The grey weevil, also called the ash weevil (Myllocerus spp.), is a small dull-grey beetle that feeds on cotton foliage, chewing ragged notches along the leaf margins. Adults are most damaging at the seedling and early vegetative stage, when heavy feeding on the growing point can stunt or kill young plants outright, while the soil-dwelling grubs feed on roots below ground. Here are 2 verified solutions for grey weevil in cotton, with real products.
Symptoms of Grey Weevil in Cotton
- Irregular, notched bite marks along the margins of cotton leaves, giving them a ragged or "C-shaped" chewed appearance
- Damage concentrated on young seedlings and terminal shoots, sometimes destroying the growing point
- Grey, ash-coloured weevils visible on leaves and shoots, often more active at dusk and early morning
- Wilting or stunted seedlings in patches where grubs have fed on roots below the soil surface
- Reduced plant stand in badly affected fields due to seedling mortality
Causes of Grey Weevil in Cotton
- Adults migrating from weedy field bunds and border vegetation into the newly sown cotton crop
- Grubs surviving in the soil from the previous season where residue and root stubble were left undisturbed
- Continuous cotton cropping in the same field without rotation, letting populations build up over seasons
- Poor field sanitation, with weed hosts around the field edge acting as a reservoir between crops
- Warm, humid conditions early in the season that favour adult emergence and feeding activity
Solutions to Control Grey Weevil in Cotton
1. Dimethoate 30% EC
A systemic and contact organophosphate insecticide that moves through the plant while also killing on direct contact, giving cover against both sucking pests and chewing pests like grey weevil. It's registered on cotton for aphids, jassids, and thrips at a lower dose, with a separate, higher dose specifically for grey weevil.
Product Recommendations
2. Bifenthrin 8% + Clothianidin 10% SC
This combination pairs a pyrethroid with a systemic neonicotinoid, giving fast knockdown on contact alongside uptake into the plant for longer residual protection. It's registered on cotton for grey weevil together with mealy bug, jassids, whitefly, aphids, and thrips, making it a wide-cover option where more than one of these pests is active on the crop at the same time.
Product Recommendation
Note: Keep field bunds and borders free of weeds, since adult weevils migrate in from this surrounding vegetation, and target sprays at the seedling stage when the growing point is most vulnerable to feeding damage.
Disclaimer: Always confirm current label registration, approved dosage, water volume, and pre-harvest interval (PHI) for your state before using any product - labels are periodically revised by regulatory authorities.
This guide is a general advisory. Do your own research and verification before using any product. Always confirm suitability for your crop stage, region, and field conditions before making any purchase, spray, or crop-management decision.
