By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov or 920-360-0665

Webbing and a collection of frass (caterpillar excrement) around these cones is the web nest of pine webworm. / Photo Credit: Wisconsin DNR
Pine webworm (Pococera robustella) is a native moth whose caterpillars feed on pine needles. In Wisconsin, the caterpillars prefer young jack pine and red pine. A single generation per year occurs in Wisconsin.
Young larvae mine needles, feeding within the needle. Older larvae form a compact web that they fill with small, oval pieces of frass. In early fall, the larvae drop to the ground to pupate and spend the winter.
The online portal for Tree City USA (TCUSA) is
Do you know of a person or organization that is making a difference in community forestry? Maybe it is a volunteer who spends their free time planting trees in the community or an organization that is committed to increasing tree diversity or a municipal employee who has dedicated their career to transforming a city’s urban forestry program. If so, please complete this short 

The Wisconsin Department of Natural Resources (DNR) is accepting seedling orders from Wisconsin landowners for trees and shrubs to be planted in spring 2026, starting Oct. 6, 2025.


