This problem is usually confined to southeast Kansas. There are several overlapping generations, and damage tends to be more severe in late planted fields and in varieties with compact heads. Larvae are active from August to October. Kansas growers should begin scouting fields by mid-August and consider treatment where infestations average five or more worms per head during the early post-bloom period.
None listed.
None listed.
Control or mow Johnsongrass because it serves as a reservoir for this pest. Destroying stubble can reduce populations of overwintering larvae.
This content may not be suitable for states other than Kansas.
|
Sorghum Webworm Management Options |
|
|
Insecticide |
Rate |
|
Alpha-cypermethrin (Fastac EC) |
1.8 to 3.8 fl. oz./acre |
|
Beta-cyfluthrin (Baythroid XL) |
0.010 to 0.022 lbs. a.i./acre (1.3 to 2.8 fl. oz.) |
|
Carbaryl (Sevin 80S) |
1.25 to 2.5 lb./acre |
|
Chlorantraniliprole (Prevathon) |
14.0 to 20.0 fl. oz./acre |
|
Chlorpyrifos (Lorsban-4E) |
Check label, but generally 1 pint/acre |
|
Chlorpyrifos plus gamma-cyhalothrin (Cobalt Advanced) |
16.0 to 38.0 fl. oz./acre |
|
Chlorpyrifos plus zeta-cypermethrin (Stallion) |
5.0 to 11.75 fl. oz./acre |
|
Deltamethrin (Decis 1.5 EC) |
0.012 to 0.018 lb. a.i./acre (1 to 1.5 fl. oz.) |
|
Gamma-cyhalothrin (Proaxis) |
0.01 to 0.015 lb. a.i./acre (2.56 to 3.84 fl. oz.) |
|
Lambda-cyhalothrin (numerous products) |
0.02 to 0.03 lb. of a.i./acre |
|
Methomyl (Lannate LV) |
1.5 pints/acre |
|
Spinosad (Blackhawk) |
0.038 to 0.075 lb. a.i./acre (1.7 to 3.3 fl. oz.) |
|
Zeta-cypermethrin (Mustang MAXX, Respect EC) |
0.011 to 0.025 lb. a.i./acre (1.76 to 4.0 fl. oz.) |