Landscape effects on Hessian fly, Mayetiola destructor (Diptera: Cecidomyiidae), distribution within six Kansas commercial wheat fields

摘要

Crop production of a significant portion of the Great Plains has greatly simplified the landscape, which can affect insect pest outbreaks. The Hessian fly is an important economic pest of wheat, a major crop grown in the region. However, outbreaks are often limited to localized events, which may be difficult to predict. Better understanding of where Hessian fly outbreaks are more likely to occur would help producers make informed management decisions. Therefore, the objective of our study was to describe the spatial distribution of Hessian fly infestation within commercial wheat fields, while examining how a simplified landscape may contribute to the distribution of Hessian fly infestations. Spatial distribution modeling was conducted in select fields (n = 6) infested with Hessian fly puparia. A geographic information system was used to create sampling grids for each field (n = 34-50 sample points/field), with one meter row of plants sampled at each sample point. The number of puparia and plants infested at each sample point were used to construct Hessian fly distribution maps for each field. Correlations between environmental factors and fly distribution were then examined. Results show that host plants (wheat and grasses) adjacent to the borders of study fields did not affect the distribution of puparia or plants infested within the field. Rather, the proportion of wheat within a 1 km radius of sampled fields affected the level of Hessian fly infestation, with a smaller proportion of wheat within the 1 km radius increasing the probability of Hessian fly infestation in sampled fields. The results of this study show previously unknown distribution of Hessian fly infestation within commercial wheat fields, resulting in new hypotheses about Hessian fly management in agroecosystems.