Cluster caterpillar








Spodoptera litura

tobacco cutworm / cotton leafworm


Caterpillars are the larvae of a moth. The upper wings are mostly mid-brown with a crisscross pattern in darker brown and white with the lower wings white with darker edging and veins. They are nocturnal and are quite strong fliers. Newly hatched larvae are translucent and have black heads. Young larvae are pale green and cream. Older larvae become much darker with black triangles running along the length of their bodies on both sides and brighter stripes. Although they all hatch together they do not remain in a cluster tending to be solitary when they are older.

Adult size: 30-38 mm

Out and about

They are most active during spring through to summer and autumn. This caterpillar lives in subtropical, tropical and temperate regions of South and East Asia and Oceania. In Australian it is concentrated on the east coast and presently doesn’t seem to be a major pest in Western Australia. An almost identical species (Spodoptera littoralis) is a pest species native to Africa and Israel and is found throughout Mediterranean Europe.

Reproduction and Life cycle

The female moth lays up to 300 eggs in a cluster which are then covered with scales from her body. The eggs take 2 to 7 days to hatch. In summer or during warmer conditions it takes about 1 month from egg to adult and up to 2 months in cooler conditions. They will reproduce all year round.

To deter

Plant nearby or bruise a few shoots and leaves then strew around. Alternatively, squeeze juice and smear on plant stems. Amaranthus (cutworm) / Artimisias- daisy family (cabbage butterfly and caterpillar) / Borage (tomato and cabbage worm) / Dill (cabbage moth) / Feverfew (moths) / Hyssop (aroma confuses cabbage white butterflies) / Mint (cabbage moth and caterpillars) / Oregano (cabbage butterfly) Rosemary (moths) / Sage (cabbage moth) Spearmint (cabbage caterpillar) / Tansy (cabbage butterfly, moths) Wormwood (cabbage butterflies, moths) Land cress (Barbarea vulgaris), belonging to the mustard family, can be planted near brassicas as a ‘trap and kill’ plant. Moths and butterflies are attracted to this plant, favouring it over brassicas, and lay their eggs on it. When the larvae hatch and begin to eat it they will actually be poisoned and die. Also known as winter rocket, bittercress, herb Barbara, and upland cress.

To control

- Bacillus thuringiensis (Bt) is available commercially. It is a bacterium which attacks the digestive system of caterpillars. It only affects caterpillars and is therefore harmless to other animals. There is a picture of a dead caterpillar which was sprayed with Bt in the photos below. - Spinosad is another bacterium available commercially. It may have an effect on newly hatched larvae when sprayed on the eggs as many larvae eat their egg shells. - Sift flour over leaves will kill caterpillars as it blocks their breathing pores and they suffocate. - Sprinkle pepper on the leaves in the morning when they are still moist will deter - A garlic tea laced with pepper as a spray will help - Molasses spray - Neem oil spray - Place cardboard collars around seedlings as a physical barrier for cutworm - Collect dead caterpillars after treating and blend them up then use this as a spray on other live caterpillars - Pieces of raw potato and carrot will trap wire worm - Keeping area clear from weeds will help with cutworm in particular as this eliminates areas for them to shelter - Lightly digging the soil surface can disturb pupae and expose the cutworms for birds and other predators

Plants to repel

Plants to attract


Some ground beetles / Lacewings / Tachinid flies / Parasitic wasps / Assassin bugs/ / Robber flies
Why they are a Pest
The larvae can completely defoliate plants attacking newly planted seedlings through to larger plants. Potato and cabbage crops are particular favourites of these caterpillars although they feed on a wide variety of plants.