Spodoptera litura

Spodoptera litura (Fabricius, 1775)
(one synonym : Prodenia tasmanica)
Cluster Caterpillar
AMPHIPYRINAE , NOCTUIDAE

Don Herbison-Evans ( donherbisonevans@yahoo.com )
&
Stella Crossley

(updated 21 August 2008)

egg mass with recently hatched baby Caterpillars

The eggs of this species are normally laid in an irregular furry mass on the underside of a leaf of a foodplant.

Initially, the Caterpillars are a translucent green with a dark thorax.

first or second instar

The young Caterpillars are smooth-skinned with a pattern of red, yellow, and green lines, and with a dark patch on the mesothorax. They initially only eat the flesh of their food leaves, leaving the veins intact.

third instar
(Photo: courtesy of the Macleay Museum, University of Sydney)

Later, as they grow, they eat whole leaves, and even flowers and fruit. They become brown with three thin yellow lines down the back: one in the middle and one each side. A row of black dots run along each side, and a conspicuous row of dark triangles decorate each side of the back.

penultimate instar, lateral view
(Photo: copyright Lyn Finn,
Hunter Region School of Photography in Newcastle,
Macquarie Hills, New South Wales)

They are an international pest and eat nearly any herbaceous plant, including :

Elephants Ear ( Alocasia macrorrhizos, ARACEAE ),

Lettuce ( Lactuca sativa, ASTERACEAE ),

Cabbage ( Brassica oleracea, BRASSICACEAE ),

Horsetail She Oak ( Casuarina equisetifolia, CASUARINACAE ),

Beetroot ( Beta vulgaris conditiva, CHENOPODIACEAE ),

Peanuts ( Arachis hypogaea, FABACEAE ),

Geranium ( Pelargonium x zonale, GERANIACEAE ),

Leek ( Allium porrum, LILIACEAE ),

Cotton ( Gossypium hirsutum, MALVACEAE ),

Banana ( Musa acuminata, MUSACEAE ),

Fuchsias ( Fuchsia species, ONAGRACEAE ),

Strawberry ( Fragaria ananassa, ROSACEAE ),

Tomatoes ( Lycopersicum esculentum, SOLANACEAE ), and

many other garden plants.

penultimate instar, dorsal view
(Photo: copyright Lyn Finn,
Hunter Region School of Photography in Newcastle,
Macquarie Hills, New South Wales)

The last instar is very dark, with four prominent yellow triangles on the mesothorax.

last instar
(Photo: courtesy of the Macleay Museum, University of Sydney)

When disturbed, the Caterpillar curls into a tight spiral withe the head protected in the centre.

defensive posture

The Caterpillar burrows into the soil below the plant for several centimetres and there pupates without a cocoon. As it does so, it produces a quantity of fluid, and will drown in this if it pupates in captivity in an empty glass jar. It will pupate successfully if 0.5 cm. of sand is provided in the container. The duration of the pupal stage in January in Melbourne is three weeks, but Caterpillars that pupate at the end of summer emerge the following spring.

(Photo: courtesy of the Macleay Museum, University of Sydney)

The adult moth is brown with a complex pattern of cream streaks criss-crossing the fore wings. The hind wings are silvery white. It has a wingspan of about 4 cms.

Male
(Photo: courtesy of Merlin Crossley)

Female
(Photo: courtesy of Nick Monaghan, Tewantin, Queensland)

The males but not the females have a blue-grey band from the apex to the inner margin of each fore wing. The pheromones of this species have been elucidated.