Studies on the Arthropod Fauna of Alfalfa: V. Spiders (Araneida)

The spider fauna of alfalfa was studied at Ithaca, N.Y., in three experimental plots and in nearby fields during 1966–69. As part of an overall study of the arthropod fauna of alfalfa, the spider populations in the study plots were recorded weekly during visual examination of the terminal 6 in. of five stems for 100 plants in each of the plots. Additional information was obtained from sweep-net and pitfall trap collections in the study plots and from sweeping several commercial plantings. The spider fauna of alfalfa was found to consist of 78 species, 10 of which were collected only from the ground layer. Tetragnatha laboriosa Hentz and Dictyna volucripes Keyserling were the most abundant species found in the weekly samples. Notes on the seasonal occurrence, location on the plants, and feeding habits are given for the common species.