The golden twin-spot moth or tomato looper (Chrysodeixis chalcites) belongs to the family of Noctuidae. It is a tropical and subtropical species originating in the Mediterranean and northern Africa. The larva is highly polyphagous and feeds on plants of over 20 families, among them crops such as cauliflower, corn, crucifer, soybean, potato, strawberry, banana, sweet pepper and tomato but also chrysanthemum and geranium. An annual migrant from southern Europe, the golden twin-spot moth (Chrysodeixis chalcites) spreads to several northerly countries and is now one of the most frequently found pest species in greenhouses.
Life cycle and appearance of Golden twin-spot moth
The golden twin-spot moth or tomato looper (Chrysodeixis chalcites) is predominantly brown-gold with two conspicuous droplet-shaped white marks on the forewing that sometimes overlap each other. The hindwings are brown. The body is brown and hairy and, when at rest, the hairy dorsal plume is characteristically distinct. The antennae are long and thin.
The eggs are white to pale green, shiny, dome-shaped with 28 to 32 vertical ribs. They are deposited singly or in pairs throughout the crop, on the lower and upper surfaces of leaves. The caterpillar passes through 6 instars. It has a green head capsule and a yellowish-green body with a clear yellow longitudinal stripe on either side, and several less conspicuous longitudinal stripes dorsally.
The body is sparsely covered with a few stiff hairs. In older caterpillars, each segment has a clear black dot above the lateral yellow lines. There are three pairs of prolegs, instead of the normal five and therefore the caterpillar moves with the same looping motion as an inchworm (geometrid). The cocoon is usually attached to the underside of leaves within folded edges, on random objects and on tomato fruit, often in a bunch of ripening tomatoes, however, it can also be found in the soil. The pupa has a pale green body, with a dark brown ventral dorsal stripe, but the body can also be entirely brown.
The golden twin-spot moth (Chrysodeixis chalcites) is primarily a foliage feeder but it also attacks fruits such as tomato and sweet pepper. Older instars eat through the leaves, which make them appear skeletonized. The last two instars may eat the entire leaf except for the midrib or other large veins. On tomatoes, the golden twin-spot moth (Chrysodeixis chalcites) can completely defoliate young plants. Infestations on ornamental plants reduce their marketability.