Cranberry Fruitworm identification

Organic Control Profile

Cranberry Fruitworm

Acrobasis vaccinii

22
Plants Affected
3
Natural Enemies
5
Control Strategies

A cranberry specialist whose larvae web blossom clusters and bore fruit, stitching berries with silk and frass—your pick for ‘why my berries are glued together.’ Moths fly in early summer when bog temperatures stabilize.

Small gray moths; pinkish larvae with dark heads tunnel flowers and green berries. Infested clusters turn brown and may hang on vines as flagging flags for scouts.

More identification photos — verified field observations

Organic Control Methods

Organic Sprays

Bacillus thuringiensis kurstaki or spinosad during early bloom to petal fall when eggs hatch—coverage into the canopy is critical on low vines.

Biological Controls

Trichogramma releases target eggs in IPM bogs; braconid parasitoids of caterpillars—preserve with selective spray windows.

Cultural Practices

Increase flooding duration where regulations allow to kill overwintering larvae; remove wild blueberry/vaccinium hosts near edges; synchronize bee-safe spray timing.

Mechanical & Physical

Vacuum or sweep adults at lights in research settings—impractical at scale but amusing at parties.

Prevention

Pheromone traps for biofix; scout for webbed tips and entry holes before larvae move into multiple berries.

Natural Enemies

Plants Affected — 22 in Database