Description of EuropeanChamaespheciaspp. (Lepidoptera: Sesiidae) feeding onEuphorbia(Euphorbiaceae), and their potential for biological control of leafy spurge (Euphorbia esula) in North America
AbstractThe description of the tenChamaespheciaspecies associated withEuphorbiain eastern and south-eastern Europe is based on external adult morphology, male and female genitalia, and the structure of the egg chorion. These species can be divided into two groups according to the shape of the setae of the dorso-basal part of the valvae in the male genitalia. MostChamaespheciaspecies are associated with one species of host-plant and all are closely tied to one habitat type. The host-plant and the structure of the egg chorion are fundamental characteristics for the determination of a few species, and very helpful for the others. All species bore into the main root of their host-plant and overwinter as larvae. With the exception of two species which have an annual or biennial life cycle, all species are univoltine. The larvae of three of the eightChamaespheciaspp. investigated feed and develop in the roots of North American leafy spurge,Euphorbia esulasensu lato. Of these, the best candidate for the biological control of leafy spurge isC. crassicornis, because the larvae have a similar survival rate on the target weed and the European host-plant,E. virgata.
