For many areas in southern Iowa ("bagworm territory"), it is now too late to treat for bagworms. Leaves and buds are both fair game for food. Because the bags are shaped like pine cones, they often pass unnoticed in conifers—until it's too late. A heavy infestation of bagworms can completely defoliate an arborvitae and kill it. Below we are to give you tips in order to help you answer the big question of: How can you get rid of bagworms in trees? Bagworms are insects that require control as they can defoliate evergreens and sometimes deciduous trees/shrubs. Also associated with an infestation of bagworms is the presence of many spindle-shaped bags up to 1 1/2" in length from late summer to spring. Identification Scout now to control bagworms this spring Kansas Forest Service notes bagworms are most easily controlled in May and June. Bagworms love arborvitae and red cedar, but they will also eat from juniper, black locust, oak, sycamore, pine, spruce and more. Bagworms “are really pretty nasty, and this is the time of year they are just finishing their destruction out there,” Raupp says. The most common species of bagworm (there are 20 species in North America), and one of just a few known bagworm pests, is the evergreen bagworm, Thyridopteryx ephemeraeformis. On the other hand, they are well protected from many pesticides by their tight, water-repellent bags. They make a cocoon-like bag in which to live, while they hang on the branches of trees and shrubs to feed. Arborvitae and red cedar are the favored host trees of the evergreen bagworm, but cypress, juniper, pine, spruce, apple, birch, black locust, elm, maple, poplar, oak, sycamore, willow, and over 100 other species are also attacked. Bagworms feed on most coniferous plants and on many deciduous trees and shrubs. Trees and shrubs with some surviving green may survive in part; those brown areas devoured by the bag worms will never recover. They are covered with dead needles, so they appear more noticeable in contrast to the green deciduous needles at this time. Cypress, spruce, juniper, pine, apple, birch, black locust, elm, maple, poplar, oak, sycamore, willow, and over 100 other species are also attacked. Bagworms are commonly parasitized by ichneumonid wasps, notably Itoplectis conquisitor. Young bagworms are difficult to see, but if bags are present, you know you have caterpillars. As homesteaders living on largely undeveloped land, bagworms aren’t generally a problem. See the file on Controlling Bagworms. Not sure if you have bagworms? Sometimes, they're so prolific that they kill their host tree. Shear back the areas the deer didn't hit, and while you're at it, you can do the others, to match. Bagworms are destructive insects that attack many species of trees and shrubs but are most often found on conifers like juniper, pine, arborvitae, cyprus, cedar, and spruce. Handpicking bagworms off the plants is the cheapest way to control them. Bagworms are most often found in the southern half of Iowa. However, by that time, bagworms may have caused substantial damage … They particularly like to infest conifers such as pine, cedar, arborvitae, Leyland cypress, and juniper. Bagworms are actually caterpillars from various moth species. The bags protect the caterpillars from their natural enemies. Once stripped, these plants are lethargic about leafing back out again. This is caused by tiny, first-stage bagworm caterpillars etching needle surfaces as they feed. Arborvitae and red cedar are the favored host plants for the Evergreen Bagworm Moth. While evergreen trees and shrubs cannot recover from complete defoliation, deciduous trees such as boxwood, The female bagworm never leaves her bag. Bagworms damage trees by feeding on their foliage. Bagworms are actually the larval or caterpillar stages of moths. MANHATTAN, Kan. – A Kansas Forest Service official says mid-May is an important time to start scouting for bagworms, a perennial problem that affects many trees common to Kansas landscapes. They get the name “bagworms” due to the insect wrapping themselves up in cocoon-like “bags” made from twigs, leaves, and self-spun silk. The male will emerge in 7-10 days as an adult moth with clear, one inch span wings. The earliest sign of bagworm injury in an evergreen is brown or stressed needles at the tips of branches. Do not cut past the growth line, where there are plenty of green stems to regrow from. Bagworms feed on the foliage of a wide variety of trees and shrubs. arbs.dying.spotty.JPG. In the spring, overwintered eggs hatch and small larva begin to feed on leaves and needles of the tree. How to treat for bagworms. Bagworms ƒ{ The bagworm caterpillar builds a silken cocoon, or bag, with silk and bits of leaves attached to the outside. Bagworms have one of the more interesting life cycles … This native pest can be very destructive especially to evergreens. Both leaves and buds are subject to attack. (Last Updated On: July 23, 2010)In one sense bagworms are not an especially devastating pest. Bagworms Bagworms by Bob Bauernfeind Although most Kansas residents are familiar with the bagworms, in most instances, bagworms go unnoticed until late in the summer after bags are of sufficient size to be noticed (Figure 1). Bagworms usually finish feeding by mid to late August when their bags are 1 to 2 inches long. It is often easy to hand-pick bagworms when shrubs and trees are small. Leaves Webbed Over, Turn Gray or Brown. Bagworms are voracious gluttons -- unless controlled, they'll quickly strip an evergreen of its foliage and may kill it. Bagworm sacks can be very hard to find because they look like pine cones. They have only a single generation each year (therefore are relatively slow to establish) and they don’t spread very quickly, because the female bagworms are wingless. Arborvitae shrubs split and break easily – These shrubs often throw out double leaders, a tendency that makes them susceptible to unsightly branch breaks. If you can reach the bagworms, handpick as many as you can now and drop into a bucket of soapy water and remove any from the ground as they can complete their life cycle. How To: Get Rid of Bagworms If you don't keep a weather eye out for these voracious little critters, you may wind up with brown, damaged, or even dead trees or shrubs. Deciduous trees such as sycamore,maple, locust, boxelder, and linden are also attacked but they are not seriously damaged. When arborvitae turn brown, there's little chance they'll recover. This pest is sometimes confused with Eastern tent caterpillar. Begin looking for bagworms during the winter or early spring. If the caterpillars are no longer visible and feeding, if the bags are no longer moving, then it is too late to treat. Though, they prefer evergreens, like juniper, arborvitae, cedar and spruce. Bagworms Description. Well, bagworms will eat deciduous plants, but they really prefer needleleaf evergreens, such arborvitae, false cypress, Leyland cypress, juniper, and spruce. Sounds like your arborvitae is infested with bagworms. Young bagworms are easier to kill than older ones, and killing them early prevents damage. A brisk wind or a pile up of snow in winter may be all it takes to create a gap in your hedge. Bagworms feed on many kinds of plants. When the caterpillars have tied the bag to the twig, sealed it shut they are pupating inside and no further feeding will occur. They show up in late spring (usually mid- to late May or very early June). These trees were eaten back, but not too far for a good recovery. Once they’ve found a tree to call home, bagworms start munching. Evergreens such as arborvitae, southern white cedar, red cedar, juniper, spruce and pine are especially vulnerable to attack. Also, don't cut the terminal growth. Common evergreen hosts include juniper, arborvitae, spruce, and pine. Conifers such as arborvitae, false cypress, fir, juniper, Leland cypress, pine, spruce and many others are unable to generate adventitious buds; nor do they have dormant buds that can generate new branches. Spray with Bacillus thuringiensis (Bt), a biological control agent that you can find where pesticides are sold. On evergreens, they’ll eat lots of the buds and foliage, causing branch tips to turn brown and then die. Most trees will see partial defoliation; however, some heavily infested trees will experience complete defoliation. The fastest way to get them looking normal will be shearing. Ask our pest crew. But if they eat more than 80 percent of the tree, the entire evergreen may die. How to Get Rid of Bagworms on Arborvitae Trees By Bridget Kelly ... Destruction begins as the larvae leave the bag, construct their own bags and begin feeding on the arborvitae's foliage. She has a yellow and white color and is soft-bodied. Typical insecticides will have no effect when sprayed on the bag full of caterpillars. If you want to save the tree, you need to start spraying as soon as you can. So there are usually no worries on the larger homestead about how to get rid of them. These small spindle-shaped bags hanging from your arborvitae's branches like Christmas tree ornaments indicate its presence. The spindle-shaped bags are made of silk and bits of foliage (needle) fragments. However, they are most commonly found on juniper, arborvitae, spruce, and other evergreens. “While deciduous broadleaf trees can recover from the defoliation that bagworms cause, conifers are often severely impacted, and sometimes killed outright by large infestations of bagworms,” Armbrust said. May 11, 2020. Appearance and Habits. It carries its bag with it as it feeds. Bagworms spin cobweb-like "bags" in trees and shrubs. Bagworm egg sacks are brown and one and a half to two inches (3.8 to 5 cm) long. Evergreen trees and shrubs cannot recover from complete defoliation; whereas deciduous trees usually develop new leaves following defoliation. Then people want to “take action” against the larvae/worms (Figure 2) residing in the bags. Conifers, especially arborvitae, cedar, juniper, and pine are the most frequently damaged host plants. They have voracious appetites and devour the needles of evergreens– particularly arborvitaes, junipers, Leyland cypresses, and cedars. Find an insecticide labeled for use against bagworms. Step 1 Pick the bags off the arborvitae and burn them. Bagworms (Lepidoptera: Psychidae) Hosts Bagworms feed on a variety of deciduous and evergreen plants including arborvitae, juniper, spruce, pine, maples, sycamores and numerous others. The bag structure itself will prevent any insecticide from entering, therefore rendering it harmless. When the mating season begins she is able to lay from 500 to 1000 eggs. They also prefer plants that are arborvitae and juniper species too. Bagworms are incredibly destructive insects that have destroyed this Arborvitae in just 1 week! The University of Nebraska recommends low-risk insecticides containing Bacillus thuringiensis (Bt), neem oil or spinosad early in the season. The greater the amount of defoliation the greater amount of stress is put on the tree which can lead to other health issues like insects and fungi that prey on weakened trees. Although bagworms can feed on a variety of different plants, 128 by one count, they generally prefer arborvitae and bald cypress in my part of Texas. Answer: Bagworms are larval insects that devour the small needles of junipers, bald cypress, Italian and Arizona cypress and arborvitae, among many other evergreens. How to Get Rid of Bagworms. The larva then attach the bags with strands of silk to a branch, seal themselves inside, and pupate. Bagworms (Thyridopteryx ephemeraeformis) By far bagworms are the more destructive of these two insects and need to be managed.