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Bag Worm (Thyridopteryx ephemeraeformis)

Order: Lepidoptera (le-pid-OP-ter-a) (Info)
Family: Psychidae
Genus: Thyridopteryx
Species: ephemeraeformis


This bug has been reportedly found in the following regions:

North Little Rock, Arkansas
Bear, Delaware
Big Pine Key, Florida
Boca Raton, Florida
Fort Lauderdale, Florida
Kissimmee, Florida
La Crosse, Florida
Leesburg, Florida
Lutz, Florida
Seffner, Florida
Wauchula, Florida
Chillicothe, Illinois
Macy, Indiana
Lansing, Kansas
Hebron, Kentucky
Melbourne, Kentucky
Adamstown, Maryland
Frederick, Maryland
Minneapolis, Minnesota
Florence, Mississippi
Marietta, Mississippi
Branson, Missouri
Chesterfield, Missouri
Hartsburg, Missouri
O Fallon, Missouri
Plattsburg, Missouri
Medford, New Jersey
Moorestown, New Jersey
Pennsville, New Jersey
Portales, New Mexico
Staten Island, New York
Columbus, Ohio
Dayton, Ohio
Hulbert, Oklahoma
Barto, Pennsylvania
Northampton, Pennsylvania
Simpsonville, South Carolina
Spartanburg, South Carolina
Summerville, South Carolina
Clarksville, Tennessee
Cypress, Texas
Fayetteville, Texas
Grand Prairie, Texas
Missouri City, Texas (2 reports)
Pilot Point, Texas
San Antonio, Texas
Santa Fe, Texas
Abingdon, Virginia
Ashburn, Virginia
Chesapeake, Virginia
Fredericksburg, Virginia
Roanoke, Virginia
Show all

Members' Notes:


On Jul 2, 2012, whittler01 from Hartsburg, MO wrote:

Very destructive. I have two Thuja green giants out of about 50 that seem to be targeted as well as a solitary arbor vitae. I have been manually picking them off the thuja trees, however, the arbor vitae is large and well established and is currently suffering the worst infestation (it's hosting a devouring army of these destructive bugs. I had no idea the trees were infested and had chalked it up to a hot dry year up until last week when I really inspected those 'funny little pinecones'. Wish I had done this sooner. The worms are still feeding so I have sprayed Sevin on all my evergreens (as of last night - will see if any good results). Picking up some BT as well to see if I can double up on firepower and knock them down before they destroy the 3 or 4 years of hard work and pleasur... read more


On Aug 13, 2011, nalcmama from Falmouth, VA wrote:

I noticed the arborvitae in the yard in Fredericksburg, VA was dying and I thought that these were just dead foliage. Then I saw some on my rose bushes and azaleas. When I looked closer some were moving. I did some research on line and wound up here. Time to go outside with some hot soapy water to take care of these pests.


On Sep 17, 2010, IthilienGarden from Grand Prairie, TX wrote:

Last year these attacked my Italian Cypresses. Looked like pine cones from a distance. One of the five cypresses was badly infested and started turning brown. I used Bayer Advanced 3-In-1 Insect, Disease and Mite control. Ready to use formula was easy to use attached to the end of the hose. You have to make sure you get into all the foliage of the tree with forceful spray. Repeated in one month. The tree bounced back but is shorter than other trees. This year the bugs were back on another tree but I treated in time. It seems I will have to treat these cypresses every spring for few years from now on. I really, really don't like these bugs.


On May 25, 2010, deighj wrote:

I have been battling bagworms, tent caterpillars or whatever for the last few years. The worst hit trees are my pecans and fruit trees. These trees are much too tall for spraying to be effective with a backpack sprayer. I was told that using a hose with a carwash attachment will dislodge the tents. I haven't done so yet but wonder if anyone out there has tried this method. I would much appreciate any advice on getting rid of these pests.


On Oct 14, 2009, Meickle2003 from Chillicothe, IL (Zone 6a) wrote:

I have found this little pest on some fur trees in our back yard. So far they have killed 2 of my trees and they are working on the other 6 trees in the row. I have tried spraying with seven spray but it has not helped. Hopefully the freeze that we had will take care of them for this season. I will start spraying earlier next spring so that they dont do the damage that they did this year.



On Jan 23, 2008, Malus2006 from Coon Rapids, MN (Zone 4a) wrote:

Those bugs are very common in my yard - I have seen them pupae on walls of the house, etc. It's tough to see any damages.


On Jan 19, 2008, ImaFarmer2 from Medford, NJ wrote:

I own a Conifer Tree Farm in South Jersey and these Bag worms have been attempting to over run my place the last few summers.There are way too many to hand pick off so I armed myself with a backpack sprayer and some liquid "seven" and battled them suckers back.I found that if I start looking for them in early to mid may when they start hatching, they are easier to eliminate with chemical.If you wait till June/July, they are very,very difficult to control because they are big enough to survive and they use their Cocoons to hide from spray applications.


On Jul 11, 2007, fiwfbn from Simpsonville, SC wrote:

Notice little cones on my Cypress by my front window last year. Alas, I was two late. The bugs have killed two large cyress this year and is working on another tree in my front yard. hopefully we will be able to kill them quckly now we know what they are. They left a trail leading from the cypress to the tree they are now attacking.



On Aug 28, 2006, shorelady from Moorestown, NJ wrote:

Found these critters on an arborvitae. Picked them off and sealed in a plastic bag. After checking the web read about the hot soapy water trick. Think we got them all but a good idea to keep spraying. Bought a chemical from Lowe's geared to bagworms--can't remember the name and have sprayed twice. Will check next spring and spray any eggs that might be growing.


On Aug 19, 2006, MzVic from Pennsville, NJ wrote:

Recently discovered what appeared to be small pinecones
on my fir tree. Looked a liitle closer, realized they were moving. Did a search. Seemed the best defense was to remove and soak in hot soapy water.


On Aug 13, 2006, TBGDN from (Zone 5a) wrote:

These insects are very, very destructive particularly on conifers here: However, they don't mind attacking any shrub or tree in the yard. Their 'bags' are often decorated with parts of foliage, and seem to be a natural part of the shrub or tree. I have a heavy infestation on a Colorado Blue Spruce on the front lawn, and have treated it twice during the past month with Sevin (Carbaryl). I have found them on crab apple trees as well. On checking today I found three or four still alive, and promptly re-sprayed. Should you want to check for what's inside, simply peel back the opening of the 'bag' where it attaches to the tree branch, and the worm can plainly be seen.


On Aug 5, 2006, garden6 from Lansing, KS (Zone 5b) wrote:

Thought these pests were little growths ( looked like little pine cones)on my cypress. Several of my cypress were heavily infested and dying in large areas. When you pick these pests off in the summer, be sure to stomp and squash them or they will wiggle out of they bags and attack a nearby tree. My neighbor says that hot soapy water in a bucket is just as effective. Next spring, in early June ,I will spray my trees to kill the emerging larvae.


On Aug 5, 2006, Dea from Frederick, MD (Zone 6a) wrote:

Destructive worms that once escape the pod will quickly destroy cypress trees in the mid-atlantic area.

Opening the tents when found early will provide food for swallows and other birds.


On Jul 31, 2006, city_of_refuge from Chesapeake, VA wrote:

Amazing worm! On my job--I work outside-I have to maintain the property on various sites within the City. Started noticing the bushes being eaten up by something. I asked about the thing and found out that it was a bagworm. I picked and disposed of all of them and stopped the death of the bushes. They are really devastating to the plant-life that they attach to!


On Jul 31, 2006, aprilwillis from Missouri City, TX (Zone 9a) wrote:

The bags contain the soft bodied worm (female), when small the are susceptible to detergent and water sprayed.