Abney Mark R, Ruberson John R, Herzog Gary A, Kring Timothy J, Steinkraus Donald C, Roberts Phillip M
Department of Entomology, North Carolina State University, Raleigh, NC, USA.
J Econ Entomol. 2008 Feb;101(1):23-35. doi: 10.1603/0022-0493(2008)101[23:rafoca]2.0.co;2.
The impact of natural enemies on cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), populations in cotton, Gossypium hirsutum L., production systems in the southeastern United States was evaluated over 3 yr in irrigated commercial cotton fields. Fungal epizootics caused by the entomopathogen Neozygites fresenii (Nowakowski) Batko reduced aphid numbers to subthreshold levels in 1999, 2000, and 2001 and occurred consistently in early to mid-July in all 3 yr. Scymnus spp. were the most abundant aphidophagous predators, although other coccinellid species and generalist predators such as spiders, fire ants, heteropterans, and neuropterans also were present. Studies using arthropod exclusion cages demonstrated little impact of predators or parasitoids on aphid populations before fungal epizootics. Arthropod natural enemies were most abundant after epizootics and may have suppressed aphid populations late in the season. Seed cotton yield, and lint quality were not affected by aphicide applications in any year of the study. Implications of these findings for aphid management in the southeastern United States are discussed.
在美国东南部的灌溉商业棉田，连续3年评估了天敌对棉花棉蚜（棉蚜，半翅目：蚜科）种群在棉花（陆地棉）生产系统中的影响。由昆虫病原真菌新接霉（Nowakowski）Batko引起的真菌流行病在1999年、2000年和2001年将蚜虫数量减少到阈值以下水平，并且在这3年中均在7月上旬至中旬持续发生。食螨瓢虫是最丰富的捕食蚜虫的天敌，不过其他瓢虫种类以及蜘蛛、火蚁、异翅目昆虫和脉翅目昆虫等广食性捕食者也有出现。使用节肢动物排除笼的研究表明，在真菌流行病之前，捕食者或寄生蜂对蚜虫种群影响很小。节肢动物天敌在流行病之后最为丰富，可能在季节后期抑制了蚜虫种群数量。在研究的任何一年中，施用杀蚜剂均未影响籽棉产量和皮棉质量。讨论了这些发现对美国东南部蚜虫管理的意义。
