The sugarcane borer (SCB), Diatraea saccharalis, is the primary pest of sugarcane in Louisiana. Management of the SCB is achieved by scouting for larval infestations from mid-May through late-August to effectively time insecticide applications. Scouting requires pulling back leaf sheaths of the top 3-4 internodes and looking for the presence of larvae which have not yet bored into the stalk. The LSU AgCenter recommended economic threshold is to apply insecticides when more than 5% of stalks have larvae feeding in the leaf sheaths. This threshold is a good starting point but other factors should be considered.
Sugarcane borer larva feeding in the leaf sheath.
Sugarcane varieties differ greatly in their susceptibility and response to SCB infestations. Susceptible varieties are often 5- to 10-fold more injured than resistant varieties if not protected. Damaging SCB infestations generally occur first in fields of susceptible varieties, and these fields should be closely monitored. Varieties also differ in their tolerance to SCB injury. Tolerant varieties may experience significant yield impacts even under low pest pressure and may require greater protection with insecticides. This guide provides information to help determine how SCB management strategies should differ among varieties.
The LSU AgCenter and the LSU College of Agriculture