Reduced Insecticide Rates and Strip-Harvesting Effects on Alfalfa Weevil (Coleoptera: Curculionidae) Larval Populations and Prevalence of Zoophthora phytonomi (Entomophthorales: Entomophthoraceae)
Authors: GILES, KRISTOPHER L.; OBRYCKI, JOHN J.
Source: Journal of Economic Entomology, Volume 90, Number 4, August 1997 , pp. 933-944(12)
Publisher: Entomological Society of America
Abstract:In 1994 and 1995, the effects of reduced insecticide rates and harvesting on Hypera postica (Gyllenhal) larval populations and prevalence of the fungal entomopathogen Zoophthora phytonomi Arthur were evaluated in alfalfa strips. Insecticide and harvest treatments were timed with predicted 1st occurrence of Z. Photonomi to maximize combined mortality. In Chariton, IA (1995), Lorsban 4 E (chlorpyrofos) applied at 0.140, 0.280, 0.560, and 1.120 kg (AI)/ha and Pounce 3.2 EC (permethrin) applied at 0.112 and 0.224 kg (AI)/ha reduced peak H. postica densities by >41 % compared with control plots during an epizootic (>50% infection) of Z. phytonomi. Combined H. postica mortality was additive (insecticide and Z. pliytonomi) in plots treated with Lorsban and Pounce and was 7.5-25.3% higher than in control plots. In Ames, IA (1994 and 1995), Lorsban, Pounce, and harvesting (1994) reduced H. postica densities during an enzootic (<50% infection) of Z. phytonomi; however, because of low levels of Z. phytonomi, combined mortality with treatments was negligible. This study demonstrated effective integrated management of H. postica by combining predictable mortality from Z. phytonomi and reduced rates of insecticides. The critical components of this integration were predictable levels of H. postica mortality by Z. phytonomi, and predictable mortality of weevil populations from reduced insecticide rates and strip-harvesting.
Document Type: Research Article
Publication date: August 1, 1997
- 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.
- Editorial Board
- Submit a Paper
- Subscribe to this Title
- Information for Advertisers
- Visit this journal's homepage
- ingentaconnect is not responsible for the content or availability of external websites