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Bagworms – Destructive Tree Pests Coming This Summer

By Stein Tree
Posted on April 2, 2014

It looks like the very destructive Bagworm is going to be around this summer.  Spring is the perfect time to make a plan for this pest and protect your at-risk trees.

Below is an excerpt from a Penn St. article on the Bagworms and their destructive activities in Southern Pennsylvania. (Full Article)

The Bagworm (Thyridopteryx ephemeraeformis) is a perennial insect pest of arborvitae, juniper, pine, spruce, and many other evergreen species. It also attacks certain deciduous trees such as black locust, honeylocust, and sycamore. The bagworm is most common in southern regions of Pennsylvania. Infestations have recently been noticed north of Interstate 80 in the state. The spread of the bagworm is slow since adult females are unable to fly. Their dispersal over wide areas occurs mainly through movement of infested nursery stock and ornamental plants, or by ballooning (wind dispersal) of small bagworm larvae during early June.


This insect is most easily recognized by the case or bag that the caterpillar forms and suspends from ornamental plants on which it feeds. The bag is made of silk and bits of host foliage. These materials are interwoven to disguise and add strength to the case. When the larva is mature, the bag may be 30 to 50 mm long. Young larvae hatching from the eggs are approximately two mm long, glossy black on the back and dull amber on the undersurface of their bodies. Mature larvae are dull, dirty gray and splotched with darker markings toward the head. Fully developed larvae are about 18 to 25 mm long. The adult female is worm-like. The adult female lacks eyes, wings, functional legs and mouthparts. She never leaves the bag that she constructed as a larva. The adult male is sooty black and moth-like with transparent wings that are nearly devoid of scales.

Stein Tree Service has significant experience at treating Bagworm and helping keep your trees healthy.  Don’t wait!  The time to make a plan is now.  We offer a free, no obligation consultation with an ISA Certified Arborist who can offer guidance, discuss risks and a plan to manage all your landscape health care needs.

Why Choose Stein Tree Service?

Our staff is the best in the business and has hundreds of years of combined experience. We have ISA Certified Arborists, Registered Consulting Arborists, Certified Tree Risk Assessor, Licensed Forester, Certified Professional Horticulturalist, Registered Tree Expert and Certified Applicator.

Our equipment is state-of-the-art and radio dispatched for immediate response. The company fleet consists of several aerial lift trucks, chippers, chipper trucks and stump grinding machines as well as various pieces of machinery for right of way work.

Our reputation speaks for itself. We have served thousands of customers throughout the Delaware Valley and maintain the highest level of customer satisfaction. The vast majority of our business comes to us via referrals from past customers.




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