Potato production requires a combination of monitoring and controlling a number of insect pests in order to maintain high productivity. Insect monitoring can utilize two general techniques: field sampling and insect trapping. The green peach aphid, Myzus persicae, is a common insect in all potato-growing regions of the United States. This aphid may cause damage by removing fluid from the plant but it is primarily a pest because it transmits potato leafroll virus (PLRV). Potato Aphid, Macrosiphum euphorbiae, can transmit PLRV, and potato viruses Y and A in a nonpersistent manner. Potato Psyllid, Paratrioza cockerelli, occurs throughout the West, but is usually only a significant pest in the central and southern states. Spider mites can be a problem in potato fields in hot growing regions of the West. The Colorado potato beetle, Leptinotarsa decemlineata, was first discovered in the midwestem part of the United States in the vicinity of the current Nebraska-Iowa border.