SAMPLING PROGRAM DEVELOPED FOR POTATO LEAFHOPPER NYMPHS, EMPOASCA-FABAE (HOMOPTERA-CICADELLIDAE), ON ALFALFA

Populations of potato leafhopper nymphs were sampled in two alfalfa fields throughout the summers of 1976 and 1977 in Montgomery County, Virginia. A dichlorvos-carton sampling method was used to collect nymphs from 3-stem alfalfa bouquets. Instars were based on head capsule measurements. The spatial distribution of nymphs generally fit the negative binomial model. Based on this distribution pattern optimum sample sizes were computed. The nymphal population can be reliably estimated within 20% c.v. during most of the alfalfa growth period. Although most variation was shown to be between samples and not between areas in the field, samples should be taken at random over the entire area of the field under study. © 1979, Entomological Society of Canada. All rights reserved.