Purdue University - Extension - Forestry and Natural Resources
Got Nature? Blog
Spring brings an opportunity to spend more time outdoors but also increases our exposure to tick bites and infection from some of the diseases that ticks carry. Taking some precautions to reduce risks of exposure and infection from ticks can make your outdoor activities more safe and enjoyable. Ticks can be found in almost any location that has animals and vegetation, so completely avoiding ticks is very difficult. But there are some practices that will help you prevent ticks from biting and passing disease organisms to you.
Here are several suggestions:
- Wear light-colored clothing that makes it easier to see ticks and remove them before they get to bare skin.
- Tuck in shirt-tails, tuck pants into boots or socks or use “tick gators” that are essentially a legging that covers where your pants and socks or boots meet.
- Wearing a hat is another good precautionary measure.
- Treat bare skin with repellants containing 20 to 30% DEET. Always read and follow label directions!
- Treat clothing (not skin!) with repellants containing permethrin prior to entering areas with ticks. Once dried on the clothing, permethrin can still be effective after several washes. Follow label directions.
- Upon your return, inspect clothing for any ticks. Tumbling clothes in a hot dryer for an hour will kill ticks. Shorter times may be effective if the clothes are not wet.
- Wash up after visiting tick-infested areas and do a body check for any ticks.
If you find a tick attached, remove it by using tweezers or a tick removal tool to grasp it as near to the skin as possible and pulling straight out. DO NOT use hot match heads or needles, nail polish, gasoline or similar techniques. Ticks that are removed shortly after they attach may not have the opportunity to pass disease organisms to you, so quick detection and removal are good prevention methods.
If you experience a rash, fever, chills, aching or other unusual symptoms after a tick bite or exposure to tick-infested areas, see your physician immediately. Most tick-borne diseases can be effectively treated with early detection.
Enjoy the outdoors by taking precautions to reduce your risks.
Purdue has an informational webpage on ticks at Purdue Medical Entomology.
The Center for Disease Control and Prevention has an information site on ticks and tick diseases.
Lenny Farlee, Sustaining Hardwood Extension Specialist
Hardwood Tree Improvement and Regeneration Center (HTIRC)
Forestry and Natural Resources, Purdue University
Although perhaps a bit late, spring has seemingly sprung upon us. One of the best signals of spring is the symphony of calling frogs and toads in and around wetlands, ponds and lakes throughout Indiana. Amphibians native to Indiana are an important component of healthy ecosystems. They play important roles as both predator and prey in food webs. We can also consider many amphibians as “bio-indicators” of environmental health. Unfortunately, many species of amphibians and reptiles are thought to be in the decline. While the causes for declines are species-specific, the actions that people take can be a contributing factor.
Unlike other vertebrates, most amphibians and reptiles can be observed up close or even
captured by hand – some more easily than others. Exploring natural habitats while searching for, catching and photographing reptiles and amphibians are great ways to gain hands-on experience with nature. However, be mindful that some activities, or the manner in which they are conducted, can harm the very creatures we value. Reptiles and amphibians represent numerous examples where interactions between wildlife and people can have negative consequences despite the best of intentions.
When you go outdoors to enjoy our amphibians and other wildlife, follow some of these simple tips:
Stay on designated roads and trail systems – Human foot traffic can affect plants and animals in some habitats (e.g., you may have noticed the compressed soil and lack of vegetation on even lightly used foot trails). Focusing foot traffic on trails can minimize human impacts on sensitive plants and animals. It is also required on some public properties.
Be a responsible pet owner – Dogs make good companions when hiking outdoors. However, research has demonstrated dogs can disturb, harass or even kill wildlife. While impacts on reptiles and amphibians are unclear, it is good practice to keep your dog leashed while exploring natural areas. Many parks and properties require dogs to be leashed.
Be a good steward of the land – Carelessly turning over logs and coarse woody debris in search of reptiles and amphibians can destroy microhabitat features that took decades to create. It is also prohibited on many public properties. If you do find an animal under a log or rock, return the object to its original location, then place the animal next to it rather than rolling the object directly over the animal.
Minimize or avoid handling animals – If you must handle a wild amphibian or reptile, 
there are safe ways to hold and restrain them. Avoid handling amphibians for long periods of time. Amphibians are prone to desiccation (drying out). There are no formal guidelines on the length of time to handle an amphibian, and it is not clear how handling impacts an animal’s health and wellbeing. Common sense dictates that handling time should be minimized to the greatest extent possible. If a frog or salamander feels “dry,” you have handled it too long, and it should be returned to its location of capture immediately. Keep your hands moist and free of chemicals (e.g., bug spray or sunscreen).
Use good hygiene – The transmission of many diseases among animals can be facilitated by people. There are a number of safeguards that can be implemented to not only protect you, but also the animal populations as well. To prevent spreading diseases and pathogens from one site to another, regularly wash clothing and especially boots that you use in the field. All equipment that contacts an animal or the water the animal was in should be decontaminated using a 1-3 percent bleach solution or air dried for at least three hours before traveling to another water body. You also should use hand sanitizer before and after handling animals in nature. Before eating or handling food, thoroughly wash hands in hot, soapy water if possible; hand sanitizer is an acceptable substitute for remote locations.
For more information about responsibly enjoying wildlife and nature, see Appreciating Reptiles and Amphibians in Nature.
Resources:
Sounds of Frogs & Toads, Purdue Extension – Forestry and Natural Resources (FNR)
Frogs & toads of Indiana, The Education Store, Purdue Extension resource center
Salamanders of Indiana Book, The Education Store
Amphibians: Frogs, Toads, and Salamanders, Purdue Nature of Teaching
The Nature of Teaching: Adaptations for Aquatic Amphibians, The Education Store
Hellbender ID, Playlist, Purdue Extension – FNR YouTube Channel
A Moment in the Wild, Playlist, Purdue Extension – FNR YouTube Channel
Dr. Brian MacGowan, Extension Wildlife Specialist
Department of Forestry & Natural Resources, Purdue University
Early spring brings the emergence of new life in the forest. Unfortunately, not all that life actually belongs there. Several invasive plants are encroaching on woodlands and crowding out the desirable native plants we enjoy and wildlife depend upon for food and shelter. One of the characteristics of some invasive plants is early leaf emergence and growth, which allows us to scout for their presence more easily, while native species are still waking up from winter. Two species that start growing very early in the spring are garlic mustard and Asian bush honeysuckles. Both plants are rapidly greening up and growing as I speak. Look for the kidney to heart shaped leaves of garlic mustard on the forest floor. This biennial will soon be sending up flower stalks from the second season plants that will have white four-petaled flowers. The flower stalks can be up to three feet tall or more depending on the health of the plant and the quality of the growing site.
Early spring leaves of garlic mustard.
Asian bush honeysuckle is a medium to large bush that also inhabits the forest understory and edge or disturbed areas. Leaves and twigs area arranged opposite each other. If you slice the stems open, they are hollow inside with fuzzy brown or tan lining. Flowers are yellow, white or even pinkish and tube-shaped. The fine twigs and stems have a light tan or gray-tan color. Leaves are rapidly expanding now, so they will be easily detected until our native plants catch up with leaf cover.
Early growth of Asian bush honeysuckle.
Controlling these plants helps native plants continue to thrive and provide habitat for our wildlife. Garlic mustard can be pulled from moist soil. If seed pods are present, remove the plants from the area and burn or bury them. Foliar herbicides like glyphosate products may be used to spray garlic mustard. If the plants have already set seed pods, the seed may become viable even if the plant has been sprayed, so removal may be the only effective treatment at that time.
Asian bush honeysuckle can be controlled in several ways, depending on the size of the plants. Small plants can be pulled from moist soil. Foliar sprays with herbicides like glyphosate can be effective. Large bushes may be cut and the stumps treated with a brush-killing herbicide. For any herbicide application, read and follow label directions.
Purdue University has invasive species information resources at FNR Extension and Indiana’s ‘Most Unwanted’ Invasive Plant Pests/Indiana Cooperative Agricultural Pest Survey (CAPS) Program.
Lenny Farlee, Sustaining Hardwood Extension Specialist
Hardwood Tree Improvement and Regeneration Center (HTIRC)
Forestry and Natural Resources, Purdue University
American chestnut fruit protected by a spiny bur. Photo: Dr. Shaneka Lawson, USDA Forest Service, Purdue HTIRC
In the late 1800s, 25% of hardwood trees in North America’s eastern forest were American chestnuts, 40 meters high and two meters across, they provided abundant resources for both people and wildlife in the form of food, shelter and building materials. Lightweight, rot-resistant, straight-grained and easy to work with, chestnut wood was used to build houses, barns, telegraph poles, railroad ties, furniture and even musical instruments. The rapid decline of the chestnut due to the pathogenic fungus Cryphonectria parasitica has been a subject of much debate and despair over the years, but now, chestnuts engineered to battle the fungus might give the iconic trees a chance to reclaim the North American stage.
Research conduced in 2014 was taking genes from wheat, Asian chestnuts, grapes, peppers and other plants and inserting them into American chestnut trees. William Powell of S.U.N.Y.–ESF and scores of collaborators, created hundreds of transgenic trees with the goal of almost 100 percent genetically identical wild American chestnut yet immune to C. parasitica. Testing and gathering data continues to help with future research.
Douglass Jacobs, the Fred M. van Eck Professor of Forest Biology at Purdue University, and a team of scientists at Purdue, use genomics which involves working with the complete set of an organism’s genetic material, to learn more about what causes disease. Genomics also can help identify the genes responsible for useful traits such as pest resistance.
Blight began afflicting the American chestnut in the 1900s, killing billions of trees. Despite being the target of decades-long tree-breeding efforts, the chestnut’s prospects remain in doubt. The list of at-risk species also includes ash, butternut, and bristlecone pine among other members of the five-needle white pine family.
The Hardwood Tree Improvement & Regeneration Center, a joint effort between Purdue and the Forest Service, for years has maintained a breeding program for pest resistance. Almost all of the center’s efforts to date have focused on traditional tree breeding and genomics.
“The chance to work with chestnut and help reintroduce it back to the landscape was a big reason I took the Purdue job in the first place back in December of 2001,” Jacobs said. “Watching species disappear from the landscape provides me personally with a lot of motivation to contribute whatever I can toward helping to save some of these at-risk species.”
To learn more about his research and collaboration with the U.S. Forest Service view full article Biotechnology offers holistic approach to restoration of at-risk forest tree species – Purdue University News, by Purdue Agriculture News.
Resources
A New Generation of American chestnut Trees May Redefine America’s Forests – Scientific American
Consequences of Shifts in Abundance and Distribution of American Chestnut for Restoration of a Foundation Forest Tree – Forests Open Access Forestry Journal
Transgenic American chestnuts show enhanced blight resistance and transmit the trait to T1 progeny – Science Direct (Plant Science)
Scientists Work to Create a Blight-Resistant Chestnut with Hopes of Restoring Tree to America, Forest Service, U.S. Department of Agriculture
FNR Hardwood – American Chestnut, Purdue Arboretum Explorer
Hardwood Tree Improvement Regeneration Center (HTIRC) Research Publications
American Chestnut Trees return to the Hoosier National Forest, Indiana Woodland Steward
Forest Regeneration and Restoration Laboratory, Purdue Forestry and Natural Resources, Dr. Doug Jacobs
Indiana American Chestnut Foundation
Purdue Extension – Forestry and Natural Resources (FNR)
Winter burn is a common occurrence to boxwood, holly, rhododendron and most conifers. Winter burn symptoms often develop when temperatures warm up in late winter and early spring. This type of winter damage is often misdiagnosed as an infectious disease or damage from excessively cold temperatures.
To understand winter injury, it is important to understand that while a plant is creating its food by photosynthesis, it is releasing large amounts of water through the process of transpiration (the evaporation of water from the plant). Over the course of a day, a large tree can lose hundreds of gallons of water. When plants are unable to obtain the water they need (due to drought or frozen soil), the water lost through transpiration cannot be replenished, resulting in dehydration, foliar damage and even death.
Contacts
Michael Mickelbart, Clinical Engagement Assistant Professor
Horticulture and Landscape Architecture
Purdue University
Janna Beckerman, Associate Professor
Botany and Plant Pathology
Purdue University
Tree owners who have broken limbs in their trees or are just taking advantage of early pruning opportunities may notice large amounts of “water” that seem to be pouring out of the branch. This is actually “sap” seeping out of the damaged area, and it would have been going into the limb or branch that was removed. However, since the limb is no longer there, the sap has nowhere to go but out of the freshly cut limb or wound.
Spring weather signals to trees to come out of dormancy, and all trees start pumping water, minerals and carbohydrates upwards into the tree to allow growth of buds, leaves and shoots and will continue throughout the growing season. Certain tree species, such as maple, birch, dogwood and elms, have an exceptionally heavy sap flow in the early spring. When pruned or wounded, these trees will “bleed” quite noticeably. Under normal circumstances, it is best to delay pruning these trees until later in the growing season when the flow of sap is slower.
There is no need for alarm if this sap flow occurs and the overall health of the tree is not going to be affected. The “bleeding” may be objectionable from a cosmetic standpoint, especially if the sap is dripping directly onto people, cars or other targets beneath the wounded area. As the affected area on the tree develops callus material and naturally seals off the wound, it will slow the flow to a stop.
It is not recommended to use any type of wound dressing or covering as this will impede the ability of the tree to seal off the damaged area. Be patient and allow natural healing of the wound to occur. Always use good pruning practices and minimize the size of cut branches to reduce wound size on the tree.
Refer to the following Purdue Extension publication, Trees Need a Proper Start: Prune Them Right, for more information.
Other resources can be found at The Education Store: Pruning Ornamental Trees and Shrubs.
Lindsey Purcell, Urban Forestry Specialist
Department of Forestry and Natural Resources, Purdue University
A recent article in ScienceDaily titled “Excessive Deer Populations Hurt Native Plant Biodiversity” shares how an overpopulation of deer is hurting native plant growth. Landowners seek best management practices as these challenges arise.
For the article from the University of Miami, view: “Excessive deer populations hurt native plant biodiversity.” ScienceDaily, 20 March 2014.
Resources
Preventing Wildlife Damage, Purdue EVERYTHING Wildlife
How to Build a Plastic Mesh Deer Exclusion Fence, Purdue Extension Publication
Don’t be fooled by the cold weather; EAB has plenty of life left.
Headlines have been circulating suggesting that EAB may “have met its match.” Although the Midwest experienced abnormally cold temperatures this winter, it is unlikely EAB populations felt these effects as significantly as your heating bill. EAB, as well as most insects in colder climates, are effective at surviving cold temperatures. One way they survive the cold is by producing an antifreeze-like substance that prevents water in their cells from crystallizing and causing damage. Also the extra insulation provided by the tree bark helps larvae withstand such cold temperatures. For EAB larvae overwintering within ash trees, death occurs when temperatures reach -28 degrees Fahrenheit.
A model produced by U.S. Forest Service scientists predicts areas in North America where temperatures were cold enough to kill EAB larvae. This model suggests that in the U.S., only northern parts of Minnesota and North Dakota have reached frigid enough temperatures to affect EAB populations.
Although some parts of the United States may have fewer adults emerging in the spring as a result of the cold temperatures, they probably won’t notice. Due to a high reproductive rate, it will likely be only a matter of time before populations rebound to previous levels.
Despite the cold weather, experts are still advising to continue with EAB management plans. One effective means of saving ash trees and reducing management costs is to partner with interested neighbors and hire a company to treat trees in your neighborhood. This collaborative approach will likely reduce transportation and consultation costs for the company, and the savings will be passed down to homeowners.
For more information on EAB, treatment options and NABB (Neighbors Against Bad Bugs), visit Emerald Ash Borer in Indiana, Purdue Extension website.
Contacts
Adam Witte, Exotic Forest Pest Educator
Department of Entomology
Matthew Ginzel, Associate Professor
Departments of Entomology & Forestry and Natural Resources
Cold winter winds, alternating extreme temperatures, ice and snow can be damaging to trees and shrubs. However, this spring, we are seeing additional damage due to the harsh winter conditions that is of the furry kind: rabbits and rodents. Mice and rabbits often damage young trees in the winter by feeding on the juicy, green cambium layer just under the bark and girdling the tree. Damage from these furry creatures occurs most commonly in winters when there is prolonged, heavy snow cover and food is scarce. Sound familiar? Rabbits feed on the bark above the snow while mice tunnel under the snow and feed near the ground level. Mouse damage is usually more severe when the trees are surrounded by heavy grass, weed cover or heavy mulch.
On young trees and multi-stemmed ornamental trees, rabbits remove the bark completely around the trunks and stems, effectively girdling them. All growth above the girdled areas will eventually decline and die, and for most situations, replacing the girdled trees is the best course of action. There are no applications that will mitigate the effects of rabbit damage or save severely damaged trees. Wound dressings, pruning paints, latex paints, wrappings and other alleged protective barriers do not help.
Many deciduous shrubs have the ability to produce new shoots or suckers at their base. Because of this ability, many severely damaged deciduous shrubs can recover. However, patience is required as several years may be required for some shrubs to fully recover. In early spring as the greening begins, prune off girdled stems just below the damaged areas. This will help rejuvenate the plant in most circumstances and replace the damage growth.
The most effective deterrent to girdling by mice or rabbits is to wrap the trunk and low branches of young trees with screen wire or hardware cloth. Be certain the wire wrap is buried below the ground line and extends high enough above the possible snow line to prevent rabbits from reaching to the trunk or branches. To help control mouse damage, maintain an area free of grass or weeds for a 1- to 2-foot radius around the base of the tree. Additionally, maintain proper mulch levels, never more than 2-3”, to eliminate the habitat for mice. Various chemicals are available to repel mice and rabbits, but these do not afford the reliability of a well-made barrier.
Resources
Preventing Wildlife Damage, The Education Store, Purdue Extension
Vole Damage in Pumpkins (and other crops), Purdue Extension – Forestry and Natural Resources (FNR) Got Nature? Blog
Moles, The Education Store, Purdue Extension resource center
Adjuvants and the Power of the Spray Droplet: Improving the Performance of Pesticide Applications, The Education Store
Preventing Wildlife Damage – Do You Need a Permit?, The Education Store
Attract Hummingbirds to Your Yard, Video, Purdue Extension Youtube Channel
How to Stop Woodland Animals from Digging in Your Flower Pots, Video, Purdue Extension Youtube Channel
Purdue Extension – Forestry and Natural Resources
A recent discussion about Asian carp as a food source has generated some concerns about the level of contamination in their fillets, and thus, whether or not they are safe to eat. Several Indiana agencies cooperate to evaluate the risks of fish consumption to the public; the agencies include the Indiana Department of Natural Resources (INDNR), Indiana Department of Environmental Management (IDEM), Indiana State Department of Health (ISDH) and Purdue University. Most of the fish assessed for contaminants are those that are regularly caught by anglers. Numerous catfish, bass, sunfish and sucker species are commonly included in tissue surveys (see links below for more info). Indiana then divides people into two risk groups: 1) men (over 15 years) and women beyond childbearing age (typically 45 years or older) and 2) women pregnant or capable of becoming pregnant and children under 15. The second group is considered the sensitive group, and allowable contaminant levels (that is, the amount of fish that is safe to consume) are set significantly lower.
It is important to recognize that there are differences in allowable contaminants among population groups mentioned above, and it is equally important to recognize that the same fish species can have different amounts of contaminants in different water bodies. Asian carp are a riverine species that frequently travel long distances, and as such, they are exposed to varying levels of contaminants. Indiana and many other states try to minimize the effects of variation in individual fish fillet by combining tissue from multiple individual fish and analyzing it as a composite. Sampling the tissue as a composite reduces the risk of a heavily contaminated fish or a fish with little contamination, giving a false impression of the risk. By combining the fillets, Indiana also saves money by not analyzing large amounts of single fillets. Indiana does divide the fish into a couple of size classes for each composite because contamination increases significantly as fish size increases. They have yet to begin testing Asian carp fillets, at least partially because of their difficulty to capture using traditional fish survey techniques.
Although most states have not started regularly testing Asian carp, there has been some published research evaluating Asian carp fillets and comparing their contaminants to other species caught in the same location. Not surprisingly, the results of the research found that Asian carp have different concentrations of contaminants depending on where they are found, and they have different levels than other species of fish including common carp. Common carp have a completely different diet than Asian carp, so it is not surprising that contamination levels are different. Like most other fish, the most common problems associated with Asian carp are Mercury and PCBs. However, where the research was conducted in Illinois and Missouri, the recommended restriction on consumption was typically one meal per week for the most sensitive groups. Most studies have demonstrated that larger fish tend to have higher concentrations in their tissues than smaller fish found in the same environments. This relates to the way Mercury and PCBs bioaccumulate in tissues – the longer a fish is around, the more contaminants per gram we would expect them to contain. This is not to say that Asian carp in Indiana is safe for that level of consumption or that it even contains the same amount of contaminants as in other states. It still needs to be evaluated by the state, but studies cited below have shown that for the most part, Asian carp are likely no riskier to consume than most of the fish species that Indiana currently evaluates.
Resources
Fish Consumption Advisory
Indiana State Department of Health
Asian Carp Solutions: Take Them to Market
Illinois-Indiana Sea Grant (IISG) Newsroom
No Bones About It: New Video Lays Out Easy Steps For Filleting Tasty Asian Carp
Illinois-Indiana Sea Grant (IISG) Newsroom
Published Papers
Levengood, J.M., D.J. Soucek, G.G. Sass, A. Dickinson, and J.M. Epifanio. In press. Elements of Concern in Fillets of Bighead and Silver Carp From the Illinois River, Illinois. Chemosphere 2013.
Rogowski, D.L., D.J. Soucek, J.M. Levengood, S.R. Johnson, J.H. Chick, J.M. Dettmers, M.A. Pegg, and J.M. Epifanio. 2009. Contaminant Concentrations in Asian Carps, Invasive Species in the Mississippi and Illinois Rivers. Environmental Monitoring and Assessment
Resources:
Walleye Farmed Fish Fact Sheet, The Education Store, Purdue Extension’s resource center
Pacific White Shrimp Farmed Fact Sheet, The Education Store
Yellow Perch Farmed Fish Fact Sheet, The Education Store
Tilapia Farmed Fish Fact Sheet, The Education Store
Rainbow Trout Farmed Fish Fact Sheet, The Education Store
American Paddlefish, The Education Store
A Guide to Small-Scale Fish Processing Using Local Kitchen Facilities, The Education Store
Aquaculture Family Coloring Book Development, The Education Store
Eat Midwest Fish, Illinois-Indiana Sea Grant online resource hub
Aquatics & Fisheries Videos, Purdue Extension-Forestry and Natural Resources YouTube Channel Playlist
Department of Forestry and Natural Resources (FNR)
Illinois-Indiana Sea Grant (IISG)
Purdue University
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