Vandervoet Timothy F, Ellsworth Peter C, Carrière Yves, Naranjo Steven E
Department of Entomology, University of Arizona, Maricopa Agricultural Center, Maricopa, AZ.
Department of Entomology, University of Arizona, Tucson, AZ.
J Econ Entomol. 2018 May 28;111(3):1056-1068. doi: 10.1093/jee/toy049.
Conservation biological control can be an effective tactic for minimizing insect-induced damage to agricultural production. In the Arizona cotton system, a suite of generalist arthropod predators provides critical regulation of Bemisia tabaci Gennadius (MEAM1) (Hemiptera: Aleyrodidae) and other pests. Arthropod predator and B. tabaci populations were manipulated with a range of broad-spectrum and selective insecticide exclusions to vary predator to prey interactions in a 2-yr field study. Predator to prey ratios associated with B. tabaci densities near the existing action threshold were estimated for six predator species found to be negatively associated with either adult and/or large nymphs of B. tabaci [Misumenops celer (Hentz) (Araneae: Thomisidae), Drapetis nr divergens (Diptera: Empididae), Geocoris pallens Stäl (Hemiptera: Geocoridae), Orius tristicolor (White) (Hemiptera: Anthocoridae), Chrysoperla carnea s.l. (Neuroptera: Chrysopidae), and Collops spp. (Coleoptera: Melyridae)] with the first three most consistently associated with declining B. tabaci densities. Ratios ranged from 1 M. celer per 100 sweeps to 1 B. tabaci adult per leaf to 44 D. nr. divergens per 100 sweeps to 1 large nymph per leaf disk. These ratios represent biological control informed thresholds that might serve as simple-to-use decision tool for reducing risk in the current B. tabaci integrated pest management strategy. The identification of key predators within the large, flexible food web of the cotton agro-ecosystem and estimation of predator to B. tabaci ratios clarifies the role of key predators in B. tabaci suppression, yielding potential decision-making advantages that could contribute to further improving economic and environmental sustainability of insect management in the cotton system.
保育生物防治可作为一种有效策略，将昆虫对农业生产造成的损害降至最低。在亚利桑那州的棉花种植系统中，一系列多食性节肢动物捕食者对烟粉虱（MEAM1）（半翅目：粉虱科）和其他害虫起到了关键的调控作用。在一项为期两年的田间研究中，通过一系列广谱和选择性杀虫剂排除措施来控制节肢动物捕食者和烟粉虱的种群数量，从而改变捕食者与猎物之间的相互作用。针对六种与烟粉虱成虫和/或大龄若虫呈负相关的捕食者物种[敏捷花蛛（亨茨）（蜘蛛目：蟹蛛科）、近散纹家蝇（双翅目：舞虻科）、苍白姬蝽（半翅目：姬蝽科）、三色小花蝽（怀特）（半翅目：花蝽科）、普通草蛉（脉翅目：草蛉科）和扁甲属（鞘翅目：扁甲科）]，估算了与现有行动阈值附近的烟粉虱密度相关的捕食者与猎物比例，其中前三种捕食者与烟粉虱密度下降的相关性最为一致。比例范围从每100次扫查中有1只敏捷花蛛到每片叶子有1只烟粉虱成虫，再到每100次扫查中有44只近散纹家蝇到每片叶盘有1只大龄若虫。这些比例代表了生物防治的参考阈值，可作为一种简单易用的决策工具，用于降低当前烟粉虱综合虫害管理策略中的风险。在棉花农业生态系统庞大且灵活的食物网中识别关键捕食者，并估算捕食者与烟粉虱的比例，明确了关键捕食者在抑制烟粉虱方面的作用，产生了潜在的决策优势，有助于进一步提高棉花系统昆虫管理的经济和环境可持续性。
