Brown marmorated stink bug (Halyomorpha halys)
Consperse stink bug (Euschistus conspersus)
Green stink bug (Chinavia hilaris)
Pest description and crop damage Adult stink bugs are all shield-shaped, with a triangle-shaped section in the middle of their backs. They are generally up to about 0.5 to 0.6 inch long. The name stink bug refers to the strong odor the insects can emit if alarmed.
The consperse and green stink bugs are native pests, and the brown marmorated stink bug is an invasive pest that is an increasing problem in apples in some regions of the PNW. See: EMERGING PEST: Brown Marmorated Stink Bug: A Threat to Pacific Northwest Agriculture
The adult consperse stink bug is pale brown, yellow underneath with red antennae. The adult green stink bug is bright green. Nymphs are similar in shape to the adults and come in a variety of colors. Brown marmorated stink bug (BMSB) is characterized by white bands on the coal-colored antennae and legs; a distinct brown "marbled" color on the back that consists of flecks of different brown colors; red eyes; and an underside that may be cream, pink, red, yellow or green. Stink bugs cause damage to plants by sucking sap from buds, leaves, stems or fruits. Cat-facing damage on fruit indicates early season damage. Late season damage may be difficult to detect and worsens in storage. Areas of corky cells will be apparent beneath the skin of the fruit, and these will brown with oxidation. Stink bug damage can superficially resemble the physiological disorder known as bitter pit, but stink bug damage tends to originate within 1 cm of the fruit surface, while bitter pit damage can occur throughout the fruit. Note that chemical controls tend to be very disruptive to orchard natural enemies.
Biology and life history Native stink bug adults overwinter in groundcover. They feed early in the season on weeds and may move later into other host plants. Stink bug damage is worst in dry summers when alternative hosts are dried up. BMSB adults overwinter in human structures including homes, shops and outbuildings. Rock outcrops, leaf litter, and dead standing timber may also be used as overwintering sites for BMSB. BMSB move out from overwintering sites into orchards in the spring where they may begin to reproduce. They may also immigrate in from forest or riparian borders, or other crops throughout the growing season.
Egg parasitoids attack native stink bug eggs. Parasitic flies (Tachinidae) attack native stink bug nymphs and adults and lay eggs on them. The egg hatches and the fly larva then penetrates the host stink bug and consumes it from the inside. Native stink bug egg parasitoids and parasitic flies have little effect on BMSB, but an accidentally introduced egg parasitoid called samurai wasp (Trissolcus japonicus) is now establishing across the PNW. Predators of different lifestages include lacewings, ladybird beetles, ground beetles, web-making spiders, praying mantids and others.
Manage weedy vegetation within and around the orchard (especially blackberry, mustard and radish). Do not mow cover crops or weeds when stink bugs are present since mowing may cause bugs to disperse to the fruit trees.
Management-chemical control: HOME USE
Spring and summer
- azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
- imidacloprid-Soil drenches may have residual activity in woody plants lasting for 12 or more months. If short-term management is the goal, consider other approaches.
- insecticidal soap-Some formulations OMRI-listed for organic use.
- kaolin clay-Applied as a spray to leaves, stems, and fruit, it acts as a repellant to some insect pests. Some formulations are OMRI-listed for organic use.
- pyrethrins (often as a mix with other ingredients)-Some formulations are OMRI-listed for organic use.
Management-chemical control: COMMERCIAL USE
Late spring and summer
- beta-cyfluthrin (Bathyroid) 2 to 2.4 oz in up to 100 gal of water per application. 12-hour reentry. PHI 14 days. [Group3]
- clothianidin (Belay Insecticide) at 6 to 12 fl oz/a (0.1 to 0.2 lb ai/a). Do not apply more than 12 fl oz (0.2 lb ai) of Belay Insecticide per acre per season. PHI 7 days. Do not feed or allow livestock to graze on cover crops from treated orchards. [Group 4]
- cyfluthrin (Tombstone) at 2.4 to 2.8 oz/a in no less than 100 gal of water per application. PHI 7 days. [Group3A]
- esfenvalerate (Asana XL) at 4.8 to 14.5 oz of product/a in up to 100 gal of water per application. Do not exceed 0.525 lb ai/a per growing season. Very toxic to predatory mites. Foliar use may cause spider mite outbreaks. This pesticide is not compatible with integrated control programs for spider mites. PHI 21 days. [Group 3A]
- fenpropathrin (Danitol 2.4 EC) at 16 to 21.3 oz/a in up to 100 gal of water per application. Can be used in Washington for stink bug control under a 24c SLN label (WA-020014). Highly toxic to fish, bees, and wildlife. PHI 14 days. [Group 3A]
- gamma-cyhalothrin (Declare, others) at 1.02 to 2.05 oz in enough water to achieve good coverage. No more than 0.08 lb AI per year. PHI days [Group 3A].
- imidacloprid (Admire Pro) at 1.2 to 2.4 oz/a. Can be applied as soil application through chemigation system, rates and restrictions differ for this application, see label. Generic labels available. PHI 7 days. [Group 4A]
- lambda-cyhalothrin (Warrior II, generics available) at 1.28 to 2.56 oz in enough water to achieve thorough coverage. PHI 21 days. [Group 3A]
- zeta-cypermethrin (Mustang Maxx) at 5 to 6 oz/a in a minimum of 100 gal of water for dilute spray. PHI 14 days. [Group 3A]