What's eating my filbert 'ennis'?

Filbert 'Ennis' is commercially important in the Pacific Northwest and shares the same pest complex as 'Barcelona': filbert worm and hazelnut weevil destroy nuts from within, big bud mite reduces bud viability, and aphids colonize new growth. Squirrels are consistently the most damaging vertebrate pest at harvest. Monitor for filbert worm with pheromone traps.

Larva tunnels into the nut, consuming the kernel; infested nuts fall early with a telltale exit hole; soil pupation continues the cycle. Use pheromone traps to time a spinosad or kaolin-clay spray at first moth flight; collect and destroy fallen nuts promptly each day.

Round, clean hole in fallen nuts indicates larval exit; the kernel is fully consumed or fouled. Destroy fallen nuts; soil cultivation under the canopy exposes pupae; pyrethroid spray at early nut development in commercial settings.

Rounded, swollen buds in winter that don't break into leaves or catkins, progressively reducing yield across seasons. Hand-remove affected buds before bud break; remove and replace plants with systemic infestation.

Colonies on leaf undersides cause yellowing and honeydew; worst in warm, dry spring conditions on young growth. Insecticidal soap or neem oil; encourage ground beetles and parasitic wasps by limiting broad-spectrum pesticide use.