Molecular identification of the light brown apple moth (Lepidoptera: Tortricidae) in California using a polymerase chain reaction assay of the internal transcribed spacer 2 locus.

A molecular protocol using a hemi-nested polymerase chain reaction (PCR) of the internal transcribed spacer region 2 (ITS2) is reported for the diagnosis of light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), in California. This protocol distinguishes the light brown apple moth from other moths in California based on size differences of PCR amplicons that are visualized on agarose gels. The molecular diagnostic tool generated no false negatives based on analysis of 337 light brown apple moths collected from California, Hawaii, England, New Zealand, and Australia. Analysis of a data set including 424 moths representing other tortricid species generated correct identification for >95% of the samples and only two false positives. Of the 761 moths tested only fourteen produced no PCR amplicons and five generated inconclusive data.