Effects of the oasis agro-landscape complexity on the population dynamics of cutworms

Abstract

The relationship between pest population dynamics and habitat management in landscape scale is full of challenge and interest. To understand the effects of oasis agro-landscape complexity on the population dynamics of cutworms, intelligent telemetry light traps were installed in three different agricultural landscapes in the Tarim Basin, North-Western China-complex landscape A (mixture with cotton and greenhouses), complex landscape B (mixture with cotton and grains), and a simple landscape (mostly cotton). GPS was used to investigate the agricultural landscape structures in a 2 km radius around the light traps with the support of Google Earth maps. The landscape diversity indexes of the two kinds of complex agricultural landscapes (complex landscapes A and B) were significantly higher than that in the simple landscape. Different species of cutworms showed different responses in the cropping landscapes. There were no significant differences in the population numbers of Agrotis segetum among the three different landscapes. In contrast, the population sizes of Amathes c-nigrum and Agrotis exclamationis in complex landscape B were larger than that in complex landscape A and the simple landscape. The population growth rate of cutworms was higher in complicated landscape B than in the other landscapes. The population dynamics of pests in complex agricultural landscapes did not show large fluctuations, compared with those in the simple landscape due to crop harvest. The results of this study can be implemented to maximize the biological pest control in cropping landscape.