The following is information on bagworms in the fall. They are now inside the bags and the only control is hand picking or waiting until they come out next year.
Obviously any type of spray applied in the fall or winter for bagworm control would be a waste of time and material. Over-wintering eggs are contained within the dead female bags. Most of the bags containing eggs are located on the upper portions of infested trees or shrubs. With this higher elevation, it is theorized that a certain percentage of a recently hatched population in late spring can more effectively be transported by the wind to new hosts. Remove individual bags by hand when populations are low and the upper portions of the plant can be reached. Otherwise, indicate in your records that sprays may be required during the late spring or early summer when the young larvae hatch and begin feeding.
Bagworms on conifers have pupated. During the fall mating and egg lying will occur within the female sack. Bagworms hatch out in mid-June from the over-wintering eggs within the dead female bag. Researchers in Kentucky have determined that most newly hatched bagworms disperse away from the ‘parental’ host plant. This may be because the offspring from only a few bags have the potential to defoliate a small plant. About 75% of immature bagworms disperse by ‘ballooning’ into the wind, and were observed traveling hundreds of feet. Failure to control populations upwind from a susceptible host may leave a potential reservoir of the pest in the future. (Reference: Cox and Potter, J. Arbor. 9/90) .
Information from Steven K. Rettke, Ornamental IPM Program Associate in the September 17, 2009 edtion of the Plant & Pest Advisory, Landscape, Nursery & Turf Edition, from Rutgers University http://njaes.rutgers.edu/pubs/plantandpestadvisory/2009/ln091709.pdf
Showing posts with label bagworms. Show all posts
Showing posts with label bagworms. Show all posts
Wednesday, October 7, 2009
Wednesday, June 24, 2009
Landscape - Bagworm Dispersal
The following is information on how bagworms are dispersed in the landscape.
The bagworm, Thyridopteryx ephemeraeformis, is a common defoliator and pest of arborvitae, spruce, juniper, Leyland Cypress and many other species of woody plants in the landscape and in nurseries.
In bagworms the adult female is both wingless and legless, so that dispersal to new locations is totally dependent on the larval, or immature stage. Bagworm eggs spend the winter inside the maternal bag, which is usually attached to the host upon which the mother developed. In spring, the newly-hatched larvae spin strands of silk and drop from the tip of the mother's bag or from the host foliage. The wind breaks the silk at the point of attachment and lifts the insect into the air with the silk trailing, a process referred to as "ballooning".
Bagworms can also disperse to a lesser degree as older larvae by crawling overground. This occurs mainly when the host foliage becomes depleted before the caterpillars have matured.
About 75% of hatched bagworms first formed a tiny bag from silk and covered it with bits of bark. Newly hatched bagworms generally exited from the maternal bag between 9 AM and noon. Most larvae that ballooned without a bag did so in the morning, while those dispersing with a bag did so mainly in the afternoon.
Larvae ballooning from 15 ft height on an 11 mph wind could easily disperse 245 ft downwind without a bag, and 150 ft with a bag. Although dispersing with a bag makes the larva heavier and reduces the distance it can be blown, dispersing with a bag may help the larvae to survive should it fail to land on a suitable host.
50% of the larvae dispersing with bags survived at least 3.5 days off of a host, whereas larvae without bags survived only 1.5 days. The bag seems to provide protection from desiccation and solar radiation, which would be readily absorbed by the dark-colored larva. This may allow time for a larva that is unsuccessful in landing on a host on its first attempt to climb back up to a suitable vantage point so it can balloon again.
Most bagworms hatching from an egg mass disperse from the "parental" host plant regardless of the degree of defoliation. Since progeny from just a few females could completely defoliate a small host, dispersal may be imperative in order to survive. These findings have significance for nurserymen, landscape managers and homeowners who must deal with bagworm problems.
New bagworm infestations originate mainly from ballooning larvae, so failure to control populations upwind from preferred hosts may leave a reservoir of potential dispersants. Since the ballooning period lasts about a month (June in DE) it may be advisable to wait for several weeks after the first larvae are observed exiting from maternal bags before implementing controls. Bagworms are a potential problem each year since most individuals hatching on hosts in wood lots or hedgerows will be ballooning regardless of host condition.
Information from "AERIAL DISPERSAL BEHAVIOR OF THE BAGWORM" by David L. Cox2 and Daniel A. Potter, Department of Entomology, University of Kentucky in the Journal of Arboriculture 16(9): September 1990
The bagworm, Thyridopteryx ephemeraeformis, is a common defoliator and pest of arborvitae, spruce, juniper, Leyland Cypress and many other species of woody plants in the landscape and in nurseries.
In bagworms the adult female is both wingless and legless, so that dispersal to new locations is totally dependent on the larval, or immature stage. Bagworm eggs spend the winter inside the maternal bag, which is usually attached to the host upon which the mother developed. In spring, the newly-hatched larvae spin strands of silk and drop from the tip of the mother's bag or from the host foliage. The wind breaks the silk at the point of attachment and lifts the insect into the air with the silk trailing, a process referred to as "ballooning".
Bagworms can also disperse to a lesser degree as older larvae by crawling overground. This occurs mainly when the host foliage becomes depleted before the caterpillars have matured.
About 75% of hatched bagworms first formed a tiny bag from silk and covered it with bits of bark. Newly hatched bagworms generally exited from the maternal bag between 9 AM and noon. Most larvae that ballooned without a bag did so in the morning, while those dispersing with a bag did so mainly in the afternoon.
Larvae ballooning from 15 ft height on an 11 mph wind could easily disperse 245 ft downwind without a bag, and 150 ft with a bag. Although dispersing with a bag makes the larva heavier and reduces the distance it can be blown, dispersing with a bag may help the larvae to survive should it fail to land on a suitable host.
50% of the larvae dispersing with bags survived at least 3.5 days off of a host, whereas larvae without bags survived only 1.5 days. The bag seems to provide protection from desiccation and solar radiation, which would be readily absorbed by the dark-colored larva. This may allow time for a larva that is unsuccessful in landing on a host on its first attempt to climb back up to a suitable vantage point so it can balloon again.
Most bagworms hatching from an egg mass disperse from the "parental" host plant regardless of the degree of defoliation. Since progeny from just a few females could completely defoliate a small host, dispersal may be imperative in order to survive. These findings have significance for nurserymen, landscape managers and homeowners who must deal with bagworm problems.
New bagworm infestations originate mainly from ballooning larvae, so failure to control populations upwind from preferred hosts may leave a reservoir of potential dispersants. Since the ballooning period lasts about a month (June in DE) it may be advisable to wait for several weeks after the first larvae are observed exiting from maternal bags before implementing controls. Bagworms are a potential problem each year since most individuals hatching on hosts in wood lots or hedgerows will be ballooning regardless of host condition.
Information from "AERIAL DISPERSAL BEHAVIOR OF THE BAGWORM" by David L. Cox2 and Daniel A. Potter, Department of Entomology, University of Kentucky in the Journal of Arboriculture 16(9): September 1990
Monday, June 22, 2009
Landscape - Insects Currently Active
The following are some insects now active in the landscape in Delaware to be on the watch for.
Dogwood borers appeared in Longwood pheromone traps this week. Four-lined plant bug damage to shrubs perennials has been noted in one or two spots. It appears as small circular holes that look like buckshot on new, but fully expanded leaves. Damage occurred several weeks ago so the control window is gone. Fletcher scale and white prunicola scale crawlers are emerging.. Control crawlers with a foliar absorbed insecticide. Redheaded flea beetle adults are out and feeding. Bagworms have hatched and are feeding now.
Information from the Ornamentals Hotline from the University of Delaware Cooperative Extension.
Dogwood borers appeared in Longwood pheromone traps this week. Four-lined plant bug damage to shrubs perennials has been noted in one or two spots. It appears as small circular holes that look like buckshot on new, but fully expanded leaves. Damage occurred several weeks ago so the control window is gone. Fletcher scale and white prunicola scale crawlers are emerging.. Control crawlers with a foliar absorbed insecticide. Redheaded flea beetle adults are out and feeding. Bagworms have hatched and are feeding now.
Information from the Ornamentals Hotline from the University of Delaware Cooperative Extension.
Landscape - Photos of Insects Now Active
The following are pictures of insect pests now active in Delaware landscapes.
Four-line Plant Bug Adult. Photo from Plant & Pest Digital Library, Purdue University.
White Prunicola Scale Crawlers. Photo from the Branching Out newsletter from Cornell Cooperative Extension.
Fletcher Scale Adults and Crawlers. Photo from the Kansas Department of Agriculture.
Dogwood borer adult female. Photo by James Solomon, USDA Forest Service, Bugwood.org
Hatching bagworm caterpillars from bag of female. Photo from the Texas A&M Landscape IPM website.
Four-line Plant Bug Adult. Photo from Plant & Pest Digital Library, Purdue University.
White Prunicola Scale Crawlers. Photo from the Branching Out newsletter from Cornell Cooperative Extension.
Fletcher Scale Adults and Crawlers. Photo from the Kansas Department of Agriculture.
Dogwood borer adult female. Photo by James Solomon, USDA Forest Service, Bugwood.org
Hatching bagworm caterpillars from bag of female. Photo from the Texas A&M Landscape IPM website.
Saturday, June 13, 2009
Landscape - Bagworm season
Bagworm season is here. Early control measures are the key to effective management. The following is an article on the subject.
Bagworm larvae are hatching, ballooning or feeding. Look for the 'dunce-cap' stage of feeding that occurs when larvae are very small and carry their bags with them in an upright position. Bagworm hatch occurs between 364 and 710 GDD (peaks at 580). Bagworms are caterpillars that prefer to feed on juniper, arborvitae, and Leyland cypress, but will eat a variety of other deciduous and coniferous plants. The bag is made up of small pieces of the plant the bagworm is eating and silk. The bags may look like pine cones or parts of the plant; thus it often is overlooked until damage becomes severe.
Larvae feed throughout the summer and begin to pupate around mid-August. Female bagworms pupate but remain in a flightless caterpillar-like state and release pheromones to attract males. Female bagworms lay 300 to 1,000 eggs in the bag after mating and die. The following summer the overwintering eggs hatch and disperse by ballooning on the wind to nearby plants. Although there is only one generation a year, damage may be encountered throughout the summer.
One control tactic is to physically remove the bags late fall through spring, but this is often too labor intensive or impractical because of tree or shrub size. Companion plants encourage parasitoids to remain in the area to attack bagworm pupae. Last summer, John Wiest and I evaluated the efficacy of Orthene (acephate), Dipel (B. thuriengensis 'kurstaki'), Conserve (spinosad) and Acelepryn (chlorantraniliprole) applied in late July without stickers. We discovered Acelepryn and Orthene provided similar levels of control (> 75%) whereas Conserve and Dipel provided less control of large bagworm larvae. Most bagworm eggs have hatched by middle to late June and applications of pesticides should be applied by July to target early instars. Products are more effective against smaller, younger caterpillars. Other products available include Confirm, Tempo, Permethrin Pro, or other pyrethroids.
Information from Brian Kunkel, Ornamental IPM Specialist, UD
Bagworm larvae are hatching, ballooning or feeding. Look for the 'dunce-cap' stage of feeding that occurs when larvae are very small and carry their bags with them in an upright position. Bagworm hatch occurs between 364 and 710 GDD (peaks at 580). Bagworms are caterpillars that prefer to feed on juniper, arborvitae, and Leyland cypress, but will eat a variety of other deciduous and coniferous plants. The bag is made up of small pieces of the plant the bagworm is eating and silk. The bags may look like pine cones or parts of the plant; thus it often is overlooked until damage becomes severe.
Larvae feed throughout the summer and begin to pupate around mid-August. Female bagworms pupate but remain in a flightless caterpillar-like state and release pheromones to attract males. Female bagworms lay 300 to 1,000 eggs in the bag after mating and die. The following summer the overwintering eggs hatch and disperse by ballooning on the wind to nearby plants. Although there is only one generation a year, damage may be encountered throughout the summer.
One control tactic is to physically remove the bags late fall through spring, but this is often too labor intensive or impractical because of tree or shrub size. Companion plants encourage parasitoids to remain in the area to attack bagworm pupae. Last summer, John Wiest and I evaluated the efficacy of Orthene (acephate), Dipel (B. thuriengensis 'kurstaki'), Conserve (spinosad) and Acelepryn (chlorantraniliprole) applied in late July without stickers. We discovered Acelepryn and Orthene provided similar levels of control (> 75%) whereas Conserve and Dipel provided less control of large bagworm larvae. Most bagworm eggs have hatched by middle to late June and applications of pesticides should be applied by July to target early instars. Products are more effective against smaller, younger caterpillars. Other products available include Confirm, Tempo, Permethrin Pro, or other pyrethroids.
Information from Brian Kunkel, Ornamental IPM Specialist, UD
Sunday, July 13, 2008
Landscape and Nursery - More on Bagworms
Bagworms are getting larger where they are found, especially on susceptible evergreens. Control measures should be applied without delay as bagworms are very hard to kill when they get large.
Bagworms are creating protective bags that are about 0.5 – 1.0” in length at this point in the season. Observe arborvitae, junipers and Leyland cypress for presence of bagworms.
Bagworms are caterpillars that prefer to feed on juniper, arborvitae, and Leyland cypress, but will eat a variety of other deciduous and coniferous plants. The bag is made up of small pieces of the plant the bagworm is eating and silk. The bags may look like pine cones or parts of the plant; thus it often is overlooked until damage becomes severe. Larvae feed throughout the summer and begin to pupate in late summer to early fall. Female bagworms lay 300 1,000 eggs in the bag after mating in the fall and die. The following summer the overwintering eggs hatch and disperse by ballooning on the wind to nearby plants. Although there is only one generation a year, damage may be encountered throughout the summer. One control tactic is to physically remove the bags late fall through spring, but this is often too labor intensive or impractical because of tree or shrub size. Weather conditions and parasitoids often keep bagworm populations under control without human intervention. Control with chemicals is best achieved when applications are made when the insect is small. Products available for control are sprays of B.t.'kurstaki' (i.e. Dipel), insect growth regulators (IGR's) such as Confirm (tebufenozide), or reduced-risk products like Conserve (spinosad). Compounds such as Tempo or Permethrin Pro or other labeled pyrethroids control older larvae as does acephate (Orthene). Applications are best made before the end of June and coverage is important for the best results. For control now in mid-July, Conserve will still work, the pyrethroids are an option, as is Orthene.
Information from the ornamental IPM programs at University of Delaware and University of Maryland.
Bagworms are creating protective bags that are about 0.5 – 1.0” in length at this point in the season. Observe arborvitae, junipers and Leyland cypress for presence of bagworms.
Bagworms are caterpillars that prefer to feed on juniper, arborvitae, and Leyland cypress, but will eat a variety of other deciduous and coniferous plants. The bag is made up of small pieces of the plant the bagworm is eating and silk. The bags may look like pine cones or parts of the plant; thus it often is overlooked until damage becomes severe. Larvae feed throughout the summer and begin to pupate in late summer to early fall. Female bagworms lay 300 1,000 eggs in the bag after mating in the fall and die. The following summer the overwintering eggs hatch and disperse by ballooning on the wind to nearby plants. Although there is only one generation a year, damage may be encountered throughout the summer. One control tactic is to physically remove the bags late fall through spring, but this is often too labor intensive or impractical because of tree or shrub size. Weather conditions and parasitoids often keep bagworm populations under control without human intervention. Control with chemicals is best achieved when applications are made when the insect is small. Products available for control are sprays of B.t.'kurstaki' (i.e. Dipel), insect growth regulators (IGR's) such as Confirm (tebufenozide), or reduced-risk products like Conserve (spinosad). Compounds such as Tempo or Permethrin Pro or other labeled pyrethroids control older larvae as does acephate (Orthene). Applications are best made before the end of June and coverage is important for the best results. For control now in mid-July, Conserve will still work, the pyrethroids are an option, as is Orthene.
Information from the ornamental IPM programs at University of Delaware and University of Maryland.
Sunday, June 8, 2008
Landscape and Nursery - Bagworm Season
Bagworm season is upon us. It is important to control bagworms when they are small. Insecticide treatments should be made this month. The following is information on bagworm.
The bagworm, Thyridopteryx ephemeraeformis, is a key pest of many evergreen species, as well as some deciduous trees and shrubs. The best time for management is when the larvae are small during mid-June. Wide dispersal occurs mainly through movement of infested plants, or by wind blown larvae in June, since adult females can’t fly. Bagworms overwinter as eggs inside the female bag (several hundred eggs in each). Eggs hatch from late May through early June. Young larvae crawl out of the bag, feed and construct silken shelters over their bodies. Over their 8-10 week feeding period, bagworms enlarge their bags with pieces of foliage. Mature larvae (in August) loop strands of silk around a twig that firmly attaches the bag. During September and early October males leave their cases and fly to bags containing females where mating occurs. Bagworm feeding on needles and leaves is especially destructive to evergreen plants since evergreens cannot reproduce new foliage. Bagworm infestations generally go unnoticed until bags are large and damage is complete. Early detection requires careful examination of plants for small bagworms attached to the leaves or needles of host plants.
Control with chemicals is best achieved when applications are made when the insect is small. Products available for control are sprays of B.t.'kurstaki' (i.e. Dipel), insect growth regulators (IGR's) such as Confirm (tebufenozide), or reduced-risk products like Conserve (spinosad). Applications should be made before the end of June and coverage is important for the best results. Compounds such as Tempo or Permethrin Pro or other labeled pyrethroids as well as acephate (Orthene) control older larvae.
Information from Gregory Hoover, Ornamental Extension Entomologist and Brian Kunkel, Ornamental IPM specialist, UD.
The bagworm, Thyridopteryx ephemeraeformis, is a key pest of many evergreen species, as well as some deciduous trees and shrubs. The best time for management is when the larvae are small during mid-June. Wide dispersal occurs mainly through movement of infested plants, or by wind blown larvae in June, since adult females can’t fly. Bagworms overwinter as eggs inside the female bag (several hundred eggs in each). Eggs hatch from late May through early June. Young larvae crawl out of the bag, feed and construct silken shelters over their bodies. Over their 8-10 week feeding period, bagworms enlarge their bags with pieces of foliage. Mature larvae (in August) loop strands of silk around a twig that firmly attaches the bag. During September and early October males leave their cases and fly to bags containing females where mating occurs. Bagworm feeding on needles and leaves is especially destructive to evergreen plants since evergreens cannot reproduce new foliage. Bagworm infestations generally go unnoticed until bags are large and damage is complete. Early detection requires careful examination of plants for small bagworms attached to the leaves or needles of host plants.
Control with chemicals is best achieved when applications are made when the insect is small. Products available for control are sprays of B.t.'kurstaki' (i.e. Dipel), insect growth regulators (IGR's) such as Confirm (tebufenozide), or reduced-risk products like Conserve (spinosad). Applications should be made before the end of June and coverage is important for the best results. Compounds such as Tempo or Permethrin Pro or other labeled pyrethroids as well as acephate (Orthene) control older larvae.
Information from Gregory Hoover, Ornamental Extension Entomologist and Brian Kunkel, Ornamental IPM specialist, UD.
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