The Use of Selective Enrichment for the Isolation of Species-Specific DNA Probes for Insects

The identification of insects and other invertebrates is often extremely difficult if not impossible to achieve when attempted by traditional methods. There are several reasons why these difficulties are encountered. They may be owing to the presence of species complexes where individuals of several closely related species are morphologically indistinguishable. The species may be too small to identify easily without slide mounting or internal examination, thereby making identification extremely time consuming and labor intensive, or it may be that immature stages including eggs need to be identified. In this latter instance very few identification keys exist for juveniles and therefore often the only course is to attempt to rear the juvenile to the adult stage. Occasions also may arise where large numbers of individuals need to be screened, and, should difficulty in identification be experienced, the work may be rendered impracticable.