Seasonal Occurrence and Diversity of Spider Mites in Cotton Fields From the Rio Grande Valley to the Coastal Bend

The incidence of spider mites was evaluated in seven locations of south Texas from the Rio Grande Valley to the Coastal Bend. This is an area with a south to north transect of 160 miles.  The cotton fields were located near the towns of Progreso and Weslaco (Hidalgo Co.), Harlingen (Cameron Co.), Raymondville (Willacy Co.), Bishop and Corpus Christi (Nueces Co.) and Sinton (San Patricio Co.).  Spider mite surveys were conducted from 12 April to 25 July, 2011, and 4 April to 24 July in2012.  In each location, the percentages of plants infested by spider mites were determined by sampling leaves in border and interior areas of each field.  Spider mites appeared early in the season in Progreso, Harlingen and Raymondville compared with Bishop, Corpus Christi and Sinton.  Seasonal incidence, population densities of all fields surveyed, and Tetranychus species found across the different locations will be discussed here.