USDA-ARS, Arid-Land Agricultural Research Center, Maricopa, AZ, USA.
Department of Entomology, University of Arizona, Maricopa Agricultural Center, Maricopa, AZ, USA.
Pest Manag Sci. 2022 Oct;78(10):3988-4005. doi: 10.1002/ps.7018. Epub 2022 Jun 24.
The population dynamics of polyphagous pests such as Bemisia argentifolii (B. tabaci MEAM1) are governed by complex, interacting factors involving its cultivated and wild host plants, seasonality, movement and demography. To understand mechanisms contributing to population development and pest success within the agroecosystem, contiguous multi-host field sites were established in three environmentally distinct areas in Arizona. Life tables quantified and partition models described mortality sources and rates for immature insect stages on each host plant.
Predation and dislodgement were the largest sources of marginal mortality, supplied the highest irreplaceable mortality and predation was the key factor. Rates of mortality were best predicted, in order, by source, temperature, host plant and season. Marginal mortality was highest for fourth-stage nymphs followed by eggs. Mortality rates were predicted in descending order by stage, temperature and season. Survivorship patterns varied among host plants, and generational mortality averaged 70% on spring cantaloupes but nearly 95% on all other hosts. Population density varied seasonally, persisting at low levels on winter hosts and expanding beginning in the spring; perennial hosts and weeds bridge populations year-round.
Survival on winter hosts such as broccoli, albeit low, enables population continuity, whereas unusually high survivorship on spring crops like cantaloupe is an ecological release propelling population growth and driving regional dynamics in the summer and fall. This detailed understanding of mortality dynamics provides clues to the success of this invasive pest in our agroecosystems and facilitates opportunities for improved pest management at a broader landscape scale. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
多寄主害虫如烟粉虱（B. tabaci MEAM1）的种群动态受其栽培和野生寄主植物、季节性、迁移和种群动态等复杂相互作用因素的控制。为了了解导致农业生态系统内种群发展和害虫成功的机制，在亚利桑那州三个环境截然不同的地区建立了连续的多寄主野外场地。生命表量化并描述了各寄主植物上未成熟昆虫阶段的死亡率来源和死亡率。
捕食和驱逐是边缘死亡率的最大来源，提供了最高的不可替代死亡率，捕食是关键因素。死亡率的预测顺序依次为来源、温度、寄主植物和季节。第四龄若虫的边缘死亡率最高，其次是卵。死亡率的预测顺序为龄期、温度和季节。寄主植物间的存活率模式不同，春季甜瓜的世代死亡率平均为 70%，但其他所有寄主的死亡率几乎为 95%。种群密度随季节变化，冬季寄主上的种群密度保持在低水平，春季开始扩张；多年生寄主和杂草全年维持种群。
冬季寄主上的生存能力虽然较低，但能维持种群的连续性，而春茬作物（如甜瓜）上异常高的存活率则是一种生态释放，推动了种群的增长，并在夏季和秋季推动了该地区的动态变化。对这种入侵性害虫的死亡率动态的深入了解为其在农业生态系统中的成功提供了线索，并为在更广泛的景观尺度上改善害虫管理提供了机会。
