Editing Winter moth (section)

==Biological control==
[[File:WinterMothLeafDamage.jpg|thumb|225px|Maple tree leaves showing damage by winter moth larvae]]
In Europe, where winter moths are native, two [[parasitism|parasitic]] species, a [[parasitoid wasp|wasp]] (''[[Agrypon flaveolatum]]'') and a fly (''[[Cyzenis albicans]]'') prey on winter moth caterpillars. The wasps insert eggs into the larvae. The flies lay eggs on leaves, which the larvae then ingest when eating the leaves.<ref name=Capinera>{{cite book|author=Capinera, John L.|title=Encyclopedia of Entomology|url=https://books.google.com/books?id=i9ITMiiohVQC&pg=PA4278 |year=2008 |publisher=Springer Science & Business Media|isbn=978-1-4020-6242-1 |page=4278}}</ref> As a [[biological pest control|biological control]], the wasp was introduced in Canada but is not being pursued in the United States because there is not sufficient evidence that the wasp would not lay eggs in larvae of other moth species.<ref name=UMass/> Introduction of ''C. albicans'', which is species-specific to preying on winter moths, has proven successful in strongly reducing, although not eliminating, winter moth infestation in Nova Scotia. Test introductions were begun in eastern Massachusetts in 2005. This proved successful, so more fly releases have taken place at sites from southeast [[Connecticut]] to coastal [[Maine]]. As moth densities can reach ten million larvae per acre, several years are needed before parasitism by the flies reaches 20–50%. Once this is achieved the winter moth density will decline and leaf defoliation will be reduced to levels not as harmful to the trees.<ref name=UMass/> The delay in establishment is likely the result of heavy mortality from predators and [[Hyperparasite|hyperparasitoids]] on the pupating ''C.&nbsp;albicans''.<ref name="Broadley et al. 2018">{{cite journal |last1=Broadley |first1=H.J. |last2=Kelly |first2=E.A. |last3=Elkinton |first3=J.S. |last4=Kula |first4=R.R. |last5=Boettner |first5=G.G. |title=Identification and impact of hyperparasitoids and predators affecting ''Cyzenis albicans'' (Tachinidae), a recently introduced biological control agent of winter moth (''Operophtera brumata'' L.) in the northeastern U.S.A. |journal=Biological Control |date=2018 |volume=121 |pages=99–108 |doi=10.1016/j.biocontrol.2018.01.011 |s2cid=90918769 |doi-access=free |bibcode=2018BiolC.121...99B }}</ref> Management of the winter moth in Massachusetts using biological control with ''C.&nbsp;albicans'' is showing positive results.<ref name="Elkinton et al. 2018 FHTET">{{cite web |last1=Elkinton |first1=Joseph |last2=Boettner |first2=George |last3=Broadley |first3=Hannah |last4=Reardon |first4=Richard |last5=Weeks |first5=Ronald |title=Biological Control of Winter Moth in Northeast North America |url=https://www.fs.fed.us/foresthealth/technology/pdfs/FHAAST-2018-03_Biology_Control_Winter-Moth.pdf |publisher=USDA Forest Service |access-date=29 December 2018}}</ref>

There are different ways to successfully control the winter moth population depending on the time of year. During the late fall and early winter, a dormant oil stray can be used to suffocate the eggs. When the eggs are newly hatched in late March and early April Bt (''[[Bacillus thuringiensis]]'') is a safe and effective way to control caterpillars. As the caterpillars get bigger, [[spinosad]] is also effective.<ref name=":1" />