Pheromone Chemicals

(Pink stem borer) – A serious pest more severe in Maize, other hosts include Ragi, Sorghum, Bajra, Wheat, Paddy and Sugarcane.

Life cycle :

The Life cycle is completed in 6-7 weeks with 4-5 generations in a year. Round pearl like yellowish eggs ranging 80-300 are laid in 2-3 longitudinal rows usually with in the sheaths of bottom leaves of young maize plant of two to three weeks old. As the time for hatching approaches, eggs become brown or shy grey.
Full grown larvae are stout smooth about 25 to 30 mm in length purplish pink on the dorsal side and white on ventral side. Newly hatched larvae remain in group behind the leaf sheath and begin chewing on the stem and epidermal layer of the sheath. Some migrate to neighboring leaf sheaths, while others penetrate the stem.
Moth is medium sized stoutly built having straw colored forewings with a mid longitudinal dark brown broad triangular streak. Hind wings are white.

Host plants :

Maize, Ragi, Sorghum, Bajra, Wheat, Paddy and Sugarcane.

Damage :

Whorl feeding of larvae results in rows of oblong holes in unfolding leaves unlike round shot holes produced by Chilo partellus. Later they bore in to central shoot resulting in the drying up of the growing point and formation of dead heart in young maize plant as a result of larval feeding some times the bottom internodes show circular ring like cuts.
Severe damage causes the stem to break. Severely infected plants due to stunting may appear to have some times the cob and tassel at one place.