the common pistachio psylla agonoscena pistaciae is a key pest of pistachio in iran. a study was conducted to determine the spatial distribution ofpsyllanymphs and eggs in a 10 ha pistachio orchard in the rafsanjan region, southeast of iran. three rows, each containing 33 trees (totally 99 trees), were randomly selected in the orchard based on a stratified sampling scheme. in each of the select...