Diurnal Sampling of the Insect Complex of Alfalfa

The appearance of the alfalfa weevil, Hypera postica (Gyllenhal), in Michigan in 1966 (Dowdy 1966) necessitated intensive testing of methods for its control. There is a con~plex of insect pests in alfalfa, and the effects of control measures for alfalfa weevil on these other pests needed to be considered. An efficient sampling method that measures as many species of the complex as possible was needed. Preliminary tests of the author showed that 20 sweeps with an insect net of 15 in. diam., a standard sampling tool for alfalfa, was satisfactory for sampling the insect complex. A means of separating the insects from the plant debris collected in the net, and information on the time of day that samples should be made were needed. Satisfactory answers to these two problems were found and are summarized here