Purdue Landscape Report: When the irises begin to bloom, expect up to 1.5 million cicadas per acre to begin boiling out of the ground. This spring Indiana will see the emergence of the 17-year cicadas (Brood X). These insects feed underground for most of their lives drinking sap from tree roots. Once every 17 years they emerge en masse, climb up trees, sing (though it sounds more like screaming), mate, and lay their eggs on the tips of tree branches. This cycle is completely natural and has a long history in written and oral records. Cicadas are not harmful to humans, provide a feast for wildlife, and mostly only cause cosmetic injury to trees. However, there are some trees that will need protection to survive.
Cicada Emergence Timing and Locations
Where can you find cicadas?
17-year cicadas can be found throughout Indiana but the biggest populations will be in southern Indiana. According to Cicada Mania, these cicadas were reported to be more abundant in the following areas during their last emergence in 2004: “Bloomington, Brookville, Clinton Falls, Dillsboro, Fishers, French Lick, Indianapolis, Lawrenceburg, Lexington, Martinsville, McCormick’s Creek State Park, Nashville, North Vernon, Skiles Test Park, Spencer”
What do cicadas look like?
Cicadas tend to have sturdy, thick bodies with mostly clear wings that are longer than their bodies. 17-year cicadas are distinctive from the annual cicadas in that their bodies are a dark, nearly black brown with amber highlights on their wing veins, and red eyes (figure 1). Check out this video to see the full life cycle and hear what a chorus of cicadas sounds like!
How many species of cicadas are there in Indiana?
There are more than you’d think! There are three main species of 17-year cicada in Indiana and about 16 species of annual and 13-year cicadas. You can find a full list here.
Cicada Damage and Control
What do cicadas prefer to eat?
17-year cicadas aren’t picky! They’ll feed on more than 270 species of woody plants. They show a slight preference for deciduous trees like maple, fruit trees, oak, and dogwood, but will generally feed on any deciduous tree or bush available to them.
How do cicadas injure plants?
Cicadas lay eggs by stabbing their ovipositor into tree bark. This can create scars in the bark. If enough cicadas lay eggs on a small branch, it can kill the twig. As a result, large trees sometimes have minor dieback at the ends of branches but overall tree health isn’t affected (figure 2). Small or young trees and shrubs, however, may be more seriously harmed.
What kind of plants should be protected from cicadas?
Cicada females prefer to lay their eggs in branches that are about 3/16 to 1/2 inch in diameter. Therefore, young deciduous trees or bushes that have major branches less than ½ inches in diameter should be protected in areas with high numbers of cicadas emerging. Mature trees do not require protection.
How should I protect my trees from cicadas?
Homeowners:
Homeowners only need to worry if they have newly planted trees (3-4 years old). The best way to protect these young trees is to cover them in a mesh fabric for the ~1 month period when the cicadas are active in the area. The mesh bags can be made from a variety of materials as long as the holes are smaller than 1 cm (~3/8 inch). Drape the fabric over all the twigs and branches that are smaller than 3/8 inches and secure it at the bottom so that cicadas cannot climb up from underneath (figure 3). The goal is to prevent the cicadas from having access to the branches so that they will lay their eggs elsewhere.
Well-maintained trees provide many benefits including increased property values, improved air quality and curb appeal. Trees are living organisms making them vulnerable to pests and environmental extremes resulting in health issues which result in defects. This publication will help guide you on where and how to identify tree defects and a better understanding of when to contact an arborist for assistance.
Resources
Tree wounds and healing, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
How to Identify Tree Defects and What to Do About It?, Got Nature? Blog
Iron Chlorosis of Trees and Shrubs, The Education Store, Purdue Extension resource center
Surface Root Syndrome, The Education store
Tree Appraisal and the Value of Trees, The Education Store
Lindsey Purcell, Urban Forestry Specialist
Purdue University, Department of Forestry and Natural Resources
Purdue Landscape Report: Tubakia leaf spot, caused by the fungus Tubakia, is the disease we find more commonly on oak than any other. Throughout the world, there are 11 species of Tubakia known to infect oak, with Tubakia dryina (previously known as Actinopelte dryina) being the most commonly encountered species in our landscapes. Apple, ash, black gum, chestnut, elm, maple, and redbud are all reported as hosts of Tubakia species, but oaks are the most frequently and severely affected. Among the oaks, the red oak group, specifically red, pin, and black oaks, are reported to be more susceptible to infection compared to those in the white oak group.
The pathogen produces conidia within shield shaped structures called pycniothyria (Figure 6) which can be found on both the top or bottom surface of the leaf and along veins (Figure 7). These structures are very small and can only be seen with a 40x or stronger hand lens. The fungus overwinters on fallen leaves and on dead stems which act as the source of inoculum for the next year. During early spring, spores are spread by wind and water splash dispersal (rain) to healthy new foliage. However, it takes time for symptoms to develop throughout the season, depending on tree stress and environmental conditions (warm wet weather favors spread).
For full article view: Purdue Landscape Report, Purdue Landscape Report.
John Bonkowski, Plant Disease Diagnostician
Purdue Department of Botany and Plant Pathology
Tom C Creswell, Clinical Engagement Professor – PPDL
Purdue Department of Botany and Plant Pathology
The Nature of Teaching team includes:
Join Purdue Extension urban forester Lindsey Purcell, exotic forest pest educator Elizabeth Barnes and entomology extension specialist Cliff Sadof as they share about how to inspect trees, what to look for, who to contact, etc., as well what invasive pests and diseases you should keep your eye out for.
If you have any questions regarding trees, forests, wildlife, wood products or other natural resource topics, feel free to contact us by using our Ask an Expert web page.
Resources
Ask an Expert, Playlist, Purdue Extension – Forestry and Natural Resources Youtube Channel
Tree Risk Management, The Education Store, Purdue Extension resource center
Tree Appraisal and the Value of Trees, The Educational Store
Surface Root Syndrome, The Education Store
Iron Chlorosis of Trees and Shrubs, The Education Store
Facebook Live – Ask The Expert: Pests in Your Woods, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Fall webworms: Should you manage them, Got Nature? Blog
How to Identify Tree Defects and What to Do about It?, Got Nature? Blog
Lindsey Purcell, Urban Forestry Specialist
Purdue University, Department of Forestry and Natural Resources
Elizabeth Barnes, Exotic Forest Pest Educator
Purdue University, Department of Entomology
Cliff Sadof, Professor / Ornamental / Pest Management / Coordinator of Extension
Purdue University, Department of Entomology
Purdue Landscape Report: Trees are incredible survivors in spite of the challenges from pests of all kinds, including us! They are vulnerable to injuries such as mechanical wounds from lawn equipment, vehicles and ice. Pruning results in an intentional wound which is of importance to consider. Tree owners and managers need to prune trees to maintain aesthetic characteristics, remove infected limbs, reduce risk, or improve structural stability. Proper pruning practice and understanding tree wounds can minimize the impact of creating wounds on trees.
Wounds attract pests due to the phytochemicals dispersed from exposed tissue. When tree tissue is damaged or wounded, the newly uncovered tissue is exposed and that is when to expect an attack. Insect pests are drawn to trees in distress, feeding on the tissue and weakening the tree. Diseases affecting trees will introduce enzymes into the cells, digesting living tissue responsible for food and water translocation (phloem and xylem) or structural support resulting in unhealthy, unsightly, or unsafe trees.
Wound wood Formation
Trees attempt to close wounds by sealing or compartmentalizing the affected area, naturally.
Wound recovery rates vary widely for different tree species. The speed of recuperation is greatly affected by developmental environmental conditions, vigor and health of the tree. Some trees may never completely close their wounds due to their genetic capacity or perhaps inadequate resources to keep the tree vigorous. However, numerous studies reveal that faster wound closure results in fewer health issues for the tree. Quick healing is always better!
A healthy tree will seal wounds faster and the same for younger trees as well. Trees that are planted in well-drained, quality soils, with good texture, structure, and containing adequate nutrition levels, grow in a way that favors the healing process. Thus, when planting trees, homeowners should be aware of the effects of site selection, soil quality, and other site factors that may impact tree growth.
Basically, the best way to help insure proper wound closure and quick and effective sealing of the tissue is a proper pruning cut and preventing damage whenever possible.
Find a professional
Be sure to always hire an insured, tree care professional, preferably and ISA Certified Arborist with the experience, expertise, and equipment to provide proper tree care. Require proof of liability insurance to protect yourself as well.
Another easy way to find a tree care service provider in your area is to use the “Locate Your Local Tree Care Industry Association Member Companies” program. For more information refer to the publication Trees and Utilities at the Purdue Education Store.
Find an ISA Certified Arborist in your area by visiting the Trees Are Good website.
Resources
Tree Pruning Essentials, Publication & Video, The Education Store, Purdue Extension resource center
Tree Pruning: What Do Trees Think?, The Education Store
Mechanical Damage to Trees: Mowing and Maintenance Equipment, The Education Store
Tree Installation Process and Practices, The Education Store
Tree Pruning for the Landscape, Webinar, Purdue Extension – Forestry and Natural Resources Youtube channel
Lindsey Purcell, Chapter Executive Director
Indiana Arborist Association
September IDNR Wildlife Bulletin Newsletter: Indiana DNR is conducting targeted surveillance for chronic wasting disease (CWD) surveillance in northwest and northeast Indiana during the 2020-21 deer hunting season. Hunters may voluntarily submit samples for testing at select fish & wildlife areas (FWAs) and state fish hatcheries (SFHs) throughout the hunting season. Deer heads can be dropped into designated coolers at select FWAs and SFHs or hunters may make an appointment for their harvested deer to be sampled by a biologist during office hours. The 2020-21 sampling locations and their hours of operation are listed on the website. Indiana DNR biologists will intensively sample hunter-harvested deer at local businesses in the surveillance areas during three weekends: Nov. 7-8, 14-15, and 21-22.
Hunters interested in testing a deer for CWD that was harvested outside the CWD surveillance areas may take their deer to select FWAs and SFHs as well. Alternatively, hunters may independently submit their deer to the Purdue Animal Disease Diagnostic Lab (ADDL) for testing for a fee. Hunters should complete the submission form and follow the shipping instructions on Purdue ADDL’s website.
Hunters who submit a deer for CWD testing will receive a Deer Management Partner magnet and metal tag reminiscent of Indiana’s historical deer harvest confirmation process.
For more information, please visit the Indiana Department of Natural Resources website.
Resources
Chronic Wasting Disease (CWD), Indiana Department of Natural Resouces (IDNR)
New Indiana Hunting & Trapping Guide, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Wildlife Habitat Hint: Trail Camera Tips and Tricks, Got Nature? Blog
Bovine Tuberculosis in Wild White-tailed Deer, The Education Store, Purdue Extension resource center
Indiana Deer Hunting, Biology and Management Food Safety & Handling Take-Home Tips (80kb pdf), Indiana Department of Natural Resources (IDNR)
Handling Harvested Game: Episode 1, Field Dressing, Video, Purdue Extension Youtube channel
Handling Harvested Game: Episode 2, Hanging & Skinning, Video
Handling Harvested Game: Episode 3, Deboning, Video
Handling Harvested Game: Episode 4, Cutting, Grinding & Packaging, Video
Indiana Department of Natural Resources (IDNR)
Many homeowners are finding their trees with dry and wilted leaves and no rain in sight. This publication describes how homeowners can deal with these drought-stressed trees, Drought? Don’t Forget the Trees!
Drought can have a major impact on tree health and survival. Water is the most limiting ecological resource for a tree, and without adequate moisture, decline and death are imminent. It reduces carbohydrate production, significantly lowering energy reserves and production of defense chemicals in the tree.
Trees in a weakened state from drought are more susceptible to pests, which can further weaken the tree, and even kill part or all of it. Although there is nothing we can do to prevent drought, it is important to know what can be done to reduce long-term effects of prolonged dry conditions.
Resources:
Water Your Trees, Video, Purdue Extension – Forestry and Natural Resources (FNR) YouTube Channel
Trees in Times of Drought, Video, Purdue Agriculture
Drought Information, Purdue Extension
Drought Information, Indiana Department of Natural Resources
Tree Planting Part 1: Choosing a Tree video, Purdue Extension-FNR YouTube Channel
Lindsey Purcell, Chapter Executive Director
Indiana Arborist Association
This time of year, many black walnut trees’ leaves may have black spots, turn yellow and begin to drop. This is commonly known as anthracnose, a fungal disease that causes trees to drop their leaves prematurely.
Anthracnose is worsened by wet weather, and some trees are more genetically susceptible to anthracnose than others. It is not fatal but can look like a serious problem. The absence of leaves can slow a tree’s growth and can reduce the nut crop, although by this time of year growth may have slowed or stopped for the season.
Anthracnose generally begins as small circular brown to black areas on the leaflets. Over the season those spots expand and cause leaf drop. There are a few other leaf spot diseases of black walnut, see the references below for descriptions of those diseases.
Although unsightly, there is no need for further action if you are growing timber and have anthracnose in a plantation or woods. It can be an issue if you are growing walnuts for a nut crop, and there are resources and spray products to help manage the fungus in those situations.
If you have individual landscaping trees and want to limit anthracnose spread there are few things you can do:
Resources
Walnut Anthracnose, Walnut Notes, U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station
Indiana Walnut Council, Industry Representatives include 45 states and 3 foreign countries
Diseases in Hardwood Tree Plantings, The Education Store, Purdue Extension resource center
Planting Hardwood Seedlings in the Central Hardwood Region, The Education Store
Regenerating Hardwoods in the Central Hardwood Region: Soils, The Education Store
Fertilizing, Pruning, and Thinning Hardwood Plantations, The Education Store
Weed Competition Control in Hardwood Plantations, The Education Store
Resources and Assistance Available for Planting Hardwood Seedlings, The Education Store
Liz Jackson, Manager Walnut Council / IN Forestry Woodland Owners Association (IFWOA) & Engage Specialist
Purdue University Department of Forestry and Natural Resources
Purdue Extension forester Lenny Farlee tells you where to find and how to identify a species that clings to many of our trees, poison ivy. Protect yourself from the itch by recognizing this species before it is a problem.
If you have any questions regarding trees, forests, wildlife, wood products or other natural resource topics, feel free to contact us by using our Ask an Expert web page.
Resources
Poison Ivy, Purdue Landscape Report
Poison Ivy, Purdue Extension
Poison Ivy, The Education Store, Purdue Extension resource center
Investing in Indiana Woodlands, The Education Store, Purdue Extension resource center
Tree Appraisal and the Value of Trees, The Education Store
Forest Improvement Handbook, The Education Store
ID That Tree, Playlist, Purdue Extension – Forestry and Natural Resources Youtube Channel
A Woodland Management Moment, Playlist, Purdue Extension – Forestry and Natural Resources Youtube Channel
Lenny Farlee, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources