University of Maryland Extension University of Maryland

College of Agriculture & Natural Resources

Stink Bugs - Vegetables

 BMSB
Adult brown marmorated stink bug (BMSB)

Back to Common Problems - Vegetables

Appearance

Eggs: light colored clusters of about 25 (up to 60 for Brown stinkbug), on end, under leaves. BMS are elliptical. Others are more barrel-shaped.
Nymphs: 5 instars flattened like adults, but rounder.
BMSB - short strips of red-brown and black. Black and white banding on antenna and around abdomen like adults, plus on legs.
Brown stinkbug - yellow-brown to brown. Green stinkbug - vary from yellow-orange to black, reddish and greenish.
Adults:
  5/8" shield-shaped bugs.
BMSB
- mottled brown and cream with black and white banding on abdomen edge and on antenna.
Brown - brown.
Green - green with white specks.  

Life cycle/Habits Brown and Green overwinter as adults on weeds, garden debris and under tree bark. BMSB uses sheltered cracks of buildings, rocks, wood piles. Eggs are laid under leaves. Young nymphs aggregate near egg-hatch. Nymphs and adults insert piercing mouthparts and suck plant sap from leaves, fruit, buds or blossoms.
Southern green stink bug feeding can infect beans with disease. Hide when disturbed. Adults are strong flyers and secrete a repellant fluid when threatened or squashed. Also emit aggregating pheromone. Annually, there are 3-4 generations of Southern green stink bug, only one of brown stink bug. BMSB may have up to 2 in Maryland.
Host Plants Bean, pepper, tomato, as well as corn, eggplant, okra, pea, soybean, squash, plus most other vegetables and fruits.
Signs/Symptoms Piercing and sucking creates superficial spots (white on young fruit or yellow on mature fruit) known as "cloudy spot" on tomato and other fruits. Pimples or wart-like growths appear on okra and bean pods.  Blossoms and pods may drop prematurely. Leaves may roll, wilt, or be stunted. Fruit may be deformed.  Corn may increase tillering, silk be delayed, and produce reduced as well as damaged.  Southern green stinkbug punctures introduce seed pit or yeast spot disease into lima pods, ruining beans.
Monitoring Check leaf undersides for egg masses. Watch young plants, then fruit for damage, especially lima pods as they are rendered inedible. Search carefully for stinkbugs as they purposefully hide.  "Healthy" lima beans may reveal cloudy spots when shelled, then grayish blotches when blanched, where bugs introduced yeast disease, Hermatospora coryli, known as seed pit or yeast spot.
Prevention/Control
  1. Clean up plant debris after season, especially crucifers and legumes.  Tilling disrupts overwintering sites.
  2. Use row cover when possible, beginning in spring.
  3. Search for egg masses and crush. Handpick bugs.
  4. Bugs hide or drop when startled. Knock into a container with soapy water held underneath.
  5. A cloudy spot in fruit can be cut out and does not affect eating quality.
  6. Insecticidal soap or botanicals such as neem or pyrethrum are only effective on young nymphs. Adults are resistant even to highly toxic insecticides.
  7. Thick organic mulch provides desirable habitat for stinkbugs. Consider removing mulch or using plastic, fabric or rolled paper mulch.
  8. Many natural predators and parasitoids are still not enough to control them, but conserve beneficial predators by using only insecticides with a short residual.
  9. Thick-skinned cultivars may provide some resistance.

 

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IET Departmentof the College of Agriculture and Natural Resources. © 2014.