Population genetic structure of the sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), in the southern United States

The sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), is a pest of sugarcane, corn and rice in the southern United States. In sugarcane, larvae feed on the apical meristem of developing stalks before above-ground internodes are present causing a condition known as a deadheart. Larval feeding in the stalk decreases the sugar content of plants and reduces biomass. This stem borer has a native distribution throughout the Caribbean, Central America, and northern areas of South America. D. saccharalis was first detected in Louisiana in the 1850s, and subsequently became a pest in Texas and Florida sugarcane. The objective of this study is to explore the population genetic structure of D. saccharalis collected from sugarcane in Texas, Louisiana and Florida. D. saccharalis larvae were collected from sugarcane in the three states throughout the growing season, mainly June-October. Larvae were reared on artificial diet until adult moths were obtained. Male adult moths were used for DNA extraction and amplified fragment length polymorphism (AFLP) genetic analyses. Using the genetic software Structure 2.2 was used to group individuals of similar genotypes. Genetic differentiation among populations was found suggesting that more than one strain of the sugarcane borer may be present in the United States. Management implications will be discussed.