Brian J. Lang

Sex Pheromone of the Soybean Aphid, Aphis glycines Matsumura, and Its Potential Use in Semiochemical-Based Control

Abstract The newly invasive soybean aphid, Aphis glycines Matsumura, has seriously threatened soybean production in North America, after having spread to >20 states in the United States and several southern provinces of Canada. Control of A. glycines has focused on applications of insecticides, which are not a long-term solution to soybean aphid pest management. In autumn, soybean aphids start producing alate females (gynoparae) that search for their overwintering host plants, the common buckthorn, Rhamnus cathartica. The gynoparae then produce pheromone-emitting wingless female offspring (oviparae) that attract male aphids. In this study, we report the chemical identification of the soybean aphid sex pheromone using gas chromatography–electroantennogram, gas chromatography–mass spectrometry, and nuclear magnetic resonance spectroscopy. Behavioral activities of males and gynoparous females in the field were also characterized. The potential applications using formulations containing specific soybean aphid pheromone compositions for reducing overwintering populations are discussed.

Foliar Fungicides in Alfalfa Production: A Five-Year Summary

and Implications Four years of research with foliar fungicides in alfalfa production indicate that the best chance for profitability is with an application in spring to first crop growth at a six to eight inch canopy height. Fungicide applications to later crops during the season are of questionable economic value, and highly dependent on crop yield potential and environments more conducive for disease development.