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
When fed to larvae of tobacco hornworm, Manduca sexta (L.), cyromazine strongly inhibited normal growth and development. Depending on the dose or period of feeding, symptoms were cuticular melanization, swellings in intersegmental regions,cuticular lesions, rupture of the body wall, and death. At >10 ppm, cyromazine in the diet initiated symptoms in fifth instars, whereas >20 ppm induced symptoms which led to death during the instar or at molting. The ratio of chitin to larval body weight in both cyromazine-exposed and control fifth instars increased slightly from ecdysis to 42 h. However, this ratio did not differ between the two groups, indicating that cyromazine had no immediate or direct effect on chitin production. When cyromazine was ingested by fifth instars, it was excreted rapidly, and a small amount (<5%) was metabolized to melamine. The amount of cyromazine found in the hemolymph remained relatively constant during the feeding period, whereas the amount present in the body wall increased with time and was localized in the KOH-soluble fraction. Cyromazine may inhibit growth or expansion of the body wall (or both) sufficiently to prevent normal internal growth, producing the observed symptoms and leading to abnormal development.
Document Type: Research Article
Publication date: February 1, 1989
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.