Abstract
Thuricides A, B, and C are the products based on the δ-endotoxin of Bacillus thuringiensis BERLINER. Effectiveness of these products on larvae of the diamondback moth, Plutella xylostella, the common cabbageworm, Pieris rapae crucivora, the cabbage armyworm, Mamestra brassicae, and the tobacco cutworm, Spodoptera litura were evaluated in laboratory and field tests. All products gave good control for the diamondback moth and the common cabbageworm, but their effectiveness on the cabbage armyworm and the tobacco cutworm were not enough in both laboratory and field tests. The common cabbageworm showed the remarkable lowering of feeding after the ingestion of cabbage leaves treated with Thuricide. Regression line between days after application and lowering of feeding was not parallel to that between days and mortality. Relation between the LC50's and days after application of Thuricide in the common cabbageworm and the diamondback moth was different from that of the cabbageworm and the tobacco cutworm. It was expressed by a straight line in the former two species and by intersected two straight lines in the latter two species.
