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Massive Webs in PA Trees: Fall Webworms, Not Spiders

Silvery nets on branch tips in SE PA = fall webworms (Hyphantria cunea). Caterpillars enclose leaves/branches in webs (unlike tent caterpillars in crotches). Feed on 85+ tree species. Two races (blackheaded/redheaded). Webs unsightly but damage minor. Outbreaks every 4–7 years. Control: BT (Bacillus thuringiensis) on young larvae; spray nest + nearby leaves. Systemics for tall trees. Orthene (ornamentals), Sevin (pecans). Maintain tree health.

Pests: Diagnosing Lawn Dieback Under Pine Trees with Webbing; Lawn Webs: Funnel Spiders or Dollar Spot Fungus?; Lackey Moth Caterpillars Defoliating UK Trees and Hedges; Massive Webs in Trees: Fall Webworms, Not "Hermit Spiders"; Pomegranate Tree Webs and Bud Drop: Spider Mites or Normal Pollination?; Funnel-Web Spiders in the Lawn: Beneficial, Not a Problem; Carpenter Ants in Trees: Nest Preferences and Prevention; Spider Mites on Indoor Tabletop Roses: Water and Systemics; Fall Spider Webs in Shrubs: A Seasonal Abundance, Not an Infestation; Orb-Weaving Spider Identification: Web Shape Is Key

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