Effects of Different Pest Management Strategies on the Community Structure of Arthropods in Cotton Fields

The objective of this study is to investigate the impact of different pest management strategies on arthropod community diversity in cotton fields, and to provide a theoretical foundation for establishing an eco-friendly cotton field management approach centered on ecological control.

Three management models—ecological control, no control, and chemical control—were established in cotton fields in Xinjiang. Six methods (visual inspection, Marshall net, sweep net, yellow sticky traps, basin-sweeping, and pitfall traps) were employed to systematically survey the species and abundance of arthropods in cotton fields. Differences in arthropod community composition among the three management models, structural and diversity characteristics of various arthropod functional groups, temporal changes in arthropod diversity indices, and the beneficial-to-pest ratio of the communities were analyzed.

Insect species richness and abundance varied significantly across management models: highest in no control fields (12 orders, 61 families, 85426 individuals), followed by ecological control fields (14 orders, 78 families, 75072 individuals), and lowest in chemical control fields (10 orders, 48 families, 41237 individuals). Hemiptera (Aphidae) and Thysanoptera (Thripidae) were the dominant groups across all three cotton fields. Carnivorous groups were most abundant in ecological control fields (34 families), followed by no control fields (23 families) and chemical control fields (20 families). Phytophagous groups were most abundant in ecological control fields (30 families), followed by no control fields (26 families), and least abundant in chemical control fields (19 families). The species richness of arthropods in cotton fields under ecological control remained at the highest level throughout the entire cotton growth cycle. The trends in diversity indices, concentration, and evenness were consistent across the three treatment groups, while dominance exhibited an inverse relationship with these three indicators. Moreover, the positive effect of ecological control on arthropod species richness and diversity indices was most pronounced during the cotton bud stage. Furthermore, ecological control fields exhibited the highest individual number ratio (1:0.882) and family number ratio (1:16.825) between carnivorous and phytophagous groups among the three models.

Ecological control can increase the abundance of arthropods and the number of natural enemies in cotton fields, thereby reducing pest populations and positively influencing the structure of arthropod communities in these ecosystems.