Characterization of spatial distribution of XXXX in peppermint in California and implication for improving sampling plan.

@entity7213 @entity6711 @entity1423
UNASSIGNED: Twospotted spider mite, @entity7213 Koch, is an important pest of peppermint in California, USA. Spider mite feeding on peppermint leaves causes physiological changes in the plant, which coupling with the favorable environmental condition can lead to @entity6711 . Significant yield loss can occur in absence of pest monitoring and timely management. Understating the within-field spatial distribution of @entity7213 is critical for the development of reliable sampling plan. The study reported here aims to characterize the spatial distribution of @entity6711 in four commercial peppermint fields in northern California using spatial techniques, variogram and Spatial Analysis by Distance IndicEs (SADIE). Variogram analysis revealed that there was a strong evidence for spatially dependent (aggregated) mite population in 13 of 17 sampling dates and the physical distance of the aggregation reached maximum to 7  m in peppermint fields. Using SADIE, 11 of 17 sampling dates showed aggregated distribution pattern of @entity6711 . Combining results from variogram and SADIE analysis, the @entity1423 of @entity7213 was evident in all four fields for all 17 sampling dates evaluated. Comparing spatial association using SADIE, ca. 62  % of the total sampling pairs showed a positive association of mite spatial distribution patterns between two consecutive sampling dates, which indicates a strong spatial and temporal stability of @entity6711 in peppermint fields. These results are discussed in relation to behavior of spider mite distribution within field, and its implications for improving sampling guidelines that are essential for effective pest monitoring and management.
