Chrysodeixis eriosoma (Green garden looper moth)
Species: C. eriosoma
Binomial name: Chrysodeixis eriosoma
Synonyms: Plusia eriosoma
Common name: Green garden looper moth (called green after the colour of the caterpillar)
Chrysodeixis eriosoma is a moth of the family Noctuidae and occurs throughout the tropical and subtropical regions of eastern Asia, Russia, USA, Hawaii and the Pacific islands as well as in Australia and New Zealand.
The adult moth is dark grey-brown, with bunched hairs on its head which look like a short pair of horns. Males have long orange hair-like scales on either side of the abdomen, which are distinctive for this species, and these are probably the origin of the scientific name, as in Greek, erion - wool, and soma - body. On each fore wing of males and females is a silvery figure of eight with the two halves separated, unlike the related species C. subsidens in which they are fused together. The absence of a tiny silver’s’ on the fore wings distinguishes it from another related species, C. argentifera. They all have a wingspan of about 3 cms. The chemical identities of the sex attractants (Pheromones) for this moth have been elucidated. Adult moths feed on flower nectar.
The moth lays her eggs on the underside of leaves. Damage is done to plants by the larvae. They feed on the underside of the leaf, making windows between the veins (young larvae leave the upper leaf cuticle and later instars make ragged holes). On tomato, larvae can chew into green fruits and can excavate legume pods. In heavy infestations, plants can be completely defoliated.
The larvae are green with the back the palest. It has a number of indistinct dorsal and lateral pale lines along the animal's length. They also sometimes have black dots along the sides. Some of their ventral prolegs are missing and this makes them move looper fashion, like the Caterpillars of Geometridae. They grow to a length > 4 cms. Caterpillars spin a silken cocoon attached to the underside of a leaf, and the brown pupa forms within this structure. The larvae are highly polyphagous (feeding on many different kinds of food). They feed on foliage and fruit of many field and vegetable crops, ornamentals and weeds. Its wide host range includes: chickpeas (Cicer arietinum), lucerne (Medicago sativa), maize (Zea mays), potato (Solanum tuberosum), sunflower (Helianthus annuus), soybean (Glycine max), tobacco (Nicotiana tabacum) - beans (Phaseolus vulgaris,) cabbages (Brassica oleracea), cucurbits (Curcurbita pepo, Cucumis sativus), peas (Pisum sativum), tomato (Lycopersicon esculentum) - many ornamentals, e.g. Coleus, chrysanthemums, dahlia, freesia, pelargonium, Tibouchina. On tomatoes the larvae can chew into green fruits and they can excavate legume pods.
In New Zealand C. eriosoma is considered as a sporadic pest of horticultural crops. Its occurrence is sporadic south of Christchurch, but is common from Blenheim (latitude 42°S) northwards in all horticultural areas.
Photographed mid March.