Field Identification
A social caterpillar that builds silken tents in the crotches of cherry, apple, crabapple, hawthorn, wild black cherry, and other rosaceous trees. Larvae emerge early in the growing season and strip branches, mostly a cosmetic issue on healthy trees but stressful during repeated heavy years or on young stock. Widespread in eastern and central North America with related Malacosoma species in western forests—collectively relevant across temperate zones roughly 3–8 where hosts occur, including shelterbelts and orchard edges from Canada through the U.S. and upland Mexico.
Adult moths are reddish brown with cream bands; larvae are black with a gold stripe down the back and blue lateral spots. Tents grow through April–May (timing shifts by latitude) as larvae aggregate for warmth at night and disperse to feed by day. Egg masses encircle twigs like shiny varnish collars—scout in winter for next season’s map.
How to Deal With It
Organic Control Methods
Bacillus thuringiensis kurstaki applied when larvae are small and actively feeding gives excellent control with minimal non-target impact. Neem or spinosad can follow label directions on orchard trees. Spot-spray only tents and surrounding foliage to preserve early-season pollinators on understory blooms.
Parasitic flies (Tachinidae) and wasps (Ichneumonidae, Braconidae) attack larvae; birds tear open tents. Avoid destroying occupied tents right before parasitoid emergence unless trees are critically defoliated.
Prune out winter egg bands when seen on young trees. Maintain orchard floor diversity without letting wild cherry thickets touch drip lines of nursery blocks. Accept light defoliation on mature trees to preserve biological control reservoirs.
Strip small tents by hand on reachable limbs and drop into soapy water—early removal prevents branch stripping. For backyard cherries, a gloved hand crushing early instars inside tents works fast. Power-wash is not recommended; it damages bark more than larvae.
Walk blocks in dormant season to flag twigs with egg masses. Map chronic crotches that held tents for targeted winter pruning. Educate clients that one bad spring does not mandate calendar sprays every year—monitor larval size before choosing Bt.
Let Nature Handle It
Natural Enemies
- Tachinid Flies (Tachinidae)
- Ichneumonid Wasps
- Braconid Wasps
- Insectivorous Birds
Threat Map