Lygus spp.
Pest description, crop damage and life history
See:
Common Pests of Vegetable Crops
Pest monitoring Sweep nets can be used to sample for lygus bugs. In the Pacific Northwest, a suggested treatment threshold is one-half adult or one-half for fourth or fifth instar nymph, per sweep. In California, for dry beans, treatment thresholds vary depending on the variety and the stage of the crop, from one-half to two lygus bugs per sweep.
Management-biological control
Generalist predators, such as lacewings, big eyed bugs, and damsel bugs, may prey on lygus bug nymphs. Parasitic wasps may also prey on lygus such as Peristenus spp. Conserve populations of these biological control agents by minimizing applications of broad-spectrum insecticides.
Management-cultural control
Lygus are likely to move when food sources become unsuitable. Common weeds that are good hosts of lygus bugs include pigweed, mustards, and wild radish. Mowed alfalfa fields nearby are commonly a source of large numbers of lygus bug adults moving into susceptible crops. There are a number of practices to reduce or control the movement of adults from alfalfa into nearby bean fields. These techniques leave uncut, tall alfalfa (attractive to lygus bug adults) within or near the cut area to serve as refugia for the insects.
Management-chemical control: HOME USE
Follow information given on the label about the timing and cutoff date for the particular vegetable you are spraying.
- azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
- carbaryl
- esfenvalerate
- malathion
- plant essential oils (rosemary, etc.)-Some have demonstrated efficacy. Some formulations are OMRI-listed for organic use.
- pyrethrins (often combined with other ingredients)-Some formulations are OMRI-listed for organic use.
- zeta-cypermethrin
Management-chemical control: COMMERCIAL USE
- acephate (numerous products) at 0.5 to 1 lb ai/a. PHI 14 days. REI 24 hr. Do not feed treated vines. Do not exceed 2 lb ai/a per year.
- beta-cyfluthrin (Baythroid XL, Tombstone Helios) at 0.019 to 0.025 lb ai/a. PHI 7 days. Retreatment interval 14 days. Do not exceed 0.5 lb ai/a per season. Do not feed treated vines or hay to livestock. Toxic to bees, fish and aquatic invertebrates. Only registered for use in WA.
- lambda-cyhalothrin (Warrior II) at 0.02 to 0.03 lb ai/a. PHI 21 days. REI 24 hr. Do not graze or feed to livestock. Do not exceed 0.12 lb ai/a per year. Do not apply within 25 ft of an aquatic habitat, 150 ft if applied by air.
- malathion (numerous products) at 1.25 lb ai/a. PHI 1 day. REI 12 hr. Do not graze or feed foliage to livestock.
- methomyl (Lannate SP) at 0.45 to 0.9 lb ai/a. PHI 14 days for harvest, feeding vines, and hay. REI 48 hr. Do not exceed 4.5 lb ai/a per year.
- naled (Dibrom 8) at 0.94 lb ai/a. PHI 1 day. REI 24 hr. Do not apply within 25 ft of an aquatic habitat, 150 ft if applied by air.
- novaluron (Rimon .83 EC) at 12 fl oz/a. Do not apply more than 36 fl oz/a per season. PHI 24 hr. REI 12 hr.
- phorate (Thimet) at 0.0563 to 0.0875 lb ai/1,000 ft row at planting; at no more than 1.5 lb ai/a. PHI 60 days. REI 48 hr, or 72 hr if annual rainfall is less than 25 inches. At planting time only. Do not graze or feed to livestock. Toxic to fish and wildlife.
- Sulfoxaflor (Transform WG) at 1.5 to 2.25 oz/a. Do not exceed 8.5 oz/a. PHI 7 days. REI 24 hr. If blooming vegetation is present 12 ft out from the downwind edge of the field, a 12 foot in-field down wind buffer must be observed.