If you are experiencing problems downloading PDF or HTML fulltext, our helpdesk recommend clearing your browser cache and trying again. If you need help in clearing your cache, please click here . Still need help? Email email@example.com
Three resistance management strategies for field-sprayed commercial formulations of Bacillus thuringiensis Berliner subspecies were tested in field cages during the dry and rainy seasons of 1995 in Honduras. A local field population of Plutella xylostella (L.) with a 21-fold resistance to B. thuringiensis subsp. Kurstaki (Javelin), but no resistance to B. thurillgiensis subsp. Aizawa (Xentari), was selected for 5-6 generations with 16 field applications of a high (1.12 kg/ha) or low (0.3 kg/ha) dose of Javelin, a high or low dose of Javelin in the presence or absence of a refuge (25%), and Xentari (1.12 kg/ha). Resistance to Javelin increased ≍1.9-4.4 times, but was significant only with the 1.12 kg/ ha rate of Javelin irrespective of the presence or absence of a refuge. Field selection with Javelin at 0.3 kg/ha or Xentari did not cause a significant increase in resistance to B. thuringiensis subsp. Kurstaki, nor did P. xylostella selected with Xentari evolve resistance to B. thuringiensis subsp. aizawai. During the same period, the LC50 of Javelin in P. xylostella left un selected did not decrease. Although the rate of resistance increase was lower for lower doses of Javelin, a smaller proportion of marketable cabbage was produced in comparison with higher doses of Javelin or Xentari. Our data suggest that the deliberate inclusion of a refuge may reduce the proportion of marketable produce, and may affect use of this resistance management strategy in both sprayed B. thuringiensis and transgenic crops expressing B. thuringiensis toxins.
Document Type: Research Article
Publication date: December 1, 1997
More about this publication?
Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.