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Show 1937] Knowlton: Some Potato Insects of Utah 153 tain localities of southern Utah. The oleander scale, Aspidiotus hederae (Vallot), occurs in Utah and may at times attack potatoes in warmer southern The greenhouse whitefly, Trialeurodes areas. ucporariorwm (Westwood), oc casionally becomes injurious to potatoes grown out of doors, but it most commonly damages plants in greenhouses.' The boxelder bug, Leptocoris trivittatus (Say), has frequently been found upon potato plants, and at times has been observed to be feeding. At pres ent, this insect is not a common pest of the potato in this state. This bug causes its principal annoyance as a household pest, and causes its chief dam age to crops by clustering upon ripening apples, plums, pears, and certain other fruits, resulting in noticeable injury. The stilt bug, I a!ystts spinosus (Say), is not uncommon in Utah, having been collected at Blue Creek, Leeds, Spring Lake, and Logan; it feeds upon potatoes and tomatoes. The western variety, 1. wickhami VanD., also occurs upon the potato, and has been taken at Uinta, Harrisville, Utah Rot Springs, City Creek Canyon, Logan Canyon, in Utah, and at Mink Creek, in Idaho. The false chinch bug, N ysius ericae (Schilling), is a common pest in this region, which attacks potato plants as well as many other crops. The big eyed bug, Geocoris decoratus Uhler, feeds upon the juices of the potato plant, as well as being predaceous upon the leafhopper, Empocsca filamenta DeL., the beet leafhopper, Euieitix tenellus (Baker), the green peach aphid, Myzus per sicae ( Sulzer) and upon certain other small insects which attack the The black grass bug, potato plant. Irbisia solani (Heid.), has seldom been noted to occur in injurious abundance upon potatoes in Utah. The two bugs, Lygus elisus VanD., and L. hesperus Knight, frequently attack potato foliage in large numbers, causing serious wilting during hot weather. Blister beetles of many kinds occur, several of which cause some injury to potato foliage. The spotted blister beetle, Epicauta maculate (Say), is very common and frequently injurious to potatoes, beets, beans and certain other vegetable crops. The black blister beetle, E. pennsylvanica (DeG.), the striped blister beetle, E. vittata Fabr., the immaculate blister beetle, M acrobasis im maculata (Say), M. unicolor (Kby.), and occasionally other species cause local damage to potato foliage. Wireworms cause serious damage to potato tubers in some localities, every year, cutting down the market value of the crop, and making varying percentages of the tubers unsalable. The following species, whose larvae are known to attack potato tubers, occur in Utah: Pheleletes californicus (Mann.), was found to be present in fields at Lewis ton during 1929, where wireworm injury to potatoes, beans and sugar-beets was severe; Limonius infuscaius Mots.; Ludius infiatus (Say); the potato wireworm, Dolopius lateralis Esch. These undoubtedly are aided by others of the numerous species, in causing injury to potatoes locally. A number of kinds of Scarabaeidae occur in Utah, the white grubs of some of these species being injurious to potato tubers. The carrot beetle, Ligyrus gibbosus (DeG.), which, in the adult stage, attacks potato foliage, occurs in southern Utah, and may cause some injury. The Colorado potato beetle, Lepiinotarsa decemlineata (Say) ; has, for the past five years, been a pest of potatoes in the Riverdale Roy area of Weber County and in the adjoining Sunset area extending a short way into Davis County. A small infestation occurred at Morgan a few years previously, but was promptly stamped out. Federal relief labor, in coopera tion with the State Department of Agriculture and Weber and Davis County officials, has done much to keep infestation from this pest as low as possible and to prevent it from extending its range materially. Control.-Four pounds of lead arsenate (or 2 pounds of Paris green and 5 pounds of hydrated lime) to 100 gallons of water, applied at the rate of 100 to 125 gallons per acre when plants are full grown (less when plants are small). Application may . |
