PrintSend to friend
Dark headed borer (DHB), Chilo poly chrysus(Meyrick)
Distribution: It has been reported from Kerala, Assam, West Bengal, Orissa and Tamil Nadu but it often assumes the status of major pest in Tamil Nadu and Kerala.
Description: The forewing is brownish ochreous with a raised dark metallic spot in the cell, a series of small black dots covered with golden scales. Female is paler with all metallic spots. Hindwings are whitish to dirty cream. Young larvae are greyish-white, with a distinctive dark-brown to black head and prothoracic shield. Fully grown final-instar larvae are 21- 25 mm long, creamy-white with five purplish-brown stripes (3 dorsal and 2 lateral) along the body. It is similar to C. auricilius.
Biology: Eggs are flat scale like and are laid in clusters overlapping each other on the lower or upper leaf surface in longitudinal overlapping rows, each cluster containing up to 80 eggs. Fecundity is around 488 eggs. Ovipositional period is 3 days. Egg period is 6 days in Kerala. Larvae feed for 23-36 days and there are 6 instars. Pupal period is 4 days. It pupates in the larval tunnel. No dormancy or diapause has been reported.
Host plants: Maize and sugarcane are the cultivated hosts apart from 33 other species being reported as alternate hosts.
DRR Technical Bulletin No. 59/2011, Rice stem borers in India: species composition and distribution