Dietary effects of phytoecdysones in the leek-moth,Acrolepiopsis assectella Zell. (Lepidoptera: Acrolepiidae).

Incorporation of certain phytoecdysones (ecdysterone, polypodine B, and ponasterone A) into a semisynthetic artificial diet induces pathophysiological effects in larvae of the leek-moth (Acrolepiopsis assectella Zell., Acrolepiidae). The effects include lethality of the newly hatched, first-instar larvae; special ecdysial failures associated with the appearance of larvae with two head capsules; and developmental anomalies during metamorphosis. The effective range of dietary ecdysteroid, as evaluated by larval mortality, varies from 25 to 250 ppm. The EC50 value is 100 ppm for polypodine B and 130 ppm for ecdysterone. The dietary effects of the phytoecdysones are similar to the previously observed effects caused by the dried flowers, but not leaves, of the leek plant. However, the active compound of the leek flowers is a saponin.