Purdue Landscape Report: Many of the leaf spot diseases we observe can cause premature leaf drop in affected plants, which can reduce plant vigor if the disease is severe enough and a large proportion of the canopy falls in one season. Elm trees are susceptible to a number of different anthracnose fungi, including Ophiognomoniaintermedia, Gloeosporium betulae, Cryptocline betularum, and Cylindrosporium sp. Cryptocline is the fungus that we encounter the most frequently on samples submitted to the lab for diagnosis.
Figure 1: Cryptocline leaf spot on Elm (photo by Paul Bachi, University of Kentucky Research and Education Center)
Figure 2: Cryptocline leaf spot on a young elm shrub. As the density of leaf spots increases, the leaf blade turns more yellow. (Photo from Purdue Landscape Report)
Figure 3: Mature Cryptocline lesions which are tan in color and have black fungal structures within (photo from Purdue Plant & Pest Diagnostic Laboratory)
Symptoms
Leaf spots may start as small, round chlorotic lesions that slowly expand over time (Figures 1 & 2). Eventually, a necrotic spot with a purple/black border and tan or white center will form (Figure 3). Lesions may begin to develop on a leaf vein and instead of being circular will follow the vein a little, creating a thin necrotic lesion (Figure 4). With increased leaf spot development, large areas of the leaf blade will turn yellow and eventually necrotic, before it falls from the tree (Figure 5). Leaf drop will typically occur in the lower canopy, areas where there is less air movement and higher humidity; however, epidemics occur during periods of we weather that can cause significant leaf drop. Leaf loss typically occurs in the summer (late July to mid-August).
Figure 4: Lesions of Cryptocline located on leaf veins, creating elongate necrotic lesions instead of the typical round lesions located elsewhere on the leaf. (Photo from Purdue Plant & Pest Diagnostic Laboratory)
Figure 5: Elm leaves which have turned yellow or necrotic and fallen prematurely from the tree. (Photo from Plant & Pest Diagnostic Laboratory)
Figure 6: Close up image of Cryptocline leaf spots with acervuli. (Photo by Paul Bachi, University of Kentucky Research and Education Center)
Life Cycle Cryptocline is only known to colonize the leaves, so it overwinters in fallen leaf tissue. In the spring, the fungus will produce ascospores which are carried in the wind to infect young elm leaves. Once initial lesions progress, black fungal structures (acervuli) will form in the necrotic tissue and being producing asexual spores (conidia) in a sticky substance, which can be spread via rain (Figure 6). The conidia act as a secondary infection cycle where it will infect foliage and create new leaf spots continuously throughout the growing season as long as the environmental conditions are conducive.
Management
Like other leaf spot pathogens that do not infect stems, removal of the foliage in the fall can reduce inoculum for the following year (though won’t eliminate the disease). Providing fertilizer (where needed) and water (hot and dry periods) will help mitigate some tree stress, as stress can predispose plants to increased disease severity. Fungicides are not normally recommended for mature trees as it is impractical to get coverage across the entire canopy, but could be practical in a nursery setting if symptoms are observed and leading to leaf drop. It is still early in the season, but the next few weeks are important to monitor for some disease issues that may explode later in the season.
For other information on management of foliar disease problems, please see the following link: Foliar Fungal Disease Management.
MyDNR,Indiana’s Outdoor Newsletter: There are many options for enjoying outdoor recreation across Indiana this fall, especially with deer hunting season upon us. Learn more about deer hunting, how to support healthy wildlife populations, important regulations and how your hunting can support Hoosiers in need. Pay special attention to deer regulation changes, season dates and the importance of purchasing your license.
Reduction Zone Season: Sept. 15, 2025 – Jan. 31, 2026
Archery Season: Oct. 1, 2025 – Jan. 4, 2026
Firearms Season: Nov. 15 – Nov. 30, 2025
Muzzleloader Season: Dec. 6- Dec. 21, 2025
Deer Hunting Regulation Changes Indiana DNR has made big changes to Indiana’s deer hunting rules. These changes are in effect for the 2025-2026 hunting season. The changes were made, in part, to make Indiana’s hunting regulations easier to understand.
Rule changes include:
The statewide bag limit is now 6 antlerless deer and 1 antlered deer.
A newly created county antlerless bag limit replaces the season antlerless bag limits and county bonus antlerless quotas. Because of this change, the new multi-season antlerless license has replaced the bonus antlerless license.
Antlerless deer cannot be taken with a firearm during firearms season at Fish & Wildlife areas.
Only 1 antlered and 2 antlerless deer can be taken with the bundle license.
The use of crossbow equipment is now allowed using the archery license.
Portable tree stands and ground blinds can now be placed on DNR properties in Deer Reduction Zones between noon Sept. 1 and Feb. 8.
State law prohibits the use of drones (unmanned aerial aircraft) to search for, scout, locate or detect a wild animal during the hunting season and for 14 days prior to the hunting season for that animal.
Hunters can now use rifles with a centerfire cartridge that has a bullet diameter of .219 inches (5.56 mm) or larger on both public and private lands.
For questions about equipment, regulations or changes in them, or which license you need, contact the Deer Information Line at INDeerInfo@dnr.IN.gov or 812-334-3795.
Hunting Safety Tips and Reminders Indiana DNR reminds you to stay safe this deer season. Hunting injuries most commonly involve elevated platforms and tree stands, so stay safe by following the guidelines below.
Tree stand safety before the hunt:
Read, understand, and follow the tree stand manufacturer’s instructions.
Check tree stands and equipment for wear, fatigue, rust, and cracks or loose nuts/bolts, paying particularly close attention to parts made of material other than metal.
Practice at ground level with a responsible adult. If you need to sight in your equipment, find a shooting range near you.
Learn how to properly wear your full-body safety harness.
Make a hunt plan and share it with someone before your hunt.
Wear your full-body safety harness.
Use a tree stand safety rope.
Make certain to attach your harness to the tree or tree stand safety rope before leaving the ground and check that it remains attached to the tree or tree stand safety rope until you return to the ground.
Maintain three points of contact during ascent and descent.
Wear boots with nonslip soles.
Use a haul line to raise and lower firearms, bows, and other hunting gear.
Make sure firearms are unloaded, action is open, and safety is on before attaching them to the haul line.
General reminders:
Hunter Orange – know when to wear it and how much is needed on a ground blind
Hunter orange is required for all deer hunters during youth, firearms, and muzzleloader season. Hunter orange must be worn at all times during the hunt, including walking to and from the hunting location. Regardless of hunting equipment being used (archery, crossbow or firearm), if it is firearms season, you are required to wear hunter orange.
A ground blind must have at least 144 square inches of hunter orange material that is visible from any direction during any season in which a hunter is already required to wear hunter orange.
Firearm Safety – Treat every firearm as if it is loaded, keep the muzzle pointed in a safe direction, keep your finger off the trigger until you are ready to shoot, and be sure of your target and what is beyond it.
Print and complete a Landowner Permission Form if hunting on private land that isn’t your own.
Remember to complete and attach a deer transportation tag immediately upon taking a deer. The tag should be attached to the deer during transportation and any time the deer is unattended.
Always bring emergency equipment with you on your hunt, such as a cellphone, flashlight, small first aid kit and extra water.
Deer Reduction Zones For information or any questions, view: Deer Reduction Zones.
Deer Disease Updates Chronic wasting disease (CWD), a fatal disease impacting white-tailed deer, has been detected in wild deer in two areas of Indiana: LaGrange County and Posey County. These detections resulted in a CWD Positive Area including LaGrange, Noble, Steuben, and DeKalb counties and a one-year CWD Enhanced Surveillance Zone including Posey, Vanderburgh, and Gibson counties.
DNR offers free, statewide CWD testing for hunters by either taking your deer to one of DNR’s drop-off coolers at select Fish & Wildlife areas (FWAs), state parks, state fish hatcheries (SFHs) or through advertised private businesses such as taxidermists. These options are available during all seasons. Find out more about how to get your deer tested here: Chronic Wasting Disease (CWD).
IN-PREPared: The Indiana State Board of Animal Health has confirmed cases of Highly Pathogenic Avian Influenza (HPAI) in northeast Indiana. As millions of wild birds traverse the state during peak migration, the risk of additional outbreaks remains high. To support awareness and preparedness, Indiana PREPared offers a comprehensive resource library with science-based information on avian influenza, biosecurity practices, and public health guidance.
What is HPAI? Avian influenza, or “bird flu,” is a contagious viral disease of domestic and wild birds. It’s a major threat to the poultry industry, animal health, trade, and the economy worldwide.
Caused by influenza type A viruses, the disease varies in severity depending on the strain and species affected. Highly pathogenic avian influenza (HPAI) strains are deadly to domestic poultry and can wipe out entire flocks within a matter of days. Low pathogenicity avian influenza (LPAI) strains typically cause few or no signs of illness. They occur naturally in wild birds around the world. However, some LPAI strains can become highly pathogenic in poultry. (USDA-APHIS)
According to the Centers for Disease Control and Prevention (CDC):
H5 bird flu is widespread in wild birds worldwide and is causing outbreaks in poultry and U.S. dairy cows with several recent human cases in U.S. dairy and poultry workers.
While the current public health risk is low, CDC is watching the situation carefully and working with states to monitor people with animal exposures.
Purdue Landscape Report: By now, the emerald ash borer (EAB) invasion is an old story for landscapes and forests in the Midwest. Since EAB was first found in North America in 2002 more millions of ash trees than we can know have died and this tiny insect continues to kill ash in an ever widening zone that currently includes 37 US states and 6 Canadian provinces. Arborists and landscape managers continue to protect valuable ash trees by use of systemic insecticides, typically applied via trunk injection every 2-3 years.
While EAB is the overarching threat, ash survival may also be threatened by wood decay fungi, which may colonize insect exit holes, injections sites and other wounds. The most common decay fungi we see in the lab are Perenniporia and Fomitopsis.
Perenniporia fraxinophila is the most frequently reported wood decay fungus on ash and causes a heart rot that contributes to loss of structural integrity of the tree. Infection sites tend to be high on the tree and may be easily overlooked until decay is advanced. The fungal structure is perennial, expanding each year, and may be confused with Ganoderma applanatum, the artist’s conk. The upper surface turns black or brown with age and the underside is white with pores instead of gills.
Figure 1: Upper ash branches colonized by a suspected Perenniporia sp. (PLR)
Figure 2: Fungal conks of a suspected Perenniporia sp., beginning to emerge from decaying ash branches. (PLR)
Figure 3: Fungal conks of a suspected Perenniporia sp., beginning to emerge from decaying ash branches. (PLR)
In the last few years, we have had a few samples of a similar fungus colonizing the trunk and base of ash trees, often near injection sites. Initially we were unable to identify the fungus, but DNA analysis revealed the fungus was a Fomitopsis species. This fungus develops a shallow shelf structure with white top and tan underside.
Fungal decay presents a greater risk to ash because it lacks the preservative enriched heartwood found in oak, walnut and other hardwoods that tends to slow down internal spread of fungi. Even fungi that initially invade dead areas of ash may rapidly colonize and degrade stem and trunk tissue.
Figure 4: Fomitopsis sp. colonizing the trunk of ash trees damaged by EAB. (PLR)
Figure 5: Fomitopsis sp. colonizing the trunk of ash trees damaged by EAB. (PLR)
Figure 6: Fomitopsis sp. colonizing the trunk of ash trees damaged by EAB. (PLR)
Fungal decay also disrupts vascular tissues in the stems and trunk, which further limits the movement and effectiveness of insecticide injections, so that infected trees may face greater damage from EAB. When found on small side branches the infection might be successfully pruned out, but in most cases the decay is in major branches or the trunk, which means the tree will need to be removed. If your ash trees that are being regularly treated for EAB but continue to show thinning and decline, check for these fungal invaders, they may be partly responsible.
Purdue Landscape Report: Aspen, cottonwood, and poplar are all names for the fast-growing Populus tree species. Used widely for building materials, these trees are often located around ponds, riverbanks, and sloping areas toward water bodies (especially cottonwood). Cottonwood flowers produce little white tufted seeds that float through the air which a lot of people love (my kids included), unless it lands in their mouth. These beautiful trees are susceptible to a fungus that can cause significant damage under the right conditions: Marssonina (newer name is Drepanopeziza).
There are three species of Marssonina that can infect Populus – different tree species may only be susceptible to one of the Marssonina species. The fungi cause the same kind of disease and develop similarly on the host. Marssonina can infect the leaves, stems and seeds of Populus, which can lead to large amounts of leaf loss during wet weather, girdled stems and dieback, and aborted seeds. Since seeds can carry the fungus, the seed will take it with it to where it lands and can become infected immediately after germinating. It is common to see high disease severity in the canopy, but unless there is significant leaf loss (up to 70% defoliation) it may not reduce plant vigor. Leaf lesions typically develop as small black to brown dots or flecks which expand in size as time goes one. As the disease progresses, large areas of the leaf will become necrotic, creating odd dead blotches, potentially killing the majority of the leaf blade.
The fungus produces asexual spores in a small black pustule on the upper surface of the leaf which will eventually burst and release the spores during humid weather early in the spring. Marssonina will continue to produce spores and cause disease the whole season, creating repeat infections on the same tree. Symptoms tend to start lower in the canopy and ascend up the tree as the season progresses. The spores are spread by water splash, so rainfall will help spread this fungus in the landscape.
For trees planted in native landscapes, this disease will likely be inevitable and may make the foliage look less than stellar. That being said, removing leaves that drop or at the end of fall will reduce total inoculum for future seasons and can reduce total disease long-term. Similarly, trees that are stressed will typically develop increased disease severity, so if you are seeing large amounts of leaf spots or leaf loss, I would recommend employing stress mitigation strategies to keep the tree happy and healthy (fertilizer, mulch, irrigation as needed, etc.). If a tree appears to develop significant disease every year and has reduced limb growth, you may consider removing the tree if you are concerned it may die early and replace with a resistant clone, as disease susceptibility can vary greatly between clones of the same species.
Fig 1: Populus sp. with significant leaf loss due to Marssonina leaf spot. Photo credit: PPDL
Fig 2: Aspen wit thinning tree canopy due to Marssonina infection. Photo credit: PLR
Fig 3: Necrotic flecks and dots associated with early infection by Marssonina. Photo credit: PPDL
Fig 4: Leaf necrosis and twig dieback caused by Marssonina. Photo credit: PLR
Fig 5: Severely leaf necrosis of an aspen tree caused by repeat infections by Marssonina. Photo credit: PPDL
Wild Bulletin, IN DNR, Division of Fish & Wildlife:Epizootic hemorrhagic disease (EHD) is a naturally occurring viral disease commonly seen in the Indiana deer herd. Each year, typically in late summer, Indiana DNR receives reports of deer displaying signs of EHD throughout the state.
This year, DNR confirmed a significant EHD outbreak that began in the northern region of the Hoosier State. In some years, EHD can affect a larger-than-normal portion of the deer and becomes widespread across a county. In those instances, DNR lowers the County Bonus Antlerless Quotas (CBAQs) in the impacted counties to offset the effect of the counties’ EHD outbreak on the deer herd in that region.
EHD is transmitted by biting midges, also known as sand gnats or “no-see-ums.” Deer infected with EHD may display unusual behaviors such as lethargy, excessive salivation, or disorientation. EHD also causes fever in deer, which can cause deer to seek water. As a result, many deer that die from EHD are found in or near open water sources like ponds and rivers. Anyone who finds a deer showing signs of EHD or dead in water is asked to report it at on.IN.gov/sickwildlife.
County bonus antlerless quotas reduced in three counties for 2024-25 Due to the number of reported deer mortalities and extent of EHD in the region, DNR has lowered the County Bonus Antlerless Quotas (CBAQs) in Wabash, Porter, and Allen counties from two bonus antlerless deer to one to help offset the effects of EHD on the deer herd in that region. During the winter, DNR biologists will fully evaluate the effects of EHD and will propose changes to bag limits as required. Hunters can stay informed about CBAQ changes at on.IN.gov/EHD-quotas.
Purdue Landscape Report: There have been a significant number of questions and problems regarding triclopyr that have come up this growing season.
Figure 1. Confirmed damage from triclopyr on sassafras shows the growth regulator-type injury on leaves. Photo courtesy of the Office of the Indiana State Chemist.
General Information about Triclopyr Triclopyr is a selective systemic herbicide belonging to the pyridine class. It is primarily used to manage woody plants, vines, and some broadleaf weeds. Unlike glyphosate, a broad-spectrum herbicide, triclopyr specifically targets the growth hormones in dicotyledonous plants, making it effective in controlling species that are difficult to manage with other herbicides. It works by mimicking plant hormones, disrupting normal growth processes, and leading to the death of the treated plant (Fig. 1).
What Triclopyr Controls Triclopyr is utilized in various settings to control unwanted vegetation. It is effective against species such as:
Woody Plants: Includes trees like tree of heaven and callery pear and shrubs like autumn olive and honeysuckle (Fig. 2).
Vines: Particularly those that can outcompete native flora, such as kudzu or English ivy (Fig. 3).
Broadleaf Weeds: Some herbaceous plants that pose ecological or agricultural problems.
Figure 2. Invasive plants, such as, Pyrus calleryana (callery pear) can be controlled by triclopyr.
Figure 3. Invasive vines, such as Hedera helix (English ivy) can be controlled via multiple applications of triclopyr.
Where and When Triclopyr is Used Triclopyr is applied in a range of environments, including:
Forestry: To clear invasive species and manage forest regeneration.
Agriculture: To control weeds and shrubs that interfere with crop production.
Aquatic Areas: Formulations that are safe for aquatic environments help manage invasive species near water bodies.
Rights-of-Way: To maintain clear paths and prevent the spread of invasive plants.
Timing of application is crucial. Triclopyr is most effective when applied during the growing season when plants are actively taking up nutrients and can transport the herbicide throughout their system.
Figure 4. Hack and squirt treatments with triclopyr is a common method to control invasive trees. Photo by Lenny Farlee.
Movement in the Plant Triclopyr is absorbed through foliage and roots and is translocated systematically within the plant. Once inside, it moves upward through the xylem and downward through the phloem (ambimobile). This systemic movement allows triclopyr to affect not just the treated areas but also parts of the plant that are not directly sprayed. This attribute makes it effective for managing large, established plants, specifically through hack and squirt treatments (Fig. 4).
Purdue Landscape Report: Early June, we received a white pine sample at the Purdue University Plant and Pest Diagnostic Lab that showed early season needle loss lower in the tree canopy (Figure 1, 2). The majority of conifers hold onto their needles for multiple years, so loss of needles, even in the fall, can come as a shock to homeowners. In this particular case, we found multiple fungi that could be contributing to needle blight or needlecast.
Figure 1: Eastern white pine trees with early season needle loss.
Figure 2: Closeup images of white pine with needlecast. Multiple fungi were present: Lophodermium, Lecanosticta, and, Septorioides. Note, primarily the older needles have been affected. New needles appear green and healthy.
The first two fungi were determined to be relatively common pathogens for Indiana: Lophodermium and Lecanosticta (brown spot). Symptoms appeared relatively typical for these pathogens where the needles turned brown over-time. However, there were other needles in the canopy and on the sample that had a lighter coloration. We found small black fungal structures dotted along the length of these needles producing light colored cirrhi (also called spore horns) (Figure 3). After examining the fungal spores, isolating the fungus, and performing DNA testing, we determined this third fungus to be Septorioides strobi, the causal agent of Septorioides needle blight of pines. This fungus has been determined to be a contributor to white pine needle damage/defoliation.
Figure 3: Black fungal structures developing on dead needles with white sporulation exuding from the top.
White pine needle damage/defoliation (WPND) was first observed in the state of Maine in 2010 and was attributed to three needle blight diseases, including Lecanosticta, and has since been observed throughout the Northeast US. However, researchers eventually determined that a new fungus, Septorioides strobi, was also found consistently in blighted needles and could be contributing to WPND.
This is the first time we have found this fungus in the state of Indiana, though it has been present for longer than a single season. We do not know how it will react to our climate nor if it will cause significant damage to affected trees. Like other needle blight pathogens, Septorioides has been observed to sporulate around the same time during humid, wet weather, but symptoms may not develop until the following year. White pines are the primary host for this needle cast disease, but it can also develop on 2, 3, and 5 needle pines. While we see white pine decline is a major problem, Septorioides will not likely be the final nail in the coffin for white pines in Indiana, though it certainly will not help us keep them healthy.
MyDNR,Indiana’s Outdoor Newsletter: As a result of Indiana’s positive detection of chronic wasting disease (CWD) in LaGrange County in April, Indiana DNR has restricted moving deer from any CWD Positive Area for rehabilitation purposes.
With the change, an individual who finds an orphaned, sick, or injured deer in a CWD Positive Area may only surrender the deer to a DNR-permitted wild animal rehabilitator that is located within a CWD Positive Area. This restriction is to help minimize the spread of CWD to new parts of the state, as deer can carry this disease without appearing sick.
Currently, there is one CWD Positive Area in Indiana. It includes LaGrange, Steuben, Noble, and DeKalb counties. While no CWD positive deer have been documented in Steuben, Noble, or DeKalb counties, those counties are considered part of the CWD Positive Area because of their proximity to where the state’s first CWD-positive deer was found in LaGrange County.
During their first few weeks of life, fawns often hide by themselves and stay motionless to avoid predators while the mother is looking for food. If you find a fawn alone, you can help it by letting it be, giving it space, and leaving the area. Its mother is likely nearby.
Purdue Landscape Report: Recently a homeowner in Hamilton County posted on the Indiana Native Plant Society Facebook page with concerns about aphids, mites, and apple scab in her maple and oak trees. She asked for a second opinion and treatment options for these pests. I reached out to the homeowner and requested permission to collect samples from the trees. Let’s look at what I found (or didn’t find) and discuss when and if these issues should be treated.
Apple Scab on Maples?
First, we can eliminate the concern about apple scab because maple and oak trees are not hosts for this pathogen. Apple scab is caused by the fungus Venturia inaequalis, and hosts include apples, crabapples, hawthorn, mountain ash, firethorn, and loquat. There are other fungal diseases which cause leaf spotting in maples, such as Anthracnose, tar spot, and Phyllosticta leaf spot. To diagnosis these diseases, homeowners can submit a sample to the Purdue Plant & Pest Diagnostic Lab, or hire a certified arborist to assess the tree. However, all these diseases are primarily aesthetic issues. A healthy tree will not die from these pathogens and does not require treatment. You can find more information about maple diseases in this publication: Diseases in Hardwood Tree Plantings. You can also find a previous article on Tar Spot in Maple in the Purdue Landscape Report (Issue 18-12).
Fig. 1. Severe spider mite damage on maple leaves. (Photo: S. D. Frank, North Carolina State University)
Spider Mites
The next pest concern on these trees is spider mites. Out of the dozens of leaves I collected, I found only two immature mites on a couple of maple leaves I examined. This is a very small mite presence, and it is not recommended to treat for spider mites unless the populations threaten the health or appearance of the tree. Limiting pesticide usage will conserve the natural enemies, which are vital to keeping mite populations in check. In fact, improper pesticide applications can kill these important natural enemies and worsen mite infestations.
When do you know if the mite population is large enough to merit intervention? Check your trees for signs of heavy feeding damage, such as leaf stippling (Fig. 1), or dense webbing on the leaves. Mites can also be monitored by placing a sheet of paper (8.5×11”) beneath a branch and striking the limb. Chemical treatments should be considered when you count ≥24 mites per strike. You can find detailed management recommendations and a full list of pesticide options in this Purdue Extension publication: Spider Mites on Ornamentals.
Fig. 2: Adult painted maple aphids found on maple in Hamilton Co, Indiana. (Photo: Andrew Johnston, Purdue University).
Aphids
The aphids I found on the homeowner’s maple trees are Drepanaphis acerifoliae, or the painted maple aphid (Fig. 2). This species only feeds on maple trees, and is not a threat to the oak tree on this homeowner’s property. Painted maple aphid is a very common aphid in our region. I found only a few aphids on one of the maple trees I sampled, which is not enough to require treatment. In addition, one of the aphids was a “mummy”, or a carcass left behind from a parasitoid wasp. This indicates that natural enemies are already at work managing the aphid population. Aphids may rarely require chemical control if their numbers grow large enough to produce significant amounts of honeydew, which can result in sooty mold outbreaks.
Tussock Moth
The only insect I found on the oak tree was a white-marked tussock moth caterpillar, Orgyia leucostigma (Fig. 3). This is the likely culprit for the minor feeding damage I noticed. These are not significant pests and do not require treatment. Don’t touch them, though! The setae of this caterpillar are irritating and may cause allergic reactions.
Overall, the pests I found were minimal and non-threatening to the trees. It’s normal to find some insect pressure in the landscape. Knowing when and if to treat requires accurate diagnosis and monitoring of pest levels. Check out PurduePlantDoctor.com for an easy-to-use diagnostic aid and treatment recommendations.
What is HPAI?
