Sweet Sorghum Stem borer

(Chilo partellus)

Symptoms

• The first indication of stem borer infestation is the appearance of small elongated windows or round holes due to feeding by the young larvae. These damage symptoms on the leaves appear in 15 to 25 days old crop.

• The third-instar larvae migrate to the base of the plant, bore into the shoot, and damage the growing point resulting in the production of a deadheart in 25 to 45 days old crop. Normally, two leaves dry up as a result of stem borer damage, while only one leaf dries up due to shoot fly damage.

• Stem borer larvae also feed inside the stem and cause extensive tunneling, which is not apparent unless we split open the stems.

• Heavy damage in the stems and peduncle result in peduncle breakage or partial seed set.

• Extended period of drought and poor plant growth result in greater damage by the stem borers.

• Spotted stem borer, Chilo partellus is important in the rainy season crop, while pink stem borer, Sesamia inferens is predominant in the postrainy season crop.

  

  Symptoms on young young seedling stem