Field tests were conducted in 1983 and 1984 to determine effect of late-season feeding damage by adults and nymphs of the threecornered alfalfa hopper, Spissistilus festinus (Say), on yield of soybeans, Glycine max (L.) Merrill. Damage and subsequent yield reduction caused by S. festinus were partitioned into damage caused by nymphs versus adults by controlling the second generation on soybeans at different stages in its development. In 1983, yield reductions averaged ca. 342 kg/ha, with the nymphs responsible for 46.4 ± 16.7% (±SEM) of the reduction. In 1984, yield reduction of 134.5 kg/ha occurred although S. festinus populations reached only 60% of the current threshold, indicating a need to modify the threshold level. Proper timing of control measures, possible effect of reinfestation populations, cause of yield reduction, and the need to modify sampling strategy and the threshold to account for damage by nymphs are also discussed.
Document Type: Research Article
Publication date: April 1, 1987
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.