Libraries at University of Nebraska-Lincoln


Document Type


Date of this Version



Thesis (M.S.)—University of Nebraska—Lincoln, 1971. Department of Entomology.


Copyright 1971, the author. Used by permission.


The purposes of this study were to determine the relative abundance and seasonal occurrence of spiders in alfalfa and to determine the effects of an insecticide (ULV malathion) on spiders in that environment.

A wide-area spray program (“Project WASP”) was conducted in Dawson County, Nebraska, in 1968, 1969, and 1970. ULV malathion was aerially sprayed on one-half of the area, and the other half of the area was designated as control.

Spider collections were made by sweeping in 1968 and 1969, and by taking drift samples in 1970. Spiders were significantly correlated with plant height in prespray and postspray samples. Crab spiders (Thomisidae) were the most abundant of the spider groups in alfalfa. Tetragnathidae were the second most important group of spiders collected in alfalfa.

Advisors: K. P. Pruess and E. S. Raun