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Defoliators Continued: Gypsy Moth and Sawflies. The gypsy moth: Lymantria dispar L. A world class problem: another Lymantriidae. The Gypsy Moth, Lymantria dispar L.
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The gypsy moth: Lymantria dispar L. A world class problem: another Lymantriidae
The Gypsy Moth, Lymantria dispar L. • Gypsy moths are native to north Africa, all across eastern and western Europe, across Siberia, the Russian Far East and on into Japan. What an enormous range? • With this enormous gene pool, it’s small wonder that gypsy moths consume the foliage of practically any hardwood.
Gypsy moth biology, ecology and control has been studied for a long time, especially in Europe.
An opening statement: A single instance of complete defoliation can kill conifers, i.e. white pine, and eastern red pine. Three consecutive defoliations kill deciduous trees, especially the oaks.
Defoliation of eastern oak white pine forests by the gypsy moth – heavy oak mortality.
The pest was brought into the U.S. by an artist, amateur astronomer and biologist, Leopold Trouvelot. • Trouvelot lived at 27 Myrtle St. in Medford, Mass. He wished to cross the gypsy moth with the satin moth and start a silk industry in the U.S. • In 1889 some moths escaped, and the rest is history!
American Naturalist. 1867. Vol.1, pp. 30-38
Etienne Leopold Trouvelot and his house on 27 Myrtle St., Medford, MA. His gypsy moths escaped in 1889. Medford Fire Department cutting and burning dead oak trees.
Medford, MA courthouse and its famous oak trees, and they are dead. The first demonstration of the power of the “Gypsy Moth.”
Spread: Eggs are laid on anything, including cars, campers, outdoor furniture, tent folds etc. If the larvae don’t land on their hosts, they can easily land on air cargo containers, trains, ships, buses etc. Not called gypsy moth for nothing!
Asian gypsy moth eggs on military equipment coming from Germany to Ft. Benning, Georgia
The entire U.S. is continually monitored for the gypsy moth. Often one pheromone trap/4 sq. mi. along highways & a trap/1 sq. mi. in population centers.
Opened pheromone trap Egg laying sites search Objects around old barns searched for egg masses Pheromone traps at hwy. rest stops Active gypsy moth tacking system in Canada also.
When males are trapped the affected area is delimited: 1st. 4 traps/sq.mi., then 8 traps and even 16 traps/sq.mi. When the source is found: The area (often a backyard) is treated with one or two Bt sprays.
When egg masses are found, three sprays of Bt bracket the emergence of the moths.
Life cycle of the gypsy moth
Lifecycle of the gypsy moth
Over the years many parasitoids and predators have been introduced from Europe to control the gypsy moth, only a few have become established. The Calosoma ground beetle is a good example.
The best natural control, however, is the Wipfelkrankheitthat somehow was introduced from Germany in 1909.
Even though the gypsy moth is an exotic pest its main natural control did enter North America. It’s a NPV virus called (in English) the wilt disease. The NPV particles enters the larvae where the virus kills the insectan blood cells and the larvae seem to wilt.
Weather Health of the population Hosts Gypsy moth population Virus epizootic Natural enemies Direct insolation Site - soil - climate Competition - intra - inter
Big current problem is the potential establishment of the Asian variety of the gypsy moth.
Asian European And she flies! The two varieties of the gypsy moth
1992 Eradication program against the Asian gypsy moth
The Sawflies: Important Defoliators of Hardwoods and Conifers. Some Are Leafminers, Skeltonizers, but Most Are Leaf-chewers.
Sawfly defoliators are larvae of a group of primitive wasps, the Symphyta. Sawfly larvae look like caterpillars, but they aren’t. Caterpillars are Lepidoptera
Caterpillars Sawflies
Oviposition of sawflies into pine needles
Sawfly larvae feeding on conifer foliage.
Sawfly defoliation of hybrid poplar plantation near Portland, OR.
Poplar sawfly pupa, new adult ovipositing and larvae devouring the foliage.
Adult in spring Sawfly larvae
Larval parasitoid Pupal parasitoid
Raining Frass My 1958 experience with the black-headed sawfly in East Texas.
1958 outbreak of the black- headed sawfly, Neodiprion exictans.
(1) Raining frass and the foliage is thinning. 2,400Acres (2) Aerial appraisal
D4 Swamp D4 Kirby Lmbr. Co. R.R. Skidway Cocoons The great 1958 spraying operation directed by Bob G.
Loading DDT The Kirby skidway used as runway