Cutworm

Onion

Name: Cutworm

Scientific Name: Agrotis ipsilon

Crop: Onion

Description:

  • The caterpillars spend their days hiding underground and feed on the surface of the plant during the night.
  • Moths emerge after dusk, mate, and lay eggs on the ventral surface of leaves and in moist soil. Freshly ploughed fields are preferred by insects for oviposition.

Damage Symptoms:

  • The fallen plants will lie on the ground with the stem still sticking out of the soil when infested.
  • Young larvae feed on tender foliage, while mature larvae cut the stem at the collar region.

Preventive Measures:

  • Fork the soil during summer months to expose larvae and pupae to avian predators and prevent infestation.
  • Install light traps during summer to attract adult moths.
  • Install pheromone traps at 5 per hectare.

Control Measures:

  • Drench the collar region of plants in the evening with chlorpyrifos 20 EC or endosulfan 35 EC at 4 ml/L a day after planting to help control the pests.
  • In endemic areas, apply NSKE 5%, endosulfan 35 EC 1 L, chlorpyrifos 20 EC 1 L, or neem oil 5 L in 500-750 L of water per hectare.