UD alumna studies leatherback sea turtles in Costa Rica

February 17, 2014 under CANR News

UD alum Lauren Cruz studies leatherback sea turtles in Costa RicaIt’s not every day that you get to see a creature that has been around for 110 million years emerge from the ocean and lay its eggs on the beach. Unless, of course, you’re like University of Delaware graduate Lauren Cruz, who spends her days in Costa Rica with the Leatherback Trust studying leatherback sea turtle nesting ecology.

Cruz, a 2013 graduate who studied wildlife conservation in UD’s College of Agriculture and Natural Resources, is tracking the demographics of the turtles that nest at Playa Grande and Parque Nacional de las baulas — which translates to the park of leatherback sea turtles — and spends her nights with a team patrolling the beach looking for nesting turtles.

When they find a turtle, they will scan it to see if it is a returning turtle. If not, they will outfit the turtle with a tag in order to track it.

“We also count the eggs, and sometimes we have to relocate the eggs, depending on whether they’re close to the water, close to the vegetation, and then after they lay the eggs, we monitor their nests and see them through until the hatchlings grow out of the nest,” said Cruz.

Cruz has worked with the organization since October and said her favorite part of the work is the turtles, but that she also enjoys learning about the Costa Rican culture.

“What’s great is that out here they have a good ecotourism program where the locals — a lot of them who used to be poachers — found that it’s more sustainable to take tourists out to see the turtles rather than take their eggs,” said Cruz, who explained that the organization will work with groups of locals to help locate nests.

“When we find a turtle, we tell them so they can grab their tourist and it’s just a great experience working with the local Costa Ricans,” Cruz said. “And my Spanish has gotten much better since I’ve been here. So it’s a cultural experience and I really like working with the community and the education aspect of it.”

Cruz said that so far this winter, they have had 24 individual leatherback sea turtles nest on the beach. She said that this figure is in line with the amount they had last year, but they are hoping to see an increase any time soon. The nesting season lasts until March so there is still some time and Cruz is optimistic that they will have more turtles nest on the beach.

Still, when compared to numbers from the past, it becomes obvious why leatherback sea turtle conservation is of the upmost importance. “When they first started doing this project, 20 years ago, they’d have 1,000 individuals or so on the beach so it’s sad that it went from 1,000 to 20,” said Cruz.

Cruz said that while the leatherback turtles who nest on the Caribbean coast have seen a population rebound in recent years, ones that nest on the Pacific coast are still critically endangered. “A major facet to their endangerment is the development because so many people want this beach,” said Cruz. “They want to develop on it and they want to build hotels, and when they build hotels they emit a lot of light and also change the topography of the beach so it makes it unusable for turtles to nest on it anymore.”

Cruz also said that climate change is a threat to leatherback sea turtles, as the species is temperature dependent on determining if a turtle will be male or female. “The pivotal point for the sex ratio of leatherback sea turtles is 29.4 degrees Celsius, so any nests that incubate above that temperature will be mostly female and any nests that incubate below that temperature will yield mostly males,” said Cruz.

Because the sand heats up sooner and there is a shorter wet season, the turtle clutches are hypothesized to yield more females than males, which will ultimately lead to a population decline. Cruz also said she has observed the eggs in the nest have been heating above their critical temperature which has cut down on nest success.

The other big threat is long line fisheries that catch leatherback sea turtles in their hooks.

As for how she got interested in turtles, Cruz said that it happened during her time at UD. “It’s definitely something that came about at UD. While at UD, I was able to participate in a lot of different research projects to figure out what I was really interested in because I knew I loved wildlife but I wasn’t sure what kind of animal or what kind of area I wanted to work with,” said Cruz.

Cruz said that it was while at UD on a study abroad trip with Doug Tallamy, professor of entomology and wildlife ecology at UD, that she fell in love with sea turtles and with Costa Rica. “I think that’s a big factor as to why I’m here and was selected for the position, because I had known of Costa Rica and had traveled here before. And also, the first time I came to Costa Rica with study abroad, I wasn’t really into birds until the end of the trip and then I really got into birding and really just fell in love with the place.”

Cruz said that it was on that trip that she gained hands on experience with sea turtles, as the group spent couple of nights on a research station and released olive ridley sea turtle hatchlings.

She added that while she loves working with sea turtles, she is “trying to keep my options open and get experience working with other species. I know that I’m interested in coastal environments and studying sea turtles is just kind of what happens naturally,” said Cruz. “But I’m also interested in shore birds and I think a lot of that interest was sparked at UD with ornithology classes.”

Cruz recently accepted a position for the summer as a “Teen Team Facilitator” with the Earthwatch Institute, where she will supervise high school students as they travel on environmental research based expeditions abroad in the Bahamas and Puerto Rico.

“I’m excited for this opportunity because it is similar to the UD study abroad program that sparked my interest in this type of research,” said Cruz. “Additionally, I believe education is a major driver of conservation and am pleased to be able to pass on this similar experience with other students.”

Article by Adam Thomas

Photos by Lauren Cruz

This article can also be viewed on UDaily.


Tallamy urges ecofriendly management of natural habitats

December 9, 2013 under CANR News

Dr. Douglas Tallamy speaks about wildlife animals and reptiles to a crowd of retired faculty at the December UDARF meeting.Doug Tallamy believes that if nature, as we know it, is going to be saved, humans will have to do a much better job of managing the ecosystems that support the biodiversity of life on our planet.

Tallamy, professor of entomology and wildlife ecology at the University of Delaware, discussed the importance of biodiversity and ecosystem protection during a luncheon meeting of the UD Association of Retired Faculty held Tuesday, Dec. 3, in Clayton Hall.

The author of Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens, (Timber Press 2007), Tallamy began his “Network for Life: Your Role in Stitching Together the Natural World” presentation by recalling President Theodore Roosevelt’s 1908 dictum of “leave it as it is” to those who advocated mining the Grand Canyon.

“It is no longer an option to leave most of our country as it once was,” Tallamy said. “Only five percent of the lower 48 states are even close to being in a pristine ecological state.”

The remaining areas, Tallamy said, have been logged, tilled, paved, drained, grazed or otherwise developed, with rivers either straightened, dammed and, in some cases, not even reaching the sea.

This state of environmental degradation can be traced to a failure to abandon the adversarial relationship with the natural world that enabled hunter-gatherer societies to survive, Tallamy said.

“Remember, it was nature that ate us, froze us, drowned us, starved us and destroyed our crops, and the more we beat back nature, tamed it or eliminated it, the better off we were,” Tallamy said. “Our war against nature worked in the past without causing ecosystem collapse because there were so few of us. Understanding this is the key to fixing the problems we have created.”

Fragmented into small, isolated pockets, the natural world has been carved into tiny remnants of its former state, with each area too small to sustain the species that run its ecosystems, Tallamy said.

Tallamy cited a study of the number of Eastern box turtles living on a 35-acre woodlot just east of the athletic facilities on UD’s south campus that has been isolated for the past century.

“When the study began in 1968, researchers found 91 turtles. There were 22 in 2002 and in 2010 there were just 12 turtles found in that woodlot,” Tallamy said. “When you take large populations of species and shrink them down to tiny populations, they are highly vulnerable to local extinction.”

Ecosystems function locally, Tallamy said, and recent research suggests that every species counts.

“We need them all, because biodiversity runs our ecosystems,” Tallamy said. “Biodiversity is essential to ecosystems because it increases stability, improves biogeochemical processes, increases productivity and decreases susceptibility to biotic invasions.”

A viable alternative to fragmentation and local species extinction is the creation and expansion of corridors linking these isolated habitats, Tallamy said.

Convenient opportunities for building such corridors include mountain ridges, riparian corridors, cross-country power lines, roads and rangelands.

“We need to expand our traditional definition of a corridor, because the ones we have are not big enough,” Tallamy said. “Biological corridors must do more than facilitate movement — they must support life.”

For such corridors to become viable connections they need to become functional habitats populated with native plants that support biodiversity and sustain ecosystems, Tallamy said.

“The more plants you have, the more animals you will have saved,” Tallamy said. “Plants provide all of the food and much of the shelter for the animals that run our ecosystems. Plants are literally a matter of life and death.”

With more than 3,300 nonnative plants introduced in the United States, selecting native species that support animal life is key to restoring the balance of nature, Tallamy said.

“Most insects, especially the ones birds eat, develop and reproduce only on the plants with which they share an evolutionary history,” Tallamy said. “We must use the knowledge that most insects are specialists to build corridors that support effective food webs.”

Land management alternatives can also be adopted in residential areas where the norm is having a large lawn and decorative plants that don’t sustain beneficial insects and the birds that feed on them, Tallamy said.

“The typical suburban yard has 90 percent less tree biomass than the natural woodlot habitats, and we have landscaped these areas the way we do because we now see plants only as decorations,” Tallamy said. “Future criteria for choosing plants for our landscapes need to include a sizeable percentage dedicated for food web, watershed, wildlife and soil restoration, accompanied by a more balanced percentage of plants chosen for decorative value.”

Tallamy said that the world is entering a new era, the ecocene, where ecological sustainability will not be just a tired cliché but a globally embraced mandate.

“Our age-old need to destroy the life around us in order to survive will be replaced by the ethical and ecological imperative to sustain it, because we have no other choice,” Tallamy said. “I for one cannot wait for the ecocene, and you won’t either. If we practice conservation in our public spaces, our work places and in our yards, we will enrich our lives.”

Article by Jerry Rhodes

Photo by Kathy F. Atkinson

This article can also be viewed on UDaily.


Doug Tallamy receives the Tom Dodd, Jr. Award of Excellence

September 17, 2013 under CANR News

Doug Tallamy receives the Tom Dodd, Jr. Award of ExcellenceDoug Tallamy, professor in the Department of Entomology and Wildlife Ecology at the University of Delaware’s College of Agriculture and Natural Resources, was presented the Tom Dodd, Jr. Award of Excellence at the Cullowhee Native Plant Conference held at Western Carolina University this summer.

Tallamy was also chosen to be a presenter at the conference for his ideas on promoting change in the landscape paradigm. “Right now, about 80% of our ornamental plants are from Asia,” said Tallamy. “Our local insects can’t eat them because they haven’t evolved to deal with the defensive chemicals within the plants. Now at the same time, 96% of birds are rearing their young on insects. In fact, about six to nine thousand caterpillars are used to rear one clutch of chickadees. So we end up creating these landscapes that are actually one of the biggest hits on biodiversity.”

Robert Wyatt, professor Emeritus of Botany and Ecology at the University of Georgia and current Director of the Cullowhee Native Plant Conference, said Tallamy is likely to be the rare entomologist chosen for the award, as past award recipients are typically botanists.

Tallamy was chosen for the award in part due to the popularity surrounding his 2007 book, Bringing Nature Home. The book makes a strong scientific case for reintroducing native plants to landscapes and eliminating the “urban deserts” created by planting an abundance of nonnative ornamentals.

Tallamy said that there is a need for ecological literacy, and stresses the importance of increasing public awareness for why native plants are so important ecologically in terms of retaining biodiversity.  His attendance at this conference is a testament to his own goal of wanting to re-landscape the entire country.

In the past 30 years that the Cullowhee Native Plant Conference has been held, the number of native plant nurseries has increased substantially as more homeowners have come to value the beauty and understand the benefits of a natural landscape.

Invasive Species

Looking at invasive exotics such as Kudzu, Chinese privet, and Japanese honeysuckle, it is easy to understand the uncontrolled dispersal and harm invasive species can have on a landscape. Free from predators, these species have affectively displaced many surrounding native plants while offering little to no food for wildlife living in the area.

The reintroduction of native species could potentially thwart the damages caused by the introduction of some of these aggressive plants.

Other examples of the potential dangers nonnative species can cause includes unintentional introduction of pests and subsequent disease, like the American Chestnut, whose nuts provided a prime food source for many animals, and whose populations were decimated by an introduced fungus.

Not all nonnative species are detrimental. However, their decreased utility by wildlife as a food source and often uncontrolled growth means that introducing them at a greater rate than native species can adapt to them could lead to decreased diversity in an ecosystem.

Examples of some native trees that people could start planting as alternatives to nonnatives include Smooth Witherod and Winterberry, which have berries that birds depend on, Redbud, which provides a convenient nectar source for early pollinators, Summersweet Clethra, another popular pollinator shrub, and Pipevine which serves as a food source for Swallowtail larvae.  With their colorful flowers and berries, these plants offer all the aesthetics that homeowners and landscapers tend to seek in nonnative ornamentals.

About the Tom Dodd, Jr. Award of Excellence

The Tom Dodd Jr. Award of Excellence is presented annually at the Cullowhee Conference on Native Plants in the Landscape and are given to individuals who excel in one of the following areas: conservation of native flora in sites; studying and promoting the understanding of our native flora; building expertise in the propagation/cultivation of native plants; and the use of native plants in a diversity of natural and designed landscapes.

Past winners have included C. Ritchie Bell, professor of botany at the University of North Carolina at Chapel Hill, Founding Director of the North Carolina Botanical Garden, and co-author of the Manual of the Vascular Flora of the Carolinas; Dick Bir, professor of Horticulture and plant breeder at the Mountain Horticulture Research Center of North Carolina State University; and Lady Bird Johnson, former First Lady of the United States and an avid proponent of native plants and natural areas.

Article by Angela Carcione


‘Earth Perfect?’ symposium to take place at UD, area gardens June 6-9

May 28, 2013 under CANR News

ApplecrossAnnette Giesecke is a professor of classics and chair of the ancient Greek and Roman studies department at the University of Delaware She also is the mastermind behind “Earth Perfect? Nature, Utopia, and the Garden,” a June 6-9 symposium taking place at UD and several local horticulture venues.

It may seem unusual for a professor of classics to organize a horticulture symposium. But this isn’t a garden-variety garden conference. If you’re only looking for tips on pruning or growing the perfect tomato, you’ve come to the wrong place.

“’Earth Perfect?’ will showcase the garden as an emblem of the ideal human relation with nature,” says Giesecke. “Anybody who is interested in the importance and meaning of gardens, and the politics of gardens, will want to attend. It’s not just an event for academics and garden professionals.”

Frankly, even those of us who never stopped to think about the meaning of gardens – we just know we like them — may find the symposium worthwhile. The eclectic program includes a lecture by UD professor McKay Jenkins on the environmental and health risks of lawn chemicals. There’s a workshop on creating “night spaces” and another on designing with edible plants. You can learn about slave gardens in the antebellum South or contemporary urban vertical farms.

Keynote speakers include Emma Marris, author of Rambunctious Garden: Saving Nature in a Post-Wild World, and UD’s Doug Tallamy, author of Bringing Nature Home: How You Can Sustain Wildlife with Native Plants. Mixed in with the lectures and workshops are special tours of Winterthur, Longwood Gardens, Chanticleer and the Mt. Cuba Center.

Giesecke, who has written widely about the gardens of ancient Greek and Rome, was inspired to create the symposium after co-editing a publication also called Earth Perfect? Nature, Utopia and the Garden.

Sue Barton, an ornamental horticulture specialist with UD Cooperative Extension, is excited to be speaking at the symposium because she wants to get more people thinking and talking about her lecture topic — livable ecosystems as a model for suburbia.

What’s a livable ecosystem?

The easiest way to explain it is to say what it’s not – a livable ecosystem isn’t a chemically treated monoculture of turfgrass with a few non-native, invasive trees plunked down in the front yard, too far from the house to shade it in summer or serve as a windbreak in winter.

In other words, a livable ecosystem is a far cry from what many suburban yards look like today.

“The traditional home landscape contains a limited palette of plants, has large areas of regularly mowed lawn, and provides relatively few ecosystem services,” says Barton. “Forests and meadows, on the other hand, provide many ecosystem services.”

Rest assured, you don’t need to remove every blade of grass and turn your yard into a jungle to create a livable ecosystem.

Take, for example, the attractive new landscape at a home in the Applecross neighborhood off Route 100 in Greenville. It does look a bit different than the neighbors’ yards – for one thing, there’s a 6,000-square-foot meadow of native grasses. It also features a newly reforested area, adjoining an existing wooded tract.  Invasive plants have been removed and replaced by white oaks, blueberry bushes, ornamental grasses and other native species.

Grass plays a role, too, but it’s been bumped from star of the show to a member of the supporting cast.

“Turf on the property is used purposefully, for recreation areas, circulation, or as the green carpet that sets off other plantings,” says Barton.

The yard is part of a UD research project on livable ecosystems. “We want to see if replacing the typical suburban yard of mostly grass with one containing diverse vegetation can help protect the environment and make landscapes more sustainable,” she says.

The Applecross property is one aspect of a multidisciplinary project involving five UD faculty members and dozens of undergraduate and grad students. Another research site is located at Winterthur, where the UD team is collecting water quality data in three streams that drain from three different landscapes – mowed lawn, meadow, and forest. They’re also collecting data on the diversity of plants, insects and birds in each of these settings.

If you won’t have a chance to hear Barton at the Earth Perfect symposium, you’ll have a second chance on June 14, at a Sustainable Landscape Tour. Sponsored by UD Cooperative Extension, the program includes a visit to the Applecross property, as well as a tour of a bio-swale and wetlands on the UD farm. Barton also will be hosting a shorter tour of the Applecross property later this season. To find out more about these Extension events, email Barton at sbarton@udel.edu.

To register for Earth Perfect or learn more at this symposium, call 831-2793 or go to this website.

Article by Margo McDonough

Photo by Danielle Quigley

This article can also be viewed on UDaily.


Tallamy receives Garden Club of America honor for conservation education

May 17, 2013 under CANR News

Doug Tallamy on the Lepidoptera trail for the Research magazine.Doug Tallamy, chair of the University of Delaware’s Department of Entomology and Wildlife Ecology, was recently awarded with the Garden Club of America’s Margaret Douglas Medal for notable service to the cause of conservation education.

Tallamy, a proponent of the use of native plants in gardening, received the medal during an award reception held earlier this month in Philadelphia.

Of the award, Tallamy said, “It’s great because it shows that the Garden Club of America is recognizing a completely new way to look at your garden. They have embraced it, and I’m very pleased about that.”

While Tallamy is thrilled with the medal, he said he is even more excited about what the recognition could potentially mean for biodiversity in suburbia and home gardens.

“It’s not about me, it’s about the message,” he said, “so what I appreciate is that they’re recognizing the message.”

The message, according to Tallamy, is that “your garden has many functions in addition to looking nice. Your garden performs critical ecological roles.”

Tallamy said he understands that thinking of gardens as part of the local ecosystem instead of just as decorations is not yet mainstream but, as the award demonstrates, it is starting to get people’s attention.

“You can make a beautiful garden that also supports local food webs, sequesters carbon, improves your watershed and helps pollinator populations all by yourself if you choose productive plants,” he said. “And your contribution to local ecosystem function plays an important role in sustaining this planet.”

Tallamy was nominated by Beverley Rowland, a Wilmington resident and a member of the Garden Club of America, as well as a supporter of the University of Delaware Botanic Gardens.

About the award

The Garden Club of America’s Margaret Douglas Medal is awarded for notable service to the cause of conservation education.

The medal was designed by art deco sculptor Rene P. Chambellan in 1952. It was presented and endowed by Mrs. Robert. D. Sterling, Garden Club of Dublin and Monadnock Garden Club, N.H., to honor Mrs. Walter Douglas, a member-at-large.

Photo by Ambre Alexander


UD expert lists top 10 landscaping plants for Mid-Atlantic

May 7, 2013 under CANR News

Doug Tallamy on the Lepidoptera trail for the Research magazineArmed with a shovel, Doug Tallamy, chair of the University of Delaware Department of Entomology and Wildlife Ecology, is leading a new American revolution, and he wants you to join him.

All you need to do is plant one native tree or shrub in your yard — perhaps an oak or willow tree, a blueberry or cranberry bush.

It isn’t hard to do, it doesn’t cost much and the paybacks, Tallamy says, will be immediate. Caterpillars will begin feeding on these native plants, and then birds will discover the caterpillars and start snapping them up. Add more native plants, and your rewards will be even greater, as a richer web of life springs forth.

In a study of randomly selected homes in suburban developments built from 1990-2005 in New Castle County, Del., and neighboring Chester County, Pa., Tallamy and his colleagues have found that 92 percent of the landscapable area around those homes is lawn, which is akin to a desert in terms of wildlife habitat. On the remaining 8 percent of landscapable area, 75 percent of the plant species are non-natives, and 79 percent of the total number of trees, shrubs and flowers are non-natives, offering very little in the way of food for insects (which do not recognize non-native plants as food) or for birds.

But homeowners can change that. Tallamy, the author of the award-winning bookBringing Nature Home, has identified the top 10 native plants for butterflies and moths in the Mid-Atlantic region. The number-one pick — the oak tree — supports 534 species of butterflies and moths (key food for birds and their nestlings), and the tree’s acorns feed deer, turkeys, bears, squirrels, even wood ducks.

Other top choices range from willow, birch, cherry and plum trees to crabapple and pine trees, blueberry and cranberry bushes. For more of Tallamy’s top selections, download this handy PDF with photos.

“When plants bring life into your yard, it’s instant gratification,” Tallamy says. “It’s especially critical for kids to understand the linkages. By putting native plants in your yard, you can make those connections for the future stewards of our planet.”

For the full story, see this recent article in the University of Delaware Research magazine.

For a video on Tallamy discussing sustainable landscapes, visit UDaily.

Article by Tracey Bryant

Photo by Ambre Alexander


Asters keep UD Botanic Gardens colorful through November

November 12, 2012 under CANR News, Cooperative Extension

Some of autumn’s pleasures are fleeting. Like the sight of migrating broad-winged hawks soaring on thermals in the September skies. Like the golden leaves of the ginkgo, which drop from the tree in a few days or sometimes mere hours. Like the big, orange, once-a-year occurrence of the harvest moon.

But other autumn pleasures – like asters – endure all season long. Asters start blooming at the same time as such early fall wildflowers as goldenrod and thoroughwort. But long after many other blooms have turned brown, the aster is still going strong.

Of course, no one species of native aster blooms straight through from September to November. Most bloom for a few weeks and then, as they die off, other varieties began to flower. Some of the native varieties that bloom the latest include aromatic and heath asters.

“It’s not unusual to see aromatic, heath and other species of asters blooming in late November,” says Sue Barton, an ornamental horticulture specialist with University of Delaware Cooperative Extension. “Asters continue to add a splash of color to the landscape in late autumn, when little else is blooming in Delaware.”

There are 33 native species and varieties of the genus Aster in Delaware, according to Bill McAvoy, a botanist with the Delaware Natural Heritage Program. Several of these varieties are classified as rare in the state. Asters are found in a wide range of habitat – woodlands, swamps, marshes, wet meadows and old fields. Some species are tall and bushy; others are groundcovers. Most prefer sunny conditions but some do well in shade.

Asters are tough and reliable, which is why they are popular with both home gardeners and commercial landscapers. “Asters – both natives and non-natives – are some of the easiest perennials to grow,” says Barton. “They don’t require much watering, fertilizing or other care.”

Doug Tallamy likes asters because they contribute to healthy local ecosystems. Asters are a valuable food source for a variety of pollinators, including native bees, honeybees, butterflies, beetles and flies, says Tallamy, chair of UD’s Department of Entomology and Wildlife Ecology and author of Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens.

“As one of the latest blooming widespread plants, asters are very important as a carbohydrate energy source for butterflies, bees, beetles and flies,” says Tallamy.

If you’re looking for a good aster to plant in Delaware you couldn’t do better than talking to Jeanne Frett, a research horticulturalist at Mt. Cuba Center. A few years ago she conducted a performance evaluation of asters in conjunction with Victor Piatt, the center’s former trial area gardener.

The duo evaluated 56 different asters over a two-year period for such factors as color, bloom period, foliage quality, disease resistance and more.

Varieties that got top marks include smooth aster, prairie aster and calico aster. A late bloomer that scored well is the large-flowered aster. Some years, this aster may start in mid-October and finish by Halloween. Other seasons, it doesn’t flower until mid-November and then continues blooming past Thanksgiving.

You can see these varieties of asters – any many more – at Mt. Cuba. Public garden tours are held Thursdays through Sundays; registration is necessary. The University of Delaware Botanic Gardens also has a great selection of asters. Late bloomers there include Aster oblongifolius “Raydon’s Favorite,” a showy variety that sports a profusion of blue-lavender flowers with yellow centers.

Mt. Cuba Center is located at 3120 Barley Mill Road in Hockessin. For more information, call 239-4244.

The University of Delaware Botanic Gardens is located on the grounds of Townsend Hall off South College Avenue in Newark. The garden is open dawn to dusk daily and is free of charge. Parking is available at meters or by purchasing a parking permit for $3 online. To learn more, call 831-0153.

Article by Margo McDonough

Photo by Danielle Quigley

This article can also be viewed on UDaily.


UD researchers use weevils to check spread of prolific mile-a-minute weed

July 2, 2012 under CANR News

Mile-a-minute weed has declared war on Doug Tallamy’s yard. This non-native, invasive vine is growing up his trees, scrambling over shrubs and smothering tree seedlings. By blocking sunlight, it weakens a plant by reducing its ability to photosynthesize.

Mile-a-minute doesn’t care one whit that Tallamy, professor and chair of the University of Delaware’s Department of Entomology and Wildlife Ecology, is a highly respected proponent of native gardening who doesn’t believe in planting any non-natives, let alone a highly invasive non-native.

“The deer brought mile-a-minute from our neighbor’s yard three years after we moved in,” says Tallamy. “We had just a few plants the first year, a few hundred the second year, and 20 trillion the third year.”

Accidentally introduced to the U.S. from China in the 1930s, mile-a-minute doesn’t actually grow a mile per minute but it definitely is prolific. Studies show it can grow six inches per day. In addition to Tallamy’s yard, it has waged battle on countless other area yards as well as on Pea Patch Island, at White Clay Creek State Park, at Coverdale Farm Preserve and at other important natural areas.

Chemical control measures aren’t very effective and native insects don’t like to eat mile-a-minute. So Tallamy hand pulls mile-a-minute and, in areas where it has spread widely, whacks it with a scythe. But thanks to UD colleague Judy Hough-Goldstein, Tallamy has another tool in his arsenal, a weevil known as Rhinoncomimus latipes.

Weevils are beetles that have snouts. The itsy-bitsy Rhinoncomimus latipes, a native of China, is host-specific to mile-a-minute; it won’t eat any other plant. Since 2004, Hough-Goldstein and cooperators have released Rhinoncomimus latipes at numerous sites in Delaware and in Chester County, Pa., including Tallamy’s backyard.

A professor of entomology who has spearheaded a number of groundbreaking research projects into the biological control of invasive plants, Hough-Goldstein had to conduct eight years of laboratory testing in quarantine before the federal government would permit fieldwork to be carried out.

She was the first researcher in the world to obtain a permit to release a biological control agent of mile-a-minute weed. Today, her lab is still the only one in the U.S. — and one of a handful in the world — attempting to control this invasive plant through biological means.

Results, thus far, have been encouraging. The weevil establishes easily because it produces multiple generations per year. Thus, only a couple hundred weevils need to be released at any one site. Adult weevils and their larvae eat and damage mile-a-minute, but even more importantly, appear to suppress seed production in the plant.

“We had a problem with mile-a-minute at Burrows Run, which is part of Coverdale Farm Preserve,” notes Dave Pro, a land and facilities steward for the Delaware Nature Society. “We participated in UD’s early field studies with Rhinoncomimus latipes and followed up with a second weevil release. Since then, we’ve seen a reduction of mile-a-minute vine and weevils have been found actively feeding.”

In June, Hough-Goldstein kicked off a new phase of her research. The U.S. Forest Service is funding a study that compares the performance of weevils already in the field against lab-reared weevils and field weevils direct from China.

“Currently, weevils that are sent to cooperators throughout the northeastern U.S. come from a Beneficial Insect Laboratory operated by the New Jersey Department of Agriculture,” says Hough-Goldstein. “However, insects that are lab-reared for 10 or more generations adapt to lab conditions and this can sometimes affect their field performance. We’ll compare the survival, longevity and reproductive abilities of the three different populations of weevils to see if it may be desirable to add wild-type genetic material to the rearing stock.”

Amanda Stout is a rising junior at UD who is participating in the Summer Scholar research program. Throughout the summer, she will be responsible for most of the fieldwork for the new project.

To her delight, she has discovered that this means doing a bit of everything. “With Dr. Hough-Goldstein’s help, I designed and constructed rearing tubs for the weevils,” says Stout. “I also spent several days installing ‘bug dorms’ in full sun as well as in full shade.”

“I really gain intellectual satisfaction out of my work at the end of the day. It’s really exciting to get results,” she says.

As for Tallamy’s backyard, weevils are making in-roads in the ongoing war against mile-a-minute, with certain limitations.

“My assessment of the weevil is that it is quite effective in dry years,” says Tallamy. “But it doesn’t outpace mile-a-minute in wet years, such as last year when we had 12 more inches of rain than usual. However, the weevils are munching away at mile-a-minute this summer, so I’m happy to have them in my yard.”

Article by Margo McDonough

Photo by Danielle Quigley

This article can also be viewed on UDaily.


Autumn fern, fringetree win state’s plant of the year title

June 8, 2012 under CANR News, Cooperative Extension

Beauty pageants like to stress that it’s not just good looks but also talent and poise that make a winner. Likewise, the Delaware Nursery and Landscape Association Plant of the Year designation isn’t given to just any pretty plant but one “particularly well suited to thrive in Delaware,” notes Valann Budischak, executive director of the association.

That being said, the newly announced 2012 Plant of the Year winners are knock-out beauties – even if these plants weren’t easy to grow you’d want them in your garden. Dryopteris erythrosora, aka autumn fern, sports a copper pink color when its leaves first unfurl in spring, eventually maturing to glossy dark green. And Chionanthus virginicus, commonly known as fringetree, is a Southern charmer, with airy panicles of fragrant, fringy flowers in May.

“Fringe tree is an apt moniker for this delightful, small flowering tree, whose white blossoms do resemble a fanciful white fringe suspended in the spring sunlight,” wrote Landenberg, Pa., landscape consultant Rick Darke, a University of Delaware alumnus, in his 2002 book The American Woodland Garden.

Delaware and southeastern Pennsylvania are the northernmost habitat for the fringetree. It also grows in south Jersey, nearly all of Maryland, Virginia and the Carolinas, into the Deep South, and as far west as Texas.

With its ethereal appearance, you’d think fringetree would be a high-maintenance plant. But it’s a cinch to grow in full sun to partial shade. “Fringetree prefers moist, well-drained soil but it also will tolerate extremely dry conditions,” says Budischak. “And it’s especially well-suited to urban sites because of its high pollution tolerance.”

Dozens of fringetrees planted in the I-95 median north of Wilmington to the Pennsylvania state line are exposed to exhaust fumes 24/7 but look just as good as if they were growing in the wild. These trees were installed as part of the Enhancing Delaware Highways project, a joint venture between UD, the state Department of Transportation and Delaware Center for Horticulture (DCH).

DCH also has planted fringetree in several spots in Wilmington, including a 911 Memorial Garden on Scott and 14th streets and along a railway embankment on Union Street. At the embankment planting, fringetree was mixed with Eastern ninebark, a hardy native shrub, and a variety of perennials, including false indigo. Fringetree also works well on its own as a specimen tree.

“I like fringetree because it’s very stalwart, very dependable and it’s a good habitat for pollinators and other wildlife,” says Lenny Wilson, assistant director of horticulture and facilities for DCH.

Female (fruit-bearing) fringetrees are especially attractive to wildlife. Bluebirds, thrashers, finch, vireo and eight species of caterpillars enjoy the tree’s dark blue fruit, according to Doug Tallamy, chair of UD’s Department of Entomology and Wildlife Ecology. The trees aren’t labeled “male” or “female” at the garden center so the only way to know if you’re getting a female tree is to buy the plant in the fall, after the fruit has appeared.

Unlike fringetree, autumn fern isn’t native to Delaware. However, Budischak is quick to note that autumn fern is not invasive and spreads very slowly over time via creeping rhizomes. An arching, vase-shaped fern, it grows in medium to wet soils, in partial to full shade. Ultimately, it reaches a height of one and one-half to two feet.

June 13 Garden Day

If you have questions about growing fringetree or autumn fern, head to the June 13 Garden Day at the New Castle County Cooperative Extension office in Newark.

Master Gardeners will be on hand to lend their expertise at this event in the Native Teaching Garden. It is held from 9 a.m. to noon on the second and fourth Wednesday of every month, through September.

There also will be an evening open house in the garden June 20 from 6 p.m. to 8 p.m.  Call 831-COOP for more info about either event.

Article by Margo McDonough

Photo by Danielle Quigley

This article can also be viewed on UDaily


UD research project hopes to curb water pollution from lawns

June 4, 2012 under CANR News, Cooperative Extension

At first glance, Tim Schofield’s internship duties don’t appear much different from what any landscape worker does. Every week, June through August, this rising junior at the University of Delaware will weed landscape beds, cut back straggly branches and rake up plant debris on a one-acre yard in Applecross, a neighborhood off Route 100 in Greenville.

But Schofield also will catalog the diversity of beneficial insects, birds and other wildlife on the property, document evidence of soil erosion, and keep precise records of the time it takes to complete his tasks. It’s all part of a UD research project to see if replacing the typical suburban yard of mostly grass with one containing diverse vegetation can help protect the environment and make landscapes more sustainable.

One of the primary goals of the project is to curb water pollution at its source — preventing pollution in the first place rather than waiting to treat contaminated water after it enters waterways.

“I think people understand that water quality in urban watersheds is degraded when you increase impervious surfaces, such as roads and parking lots,” says Doug Tallamy, chair of UD’s Department of Entomology and Wildlife Ecology and a co-investigator of the research project. “But they don’t always realize that increasing the amount of grass in an urban watershed also degrades water quality.”

A landscaping philosophy that views plants as mere ornaments has prevailed for more than a century, resulting in the replacement of native plant communities with expansive lawns. Today, a whopping 92 percent of all suburban yards consist of turf grass. Because plants are the mechanism in which water is cleaned and stored, carbon is sequestered and complex food webs are maintained, any reduction in native plant communities can only mean bad things for water quality.

“People care about clean water,” says Tallamy. “If homeowners realize that they can use their properties to clean water, sequester carbon and help pollinators, it could help change the mind set of those who demand huge lawns.”

The Applecross property is just one aspect of the UD multidisciplinary project involving five faculty members and dozens of undergraduate and graduate students. Another research site is located at Winterthur, where the team will compare the quality of a stream impacted by traditional mowed landscapes versus another stream that only receives runoff from meadows, forests and landscape beds.

Co-researchers Sue Barton, Cooperative Extension ornamental horticulture specialist and Jules Bruck, associate professor of landscape horticulture and design, worked together to create a landscape plan for the Applecross property to replace the existing turf grass monoculture. The homeowners received the landscape installation at no cost and have agreed to allow researchers onto the site every week for the next three years.

“We were starting with the typical suburban landscape with lots of grass, some foundation plantings and one or two trees in the yard,” says Barton.

Last month, Schofield and other students and volunteers set to work on the new landscape, planting 200 woody plants and 1,200 plant plugs in a matter of days. They created a 6,000 square-foot meadow of native grasses and reforested an area of lawn that adjoins a wooded tract. Invasive plants were removed and replaced by white oaks, blueberry bushes, ornamental grasses and other native species.

“There is still turf on the property but it’s being used purposefully, for recreation areas, circulation, or as the green carpet that sets off other plantings,” notes Barton.

Although the new landscape will need a year or so to fully fill in, it’s already attractive and a vast improvement over the previous vast expanse of grass.  The UD researchers recognize that homeowners aren’t going to change their ways to improve the environment unless the results look good.

“Some people have the misconception that native plants are sloppy or somehow less appealing than non-natives,” says Barton. “I think the landscape we have created in Applecross is dense, rich and beautiful and should put such misconceptions to rest.”

UD will host several public tours of the Applecross property beginning in 2013. To receive a notification of tour dates, email Barton at sbarton@udel.edu.

Schofield, who is double majoring in landscape design and agribusiness, is excited to be a part of the research project. He says he wants to learn as much as he can about sustainable landscaping so he can incorporate into his own practices. He has operated a small landscape company in Malvern, Pa., since high school and hopes to expand the business after college.

Article by Margo McDonough

Photo by Danielle Quigley

This article can also be viewed on UDaily