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{{about|the European or North American gypsy moth|the Lymantria dispar species|Lymantria dispar|other uses|Gypsy moth (disambiguation)}}
{{Taxobox
| name = North American gypsy moth, European gypsy moth
| image = Lymantria dispar 8-8-2006 19-20-14.JPG
| image_width =
| image_caption = Adult female gypsy moth
| image2 = Lymantria dispar01.jpg
| image2_width =
| image2_caption = Adult male gypsy moth
| regnum = [[Animal]]ia
| phylum = [[Arthropod]]a
| classis = [[Insect]]a
| ordo = [[Lepidoptera]]
| familia = [[Erebidae]]
| genus = ''[[Lymantria]]''
| species = '''''[[Lymantria dispar|L. dispar]]'''''
| subspecies = '''''L. d. dispar'''''
| trinomial = ''Lymantria dispar dispar''
| trinomial_authority = ([[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]])
| synonyms =
}}

'''''Lymantria dispar dispar''''' commonly known as the '''gypsy moth''', '''European gypsy moth''', and '''North American gypsy moth''', is a [[Lepidoptera|moth]] in the family [[Erebidae]] of Eurasian origin. It has a range which covers in Europe, Africa, North America.

Linnaeus first described the species ''Lymantria dispar'' in 1758. The subject of classification has changed throughout the years, resulting in confusion surrounding the species taxonomy. This caused many references to describe this one species in different ways. The family has jumped between ''Lymantriidae'', ''Noctuidae'' and ''Erebidae''. ''Lymantria dispar dispar'' has been designated a sub-species of ''[[Lymantria dispar]]'',

It is classified as a pest, and its [[larva]]e consume the leaves of over 300 species of trees, shrubs and plants. The gypsy moth is one of the most destructive pests of hardwood trees in the eastern United States.

== Taxonomy ==

Linnaeus first described the species ''Lymantria dispar'' in 1758.<ref name=review />{{rp|2}} The subject of classification has changed throughout the years, resulting in confusion surrounding the species taxonomy. This caused many references to describe this one species in different ways. The family has jumped between Lymantriidae, Noctuidae and Erebidae. The species ''Lymantria dispar'' has been split into sub-species such as ''[[Lymantria dispar asiatica]]'' and ''[[Lymantria dispar japonica]]''. Differences between the subspecies are poorly understood even at the government level.

=== Order ===
The order ''Lepidoptera'' contains moths and butterflies characterized by having a complete metamorphosis; larvae transform to pupae and then metamorphose into adult moths or butterflies.<ref name=USDA />{{rp|9}} The family is ''Lymantriidae''.<ref name=USDA />{{rp|9}} Lymantriid larvae are commonly called [[tussock moth]]s because of the tufts of hair on the larvae.<ref name=USDA />{{rp|9}}

=== Classified as Lymantriidae ===
''Lymantriidae'' was separated from [[Lariidae]] and was classified as its own family by (Hampson 1893).<ref name=Watson /> The ''[[Lymantriidae]]'' family had previously been referred to as ''[[Orgyiidae]]'' (Wallengren 1861) and ''[[Dasychiridae]]'' (Packard 1864)), but consensus formed in favor of ''Lymantriidae''.<ref name=Watson>Watson, A., Fletcher, D.S. & Nye, I.W.B., 1980, in Nye, I.W.B. [Ed.], The Generic Names of Moths of the World, volume 2 © Trustees of the British Museum (Natural History), Publication Number 811 ISBN 0-565-00811-0 http://www.nhm.ac.uk/research-curation/research/projects/butmoth/pdf/GNMW_Vol_2.pdf </ref> Lymantriidae has had numerous taxonomical changes which was solidified by Ferguson in 1978.<ref name=Watson />

=== Reclassified as Noctuidae ===
Lymantriidae was reclassified into the family Noctuidae in 2006.<ref name=review />{{rp|2}} Noctuidae is defined as a group in which hindwing vein M2, originates in the lower third of the discal cell, but it is as strong as vein M3.<ref name=review />{{rp|2}} This results in the cubital vein appearing to have four branches.<ref name=review />{{rp|2}} The classification of Noctuidae came from Mitchel et al. (2005).<ref name=review />{{rp|2}} Lafontaine and Fibiger (2006) agreed that ''Lymantriidae'' belonged within Noctuidae, but disagree with the classification as a subfamily.<ref name=review />{{rp|2}} Fewer taxonomic changes are required with the reclassification of ''Lymantriidae'' being a subfamily in the monophyletic group of Noctuidae<ref name=review />{{rp|2}}. Sources published prior to the reclassification in 2006 and shortly thereafter may refer to [[Lymantriidae]].<ref>[http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8485008 The Canadian Entomologist] / Volume 138 / Issue 05 / October 2006, pp 610-635 DOI: http://dx.doi.org/10.4039/n06-012 (About DOI), Published online: 02 April 2012</ref> Lafontaine and Fibiger (2006)'s classification as a subfamily of Noctuidae has received acceptance, but it not yet universal.<ref name=review />{{rp|2}}<ref name=ITIS>[http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=709249 Lymantria dispar (Linnaeus, 1758) Taxonomic Serial No.: 709249</ref><ref>[http://bugguide.net/node/view/8780 Bugguide.net's Taxonomic data.]</ref><ref>[http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=690910&lvl=3&lin=f&keep=1&srchmode=1&unlock NCBI Taxonomy browser]</ref>

=== Reclassified as Erebidae ===

In 2012, Lymantriidae was moved from Noctuidae to Erebidae, further complicating the taxonomy.<ref name="Zhari">{{cite web | url=http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3113.2011.00607.x/full | title=Molecular phylogenetics of Erebidae (Lepidoptera, Noctuoidea) | publisher=Systematic Entomology | date=January 2012 | accessdate=September 15, 2012 | author=Zhari et al}}</ref> The newly created family has been reflected in some sources.<ref>[http://www.butterfliesandmoths.org/species/Lymantria-dispar Butterfliesandmoths.org Lymantria dispar classified as Erebidae]</ref>

{{collapse top|title=Full taxonomy of ''Lymantria dispar dispar''}}
*Superregnum: Eukaryota
*Regnum: Animalia
*Subregnum: Eumetazoa
*Cladus: Bilateria
*Cladus: Nephrozoa
*Cladus: Protostomia
*Cladus: Ecdysozoa
*Cladus: Panarthropoda
*Phylum: Arthropoda
*Subphylum: Hexapoda
*Classis: Insecta
*Cladus: Dicondylia
*Cladus: Pterygota
*Cladus: Metapterygota
*Cladus: Neoptera
*Cladus: Eumetabola
*Cladus: Endopterygota
*Superordo: Panorpida
*Cladus: Amphiesmenoptera
*Ordo: Lepidoptera
*Subordo: Glossata
*Infraordo: Heteroneura
*Divisio: Ditrysia
*Sectio: Cossina
*Subsectio: Bombycina
*Superfamilia: Noctuoidea
*Familia: Erebidae
*Subfamilia: Lymantriinae
*Tribus: Lymantriini
*Subtribus: Lymantriina
*Genus: Lymantria
*Species: Lymantria dispar
*Subspecies: Lymantria dispar dispar
{{collapse bottom}}

=== Etymology ===
The meaning of the name ''Lymantria dispar'' is composed of two Latin derived words. Lymantria means 'destroyer'.<ref>[http://www.thefreedictionary.com/Lymantria Free Dictionary for Lymantria]</ref> The word 'dispar' is derived from the Latin word that means 'to separate' and it depicts the differing characteristics between the sexes.<ref name=USDA />{{rp|9}}

=== L. d. dispar versus L. dispar usage ===

For the purposes of taxonomy, the common names, North American gypsy moth and the European gypsy moth, are the same species.<ref name=review />{{rp|6}} To difference between subspecies of ''Lymantria dispar'' the usage of ''Lymantria dispar dispar'' to refer to the sub species has entered usage. <ref name=review />{{rp|6}}

Confusion over the species and subspecies, is widespread. The U. S. Department of Agriculture defines the Asian Gypsy Moth as "any biotype of ''Lymantria dispar'' possessing female flight capability",<ref name=review />{{rp|5}} despite ''Lymantria dispar asiatica'' not being the only classified subspecies that is capable of flight.<ref name=review />{{rp|6}}Traditionally, ''Lymantria dispar'' has been referred to as "gypsy moths" even when referring to Japanese, Indian and Asiatic gypsy moths.<ref name=review />{{rp|5}}

== Range==
The Gypsy moth, ''Lymantria dispar dispar'', is indigenous to Europe, and was introduced in North America.<ref name=review>{{cite web | url=http://www.fs.fed.us/foresthealth/technology/pdfs/Pogue_Lymantria_web.pdf | title=A review of selected species of Lymantria Huber [1819] | publisher=Forest Health Technology Enterprise Team | accessdate=September 14, 2012 | author=Pogue, Michael}}</ref>{{rp|5}} Though the Asiatic and the Eurasian moths were not classified as different species in the 1980s, the differences were already notable.<ref name=USDA>The Gypsy Moth: Research Toward Integrated Pest Management, United States Department of Agriculture, 1981</ref>{{rp|9}}

=== Introduction to North America ===
[[File:Gypsy moth spread 1900-2007.gif|thumb|Progressive spread of the gypsy moth (''L. dispar'') across north east US from 1900–2007; compiled from county data by US Forest Service]]
The gypsy moth was introduced into North America in 1869 from Europe.<ref name=USDA />{{rp|9}} Professor [[Étienne Léopold Trouvelot]] imported the moths to rear them in his backyard but some accidentally escaped<ref name=USDA />{{rp|9}} from his residence in [[Medford, Massachusetts]].<ref name=USDA />{{rp|10}} There are conflicting reports on the resulting actions. One states that despite issuing oral and written warnings of possible consequences, no officials were willing to assist in searching out and destroying the moths.<ref name=USDA />{{rp|10}} The other notes that he was aware of the risk and there is no direct evidence that shows he contacted government officials.<ref name="review"/>{{rp|1}}

As noted in ''The Gypsy Moth''(1896) by Forbush and Fernald, the gypsy moth was considered a nuisance just ten years after their release.<ref name=USDA />{{rp|10}} It included an account of all the trees being defoliated, caterpillars covering houses and sidewalks and that the caterpillars would rain down upon residents.<ref name=review />{{rp|1}}

The first outbreak occurred in 1889.<ref name=USDA />{{rp|10}} An eradication program was begun in 1890.<ref name=review />{{rp|1}}

=== Spread ===

The small larvae of the gypsy moth take to the air and are carried by the wind.<ref name=USDA />{{rp|10}} The larvae spin silken threads and hang from them, waiting for the wind to blow.<ref name=USDA />{{rp|10}} The light larvae have long hairs that increase their surface area, which are suitable for being carried aloft.<ref name=USDA />{{rp|10}} The natural spread is slow, but transportation of the moth has led to isolated gypsy moth populations, with accidental transport of the eggs being noted.<ref name=USDA />{{rp|10}} According to the United States Department of Agriculture, without intervention, this pest spreads about 13 miles per year.<ref name="gm">{{cite web | url=http://www.na.fs.fed.us/spfo/pubs/pest_al/gm/gm.htm | title=Gypsy Moth | publisher=United States Department of Agriculture | accessdate=September 14, 2012}}</ref> Typically, short distances can be traversed by larva, but there is suspicion that long distance flights are possible. It has been hypothesized that storms carried the larva across Lake Michigan to the western shore, the span of dozens of miles.<ref name="kl">{{cite web | url=http://www.ncbi.nlm.nih.gov/pubmed/22842865?dopt=Abstract | title=Interpretation of gypsy moth frontal advance using meteorology in a conditional algorithm. | accessdate=September 14, 2012 | author=KL Frank}}</ref>

Firewood is a common way to transport eggs, moths will lay their eggs on firewood.<ref name="chop">{{cite web | url=http://www.laurinburgexchange.com/view/full_story/19920026/article-Chop-local?instance=popular | title=Chop local | publisher=Laurinburg Exchange | accessdate=September 14, 2012 | author=Witten, Scott}}</ref> Firewood should be purchased and used locally, within 50 miles of where it is cut, to prevent the spread of the moths.<ref name=chop /> The website ''Don't move Firewood'' offers useful information for Americans about the pests, like the gypsy moth, that can be transported specifically by firewood.<ref>http://www.dontmovefirewood.org/</ref>

== Life Cycle ==

=== Eggs ===

Gypsy moth [[Egg (biology)|egg]] masses are typically laid on branches and trunks of trees, but may be found in any sheltered location, including rocks, foliage and vehicles.<ref name=USDA />{{rp|12}} Female gypsy moths are flightless, so they lay eggs on the near where they emerged from their pupa.<ref name=USDA />{{rp|12}} The eggs are covered in in a coating of hairs.<ref name=USDA />{{rp|12}} The covering provides protection from predators and parasites and may be important for insulating the eggs from cold temperatures and sealing in moisture.<ref name=USDA />{{rp|12}}

The larva inside the egg becomes fully developed in about one month.<ref name=USDA />{{rp|13}} The egg is the overwintering stage lasting for eight or nine months.<ref name=USDA />{{rp|13}} Development ceases in preparation for the winter.<ref name=USDA />{{rp|13}} After an acclimation stage, which the larva inside the egg reduce the water content, eggs can withstand freezing temperatures.<ref name=USDA />{{rp|13}} The larva inside the egg resumes activity in the spring, and reabsorbs water.<ref name=USDA />{{rp|13}} The larva will chew through the chorion of the egg and the protective hair of the egg cluster in the spring.<ref name=USDA />{{rp|13}}

Egg clusters, usually an oval about 3/4 of an inch wide and 1.5 inches long.<ref name="Illinois">{{cite web | url=http://urbanext.illinois.edu/gypsymoth/biology.html | title=Gypsy moth: Biology & Life Cycle | accessdate=September 14, 2012}}</ref> The egg masses are a buff yellow-brown color, likened to a manila folder, but may bleach out over the winter months.<ref name="eggpamp">{{cite web | url=http://walworth.uwex.edu/files/2010/05/gypsymotheggs.pdf | title=Identifying and managing Gypsy Moth egg masses | publisher=Chris Williamson and Andrea Diss | accessdate=September 14, 2012}}</ref> As the female lays them, she covers them with hair-like [[seta]]e from her abdomen. Egg clusters contain from 100 to 1000 eggs.<ref name=USDA />{{rp|12}} Due to the appearance of the eggs, several common names have emerged; ''Schwammspinner'' is German for "fungus spinner" and ''la spongieuse'' is French for the texture of the egg cluster.<ref name=USDA />{{rp|12}}

=== Larvae ===
[[Image:Gypsy moth larva.jpg|thumb|right|232px|Gypsy moth caterpillar]]

Larvae ([[caterpillar]]s) emerge from egg masses in the spring.<ref name=USDA />{{rp|13}} Most larvae hatch within a week, but it could take as long as a month.<ref name=USDA />{{rp|13}} The new larvae remain on or near the egg cluster if they hatch in rainy weather or if the temperature is below 7C.<ref name=USDA />{{rp|13}} The larva will disperse even if there is enough foliage for growth, they hang from silk threads and wait for the wind to send them aloft.<ref name=USDA />{{rp|13}} The larva are about 3&nbsp;mm when they first hatch and will grow to 50 or 90&nbsp;mm in size.<ref name=USDA />{{rp|14}}

The larva will first feed on the leaf hairs and then move onto the leaf epidermis.<ref name=USDA />{{rp|14}} Feeding occurs in the daytime, primarily in the morning and late afternoon.<ref name=USDA />{{rp|14}} As the larva grow, the feeding becomes a nocturnal activity.<ref name=USDA />{{rp|14}} When not eating, the larva will remain on the underside of the leaf and make a mat of silk for attachment.<ref name=USDA />{{rp|14}}

[[Image:IC Caterpillar2.JPG|thumb|left|200px|Older gypsy moth caterpillar in frontal view]]

To grow, the larva must [[molt]].<ref name=USDA />{{rp|14}} Larva are characterized by the term 'instar', which refers to the number of times a larva has molted; a first-instar has not yet molted, a second-instar has molted once, a third-instar has molted twice, etc.<ref name=USDA />{{rp|15}} Males typically are five instars and females are six instars.<ref name=USDA />{{rp|15}} When the larvae reach the fourth instar, they become nocturnal feeders, and will return to their resting places at dawn, hiding under flaps of bark, in crevices, or under branches - any place that provides protection.<ref name=USDA />{{rp|15}}

Newly hatched larvae are black with long, hair-like setae. Older larvae have five pairs of raised blue spots and six pairs of raised brick-red spots along their backs, and a sprinkling of [[setae]].<ref name=USDA />{{rp|15}} As the larval stage comes to an end they cease feeding and surround themselves in a silken net.<ref name=USDA />{{rp|15}}

==== Distinguishing the Larvae from other species ====

Larvae can be distinguished from other species of caterpillar by its spots. Close to the head, 5 pairs of blue spots and 6 pairs of red spots to its tail.<ref name=pp /> This distinction will prevent confusion with the [[Spiny elm caterpillar]] and other caterpillars. <ref name=pp /> [[Tent Caterpillars]] are one example, which can be distinguished by its silky tents in trees, a stripe on its back, and its preference for cherry trees.<ref name="New Jersey">{{cite web | url=http://www.state.nj.us/dep/parksandforests/forest/images/gypsy_moth_2.pdf | title=Gypsy Moth in New Jersey | publisher=Forest Resource Education Center New Jersey Forest Service Department of Environmental Protection | accessdate=September 21, 2012}}</ref>

=== Pupae ===
[[Image:Lymantria dispar - growth A - 07 - chrysalis (2009-06-25).jpg|thumb|left|200px|Pupa]]
The larvae reach maturity between mid-June and early July, then enter the pupal stage, during which larvae change into adult moths. Pupation lasts from seven to 14–17 days.<ref name=USDA />{{rp|16}} The adult moth will emerge, fully developed, by splitting the pupal skin.<ref name=USDA />{{rp|16}}

When the population is spread out and running low, pupation can take place under flaps of bark, in crevices, under branches, on the ground, and in other places where larvae rested. During periods when population numbers are dense, pupation is not restricted to these locations, but can take place in sheltered and open locations, even exposed on the trunks of trees or on foliage of nonhost trees. Usually, the caterpillars create flimsy cocoons made of silk strands holding the leaf together, while others do not cover their pupae in cocoons, but rather hang from a twig or tree bark, like butterfly pupae do.

=== Adults ===
[[Image:Lymantria dispar 8-8-2006 19-20-14.JPG|thumb|left|200px|Adult white female gypsy moth]]
[[Image:Lymantria dispar01.jpg|thumb|left|200px|Adult male gypsy moth]]

Males of the species are mottled brown with black wing markings and females are white or cream colored with black markings on the wings.<ref name=USDA />{{rp|10-11}} The antennae are also different, with males having a feathery antennae versus the thin antennae of females.<ref name=USDA />{{rp|11}} Size differences are also noted, with the forewing of the male moth is 20–24&nbsp;mm long, and that of the female 31–35&nbsp;mm.<ref>(Waring ''et al.'', 2003)</ref> Obviously, from this it is noticeable that the females are bigger than the males. Another important difference between the sexes, females possess fully formed wings, but do not fly.<ref name=USDA />{{rp|11-12}} Female flight is common in Eurasia and Asia, but these moths may be of a different species.<ref name=USDA />{{rp|11-12}} The other species is called the Asian Gypsy Moth.

Moths emerge from pupae usually in July, but it can very with population density and climate.<ref name=USDA />{{rp|11}} The brown male gypsy moth emerges first, usually one or two days before the females do.<ref name=USDA />{{rp|11}} The males fly in rapid zigzag patterns, but are capable of direct flight.<ref name=USDA />{{rp|11}} The males fly up an down tree trunks, or other vertical objects in search of females.<ref name=USDA />{{rp|11}} When heavy, black-and-white egg-laden females emerge, they emit a [[pheromone]] that attracts the males.<ref name=USDA />{{rp|12}} The female has a small gland near the tip of the abdomen which releases the pheromone, with a pumping motion, termed 'calling'.<ref name=USDA />{{rp|12}} It can attract males from long distances, tracking the scent through its erratic flight pattern.<ref name=USDA />{{rp|12}}

Courtship is not elaborate; the female must raise her wing to allow the male to couple with her.<ref name=USDA />{{rp|12}} The moths remain in [[Copula]]{{Disambiguation needed|date=October 2012}} for up to an hour, but the transfer of the [[spermatophore]] is usually accomplished within 10 minutes.<ref name=USDA />{{rp|12}} Male moths can inseminate more than one female.<ref name=USDA />{{rp|12}} Multiple mating in females is possible, but uncommon, because the female stops releasing the attracting pheromone after mating.<ref name=USDA />{{rp|12}} After mating, the females being depositing the eggs.<ref name=USDA />{{rp|12}}

The adult moths live about one week.<ref name=USDA />{{rp|12}} They do not possess an active digestive system and cannot feed, but can drink in moisture.<ref name=USDA />{{rp|12}} The reproductive chance for females lasts about two days, with the pheromone for attracting males being diminished by the third day.<ref name=USDA />{{rp|12}} Due to the phermone's potency, most females will mate.<ref name=USDA />{{rp|12}}

The females also produce offspring after they mate with a male, laying eggs on trees, shrubs, rocks, vehicles, and plants of many types. She typically lays about 500 eggs. The eggs are covered with a peachy fuzz that can cause serious rashes if they are touched by bare skin or fur, especially on humans and mammals. Then the female leaves to eat, while her eggs are protected. She does not live to see her offspring. <ref name=USDA />{{rp|12}}

== Host trees and shrubs==

Over three hundred species of trees and shrubs are host to the gypsy moth.<ref name=USDA />{{rp|16}} Gypsy moth larvae prefer [[oak]] trees, but may feed on many species of trees and shrubs, both hardwood and conifer.<ref name=USDA />{{rp|16}}

In the eastern US, the gypsy moth prefers oaks, [[aspen]], [[apple]], [[Liquidambar|sweetgum]], [[speckled alder]], [[basswood]], [[gray birch|gray]], [[paper birch]], [[poplar]], [[willow]], and [[Crataegus|hawthorns]], amongst other species.<ref name=McManus /> Older larvae feed on several species of softwood that younger larvae avoid, including [[Populus sect. Aegiros|cottonwood]], [[Tsuga|hemlock]], [[Atlantic white cypress]], and [[pine]] and [[spruce]] species native to the east.<ref name=McManus>{{cite web|coauthors=M.McManus, N. Schneeberger, R. Reardon, and G. Mason |url=http://na.fs.fed.us/spfo/pubs/fidls/gypsymoth/gypsy.htm |title=Forest Insect & Disease Leaflet 162 – Gypsy Moth |publisher=U.S. Department of Agriculture Forest Service |date=October 1989 |accessdate=2010-07-10}}</ref> The gypsy moth avoids [[Ash (Fraxinus)|ash trees]], [[tulip-tree]], [[American sycamore]], [[butternut (tree)|butternut]], [[black walnut]], [[catalpa]], [[flowering dogwood]], [[balsam fir]], [[arborvitae|cedar]], [[American holly]], and [[Kalmia latifolia|mountain laurel]] and [[rhododendron]] shrubs, but will feed on these in late [[instar]]s when densities are extremely high.<ref name=McManus />

== Behavior ==

Population density of larva plays a major role in their behavior. At low density, larva remain inactive during the day, but in high populations become hyperactive.<ref name=USDA />{{rp|16}} Larva will climb up any object in their path in search of food, including telephone poles, vehicles, even people.<ref name=USDA />{{rp|16}}

Interbreeding produces deleterious genetic effects, and dispersal serves to reduces this effect.<ref name=USDA />{{rp|23}}

== Natural control ==

=== Parasites ===

Four species of parasitic flies prey on gypsy moth larva.<ref name=USDA />{{rp|20}} ''[[Parasetigana silvestris]]'' and ''[[Exorista larvarum]]'' lays an egg on the gypsy moth larva. If that egg hatches before the gyspy moth larva molts, the fly larva will penetrate the host.<ref name=USDA />{{rp|20}} ''[[Compsilura concinnata]]'' pierces the gypsy moth larva and deposits its own larva inside.<ref name=USDA />{{rp|20}} ''[[Blepharipa pratensis]]'', lays its eggs on leaves, the gypsy moth larva will consume the egg and the fly larva will hatch inside its gut.<ref name=USDA />{{rp|20}}

Six species of parasitic wasps attack the gypsy moth. ''[[Ooencyrtus kuvanae]]'' and ''[[Anastatus disparis]]'' attack the eggs.<ref name=USDA />{{rp|20}} ''Ooencyrtus kuvanae'' attacks the eggs, but the [[ovipositor]] can only penetrate the surface layer of the egg cluster.<ref name=USDA />{{rp|20}} ''Anastatus disparis'' can only attack unembroyonated eggs and the female wasps do not have wings.<ref name=USDA />{{rp|20}} ''[[Apanteles melanoscelus]]'' and ''[[Phobocampe disparis]]'' parasitize the early larva stages.<ref name=USDA />{{rp|20}} ''[[Brachymeria intermedia]]'' and ''[[Monodontomerus aureus]]'' parasitize the gypsy moth pupae.<ref name=USDA />{{rp|20}}

A native parasite to North America, ''[[Itoplectes conquisitor]]'' attacks and kills gypsy moth pupae, but development is rare within the host; the number of the attacks themselves are also low.<ref name=USDA />{{rp|20}}

=== Pathogens ===

The most important pathogen is the [[Lymantria dispar multicapsid nuclear polyhedrosis virus]] (LdMNPV), sometimes referred to as NPV or ''Borralinivirus reprimens''.<ref name=USDA />{{rp|21}} The viral particles are consumed by the larva when eating through the egg chorion and will die in the first [[instar]].<ref name=USDA />{{rp|21}} The bodies disintegrate, spreading the virus on the foliage which will then be consumed by other larvae.<ref name=USDA />{{rp|21}} The virus' mortality is dramatic in outbreaks, which causes high mortality,<ref name=USDA />{{rp|21}} and the odor of the decaying larvae permeates the area.<ref name=USDA />{{rp|19}} The pathogen is used as an insecticide under the name [[Gypchek]] <ref name=USDA />{{rp|21}}

''[[Steptococcus faecalis]]'' is another pathogen which is notable for its mortality.<ref name=USDA />{{rp|21}} Larva killed by the pathogen have a shrivelled appearance.<ref name=USDA />{{rp|21}}

=== Predators ===

''[[Calosoma sycophanta]]'' is a beetle that preys upon the gypsy moth larvae and pupae. Larvae and adults of the species tear open their prey and feed upon them.<ref name=USDA />{{rp|21}}

Insectivorous birds prey upon the larva of the gypsy moth, because the egg clusters are protected by their hair coverings.<ref name=USDA />{{rp|21}} The effects of bird predation have not been fully studied in North America,<ref name=USDA />{{rp|21}} but it has been well-documented in Japan and Eurasia.<ref name=USDA />{{rp|21}} When outbreaks of gypsy moths occur, bird predation has no significant effect on the population.<ref name=USDA />{{rp|105}} Birds that consume gypsy moth larvae, pupae and adults include the [[bluejay]], [[red-eyed vireo]], [[rufous-sided towhee]], [[northern oriole]], [[catbird]] and the [[robin]].<ref name=USDA />{{rp|105}} The [[black-capped chickadee]] preys upon the entire life-cycle, including the eggs.<ref name=USDA />{{rp|105}}

The [[white-footed mouse]], ''Peromyscus leucopus'' is considered important for regulating sparse gypsy moth populations.<ref name=USDA />{{rp|21}} Rodents consume larvae and pupae that seek resting sites near or on the ground.<ref name=USDA />{{rp|21}} The white-footed mouse is the most common and widely distributed small mammal in the Northeast.<ref name=USDA />{{rp|108}} The [[shorttail shrew]] is common east of the [[Rocky Mountains]] and will consume the larva and pupa.<ref name=USDA />{{rp|108}}

=== Fungi ===

''[[Entomophaga maimaiga]]'' a Japanese fungi also helps control the population.<ref>{{cite web | url=http://www.questia.com/read/1G1-56797124/nature-saves-trees-from-gypsy-moths-fungus-helps | title=Nature Saves Trees from Gypsy Moths: Fungus Helps Stop Spring Caterpillars Cold | publisher=The Washington Times (Washington, DC) | accessdate=September 19, 2012 | author=Ferrechio, Susan}}</ref>

=== Weather ===

Temperature is important to the gypsy moth. Low temperatures are fatal. Temperatures of -9 C can be withstood during the winter, an extended period will kill the larvae inside and -23 C even for a short time is lethal.<ref name=USDA />{{rp|22}} Egg deposits that are low or on the ground can be insulated against temperatures, including snow, and survive the lethal temperatures.<ref name=USDA />{{rp|22}} Temperatures above 32 C increase growth and development.<ref name=USDA />{{rp|22}} Rainfall can drown larva before they are established, low populations are correlated to heavy rainfall during the larval stage.<ref name=USDA />{{rp|22}} Wind is also critical to the dispersal of the larva, wind speeds of several miles per hour are enough to break the silk threads and disperse the larva.<ref name=USDA />{{rp|23}}

=== Pheromones ===

[[Disparlure]] has been synthesized artificially, and has been used to confuse mating patterns or lead male moths into traps, however this technique is less successful against concentrated populations, hence its main use may be to delay infestation until other ecological solutions are found.<ref>{{cite book|last=Gerardi|first=Michael H.|title=The history, biology, damage, and control of the gypsy moth, Porthetria dispar (L.)|year=1978|publisher=Fairleigh Dickinson University Press|location=Rutherford [N.J.]|isbn=083862023X|coauthors=Grimm, James K.}}</ref>

== Impact ==

''Lymantria dispar dispar'' causes widespread defoliation and costs the economy millions of dollars in damages. Total defoliation in America from 1970 to 2010, was 80.4 million acres.<ref name=defolchart>[http://www.na.fs.fed.us/fhp/gm/maps_charts/charts/defoliation1970-2010.pdf Defoliation chart from US Forest Service]</ref> With 1981 being the worst year with 12.9 million acres defoliated.<ref name=CSM>Gypsy Moths Return to Northeast Worst Outbreak in a Decade Descends on Northeast; Entomologists Do Not Know How to Stop It. SUMMER'S MUNCH, Laurent Belsie, The Christian Science Monitor, July 2, 1990</ref><ref name=McManus /> In 2010, 1,207,478 acres were defoliated.<ref name="pp">{{cite web | url=http://sfec.cfans.umn.edu/prod/groups/cfans/@pub/@cfans/@sfec/documents/article/cfans_article_380545.pdf | title=European Gypsy Moth (Lymantria dispar) | accessdate=September 21, 2012}}</ref>

== References ==
{{reflist|2}}

[[Category:Insect pests of temperate forests]]
[[Category:Invasive insect species]]
[[Category:Butterflies and moths of North America]]
[[Category:Animals described in 1758]]
[[Category:Erebidae]]

[[az:Lymantria dispar]]
[[ca:Cuca peluda del suro]]
[[de:Schwammspinner]]
[[es:Lymantria dispar]]
[[eo:Lana tineo]]
[[fr:Bombyx disparate]]
[[hr:Gubar glavonja]]
[[it:Lymantria dispar]]
[[ka:არაფარდი პარკხვევია]]
[[hu:Gyapjaslepke]]
[[nl:Plakker]]
[[ja:マイマイガ]]
[[no:Løvskognonne]]
[[pms:Lymantria dispar]]
[[pl:Brudnica nieparka]]
[[pt:Mariposa-cigana]]
[[ru:Непарный шелкопряд]]
[[sr:Губар]]
[[fi:Lehtinunna]]
[[vi:Lymantria dispar]]

Revision as of 17:32, 27 March 2013

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