Green cloverworms are commonly found in soybean. The caterpillar (larva) is green, slender and reaches a length of about 1 inch. It has three pairs of abdominal prolegs. This distinguishes it from other caterpillars found in soybean. It feeds only on leaves, and the feeding damage is similar to that of loopers. Smaller green cloverworm larvae crawl in a looping, inch-worm fashion similar to loopers. However, green cloverworm larvae often wriggle spastically when disturbed or prodded, helping to distinguish them from loopers. They may be found at any time during the season, but they are damaging only at high populations or in combination with other defoliators.
In an average sized field, take 25 sweeps with a sweep net and count the number of larvae that are found at 4 locations. Increase the number of sampling sites in large fields (> 50 acres). Also, visually estimate percent defoliation at each sampling point. It is important to document what other pests are present and may also be contributing to defoliation.
Treat at 30% defoliation until bloom (R1), 20% from bloom to full seed (R1-R6), and 30% after R6 to R6 plus 7-10 days. Alternatively, treatment can be made based on a threshold of 38 green cloverworms per 25 sweeps.
|Insecticide (Trade Names) for GREEN CLOVERWORM||Lb Active Ingredient per Acre||Amount Formulation per Acre||Performance Rating|
|acephate 90 (Orthene 90S)||0.75 - 0.99||0.83 - 1.10 lb||8|
|bifenthrin (Brigade 2E, Discipline 2E, Fanfare 2E)||0.063 - 0.10||4 - 6.4 oz||9|
|chlorantraniliprole (Prevathon 0.43 SC)||0.047 -0.067||14 - 20 oz||9|
|chlorantraniliprole, λ-cyhalothrin (Besiege)||See label||6 - 8 oz||9|
|chlorpyrifos (Lorsban 4E, Nufos 4E)||0.25 - 0.5||8 - 16 oz||8|
|chlorpyrifos (Lorsban Advanced 3.755)||0.25 - 0.47||8.5 - 16 oz||8|
|diflubenzuron (Dimilin 2)||0.031 – 0.063||2 - 4 oz||9|
|esfenvalerate (Asana XL 0.66E)||0.015 - 0.03||2.9 - 5.8 oz||9|
|indoxacarb (Steward 1.25)||0.055 - 0.11||5.6 - 11.2 oz||9|
|methomyl (Lannate LV 2.4)||0.23 - 0.45||12 - 24 oz||9|
|methoxyfenozide (Intrepid 2)||0.063 - 0.125||4 - 8 oz||9|
|permethrin (Pounce 3.2E)||0.05 - 0.1||2 - 4 oz||8|
|spinetoram (Radiant SC 1)||0.016 - 0.031||2 - 4 oz||9|
|spinetoram, methoxyfenozide (Intrepid Edge)||See label||4 - 6.4 oz||9|
|spinosad (Blackhawk 36% WDG)||0.034 - 0.05||1.1 - 2.2 oz||9|
|β-cyfluthrin (Baythroid XL 1)||0.025 - 0.044||1.6 - 2.8 oz||9|
|γ-cyhalothrin (Declare 1.25)||0.0075 - 0.0125||0.77 - 1.28 oz||9|
|λ-cyhalothrin (Karate 2.08, Warrior II)||0.015 - 0.025||0.96 - 1.6 oz||9|
|Z-cypermethrin (Mustang Max 0.8E)||0.0175 - 0.025||2.8 - 4 oz||9|
- Do not confuse green cloverworm (3 pairs of prolegs) with loopers (2 pairs), which are more difficult to control with insecticides.
- For more information see http://www.utcrops.com/soybean/soybean_insects/SoybeanGCW.htm.