Abstract:The spatial patterns for arrowhead scale(Prontaspis yanonensis Kuwana) and its natural enemies are analyzed by means of Iwao‘s method of regression of mean crowding(m*) on mean density(m) using data from Guiyang, Guizhou province. The results indicated that arrowhead scale(Prontaspis yanonensis Kuwana)and its natural enemies, Chilocorus bijugus Mulsant, Cybocephalus nipponicus Endrody-Younga, Aphytis yanonensis De Bach et Rose, all distribute in aggregation within the crown of citrus tree. The populations o...