Comparison of water trap pans and leaf counts as sampling techniques for green peach aphids on potatoes

Green peach aphid populations were monitored by using water trap pans and by taking leaf samples in 38 southwestern Idaho potato fields from 1972 to 1975. Numbers of winged aphids in trap pans were correlated with populations of aphids developing in adjacent fields but were not predictive of future population trends. Trap pan data are, however, useful in alerting growers to the possibility of damaging field populations which exist in a field at the time of sampling.