Hazelnut-Filbertworm

Cydia latiferreana

Pest description and crop damage This insect is the key pest of hazelnuts in the Pacific Northwest. It is a close relative of codling moth, one of the most economically significant insects worldwide. Adult moths are gray to reddish with golden bands across each forewing. Larvae feed within the nut and destroy the kernel. When fully developed, the larvae are whitish with a brown headcapsule and are approximately 0.5 inch long. The entry hole into the shell is not often seen, but the much larger exit hole is apparent after the larvae has finished devouring the kernel.

Biology and life history The insect is found in many wild and cultivated nuts in North America but is particularly common in acorns and hazelnuts. The filbertworm overwinters as a larva in a silken cocoon. These are found under leaves and debris on the ground or in cracks and crevices on trees. Some larvae also overwinter 1 to 2 inches beneath the soil surface. The larvae pupate and the adults begin to emerge mid-June through October. After mating the female moths begin to lay single eggs near developing nuts. Eggs hatch in 8 to 10 days, and the tiny larvae search out nuts. They burrow into the nut to feed on the kernel for 2 to 4 weeks before they bore their way out. Most then form cocoons (hibernaculae) to overwinter, although some may pupate and become moths within the season (i.e., there may be a partial second generation). Sprays are timed to target the eggs and the wandering early larvae before they penetrate the nuts. Note that spray timing is critical when selecting materials with lower residual, use the degree day model available from the Integrated Plant Protection Center: http://uspest.org/wea/.

Pest monitoring Filbertworm flight has been starting earlier in the season compared to historic norms. Previous recommendations were to start hanging pheromone traps before the flight of filbertworm moths begins in mid-June, but now it is clear that traps should be placed mid-May to capture the first moths. Use four traps for the first 10 acres and one for each additional 4 acres. Place the traps in the upper third of the canopy. The action threshold is 2-3 moths per trap or five moths in any one trap. Note that very early moth flight may not threaten the crop if there are no nuts present. Apply insecticides 8-12 days after filbertworm moths emerge in your orchard block to target larvae emerging from eggs prior to nut penetration (first egg hatch occurs when 955 degree days have accumulated after April 1). A second application may be necessary in 2-3 weeks, or if moths continue to be caught in traps at rates above the threshold. Moths flying late in the season can cause unexpected crop damage so it is important to keep monitoring through harvest.

Management-mating disruption

Isomate FBW ring (Pheromone)-OMRI approved for organic use. Apply dispensers in the upper 1/3 of the canopy before first moth flights at a minimum of 20 dispensers per acre. Minimum block size of 10 acres. Renew dispensers each season and continue to monitor traps.

Management-chemical control: HOME USE

  • acetamiprid-Do not apply until after trees have flowered or when bees are actively foraging. Do not make more than one application a year. PHI minimum of 7 days.
  • carbaryl
  • esfenvalerate
  • gamma-cyhalothrin
  • kaolin-Some formulations are OMRI-listed for organic use.
  • lambda-cyhalothrin
  • pyrethrins
  • spinosad-Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin

Management-chemical control: COMMERCIAL USE

Filbertworm emergence notices are sent to growers. Time sprays accordingly. Pheromone trapping is encouraged for accurate spray timing.

  • alpha-cypermethrin (Fastac CS) at 3.2 to 3.8 fl oz/a. PHI 7 days. REI 12 hr. Do not exceed 11.4 fl oz/a per season. Highly toxic to bees, extremely toxic to fish and aquatic invertebrates. Do not apply within 25 feet of aquatic habitats, or with 150 ft if aerial application. Apply as indicated by scouting.
  • acetamiprid (Assail 70WP) at 0.57 to 1 oz/100 gal water (2.3 to 4.1 oz/a). PHI 14 days. No more than 4 applications per season.
  • chlorpyrifos-Generic labels for chlorpyrifos are also available.
    • Lorsban 4E at 3 to 4 pints/a. PHI 14 days. REI 1 day. No more than three applications per season. Extremely toxic to fish. Toxic to birds and wildlife.
    • Lorsban 75 WG at 2 to 2.67 lb/a. PHI 14 days. REI 1 day. No more than three applications per season. Extremely toxic to fish. Toxic to birds and wildlife.
  • chlorpyrifos + gamma-cyhalothrin (Cobalt) at 6.5 to 14.2 oz/100 gal (26 to 57 fl oz/a). PHI 14 days. Do not make more than 3 applications per season of Cobalt or other product containing chlorpyrifos for hazelnuts.
  • chlorpyrifos + O-diethyl-O-(3,5,6-trichloro-2-pyridinyal) phosphorothioate (Vesper,Vulcan) at 3 to 4 pints/a. PHI 14 days. REI 24 hr. Do not make more than 3 applications per season.
  • chlorantraniliprole (Altacor) at 3 to 4.5 oz/a. PHI 10 days. REI 4 hr.
  • cyfluthrin (Baythroid XL) at 2 to 2.4 oz/a. PHI 14 days. REI 12 hr.
  • diflubenzuron (Dimilin 2L) at 12 to 16 fl oz/a. PHI 28 days. REI 12 hr. Extremely toxic to aquatic invertebrates. Do not apply within 25 ft of bodies of water.
  • emamectin benzoate (Proclaim) at 3.2 to 4.8 oz/a. PHI 14 days.
  • esfenvalerate (Asana XL) at 8 to 12 fl oz/100 gal water (10 to 18 fl oz/a). PHI 21 days. REI 12 hr. Do not apply more than 0.2 lb ai/a per season. Extremely toxic to fish and aquatic habitat.
  • esfenvalerate (S-fenvaloStar) at 9.6 to 12.8 fl oz/100 gal water (10 to 18 fl oz/a). PHI 21 days. REI 12 hr. Do not apply more than 0.2 lb ai/a per season. Extremely toxic to fish and aquatic habitat. Apply with first filbertworm moth flight in early summer, do not apply second treatment within 3 weeks. Do not apply more than 0.2 lb ai per season. Highly toxic to bees, fish, and aquatic invertebrates.
  • flubendiamide (Belt) 3 to 4 fl oz/a. PHI 14 days. REI 12 hr.
  • lambda-cyhalothrin-
    • Warrior II at 1.28 to 2.56 fl oz/a. PHI 14 days. REI 24 hr. Do not exceed 0.16 lb ai/a per season or 0.12 lb ai post bloom.
    • LambdaStar at 2.56 to 5.12 fl oz/a. PHI 14 days. REI 24 hr. Do not exceed 0.16 lb ai/a per season or 0.12 lb ai post bloom.
    • Grizzly Too at 1.28 to 2.56 fl oz/a. PHI 14 days. REI 24 hr. Do not exceed 0.16 lb ai/a per season or 0.12 lb ai post bloom.
    • Drexel L-C at 2.56 to 5.12 fl oz/a. PHI 14 days. REI 24 hr. Do not exceed 0.16 lb ai/a per season or 0.12 lb ai post bloom.
  • methoxyfenozide (Intrepid 2F, Troubadour 2F) at 8 to 16 fl oz/a. PHI 14 days. REI 4 hr. Apply when egg hatch begins. Reapply at 14 to 21 day intervals under high pressure or sustained moth flight. Do not exceed 24 fl oz/a per application or 64 fl oz/a (1 lb ai/a) per season. Do not apply within 25 ft of an aquatic habitat, 150 ft if applied by air.
  • permethrin-
    • Ambush 25W at 12.8 to 25.6 oz/a. PHI 14 days. Do not graze treated orchards. Extremely toxic to fish and aquatic habitat.
    • Ambush 2E at 0.8 to 1.6 pints/a. PHI 14 days. REI 12 hr. Do not graze treated orchards. Extremely toxic to fish and aquatic habitat.
    • Pounce 3.2 EC at 0.5 to 1 pint/a. PHI 14 days. REI 12 hr. Do not graze treated orchards. Extremely toxic to fish and aquatic habitat.
    • PermaStar AG at 8 to 16 oz/a. PHI 14 days. REI 12 hr. Highly toxic to bees, toxic to fish and aquatic invertebrates.
  • pyriproxyfen (Esteem 35 WP ) at 4-5 oz/100 gal water. Do not apply more than twice per season. PHI 21 day. REI 12 hr.
  • spinetoram (Delegate WG) at 1.5 to 1.75 oz/100 gal water (4.5 to 7 oz/a). PHI 14 days. Apply no less than one week apart, with a maximum 4 applications per season.
  • spinosad (Success 2L) at 1 to 2 oz/100 gal water (4 to 8 oz/a.) PHI 1 day. Do not exceed 29 oz/a per season.
  • spinosad (Entrust SC) at 4 to 10 oz/a. PHI 1 days. REI 4 hr. OMRI-listed for organic use.
  • tebufenozide (Confirm 2F) at up to 30 oz/a. PHI 14 days. REI 12 hr. Apply when egg hatch begins. Do not exceed 30 oz/a per application or 122 oz/a for the season.