Melanitis leda ismeneinsect
The greenhorned caterpillar rest on the undersides of leaves, parallel to the midrib, and feed on the leaves mostly at night. Feeding takes place along the leaf axis and large patches of tissue are removed, including the slightly harder veins. The damage is similar to that caused by the rice skipper and the green semilooper, so it is essential to detect the caterpillar to differentiate these species. The larvae can also feed on a large series of alternate hosts that may help to complete their life cycle and support their continuous development in the field.
The symptoms on leaves are usually caused by the caterpillars of the greenhorned caterpillar, Melanitis leda ismene but other species of the genus Mycalesis can be involved. These insects are found in all rice environments and they are most common in rainfed areas. Adults are large golden brown butterflies with characteristic eyespots on the wings. Notably, they are not attracted to light traps. Females lay shiny, pearl-like eggs singly on in rows on rice leaves. The larvae blend easily with the rice foliage because of their yellow green color and their body covered by small and yellow bead-like hairs. They have two prominent brown horns on their head that give them their common name. They feed on alternate hosts that may also support their continuous development in the field. Pupation occurs on the leaves. Greenhorned caterpillars are minor pests of rice. Their potential severity is generally too low to cause yield loss.
Natural enemies of the greenhorned caterpillar include chalcid wasps (Trichogramma species) and two species of tachinid flies that parasitize the larvae. Some species of vespid wasps prey on the larvae. Since this pest usually occur in low number and the pressure from beneficial insect is high, the plant can recover from the feeding damage by itself.
Always consider an integrated approach with preventive measures and biological treatments if available. There are no chemical control measures that target specifically Melantis leda ismene. Broad-scale insecticides can kill the pest, but at the same time their natural enemies. Accordingly, it is only recommended to spray these kinds of insecticides in very severe infestation cases.