SPIDER FAUNA AND INFLUENCE OF TRAPPING METHOD AND FIELD MARGIN ON SPIDER POPULATION DENSITY IN SUGAR BEET FIELDS

Experiments were carried out at the experimental farm of Sakha Agricultural Research Station in 2006/07 and 2007/08 sugar beet seasons. The spiders inhabiting the sugar beet  fields were surveyed, which indicated to the occurrence of 30 spider species belonging to Araneidae, Dictynidae, Dysderidae, Gnaphosidae, Linyphiidae, Lycosidae, Miturgidae, Philodromidae, Salticidae, Tetragnathidae, Theridiidae and Thomisidae. In all sugar beet plantations (August, September and October), the pitfall traps captured more spiders of families Lycosidae and Gnaphosidae (Ground-dwelling spiders) and Philodromidae and Salticidae (wandering spiders) than did D-vac machine which captured more linyphiids and araneids (orb-weaver spiders). Population density of spiders in the field margins were usually greater than that  inside the field for the seven considered families. Traps used inside the field captured less spiders than those used in the margins by 32.50-82.14 % overall spider families.