Drought reduced the adaptability of Myzus persicae on drought-tolerant potato cultivars

Abstract: Drought and aphids are the key abiotic and biotic stresses on potato, respectively. Understanding the adaptability of aphid populations on potato cultivars that exhibit contrasting drought-tolerance (hereafter as different potato cultivars) under drought conditions is key for developing effective aphid management strategies in the context of climate change. We assessed the adaptability of the peach potato aphid, Myzus persicae, on various potato cultivars under drought conditions using the age-stage, two-sex life table theory. We found that drought reduced M. persicae adaptability in the three cultivars: Qingshu 9 (drought-tolerant), Longshu 3 (moderately drought-tolerant), and Atlantic (drought-susceptible). This was demonstrated by the longer developmental duration and total pre-reproductive period, lower adult longevity, survival rate, and fecundity, shorter reproduction days, as well as the lower net reproductive rate (R 0), intrinsic rate of increase (r), finite rate of increase (λ), and population size under drought conditions. Under drought conditions, M. persicae pre-adult survival rate, proportion of female adults (Nf /N), and R 0 suffered a greater reduction on Qingshu 9. Population projection showed a 100-fold reduction of aphid population size on Qingshu 9 after 90 days. The findings suggest that drought increased the resistance of the drought-tolerant cultivar to the aphid. Based on the present findings, drought-tolerant cultivars are encouraged to plant in arid lands under drought conditions to increase potato resistance to aphids while maintaining their growth under drought conditions.