Identification of Tobacco Budworm and Corn Earworm (Lepidoptera: Noctuidae) during Early Developmental Stages by Polymerase Chain Reaction and Restriction Fragment Length Polymorphism

The identification of immature insects is often difficult or impossible. This can cause problems in situations where species-specific control programs are used. Heliothis virescens (F.), and Helicoverpa zea (Boddie) are 2 moths with somewhat overlapping host plant species. Where the 2 are found on the same crop, it can be useful to determine which species is present before the life cycle is complete and the damage is done. Early species identification also is imperative where 1 of the species has acquired insecticide resistance limiting the use of certain insecticides. Restriction enzyme cleavage of PCR-amplified segments (PCR-RFLP) of mitochondrial DNA provides an accurate method of differentiating these 2 species at any developmental stage from egg to adult. Portions of the 12S rRNA gene and the COI-COII junction both contain distinctive restriction sites.