Spider Populations of a Southeast Texas Rice Field

Abstract

Spider populations were studied in a rice field of the Texas A&M University Agricultural Research and Extension Center. Monthly collections were made from 2 March 1973 to 4 November 1973. A total of 752 specimens were collected representing 25 genera and 44 species from 10 families. Number of species collected each month varied from 8 to 19. Monthly and total species diversity was calculated using the formula H' = pi logb Pi 'c/N (N logo N I ni logo ni) derived from information theory. Monthly diversity ranged from 1.495 in October to 3.774 in November. Total diversity for the study was 2.472. The earliest published records of spiders in the United States originated in the nineteenth century. Kaston (1948) stated that most of these reports were lists of spiders found in specific areas. The reports dealt mainly with spiders from New England, the southeastern states, or the west coast (Fitch 1963). Surveys during the early twentieth century identified spiders found in a variety of habitats including forests, prairies, xeric dunelands, and desert communities. Branson (1966) published an account of spiders in Marshall County, Oklahoma near Lake Texoma. Dorris (1968) conducted a taxonomic study of spider fauna of Clark County, Arkansas, and Carpenter (1972) reported on jumping spiders of Wichita County, Texas. Recently, surveys have been published of spiders in specific field crops. Chant (1956) and Specht and Dondale (1960) reported on spiders in orchards. Whitcomb, Exline, and Hite (1963) compared spider populations in a pasture to those of a cultivated field. Whitcomb, Exline, and Hunter (1963) and Leigh and Hunter (1969) reported on spiders in cotton fields. Bailey and Chada (1968) studied spider populations of grain sorghums. Howell and Pienkowski (1971) surveyed 1 Present Address: Blinn College, 307 South Main, Bryan, Texas 77801.