Juniper webworm
Dichomeris marginella
0 host plants
Last updated
Juniper webworm caterpillars spin silken webs binding juniper foliage together in distinct web masses visible on branch terminals and branch crotches from mid-summer through fall. The pale, greenish caterpillars feed within the webbed area, causing the enclosed foliage to brown and die. You notice these conspicuous web masses easily; they resemble spider webs but are more tightly constructed. Heavy infestations cause significant cosmetic damage.
Remove webbed foliage by hand or pruning shears during summer as webs appear; this is practical for smaller populations. For heavier infestations, spray directly into webbed areas with spinosad or biological insecticides targeting caterpillars. Repeat every 7 to 10 days as new growth is webbed. For heavily infested junipers, prune to improve air circulation.
Quick Reference
Cultural Controls
- Hand-pick and destroy caterpillars.
- Prune out and destroy nests.
- Several natural enemies help control juniper webworm populations.
- Avoid use of broad-spectrum insecticides which may kill these beneficial predators and parasites.