Use of cryptic species for biological control of weeds

Behavioral experiments have revealed that some species of insects previously thought to attack a range of plant species really consist of multiple biotypes that each have more restricted host plant specificity. Molecular genetic tools enable us to confirm that such biotypes are reproductively isolated. Recent examples include Psylliodes chalcomera (Chrysomelidae), Ceutorhynchus assimilis (Curculionidae) and Trichosirocalus horridus (Curculionidae). However, it is critical to develop methods to confirm the identity of live insects before releasing them as classical biological control agents. The existence of stable biotypes or cryptic species may greatly increase the number of prospective biological control agents available; however, it also creates new challenges for the governmental regulation of such agents.