In Australia, several species of cutworms can cause damage to vegetable gardens and other plants. Cutworms are the caterpillar stage of various noctuid moths. Here are some common cutworm species found in Australia and their visual descriptions:
- Black cutworm (Agrotis ipsilon)
The black cutworm has a smooth, plump body that is greyish-brown to black in colour. The caterpillar can grow up to 5 cm long and has a light stripe running along each side of the body. The skin appears greasy, and when disturbed, the caterpillar typically curls up into a C-shape.
- Variegated cutworm (Peridroma saucia)
The variegated cutworm is a plump, smooth caterpillar that can grow up to 4.5 cm long. It has a mottled appearance, with colours ranging from pale brown to black. A distinguishing feature is the presence of a series of irregular, pale, dorsal markings along the back.
- Brown cutworm (Agrotis munda)
The brown cutworm is a plump, smooth caterpillar that can grow up to 4 cm long. Its body colour ranges from pale brown to dark brown, often with a faint diamond-shaped pattern on the back. When disturbed, the brown cutworm also curls up into a C-shape.
- Dingy cutworm (Feltia jaculifera)
The dingy cutworm is a smooth, plump caterpillar that can grow up to 3.5 cm long. It is typically greyish-brown with a series of diamond-shaped markings along the back. The caterpillar's body may have a slightly pinkish hue.
- Armyworms (Mythimna and Spodoptera species)
Although not true cutworms, armyworms are closely related and sometimes cause similar damage in the garden. These caterpillars can vary greatly in colour and markings, but they usually have longitudinal stripes along their body. When disturbed, armyworms tend to move quickly and do not curl up like cutworms.
Control measures for cutworms:
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Monitoring: Inspect your garden regularly for signs of cutworm damage, such as severed seedlings or holes in leaves. Look for cutworms in the soil or under debris near affected plants.
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Physical control: Handpick cutworms found in your garden during the evening or early morning hours when they are most active. Dispose of them in soapy water or by squashing.
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Barriers: Create barriers around seedlings using cardboard or plastic collars, which prevent cutworms from reaching the plants.
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Cultural control: Keep your garden clean by removing plant debris and weeds, which can provide shelter for cutworms.
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Biological control: Apply beneficial nematodes to the soil to control cutworm populations. These microscopic worms parasitise and kill cutworm larvae.
By understanding the different species of cutworms in Australia and their visual characteristics, you can better target your pest control efforts and maintain a healthy vegetable garden.
