Chilo sacchariphagus indicus
The caterpillars first feed on the young rolled leaves causing shot holes. During the early stage of plant growth, they feed on growing points producing dead hearts. Internodes are constricted and shortened with a number of boreholes. When entering the stems and feeding on the inside they block the entry holes with excreta. The larva moves up within the stem tissues, causing redness and damaging the nodes. Plant stalks are weakened and are easily broken by the wind. Reduced growth is among the other symptoms.
Damage to the plant is caused by the larvae of Chilo sacchariphagus indicus. The adult moths are small, straw-coloured, with white hind wings and a dark line on the margin of the forewings. They remain active throughout the year, with about 5-6 generations being completed in one year. Plants are normally affected from the early stage until the harvest. The larvae bore into the nodal region of the plant, enter the stem and tunnel upwards. Waterlogged conditions around the cane shoot favours the build-up of the internode borer, so does high dosages of nitrogen as well as low temperatures and high humidity. Other hosts are maize and sorghum.
For this pest, no biological pesticides are known, but parasitoids are able to reduce the incidence of internode borer. Inundative release of Trichogramma australiacum @ 50,000 parasites/ha/week. Release the egg parasitoid Trichogramma chilonis @ 2.5 ml/ha 6 times from the 4th month onward at 15 days intervals. Larval parasitoids are Stenobracon deesa and Apanteles flavipes. For the pupal stage, the parasitoids Tetrastichus ayyari and Trichospilus diatraeae can be released.
Always consider an integrated approach with preventive measures together with biological treatments, if available. Spray monocrotophos, a contact insecticide, fortnightly during the growing seasons. Apply carbofuran 3G granules on the soil at 30 kg/ha if the damage is severe.