at the UDairy Creamery. The first batch of the 2012 season should be available for sale in late July or August.

Grad student Katherine Darger doesn’t utilize either UD colony for her bee research. Working closely with Delaney, Darger is testing for Africanization tendencies in unmanaged colonies from Florida to Maine. However, since Darger says she is “happiest when knee-deep in a colony,” she tries to get out to the UD hives as much as she can.

She will be showing off her hive-handling skills at Ag Day, performing several of the caged demonstrations, which take place at 10 a.m., 1 p.m. and 3 p.m.

Darger likes Ag Day and other public events almost as much as she likes being in the apiary. “I love doing outreach,” she says. “I hope to inspire more people to become beekeepers, plant gardens to attract and support native insects, and reduce the fear that draws people to insecticide cans.”

Article by Margo McDonough

Photo by Danielle Quigley

This article can also be viewed on UDaily

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CANR Study Abroad Blogs

January 10, 2012 under CANR News

Many of our CANR students are spending winter session studying abroad.  Follow them on their journeys through the blogs that they and/or their faculty leaders are writing.

Brazil http://udbrazil.blogspot.com (Plant and Soil Sciences)

Dominica http://dominica2012.wordpress.com/ (Food and Resources Economics/Geography)

Singapore and Indonesia http://agdev.anr.udel.edu/longwoodgradblog/ (Longwood Graduate Program in Public Horticulture)

Tanzania http://udtanzania2012.blogspot.com/ (Entomology and Wildlife Ecology/Art)

In addition, there is another CANR study abroad program traveling to Ecuador and the Galpagos (Plant and Soil Sciences/Biology). For more information about University of Delaware study abroad programs, visit UD’s Institute for Global Studies website.

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Native Delaware: Beneficial Spiders

October 27, 2011 under CANR News, Cooperative Extension

A big, furry, fake spider, dangling over a doorway or front porch, should produce a few screams from unsuspecting trick-or-treaters — before they dissolve in giggles when they discover that this particular arachnid is made of plastic.

As for real spiders, people don’t have much to fear, especially here in Delaware, according to Brian Kunkel, an entomologist with University of Delaware Cooperative Extension.

Most large, hairy, and scary-looking spiders, such as the wolf spider, will hurt a fly but they won’t hurt you.

“Delaware’s native spiders are more friend than foe,” says Kunkel.  “Only one poisonous spider is found in Delaware, the black widow. Of course, for those who are allergic, any spider bite can be a problem.”

Spiders are considered beneficial because they keep insect populations in check. Insects and spiders are both classified as arthropods but insects have three body parts and six legs, while spiders have two body parts and eight legs. In addition, spiders have two hand-like appendages called pedipals that they use to hold food. The pedipals contain sensory organs that allow spiders to taste their food. These sensory organs also are found on the spider’s legs.

The majority of spiders have eight eyes but despite all those eyes most spiders have bad vision, says Kunkel.  An exception is the jumping spider, which relies on its keen eyesight to locate its next meal. After spotting its prey, this spider takes a flying leap and, if successful, lands right on top of it. The wolf spider also captures its prey by hunting and chasing it down, though it’s more a sprinter than a jumper.

Another group of spiders captures its prey by using the ambush method – they just hang out, motionless, until a tasty little insect comes along into easy grasping range.

Constructing a web is the most common method that spiders use to capture prey. Web spinners in Delaware include the orb weaver, comb-footed, sheet web and funnel web spiders.

When it comes to dining habits, spiders are generalists, meaning they’re a lot like the guy at the smorgasbord sampling one of everything. In contrast, the monarch butterfly caterpillar is a specialist because it eats milkweed and only milkweed. If you want to attract spiders to your yard – so they’ll gobble up all the bad bugs – plant a variety of plants and plant types, says Kunkel. Use as little pesticide as possible; it can kill spiders as well as the pest insects.

“Spiders are a sign of a healthy garden,” says Kunkel. “They are often the most important biological control of pests in the home landscape as well as on cropland. In addition, spiders are a good source of food for birds and small mammals, particularly in winter and spring.”

Doug Tallamy, chair of UD’s Department of Entomology and Wildlife Ecology, can personally attest to the role of spiders in controlling pests. The first summer he lived in his house it was overrun with flies, thanks in part to a nearby horse barn.

Then Tallamy and his wife began transforming their barren yard. “When we moved in, the yard supported little more than mustard grass and ragweed,” he says.

After he planted a wide variety of native trees and plants, the wildlife came – everything from bluebirds to spiders.

“One predator, in particular, that I saw pouncing on the flies is a species of jumping spider,” says Tallamy. “These small but powerful spiders learned that our windows are great hunting grounds for flies.”

Because our trees and shrubs have grown since that first summer, the jumping spider now has plenty of places to hide and lay its eggs. And our native plantings provide an alternative food source, as well.”

So go ahead and scare someone with a fake spider this Halloween – just don’t scare off the real, beneficial spiders in your yard and garden.

Article by Margo McDonough

Photo by Evan Krape

View the original post on UDaily by clicking here.

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Stink Bug Season

October 3, 2011 under CANR News, Cooperative Extension

Pull up the welcome mat; they’re back. It’s early fall in Delaware, which means pumpkins on the vine, apples on the trees and stink bugs in the house.

“Last year, I got a flood of calls about stink bugs during the last week of September,” said Brian Kunkel, an entomologist with the University of Delaware’s Cooperative Extension. “Sure enough, this past week, Extension has been hearing from homeowners trying to get rid of stink bugs.”

“As the days grow shorter and the evening temperatures cooler, Delawareans are discovering these uninvited houseguests in their garages, porches and decks, as well as inside the house,” Kunkel said. “The brown marmorated stink bug becomes a nuisance pest when it heads inside to find overwintering sites.”

While merely an annoyance to most homeowners, the brown marmorated stink bug (BMSB) poses an economic threat to Delaware agriculture. Fruit crops seem to be at greatest risk, especially peaches and apples. About 18 percent of the mid-Atlantic apple crop had stink bug damage last year, according to the U.S. Apple Association.

“West Virginia apple orchards experienced significant crop loss last season because of the BMSB,” Kunkel said. “Here at UD, we’re doing everything we can to make sure that we don’t see the kind of crop loss that West Virginia had.”

Several of Kunkel’s colleagues in Extension and UD’s College of Agriculture and Nature Resources are researching BSMBs in soybean, lima bean, sweet corn, field corn and sweet pepper fields.

Two of the most active researchers are Joanne Whalen, the Extension’s integrated pest management specialist, and Bill Cissel, an Extension associate who is investigating stink bugs as part of his graduate studies.

Cissel and Whalen, assisted by two interns, are examining stink bugs in conditions similar to home yards and gardens, too. In UD’s Garden for the Community, a one-third-acre plot on the Newark campus, the duo surveyed stink bug nymphs, adults and egg masses on plants commonly grown in home gardens — tomatoes, zucchini, yellow squash, cucumbers, eggplant, sunflowers and bell peppers. Plus, they’re studying a plot of ornamental plants to see which plants stink bugs use as hosts.

Rutgers University, Virginia Tech, the University of Maryland and the Delaware Soybean Board are some of the partners on one or more of these projects.

Although Delaware has several native stink bugs, BMSBs originates in Asia and were accidentally introduced to the United States. First collected in Allentown, Pa., in 1998, BMSBs have been spreading across the eastern half of the U.S. ever since.

Kunkel said spiders and birds have been known to eat BMSBs (he’s heard reports of house cats eating them, too) but the pest has no recognized natural predator here.

The USDA Beneficial Insects Introduction Research Lab, housed on UD’s campus, is investigating biocontrol measures. Biocontrol introduces natural predators into an environment to control, if not eradicate, the pest problem. But the rigorous research process and government approvals needed for biocontrol measures can take years, even decades.

Delaware’s farmers are asking for help now. So the focus of Whalen and Cissel’s research is on monitoring to determine when to control stink bugs, as well as which insecticides provide the best control.

Field observations in 2010 indicated that stink bug infestations usually start on the perimeters of fields, Cissel noted. “We’re studying whether perimeter applications of insecticides will prevent stink bugs from penetrating the interior parts of soybean fields,” he said.

“In our corn research, we are trying to determine how much damage stink bugs are causing and when the plant is most sensitive to damage — is it when it’s silking, during grain fill or closer to harvest?”

Insect research projects typically run for two to three seasons, and most of the UD studies are in their first year. So it’s too early to discuss preliminary results, Cissel said, especially since the BMSBs weren’t as active this summer as previously.

“We had a really large outbreak last year,” Kunkel said, “but we’re not seeing those kinds of numbers this year.”

Tell that to Kathy Fichter, a resident of Chadds Ford, Pa.

“It’s just as bad as last year and it’s only the beginning of stink bug season here,” said Fichter, who always has a tissue at hand, ready to scoop up stink bugs. “My two sons won’t go near them, and these are boys who like bugs,” she said.

“Our neighborhood seems to be a ‘vacation destination’ for stink bugs. They come here by the hundreds, maybe even thousands,” she added. “My neighbors are in the same predicament. Yet, a few miles away, they aren’t such a nuisance.”

Kunkel isn’t surprised by Fichter’s stink bug woes, even though regional conditions are generally better. “Stink bug outbreaks — and insect outbreaks in general — tend to be localized,” he said. “We often hear of one neighborhood getting slammed while another neighborhood a half-mile away will have very few bugs.”

If the BMSB already has arrived at your house — or you want to make sure it doesn’t — take control measures now. The best thing you can do, Kunkel said, is to seal all cracks around windows, doors, siding, utility pipes and chimneys. Often overlooked, he said, are the cracks that can appear around dryer vents and gaps around window air-conditioning units.

“Try to look on the bright side,” Kunkel said. “Stink bugs that get inside are helping you to winterize your house. Wherever they got in today is where the cold winter winds will, later this year.”

Article by Margo McDonough

This post also appears on UDaily.

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Corn Hybrid Trial Tour, Meeting

August 16, 2011 under CANR News, Cooperative Extension, Events

All farmers and crop advisers are invited to attend the University of Delaware corn hybrid variety trial and twilight meeting on September 1, 2011. The corn hybrid plots will be open for viewing at this irrigated location starting at 4:00 p.m. Extension specialists will be on hand to discuss insect pest management in corn, management of diseases commonly found in our area, and weed control issues. Optimizing nutrient applications in corn will also be discussed. Dinner will be provided. CCA, DE Nutrient Management, and DE Pesticide credits will be available. Contact Phillip Sylvester, Extension Ag Agent, Kent County, with questions at 302-730-4000 or email at phillip@udel.edu.

When: Thursday, September 1, 2011
Time: 4:00 PM to 7:30 PM
Location: Dickerson Farms, 1730 Bayside Drive, Dover, DE (From Rt.1, take the Rt. 9 exit towards Little Creek. Farm entrance is on the right after Bergold Lane.)
Registration: Please RSVP by calling (302)-730-4000 by August 29 or email Phillip Sylvester phillip@udel.edu.

Schedule:
4:00 to 5:30 Sign-in and Tour Corn Hybrid Plots, Dr. Richard Taylor, Extension Agronomist and Tecle Weldekidan, Scientist, UD
5:30 to 6:00 Dinner
6:00 to 6:20 Late season insect pest update, Joanne Whalen, Extension IPM Specialist, UD
6:20 to 6:40 Common corn diseases in Delaware, Bob Mulrooney, Extension Plant Pathologist, UD
6:40 to 7:00 Weed control issues in corn, Dr. Mark VanGessel, Extension Weed Specialist, UD
7:00 to 7:30 Optimizing nutrient applications in corn, Dr. Greg Binford, Associate Professor and Extension Specialist of Soil Fertility, UD

Submitted by Phillip Sylvester

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Enchanting Butterflies

July 18, 2011 under CANR News

Sheila Vincent may be the only person in Delaware who gets paid to catch butterflies. Every summer day, Vincent heads out with a net and collects butterflies, caterpillars and larvae to stock Ashland Nature Center’s Butterfly House.

As group program coordinator for the Delaware Nature Center, Vincent spends the bulk of her time teaching natural history programs and only about 15 minutes with her butterfly net. “I really look forward to butterfly catching. It’s a bit of peace and quiet during hectic workdays,” she says.

Last season was a “spectacular butterfly season,” according to Vincent and this summer looks to be shaping up to be a good one, too.

“Most years, butterflies are abundant in Delaware from June through August,” says Brian Kunkel, an entomologist with University of Delaware Cooperative Extension. “Mid-July to mid-August is typically the peak of activity.”

But bad weather or insufficient food sources can be game changers. Two years ago, the butterfly season was lackluster because of too many cool, rainy days. Other times, host plants may not be well developed.

Delaware is a good place for butterfly watching. There are about 120 species of resident breeding butterflies in the state. Some entomologists make a distinction between butterflies and skippers – in which case, there are 70 species of butterflies and 50 of skippers. Named for their rapid flight pattern, skippers have small, angular wings and bodies that are proportionately larger than true butterflies, says Kunkel. There’s even a skipper known as the Delaware skipper because it was first spotted here.

But speedy skippers aren’t good for teaching purposes. Monarchs are Vincent’s go-to butterfly for nature programs, especially when she’s working with kids. Monarchs are fairly slow, abundant and easily recognizable. Her own personal favorites include the pipevine swallowtail, a relatively rare species that has orange spots and iridescent blue wings. Vincent also appreciates what she calls the “somber beauty” of the mourning cloak butterfly, which is dark brown with yellow borders around the wings and a row of blue spots.

The black swallowtail butterfly, which has distinctive yellow and bright-blue markings, tops Kunkel’s list of favorites. His wife grows herbs on their deck and always plants dill or fennel, which attract black swallowtails and their caterpillars. Kunkel also likes the Eastern-tailed blue. The males are usually light blue and the females a charcoal color but some varieties are pink or purple.

When Kunkel was a boy, he saw scores of Eastern-tailed blues in his yard every summer. That’s because his parents weren’t perturbed by a bit of clover in the their lawn.

“The caterpillars of Eastern-tailed blues feed on clover,” says Kunkel. “If you eradicate every piece of clover in your yard, I guarantee you won’t see any Eastern-tailed blues.”

Kunkel says he’s a “lawn guy,” who loves a carpet of green, but he’s happy to let clover or wild strawberries coexist with turf. He also can handle a little leaf damage on ornamental plants for the sake of the butterflies.

“Don’t get overly excited about caterpillars on your plants,” he says. “Yes, they’ll munch on some leaves but if you want butterflies, you’ve got to have host plants for the larvae, too.”

Vincent has incorporated plenty of host plants for caterpillars, as well as food plants for butterflies, into her New Castle yard. Her perennials include butterfly weed, milkweed, phlox, asters and goldenrod.  She also plants parsley and fennel in the ornamental beds to attract black swallowtails.

If your yard isn’t lepidoptera friendly just yet, there are other places to spot butterflies. To see the largest number, as well as the most species, choose a sunny, open location – like a meadow or field – that features plant diversity. Vincent recommends the meadow at Ashland Nature Center, Middle Run Natural Area, and White Clay and Brandywine Creek state parks.

Kunkel suggests the UD Botanic Gardens, which opened its Lepidoptera Trail in 2009. This self-guided interpretative trail showcases trees, shrubs, wildflowers and native grasses that provide food for butterflies and moths during both the caterpillar and adult stages. Right now, the Trail is abundant with butterflies.

Special events

• Open House in the Native Plant Teaching and Demonstration Garden will be held Monday night, July 18. Join Kunkel for a plant, pest and beneficial insect walk. Get your questions answered about butterflies, caterpillars and other insects. New Castle County Cooperative Extension Office, Newark. 6-8 p.m. For more information, call 831-COOP or email cjmurphy@udel.edu.

• A Mid-Summer Night’s Stroll through the Gardens will be held Wednesday, July 20. Watch butterflies feast on natives on the Lepidoptera Trail and enjoy all the mid-summer blooms in the UD Botanic Gardens. Live steel drum music and light refreshments. 4-6:30 p.m. Reserve a spot by contacting Donna Kelsch, 831-2531 or botanicgardens@udel.edu.

Article by Margo McDonough

Photo by Danielle Quigley

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Nature’s Fireworks

July 11, 2011 under CANR News

 Annelid worms do it. Certain species of centipedes and millipedes do it. Even a tropical land snail can do it.

But here in Delaware, fireflies and glow worms are the only terrestrial creatures that light up the night with their own built-in flashlights.

Bioluminescence results from a chemical reaction in which chemical energy is converted to light energy, according to Doug Tallamy, chair of the University of Delaware’s Department of Entomology and Wildlife Ecology in the College of Agriculture and Natural Resources.

Fireflies (Lampyridae) aren’t actually flies and glow worms (Phengodidae) aren’t really worms. Both are considered to be beetles and are closely related species.

The fireflies’ glow adds beauty to a summer night but there are several pragmatic reasons for bioluminescence, too. Fireflies and glow worms light up to attract the opposite sex. Adult fireflies, both male and female, flash coded messages to attract prospective mates. Males fly about while they flash, females usually flash while hanging out in bushes. It’s all about “speed dating” not lengthy courtships — there’s no time to waste since adulthood only lasts for about two weeks.

There’s another reason why fireflies light up, at least in the case of juvenile larvae. Almost a decade ago, UD scientists led by Tallamy discovered that baby fireflies light up to keep predators at bay.

Previous studies had shown that mice and other would-be predators shun adult fireflies because of a compound in fireflies’ body that produced a bitter taste. The UD study demonstrated that baby fireflies flash to advertise that they also exhibit this bitter taste.

“A flashing neon sign may lure hungry humans to an all-night diner but the bioluminescence of firefly larvae sends a very different message to would-be predators,” says Tallamy.

Summer season

This summer is shaping up to be a good but not spectacular season for fireflies.

“Lightning bug populations at my house have been strong but not record-breaking,” says Tallamy. “In general, populations fluctuate from habitat availability more than from weather. However, if we get a bad drought during the summer and fall that does impact the population of lightening bugs the following summer.”

Fresh strawberries for a few short weeks around Memorial Day. Carnival rides at the State Fair for 10 days in July. Like other summertime pleasures, firefly season is short-lived.  “Nature’s fireworks” begin a few weeks before July 4th and are at their peak now. By the end of July they’re gone, save for a few stragglers.

Where to find different species

Several species of fireflies can call themselves native Delawareans. The beach region of Sussex is home to the coastal firefly, which prefers sandy, even salty, soil and generally stays close to the ground. Inland Sussex and Kent counties are home to yet another species. But the greatest diversity in firefly species is found north of the Chesapeake and Delaware Canal, says Tallamy.

“Fireflies are especially abundant in the Piedmont region, in the northernmost part of Delaware,” he says. “Most firefly species favor ‘old field habitat.’ In New Castle County, that type of habitat is most commonly found around the White Clay and Red Clay creeks and along the Brandywine River.”

At first glance, one species of firefly may not look much different from another. But pay close attention to fireflies as they begin to light up. “If you look closely, you’ll start to notice some distinct variations in their flash pattern,” says Tallamy.

There are three characteristics that differentiate firefly species:

  • Where the fireflies are located. Some species like to be close to the ground; others prefer shrubs and low trees.
  • The flight track, or style of flying, varies from species to species. Some fly in a “J” pattern then swoop down low, others take looping flights.
  • The pattern of the bug’s flashing. Think of the flashes like Morse Code — do they resemble a dash-dash-dash pattern or dash-dot-dash?

If your kids like to catch fireflies and put them in a jar, go for it, says Tallamy, as long as you punch some holes in the lid and release the fireflies after a few hours. Fireflies are beneficial insects; in their larval form they feed on garden and crop pests.

Article by Margo McDonough

The article can also be viewed online on UDaily.

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Happy National Pollinator Week

June 21, 2011 under CANR News

Debbie Delaney looked like she was feeling the heat on a recent 95-degree day at the University of Delaware apiary, despite the shade of black walnut and tulip poplar trees. It was hard to tell how the 22 hives of honeybees – some two million bees in all – were handling the steamy weather.

But Delaney, an assistant professor of entomology and wildlife ecology in the College of Agricultural and Natural Resources, had no worries. “Bees are much better at thermoregulation than humans are,” says Delaney. “Honeybees maintain strict temperature control. The colony always stays between 89 and 92 degrees, ideal for a honeybee, and the humidity never varies more than 5 percent. Worker bees flap their wings to cool the air and some periodically leave the hive to reduce the effects of body heat.”

Delaney has been researching bees for years but continues to be amazed at their abilities, including staying comfortable in the heat while we wilt. She’d like to see bees get a bit more respect — if not the all-out enthusiasm she displays.

She’ll have an opportunity to spread the word about bees this week, which marks National Pollinator Week. The event recognizes not only bees but all pollinators – birds, butterflies, bats and beetles. One in every three bites of food humans consume has been made possible by one of these pollinators.

Pollinator Partnership, a nonprofit organization that sponsors the week, calls bees the primary pollinator of most plants. Delaney agrees, with a slight qualification.

“Bees are definitely the most important pollinator in our state in terms of the numbers and the importance of the crops they pollinate,” she says. “But bats also are important in a different way. Bat-pollinated flowers generally open at night and have distinct floral tube sizes and shapes that can accommodate bats.  So bats are very important pollinators for a certain subset of plants.”

Even while giving bats their due, Delaney rattles off the Delaware crops that bees do pollinate: apples, asparagus, blueberries, broccoli, cabbage, carrots, cantaloupe, cucumber, eggplant, honeydew melon, nectarines, peaches, pears, peppers, pumpkins, okra, onion, squash, strawberries, tomatoes and watermelon. She’s quite sure she has missed a few. After all, bees pollinate more than 90 crops in North America.

Non-native honeybees are responsible for some of this pollination. But Delaware’s native bees deserve credit, too.

There are at least 200 native bees in the state, according to the state Department of Agriculture, which recently completed a five-year study of native bees. “Recent research has shown that native bees can play a major role in pollinating agricultural crops,” notes Delaney. “Native bees often will visit flowers in wet or cold weather when honeybees don’t want to come out of their hives. And farmers who use managed honeybees will see increased yields when native bees interact with the crops.”

Wild honeybees – descendants of honeybees introduced by European colonists – also play a role in agricultural pollination. Research on these feral bees may even help combat colony collapse disorder, a poorly understood syndrome that can wipe out entire hives of managed honeybees.

The Feral Bee Project, sponsored by North Carolina State University, asks beekeepers and “citizen scientists” to log the location of wild honeybee hives at the Save the Hives website.

“Colony collapse disorder in domestic honeybees continues to be a major concern,” says Delaney. “We still don’t know the cause or causes of this syndrome. But the Feral Bee Project may give us a better understanding of the role that natural resistance plays in fighting disease or environmental stress, as well as a better understanding of genetic components that contribute to ‘survivor stock.’”

Learn more

To find out more about pollinators and National Pollinator Week, go to the Pollinator Partnership website.

The Brandywine Zoo will be hosting “Pollinator Power” on June 25, a family friendly event from 10 a.m. to 4 p.m.

Article by Margo McDonough

Photos by Danielle Quigley

This article can also be viewed online on UDaily by clicking here.

 

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Ducks in the dark

June 14, 2011 under CANR News

Orrin Jones is doing field work using night-vision riflescopes to study the behavior of the American black duck.

Chris Williams and his University of Delaware research team employ standard tools of the trade for waterfowl research – core drills for core sampling, binoculars for waterfowl viewing and lots of coffee for long stints in duck blinds. But Williams may be the first wildlife biologist to use apparatus more commonly seen on the battlefield – night-vision riflescopes.

Williams, associate professor of wildlife ecology in the College of Agriculture and Natural Resources, is studying the behavior of the American black duck to determine if there are adequate food resources on the Mid-Atlantic coast to support this dabbling duck, which has been identified as a “species of concern” by the U.S. Fish and Wildlife Service.

Although there’s lots of data on the daytime behaviors of the black duck, up until now no one had a good idea what it was up to at night.

“We were aware that the American black duck isn’t exclusively diurnal because of anecdotal knowledge about its nighttime calls,” says Williams. “But we didn’t know the extent of its nocturnal activities because we didn’t have the tools to study this.”

Until recently, night-vision technology wouldn’t have been up to the challenge of detecting subtle movements in the dark-colored (and aptly named) black duck, which is just 13 to 19 inches in height. But night-vision technology has improved dramatically since the military began using it extensively during the Iraq war. The latest devices can amplify light up to 50,000 times, producing clear images even on moonless nights.

It’s critical for Williams to know what black ducks do at night, as well as during the day, so he can accurately determine how much energy the birds expend. With this data, Williams and his research team will be able to establish an area’s “carrying capacity,” the number of birds a habitat can support.

“Habitat loss is a threat to the American black duck,” notes Williams. “Nationwide, black ducks have declined by as much as 60 percent. We need to understand the carrying capacity for the black duck so we can make appropriate land management decisions.”

Graduate student Orrin Jones led the field research for the project, which took place in Edwin B. Forsyth National Wildlife Refuge, six miles north of Atlantic City.  American black ducks overwinter on the Jersey shore, as well as refuges and open land on Delaware’s coast, from November through March.

Field work is never a piece of cake but the black duck project could have qualified for that old reality show America’s Toughest Jobs. Jones, graduate student Jeremiah Heise (who is studying the Atlantic brant but helped with the duck research) and four technicians divvied up round-the-clock shifts, five days a week.

Because it was important to study the duck’s behaviors in a variety of habitat, from high marsh to mud flats, some study sites were only reachable by boat. After 15-minute paddles in a canoe or hour-long motor boat rides, Jones would settle in for the 9 p.m. to 3 a.m. shift and painstakingly record each time a duck swam, flew or preened. Weather ran the gamut – the infrequent mild spell, but more often, cold, rain, snow or outright blizzard conditions.

“We only missed one day of observation, during the 2010 Super Bowl blizzard, because the snow was too deep even using our 4×4 work trucks,” he says.

But for Jones field work is a piece of cake compared to what this summer holds – hour after hour inside a climate-controlled laboratory, where Williams’ research team is cataloging how much energy was available in the marsh core samples.

Working in the laboratory as part of the black duck research are Zariel Johnson, Alexandra Joesten, Amanda Dunbar and Marissa Goldstein.

“I enjoy the challenges of rugged field work; it’s one of the reasons I got into avian research,” says Jones. “It’s going to be hard to be stuck inside.”

Hard but necessary. It takes about 64 hours in the lab to analyze data from each quadrant of marsh studied, estimates Williams. All told, that’s 8,000 hours of lab work for Williams’ research team.

“The American black duck was once one of the more abundant waterfowl species in eastern North America,” says Williams. “I hope this research gives us a much better understanding of the black duck’s habitat needs.”

Article by Margo McDonough

Photos by Danielle Quigley

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Stink bugs shouldn’t pose problem until late summer

April 1, 2011 under CANR News, Cooperative Extension

Last fall, Stephanie Sturmfels battled stink bugs at her Pike Creek home and yard. “Stink bugs were on my deck, they were on my front porch, some were even in my house,” recalls the mother of two small children. “My four-year-old daughter, Madison, would go around and collect stink bugs in pieces of tissue.”

Now that spring has arrived, Sturmfels is worried that stink bugs may return in full force. So far, she has seen a few stink bugs but nothing like the invasion last September and October.

Brian Kunkel, a UD Cooperative Extension entomologist, has some good news for Sturmfels and anyone who despises the brown marmorated stink bug. “The adult stink bugs that were driving people crazy last fall will be giving birth this June and dying off soon afterwards. From now until then, they will be too busy feeding on plants in the landscape to spend much time around houses.”

“Their offspring — the nymphs — will spend most of the warm-weather months outside as they mature. They don’t feed in houses so you shouldn’t expect to see many on decks and patios or inside houses this summer,” adds Kunkel.

Best yet, nymph stink bugs can’t fly — they have wingbuds but not mature wings — so they can’t land in your hair, on your shoulders, or in a bowl of potato salad, the way those annoying adults were doing last autumn.

So rest easy and host a Memorial Day or Fourth of July cook-out, says Kunkel. You shouldn’t worry about scads of brown marmorated stink bugs crashing the party. However, when Labor Day rolls around, your guest list could unexpectedly rise.

“By late August, the nymphs have become adults and are able to fly,” says Kunkel. “What’s more, they start to congregate in houses, decks, garages and other warm spots during this time period. There is a lot that researchers don’t yet understand about the stink bug’s behavior but we do know that cooler temperatures at night motivate them to seek shelter.”

Twenty-six states now have populations of the non-native brown marmorated stink bug. If you have friends in other regions who shrug off stink bugs as a minor annoyance, you may have already guessed that Delaware has more of the critters than most places.

“This region is the epicenter of the stinkbug outbreak,” says Kunkel. Brown marmorated stink bug were first found in this country in Allentown, Pa. They arrived in 1998, as stowaways in packing crates from Asia, where they’re native. Here in the U.S., they have few natural predators. Some spiders, including arboreal spiders, feed on the brown marmorated stink bug.

“Don’t get rid of spiders in your yard and garden,” notes Kunkel. “Spiders are beneficial. In addition to stink bugs, they eat a wide variety of other pests.”

Keep in mind, though, that not all of Delaware’s stink bugs are bad guys; a native stink bug known as the spined soldier bug eats aphids and other pests. Delaware is home to three other native stink bugs: green, brown and dusty.

The brown marmorated stink bug has been more of a nuisance than a pest in the home landscape, thus far, but Delaware’s agricultural industry is monitoring the insect closely. This stink bug feeds on many plants, including lima beans and sweet corn, but is a particular threat to fruit-bearing trees.

“There are some orchards in other states that may go bankrupt this year because they had so much fruit damage from the brown marmorated stink bug last year,” says Kunkel.

He and other UD experts are launching several research projects aimed at protecting Delaware’s growers. One project will focus on when the stink bugs arrive in fields or at greenhouses, their life cycle, and the natural enemies (native parasitoids, predators) attacking this pest. Another project will evaluate the effectiveness of insecticides against the brown marmorated stink bug.

According to Kunkel, current insecticides provide little help in keeping this pest out of the house. Exclusion is the best approach. “Seal up every opening — caulk around windows, repair screens, install screens over your attic vents and replace any rotten wood on your house,” says Kunkel.

And take comfort in the fact that you won’t have stink bugs landing in your hair until later in the summer.

Article by Margo McDonough

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