Contrasting arthropod communities in wolfberry orchards of different management regimes in Northwestern China.
Résumé
The arthropod community structure in wolfberry orchards of different management regimes were monitored from April to August in 2012 at Ningxia Hui Autonomous Region of Northwestern China. The three different management regimes included (1) orchard free of pesticide, (2) organic orchard, and (3) conventional orchard. Totally, 167 species (4 classes, 27 orders, and 76 families) contained 61 natural enemy species and 106 pest species were recorded in the experiment. The species richness of the orchard free of pesticide, organic orchard with biological control and conventional orchard with chemical control was 61, 30 and 23 species, respectively. Moreover, the corresponding coefficients in the orchard free of pesticide, conventional orchard and organic orchard were 0.864, 0.684 and 0.733, respectively. The different modules of pests varied in their responses to environmental factors depending on different feeding types. The linkage between arthropod community and environmental factors indicated that vegetation diversity, plant coverage, pesticide application and irrigation times exerted detectable contrasting effects on arthropod community and population dynamics. Finally, we suggest that habitat management (i.e. increase in plant cover and diversity) may serve as effective tactics for preventing pest population from reaching the economic injury level which minimizing the input of pesticides and fertilizers.