As many cutworms use weed growth to ‘migrate’ between cultivated and wild plants, the female moth will have nothing to lay its eggs on. Seven to 10 days prior to planting, the soil should be ploughed and weed infestation reduced to a minimum. Ploughing during winter exposes the caterpillars or pupae to predators such as birds, lizards, frogs and scorpions. Other: Many adult caterpillars overwinter in the soil and pupate the following summer. Natural predators can have a success rate as high as 90%. Most are either parasitic wasps or flies – such as the Braconid and Ichneumon wasp (Enicaspilus spp) and Tachinid flies (Tachinidae), especially the cutworm fly Gonia bimaculata. Natural control: A number of natural predators prey on cutworms. A walk through the crop during the evening with a torch will confirm this.Ĭhemical: Sprinkling cutworm bait over the soil during the evening will reduce their numbers, as will spraying plants with a chlorpyrifos insecticide such as Lorsban. ‘Felled’ seedlings are a sure sign that cutworms are present. In South Africa, the life cycle is completed in six to eight weeks. Just before the adults emerge, they turn black. Pupation occurs in the soil or in silken cocoons. A single female can lay more than 2 000 eggs during her life. Initially creamy-white in colour, the eggs darken to almost black as they near hatching. An infestation can wreak havoc within a short time.ĭepending on the species, females lay their eggs singularly or in small clusters on the stems or leaves of the host plant. Many of the caterpillars also attack roots and tubers by day. Other susceptible crops include beans, cabbage, carrots, cauliflower, lettuce, peas, potatoes and tomatoes. In addition to eating the stem, buds, flowers and pods, cutworms may attack the seeds, ears and leaves. While young caterpillars feed on the leaves and stems, mature caterpillars are the most destructive: they drag the felled plant back to their burrows to consume during the day.

They generally attack plants during the early growing phase. They get their name from their habit of chewing (cutting) away at the base of seedling stems, which eventually fall over.

Cutworms are considered the second-worst pest of maize.

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