Local and landscape features of hypothesized to exert important influences on Andean potato weevil infestations (Premnotrypes spp.).

aFarmers apply a layer of ash directly below the potato seed at the time of planting; this practice is intended to kill potato weevils.bFertilization can influence crop defenses against herbivores [17].cMany agronomists recommend hilling the plants (piling dirt up around the stem of the plant) higher to lengthen the distance weevil larvae must travel to find tubers.dEarly harvest shortens the exposure of tubers to neonate larvae [18].eLarger fields have lower perimeter to area ratios and have been suggested to have lower infestations [19].fEarly emerging plants may experience greater infestations [20].gPlanting density may influence the abundance of many insect pests [21].hPlanting potatoes following a potato planting should lead to very high infestations [19], but implementing a single host free period should eliminate this risk. Rotation 2007 indicates if potatoes were sown in the field the previous season while Rotation 2006 indicates if potatoes were sown there two seasons before the study.iThe study hypothesized that weeds may serve as refuges for adult weevils before potato plants emerge.jWeevils are poorly adapted to elevations above 3,700 meters [18].kThe study hypothesized that greater soil erosion in steeper slopes may increase tuber exposure to weevils.lModern cultivars like Yungay may be more susceptible to insect pests [22].mThe study was interested in exploring any soil influences on weevil infestations without any strong a priori expectations.nA measure of potato fields sown the within 100 m of the focal potato field; these current fields dilute the effect of immigrating weevils [15].oA measure of potato fields harvested the previous season that lie within 100 m of the focal potato field; these previous fields may be sources of overwintering weevils that immigrate into focal fields [14], [15].pPotato storage units are facilities adjacent to farmer houses and are known to concentrate high densities of overwintering weevils that may immigrate into focal fields [14]–[15].