Highly repetitive DNA sequence elements from Orseolia oryzae (Wood-Mason) discriminate between the Indian isolates and the Asian rice gall midge and the paspalum midge.

We described multicopy DNA clones isolated from a partial genomic library of Orseolia oryzae, based on reverse genomic hybridization, suitable for studying genetic variation in the Asian rice gall midge and other isomorphic species. Three clones produced monomorphic DNA band patterns between biotypes of O. oryzae but polymorphic patterns were produced between O. oryzae and O. fluvialis, the paspalum midge. These probes detect changes in the repetitive sequence structure between species and constitute the first genetic markers for distinguishing between field isolates of rice gall midge and related species of Orseolia. These will be useful in identifying and perhaps eradicating alternative hosts for this pest, and detecting early-season outbreaks of O. oryzae from light trap collections.