Economic injury level of the sugarcane borer (Lepidoptera: Pyralidae) on sweet sorghum, Sorghum bicolor (L.) Moench

The sugarcane borer, Diatraea saccharalis (F.), reduced sweet sorghum sugar yield up to 46% in artificial infestation field trials. A significant relationship between D. saccharalis damage and yield loss indicated an economic injury level of 10% bored internodes. Stalk weight, percent sucrose, and total sugars were negatively correlated to D. saccharalis damage. Increased fiber content, resulting in less juice, was positively correlated to percent bored internodes. Information from damage levels, along with survival records, indicated that the economic threshold was reached when 5% of the sweet sorghum plants contained small D. saccharalis larvae in their leafsheaths