Fall webworm 2539203 221507276 2008-06-24T20:25:28Z ClueBot 4928500 Reverting possible vandalism by [[Special:Contributions/96.225.67.102|96.225.67.102]] to version by Eubot. False positive? [[User:ClueBot/FalsePositives|Report it]]. Thanks, [[User:ClueBot]]. (424037) (Bot) {{Taxobox | name = Fall Webworm | regnum = [[Animal]]ia | phylum = [[Arthropod]]a | classis = [[Insect]]a | ordo = [[Lepidoptera]] | familia = [[Arctiidae]] | genus = ''[[Hyphantria]]'' | species = '''''H. cunea''''' | binomial = ''Hyphantria cunea'' | binomial_authority = [[Dru Drury|Drury]], [[1773]] }} '''Fall webworm''', ''Hyphantria cunea'', is a [[moth]] in the family [[Arctiidae]] known principally for its larval stage, where it creates the characteristic webbed nests on the tree limbs of a wide variety of [[hardwoods]] in the late summer and fall. It is mainly an aesthetic [[Pest (animal)|pest]] and is not believed to harm otherwise healthy trees. It is well-known to commercial tree services and [[Arboriculture|arboriculturists]]. ==Range== The moth is native to [[North America]], ranging from Canada to Mexico, and is one of the few insect pests introduced from North America into other continents. Introduced to what was formerly Yugoslavia in the 1940s, it now has occupied probably its entire range in Europe from France to the Caspian Sea in the east. It was also introduced into Japan in 1945, and has adjusted its number of generations per year since its arrival.<ref>{{cite journal | last = Gomi | first = Takeda | title = Changes in life-history traits of Fall Webworm within half a century of introduction into Japan. | journal = Functional Ecology | volume = 10:384-389 | date = 1996}}</ref> It spread into Korea and China and now is considered [[Holarctic]] in distribution. ==Life cycle== One generation per year emerges in the northern part of [[North America]], with larvae appearing in late summer through early fall. South of an approximate [[List_of_cities_by_latitude#40.C2.B0_North|latitude of 40 degrees north]] there are two or more generations annually, with webs appearing progressively earlier further south.<ref>{{cite book|author=DL Wagner|last=Wagner |first=DL |title=Caterpillars of Eastern Forests |publisher=Princeton Univ. Press | location=Princeton, NJ | year=2005}}</ref> ===Egg=== The adult moth lays her eggs on the underside of leaves in 'hair'-covered clusters of a couple of hundred.<ref name="Douce">Douce, GK. [http://www.bugwood.org/factsheets/webworm.html "The Fall Webworm"]. Accessed August 21 2006. </ref> Eggs hatch in about a week.<ref name="Hyche">Hyche, LL. [http://www.ag.auburn.edu/enpl/bulletins/fallwebworm/fallwebworm.htm "Fall webworm: A Guide to Recognition and Habits in Alabama"]. Accessed August 21 2006. </ref> <gallery> Image:Hyphantria.JPG | late instar larva Image:Hypahntria web.JPG | Web on willow </gallery> ===Larva=== The larvae are highly variable in coloration, ranging from a pale yellow, to dark grey, with yellow spots and long and short bristles.<ref>{{cite book|author=DL Wagner|last=Wagner |first=DL |title=Caterpillars of Eastern Forests |publisher=Princeton Univ. Press | location=Princeton, NJ | year=2005}}</ref> There are two cream stripes along the sides. There are two races, one more common in the north, the other in the south, differing in head capsule coloration.<ref name="Hyche">Hyche, LL. [http://www.ag.auburn.edu/enpl/bulletins/fallwebworm/fallwebworm.htm "Fall webworm: A Guide to Recognition and Habits in Alabama"]. Accessed August 21 2006. </ref> Maximum length, 35mm. Webs are progressively enlarged, and much messier looking than those of [[Malacosoma|tent caterpillars]] (which occur only in spring and have shorter hairs and very little yellow on their bodies). Larvae feed inside the tents until the late instars. Very young larvae feed only on the upper surfaces of leaves. Later, they consume the whole leaf. The larval stage lasts about 4-6 weeks.<ref name="Hyche">Hyche, LL. [http://www.ag.auburn.edu/enpl/bulletins/fallwebworm/fallwebworm.htm "Fall webworm: A Guide to Recognition and Habits in Alabama"]. Accessed August 21 2006. </ref> ===Pupa=== The pupal stage overwinters in the bark and leaf litter at the base of the trees. It is dark brown and about 10 mm long. They have thin brown cocoons made of silk with bits of detritus interwoven.<ref name="Hyche">Hyche, LL. [http://www.ag.auburn.edu/enpl/bulletins/fallwebworm/fallwebworm.htm "Fall webworm: A Guide to Recognition and Habits in Alabama"]. Accessed August 21 2006. </ref> This stage overwinters. ===Adult=== The adult is mostly white in the north, but in the south it may be marked with black or brown spots on the forewings.<ref name="Hyche">Hyche, LL. [http://www.ag.auburn.edu/enpl/bulletins/fallwebworm/fallwebworm.htm "Fall webworm: A Guide to Recognition and Habits in Alabama"]. Accessed August 21 2006. </ref><ref name="Douce">Douce, GK. [http://www.bugwood.org/factsheets/webworm.html "The Fall Webworm"]. Accessed August 21 2006. </ref> It is quite 'hairy', and the front legs have bright yellow or orange patches. The underwings will have less marking than the forewings, and the abdomen often has a sprinkling of brown hairs. Wingspan of 35-42 mm. ==Food plants== The fall webworm feeds on just about any type of deciduous tree. Worldwide, it has been recorded from 636 species,<ref>{{cite book|author=Warren, LO and M Tadic|last=Warren |first=Tadic |title=The fall webworm, Hyphantria cunea (Drury) |publisher=Arkansas Agric. Exp.Sta. Bull | year=1970}}</ref> and is considered to be among the most polyphagous of insects. In the eastern U.S., pecan, walnut, American elm, hickory, fruit trees, and some maples are preferred hosts; in some areas persimmon and sweetgum are also readily eaten. In the west, alder, willow, cottonwood and fruit trees are commonly used.<ref name="Douce">Douce, GK. [http://www.bugwood.org/factsheets/webworm.html "The Fall Webworm"]. Accessed August 21 2006. </ref> ==Control== Cutting off and then burning the affected limb works. Application of ''[[Bacillus thuringiensis]]'' early in [[spring (season)|spring]] is also useful. In terms of chemical warfare, [[Sevin]], [[permethrin]], and [[cyfluthrin]] can also be used. The female of the various species of the ''[[Trichogramma]]'' wasp is the natural parasite, laying her own eggs into the eggs of the moth. Fall webworm is not considered as harmful to [[orchards]] as the [[Eastern tent caterpillar]], because it feeds late in the season and only shortly before leaf drop. ==Notes== {{reflist}} ==References== Douce, GK, 2003. The fall webworm. http://www.bugwood.org/factsheets/webworm.html . Accessed Aug 21, 2006. Gomi, T and M Takeda. 1996. Changes in life-history traits of Fall Webworm within half a century of introduction into Japan. Functional ecology 10:384-389. Hyche, LL, 1999. Fall webworm: A guide to recognition and habits in Alabama. http://www.ag.auburn.edu/enpl/bulletins/fallwebworm/fallwebworm.htm Accessed Aug 21, 2006. Wagner, DL. 2005. Caterpillars of eastern forests. Princeton Univ. Press. Warren, LO and M Tadic. 1970. The fall webworm, ''Hyphantria cunea'' (Drury). Arkansas Agric. Exp.Sta. Bull. 759. ==Sources== *[http://www.umassgreeninfo.org/fact_sheets/defoliators/fall_webworm.html U. Mass site] *[http://www.bugwood.org/factsheets/webworm.html U. Georgia site] *[http://ohioline.osu.edu/hyg-fact/2000/2026.html Ohio State U. site] *[http://bexar-tx.tamu.edu/HomeHort/F1Column/2004Articles/MAR21.htm Texas A&M site] [[Category:Spilosomini]] [[it:Hyphantria cunea]] [[ko:미국흰불나방]] [[ka:ამერიკული თეთრი პეპელა]] [[ja:アメリカシロヒトリ]] [[no:Hyphantria cunea]]