3.1.08 sr: notes ana: match the host plants list with the respective datasheets; although cutworms have many host plants, they are no major pests of all of them, therefore they have not been included in all datasheets of the above mentioned crops; s. by monitoring and decision making: pheromone traps are not available locally. economic threshold for which crop? where? under which conditions?;
Cutworms (Agrotis spp.)
Cutworms are caterpillars of Agrotis moth. The adult moth is grey to brown with a wingspan of about 4 cm and have lighter coloured hind wings. Whitish yellow eggs are laid at night on leaves. The eggs turn darker as hatching approaches. Young larvae may feed on leaves and cause tiny holes but they drop to the ground after a few days.
Mature larvae are about 4 cm long. They are easy to recognise by their smooth skin, greasy grey / orblack colour and C-shaped posture when disturbed. Cutworms emerge at night causing serious damage by cutting young plants at the base of the stem. Cutworm infestation is often associated with fields that are weedy, have high amounts of organic residue or are very wet due to poor drainage or heavily irrigated.
- Till weeds early, before harvest.
- Use light traps against moths, where feasible.
- Ploughing can help by exposing larvae to predators and can also bury others so that they cannot reach soil surface.
- Flooding of the fields a few days before planting can kill larvae in the soil.
- Use preparations made of neem or pyrethrum.