Purdue University - Extension - Forestry and Natural Resources
Got Nature? Blog
Purdue Landscape Report: Have you noticed large, messy webs on trees? You may have seen a colony of fall webworms. These caterpillars hatch in mid-July but tend to become more noticeable as the summer progresses. They often eat branches bare of leaves but are they a threat to tree health?
What do they look like?
Fall webworms are small, fuzzy pale-yellow caterpillars (figure 1) that build large, conspicuous white webs in trees in the late summer (figure 2). Their webs stretch over tree branches and grow over the course of the summer. When disturbed, the caterpillars will violently thrash back and forth in a bid to ward off predators.
Fig1. A colony of fall webworm caterpillars feeding on a leaf. Note that the web covers the leaves they are currently eating. Photo by Judy Gallagher.
Fig2. Trees will often have multiple fall webworm webs on them. This photo shows a typical number of webs for a large tree. Notice that the webs tend to be on the ends of branches and that the leaf damage is concentrated close to each web. Photo by Ken Gibson.
What kind of damage do they cause?
Fall webworms eat the leaves of many species of deciduous trees and bushes. This damage occurs late in the summer shortly before the trees normally drop their leaves for fall. Therefore, fall webworms very rarely do serious damage to trees. In most cases the trees will grow their leaves back the following spring. On rare occasions, a tree that is already highly stressed may be further weakened by fall webworm damage. However, most trees, even heavily infested trees, are minimally affected and show no signs of damage the following spring.
Do they need to be managed?
Fall webworm damage generally looks much worse than it is. In general, trees only need to be managed for fall webworm if the owner is concerned about aesthetics. In that case, the easiest means of management is pulling the web off the tree by hand and putting it in a bucket of soapy water or freezing it. Some people may be sensitive to the caterpillars’ hairs so gloves should be worn to prevent contact.
In cases where the webs are too high up to be reached, they can be managed through insecticides. Further instructions can be found here.
Cover image by Photo by msumuh on Flickr.
Resources
Fall Webworm Bulletin, Purdue Extension -Entomology
Which Web is Which, Purdue Landscape Report
Will My Trees Recover After Losing Their Leaves?, Purdue Landscape Report
Safe Caterpillar Control, Purdue Landscape Report
Mimosa Webworm, The Education Store, Purdue Extension resource center
Sod Webworms, Turf Science at Purdue University
Bagworm caterpillars are out feeding, be ready to spray your trees, Purdue Extension – Forestry and Natural Resources
Elizabeth Barnes, Exotic Forest Pest Educator
Purdue University Department of Entomology
Join Kara Salazar, Assistant Program Leader and Extension Specialist for Sustainable Communities, and Sarah Hanson, Ag & Natural Resources Educator for Purdue Extension in Johnson County, as they introduce you to the world of rainscaping and rain gardens.
If you have any questions regarding wildlife, trees, forest management, wood products, natural resource planning or other natural resource topics, feel free to contact us by using our Ask an Expert web page.
Resources
Rainscaping Education Program, Purdue University
Master Gardeners Program
Ask An Expert, Playlist, Purdue Extension – Forestry and Natural Resources Youtube channel
Rainscaping, Playlist
Rain Gardens Go with the Flow, Indiana Yard and Garden, Purdue Horticulture
Rainscaping Education Program Highlighted in NOAA Annual Report, Got Nature? Post, Purdue Extension
What is Rainscaping? Purdue Rainscaping Education Program Video, Purdue Extension
Q&A About Drainage Water Recycling for the Midwest, The Education Store, Purdue Extension resource center
Become a Purdue Master Gardener, The Education Store
Kara Salazar, Assistant Program Leader and Extension Specialist for Sustainable Communities
Department of Forestry and Natural Resources
Sarah Hanson, Ag & Natural Resources Educator
Purdue Extension for Johnson County
Meet the Hackberry. Purdue Extension forester Lenny Farlee introduces you to this native tree with single toothed leaves, an uphill/downhill shaped base of the leaves and a gray, ashy bark with warty/bumpy areas with smooth spots in between.
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
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
Hackberry/Sugarberry, The Education Store, Purdue Extension resource center
Investing in Indiana Woodlands, The Education Store
Tree Appraisal and the Value of Trees, The Education Store
Forest Improvement Handbook, The Education Store
Lenny Farlee, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources
Healthy forests provide many benefits for private landowners and for society at large. Talk with the experts in this Facebook LIVE session as they share materials, information, and assistance available for conservation tree planting.
Speaker: Dr. Carrie Pike, USDA Forest Service, Northeastern Area State and Private Forestry Regeneration Specialist and Lenny Farlee, Purdue University, Sustaining Hardwood Extension Specialist.
Time: 3:00 PM ET
More Information: More information will come out on our Forestry and Natural Resources Facebook Event page.
Resources
Resources and Assistance Available for Planting Hardwood Seedlings, The Education Store, Purdue Extension resource center
Ordering Seedlings from the State Forest Nursery System, Got Nature?, Purdue Extension-FNR
Instructions for Ordering Tree Seedlings – Indiana DNR Division of Forestry
Importance of Hardwood Tree Planting – The Education Store, Purdue Extension Resource Center
Forest Improvement Handbook – The Education Store
Designing Hardwood Tree Plantings for Wildlife – The Education Store
Lenny D Farlee, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources
In this edition of ID That Tree, Purdue Extension forester Lenny Farlee introduces you to the Eastern White Pine, Indiana’s only native five-needle pine. This species, which can grow to 150 feet tall, grows a ring of branches as it ages. Learn more inside.
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
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
White Pine and Salt Tolerance, The Education Store, Purdue Extension resource center
Tree Diseases: White Pine Decline in Indiana, The Education Store
Investing in Indiana Woodlands, The Education Store
Tree Appraisal and the Value of Trees, The Education Store
Forest Improvement Handbook, The Education Store
Lenny Farlee, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources
Purdue Extension forester Lenny Farlee introduces you to one of Indiana’s most common trees, the sugar maple. This species, which is often used to produce maple syrup, is easily identifiable by its five-lobed leaves, opposite leaf and branch arrangement, and ability to thrive in the understory.
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
The Story Behind a Sugar Maple Scar, Purdue Extension
Sugar Maple, The Purdue Arboretum
Hard or Sugar Maple, The Education Store, Purdue Extension resource center
Investing in Indiana Woodlands, The Education Store
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
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
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
Join Purdue Extension forester Lenny Farlee as he introduces you to the Sassafras in this edition of ID That Tree. The Sassafras is well known for the tree made from its bark and also for having a variety of shaped leaves from zero to three lobes.
If you have any questions regarding trees, forests, wildlife, or other natural resource topics, feel free to contact us by using our Ask an Expert web page.
Resources
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
Sassafras albidum, Purdue Arboretum Explorer
Sassafras, The Education Store, Purdue Extension resource center
Investing in Indiana Woodlands, The Education Store
Tree Appraisal and the Value of Trees, The Education Store
Forest Improvement Handbook, The Education Store
Lenny Farlee, Sustaining Hardwood Extension Specialist
Purdue University Department of Forestry and Natural Resources
August IDNR Wildlife Bulletin Newsletter: Fascinated with the natural world? Tag along with an Indiana DNR biologist on one of their upcoming excursions to learn more about wildlife and their habitats. Hone your identification skills while enjoying the outdoors.
Aug. 8 – Bike with a Biologist, Amo
For those who are new to hunting and fishing, DNR also hosts workshops through the Learn to Fish and the Learn to Hunt, Shoot, & Trap programs. Find more upcoming educational events.
Aug. 7 – Learn to Hunt: Frogs, Martinsville
Sept. 12 – Learn to Stream Fish, Atterbury Fish & Wildlife Area
Sept. 26 – Family Learn to Fish, Cicero
Resources
Ask an Expert: Wildlife Mythbusters, Video, Purdue Extension – Forestry and Natural Resources Youtube channel
Best Practices Guide for Charter Fishing and COVID-19, The Education Store, Purdue Extension resource center
Resourceful Animal Relationships, The Education Store
Considerations for Trapping Nuisance Wildlife with Box Traps, The Education Store
Handling Harvested Game From Field to Table, Got Nature? Blog, Purdue Extension – Forestry and Natural Resources
Indiana Department of Natural Resources (IN DNR)
In this edition of ID That Tree, Purdue Extension forester Lenny Farlee introduces you to the American Sycamore, one of Indiana’s largest deciduous trees. You can identify the tree from the upper part of the canopy, which glows with smooth white/light green bark.
If you have any questions regarding trees/forests, or other natural resource topics, feel free to contact us by using our Ask an Expert web page.
Resources
Sycamore, The Education Store, Purdue Extension resource center
Investing in Indiana Woodlands, The Education Store
Tree Appraisal and the Value of Trees, The Education Store
Forest Improvement Handbook, The Education Store
American Sycamore, The Purdue Arboretum
What is happening to the local sycamore trees?, Purdue Extension
Sycamore Anthracnose, Purdue Extension
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
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