Pest description and crop damage An invasive pest that an increasing problem on hazelnuts in the Willamette Valley. There are five immature stages, and all but the first can feed on hazelnut trees. Feeding may be on vegetative structures or on nuts (shell thickness or hardness does not protect kernels from feeding damage). Vegetative feeding may not be problematic on its own, but the later instar nymphs and adults can damage kernels, and depending on when the damage occurs, they can cause blank nuts, shrivel or corking damage on the kernels. (See OSU EM 9102: How to recognize brown marmorated stink bug damage in commercial hazelnuts as a guide to hazelnut damage.)
Biology and life history
Pest monitoring Pheromone traps, visual samples, or beating trays are good methods for detection. (See OSU EM 9138: How to monitor for brown marmorated stink bug in specialty crops.) Place traps on orchard borders and monitor orchard border vegetation. Management thresholds based on trap captures or other sampling methods are not yet firmly established, but trap captures of adults in the orchard may represent a damaging population. Presence of nymphs in the crop can also be an indicator that damage will occur. Stink bugs are very cryptic and can be difficult to detect in the crop. Slow movement when scouting can be important to detect nymphs without triggering a hiding or flight response. Scan the underside of leaf surfaces for egg masses and early nymphs. Standardize the amount of time spent visually searching for stink bugs (e.g., two minutes) to compare samples from different times of the season or locations. Note that the highest pressure from this pest will be late in the season (Aug thru Oct), although damaging levels may also occur early in the season.
An adventive parasitoid wasp from Asia, Trissolcus japonicus, was detected in Portland, Oregon in 2016. This parasitoid is expected to eventually become widespread, and there is a current effort to redistribute it. This wasp attacks the eggs and is very effective against brown marmorated stink bug in Asia. Native parasitoids and predators can also help limit populations, but are not effective enough to keep populations in check.
Hand collecting and killing of egg masses, nymphs, and adults can be an effective management strategy if there are very few trees, but this method is not practical on a commercial scale. Eliminating or excluding aggregations of adults in their overwintering sites, including farmhouses and out buildings, may be beneficial to reduce local populations for commercial growers and homeowners.
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 7 days.
- azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
- kaolin-Some formulations are OMRI-listed for organic use.
- plant-derived essential oils-Some formulations are OMRI-listed for organic use and have shown efficacy against aphids.
- pyrethrins (often as a mix with other ingredients)-Some formulations are OMRI-listed for organic use.
Management-chemical control: COMMERCIAL USE
- 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.
- Brigade WSB at 0.05 to 0.2 lb ai/a. PHI 7 days. REI 12 hr. Do not graze livestock on treated cover crops. Highly toxic to bees and toxic to fish and aquatic invertebrates.
- Fanfare EC at 3.2 to 12.8 fl oz/a. PHI 7 days. Do not graze livestock on treated cover crops. Highly toxic to bees and toxic to fish and aquatic invertebrates.
- cyfluthrin (Baythroid XL) at 2 to 2.4 oz/a. PHI 14 days. REI 12 hr.
- diflubenzuron + lambda-cyhalothrin (DoubleTake) at 4 to 5 fl oz/a. PHI 28 days. REI 24 hr. Do not exceed 20 fl oz/a per growing season or 15 fl oz/a per year growing season post bloom. Extremely toxic to aquatic invertebrates. Do not apply within 25 ft of bodies of water, 150 ft if applied by air.
- imidacloprid (Admire Pro 1.6) at 1.2 to 2.4 fl oz/a. PHI 7 days. REI 12 hr. Generic labels for imidacloprid are available.
- 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.