The clover leaf weevil (Hypera punctata) is a sporadic pest of alfalfa (Medicago sativa L.) in Nebraska. Economic outbreaks tend to occur during years with mild winters followed by dry springs. A 2 year study was initiated in 2001, which simulated adult clover weevil injury on alfalfa. The general objectives are to determine the effects of adult clover leaf weevil feeding on alfalfa and to develop appropriate economic thresholds. Experimental design was a randomized complete block with four replications and three treatments. Final leaf area index (LAI) was used to determine the treatment levels. A LAI-2000 plant canopy analyzer was used to measure leaf area index. The treatments consisted of a control (LAI=4), a mid-level defoliation (LAI=2), and a high level defoliation (LAI=1). The defoliation occurred over a period of ten days to simulate adult clover leaf weevil feeding. Because adult clover leaf weevils tend to feed from the bottom of the plant up, lower leaflets were removed first. Plant samples were taken weekly from the beginning of the defoliation through the second cutting. Growth parameters were recorded. Plots were harvested at the end of the first and second growth cycles. In addition to plot yields, nutrient quality also was assessed. Results from the 2001 growing season will be presented.
Species 1: Coleoptera Curculionidae Hypera punctata (clover leaf weevil)
Keywords: alfalfa, LAI
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA