[Effects of herbicides on diversity indices of cotton field arthropod community].

This paper studied the differences of the diversity, abundance and evenness of arthropod community and sub-community in cotton field among treatments haloxyfor-k (A), paraquat (B) and contrast (CK). The results showed that in the diversity of phytophagous sub-community, tA-CK = 3.099 and tB-CK = 2.449 (t > t0.05 = 2.228), the difference being significant, and in the diversity of predatory sub-community, tA-B = 2.260 and tA-CK = 2.377 (t > t0.05 = 2.228), the difference being also significant. In the arthropod community and sub-community, no significant difference was found for A-CK, B-CK and A-B. The abundance of arthropod community tA- CK = 4.359, and that of phytophagous sub-community tA-CK = 2.963, the effect being all significant (t > t0.05 = 2.228). No significant difference was found in the evenness of arthropod community and sub-community for A-B, A-CK and B-CK. The biodiversity had the same change trend for treatments haloxyfor-R (A) paraquat (B) and contrast (CK).

[Seasonal dynamics of arthropod community diversity, evenness and relative stability in peach orchards].

This study showed that the diversity index of total arthropod community in peach orchards was significantly correlated to the diversity index of both phytophages (r = 0.9480) and predators sub-communities (r = 0.7855), and the two sub-communities were correlative (r = 0.6741). It was also significantly correlated to the evenness index of total community (r = 0.7870), but not correlated to the evenness index of both sub-communities. The diversity index (H') of total community was significantly correlated to the ratio of predators individuals (Sd) and phytophages individuals (Sz) (r = 0.8112) and of species (Ss) and individuals (Si) (r = 0.9188), but not correlated to the ratio of predators (Spl) and phytophages (Szl).

[Clustering analysis and optimal cut-apart of arthropod community in megranate orchard].

Based on the principles of community ecology and by the method of fuzzy clustering, this paper studied the temporal and quantitative dynamics of the arthropod community and sub-community in megranate orchard, aimed to utilize natural enemy resources for pests control. The results showed that both of total community and natural enemy sub-community could be grouped into 4 clusters, and non-natural enemy sub-community could be grouped into 3 clusters. This clustering reflected the complexity of the community structure. The optimal cut-apart could divide the total community and sub-community into 3 stages, i. e., April-August, September-October, and November.