Scouting time
Scout during fall or spring in mild to cool weather. During mild winters, overwintering greenbugs can rapidly develop into damaging infestations during warm periods in February and March. Close field surveillance is necessary if greenbugs are present.
Sampling method
Producers may benefit from the Oklahoma State University ‘Glance ‘n Go’ sampling program, which calculates a greenbug threshold based on the cost of control, the market value of wheat and the month of the year. To use this method, log in or create account to access the Glance n' Go sampling tool under Scout a Field in the main menu.
Thresholds
Treatment during early fall is advisable as soon as the threshold is reached unless a great number of beneficial insects are active. Look for lady beetles and their alligator-like larvae on the wheat, and the brown, dried up husks of parasitized aphids (mummies) adhering to leaves. Greenbug numbers decline naturally in December and January, and treatment usually becomes unnecessary. Greenbug control on small grains is occasionally needed during periods of relatively cool weather (below 60°F, but above freezing). Experience has shown that good results are possible under these conditions with some, and perhaps most, of the recommended insecticides.
Chemical control
|
Greenbug Options |
|
|
Insecticide |
Rate |
|
Alpha-cypermethrin (Fastac EC) |
3.2 to 3.9 fl oz. (0.020 to 0.025 lb. a.i.)/acre |
|
Chlorpyrifos (Lorsban-4E) |
Check label, but generally 0.5 to 1 pint/acre |
|
Chlorpyrifos plus gamma-cyhalothrin (Cobalt Advanced) |
6 to 13 fl. oz./acre |
|
Chlorpyrifos plus zeta-cypermethrin (Stallion) |
9.25 to 11.75 fl. oz./acre |
|
Endosulfan (Thionex 3EC and 50 WSB) |
2/3 to 1 quart/acre |
|
Gamma-cyhalothrin (Proaxis) |
0.015 lb. a.i./acre (3.84 fl. oz.) |
|
Lambda-cyhalothrin (Grizzly Z) |
0.03 lb a.i./acre or 3.84 fl.oz./acre |
|
Malathion |
5 1.5 pints/acre |
|
Sulfoxaflor (Transform WG) |
0.75 to 1.5 fl. oz./acre (0.023 to 0.047 lb ai/acre) |
|
Zeta-cypermethrin (Mustang MAXX, etc.) |
0.02 to 0.025 lb. a.i./acre (3.2 to 4.0 fl. oz.) |
|
Approximate Damaging Levels of Greenbugs |
|
|
Stage and development of plants |
No. of greenbugs/linear ft |
|
Seedlings, thin stands less than 3 tillers |
50 |
|
3- to 6-inch wheat, 3 tillers or more |
100 to 300 |
|
6- to 10-inch wheat |
300 to 500 |
Non-chemical controls
Beneficial insects such as lady beetles, lacewings, and hoverflies become increasingly effective in reducing greenbug populations around mid-April. Once parasitism levels reach between 10 and 15 percent, greenbug populations usually decline fairly rapidly.
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Disclaimers
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