Study On Diversity Of Spider And Its Control Effect On Aphis Gylcnies Matsumura In Soybean Fields In Xiuyan

Study this experiment selected soybean field in Xiuyan County of Liaoning Province and Shenyang Normal University indoor laboratory as the research location. Using pitfall traps and directing searching method to collect spiders. It aims to explore control function of spiders on aphids in two aspects-field survey and indoor observation. The main findings are as follows:1. The total number of soybean field spiders are 5109, the adult spiders are 3627, belonging to 62 species, 36 genera and 15 families. Among them, ground dwelling spiders has been collected were 4527 heads, the number of adult spiders are 3312, belonging to 38 species, 23 genera and 11 families, accounting for 73.2% of the total number. Spiders dwelling over the ground are 582 heads, 315 adult spiders, belongs 27 species and 8 families.2. The result showed, Lycosidae and Linyphiidae were ground dwelling dominant families; Alopecosa albostriata, Pardosa chionophila, P. hedini, Hylyphantes graminicola and Erigone koshiensis were dominant species. Spiders dwelling over the ground dominant families are Theridiidae and Araneidae, P.cespitum and E. tricuspidata are dominant species.3. The results showed that the number of species, Margalef species richness(Dmg) and ShannonWiener’s diversity index(H′) were descended from the edge to the interior of soybean field, which indicated that ground-dwelling spiders were affected obviously by edge effect. The community similarity analysis also confirmed the above results. Our finding also indicated that the intercrop of soybean and corn can significantly improve the Pielou evenness index(J) while has little effect on spider diversity and abundance.4. The result of dynamic analysis of the dominant species showed an obvious dynamic change of time to ground-dwelling spiders in soybean field. Dominant species in July are A.albostriata, H.graminicola and P.chionophila; dominant species in August are H.graminicola, E. koshiensis and N. oidedicata. In July the largest population is A.albostriata, while in the August is H.graminicola.5. Dynamic system of soybean aphid and spiders community survey found that the number of soybean field spiders and relative stability of soybean aphid population dynamics is certain to follow, but the peak of soybean aphid in soybean aphid control function is limited. The result of Correlate showed that, when A. gylcnies immigrate in the early stage, the spider has obvious control effect on them; when A. gylcnies occurrence reach the peak, control function of spider on aphid is not obvious; when Aphis gylcnies immigrate in the second period, Web building spider has some control function on aphids.6. Under the lab conditions, the soybean fields dominate species(E.tricuspidata) predation function on Aphis gylcnies showed, the number of Aphid Misumenops tricuspidatus preyed is determined by its density, It fitted to Holling-II model well. The predatory functional response models is respectively: Na = 0.1742Nt/(1+0.0146Nt).