Scaling and the Effects of Plant, Soil, and Landscape Characteristics on Sap-Feeding Herbivores in Cotton

Abstract Soil physical and chemical properties can affect plant growth and nutrition, which in turn can affect a plant’s attractiveness and susceptibility to insect herbivores. A further source of variation in these relationships is the spatial scale at which patterns are measured. Both the size of the area being sampled, or scale, and the distance between measurements, or grain, are parameters that affect interpretation of insect abundance patterns. Our objectives in this study were to determine both the relationship of various landscape, plant, and soil characteristics to densities of sap-feeding insect herbivores in cotton and to determine the effects of sampling scale and sampling grain on these relationships. We included three sap-feeding herbivores in our study: Aphis gossypii Glover, Frankliniella occidentalis (Pergande), and Bemisia tabaci Gennadius. We found that abundance of each insect species was related to several single factors within the cotton field and that these relationships were always...