Effect of cutting prairie on movement of beneficial arthropods into adjacent crop fields

Native prairies in Northeast Nebraska are being utilized for agricultural purposes, primarily livestock pasture and hay production. Native, non-crop habitats can serve as important reserves for beneficial insects. Previous research has shown that prairies host a number of invertebrate predators and parasitoids of economically damaging pest insects. It has also been demonstrated that non-crop habitat is important for conservation of bees. The impact of hay cutting on arthropod natural enemies in prairies is not understood nor is the extent to which these natural enemies move into and out of adjacent crop fields. Also, the plant community present can influence populations of natural enemies and pollinators. Our main objective was to determine if and how far beneficial insects move into adjacent crops. A secondary objective was to determine the effect of hay cutting on the abundance of beneficial insects in prairie hay fields. Yellow sticky cards (YSCs) were used to sample arthropods in prairie hay fields and into adjacent crop fields. The YSCs were deployed for 24 hours and then collected. Arthropods were identified and tallied to be able determine abundance and community composition. Beneficial arthropod abundance was analyzed using an ANOVA with split plot and repeated measures. The only significant difference (p<0.05) in the abundance of beneficial insects caught by YSCs was two weeks after the first cutting of the two cutting treatment. Differences in beneficial insect community composition were analyzed using Non-metric Multidimensional Scaling (NMDS). The NMDS revealed differences in beneficial insect community composition.