Primary reliance on synthetic insecticides for control of diamondback moth has usually failed because of insecticide resistance and/or reduction of natural enemies by insecticides. Insecticide resistance has also been more recently documented with biological insecticides such as Bacillus thuringiensis and some growth regulators. Insecticide resistance management programs must be implemented and...

The susceptibility of two New Zealand populations of diamondback moth, Plutella xylostella, to insecticides from three classes was compared with the susceptibility of a standard North American population (Geneva 88) in laboratory assays at the New York Experiment Station during 1993. Leaf dip assays showed that the New Zealand populations had developed moderate resistance to permethrin compared...

The shrimp Leander tenuicornis is abundant in southeastern Queensland intertidal marsh pools and was chosen as an indicator species for toxicological studies with pesticides. Acute toxicity to this crustacean of temephos and 3 pesticide compounds under evaluation for registration in Australia (Bacillus thuringiensis var. israelensis, s-methoprene, and pyriproxyfen) was tested in 96-h laboratory...

The insecticidal activity of the delta-endotoxins of 14 Bacillus thuringiensis strains belonging to 12 subspecies was determined against Pieris brassicae, Heliothis virescens, and Spodoptera littoralis. Larvae of P. brassicae were highly susceptible to purified crystals of strains of B. thuringiensis subsp. thuringiensis and B. thuringiensis subsp. morrisoni, whereas H. virescens responded best...

The long-term usefulness of Bacillus thuringiensis Cry toxins, either in sprays or in transgenic crops, may be compromised by the evolution of resistance in target insects. Managing the evolution of resistance to B. thuringiensis toxins requires extensive knowledge about the mechanisms, genetics, and ecology of resistance genes. To date, laboratory-selected populations have provided information...