Kerns D L, Yates J A, Baugh B A
Louisiana State University Agricultural Center, Macon Ridge Research Station, Winnsboro, LA 71295.
Texas A&M AgriLife Research and Extension Center, Texas A&M System, 1102 E. FM 1294, Lubbock, TX 79403.
J Econ Entomol. 2015 Aug;108(4):1795-803. doi: 10.1093/jee/tov161. Epub 2015 Jun 24.
Cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), is a common pest of cotton throughout much of the world. In the United States, insecticide applications targeting cotton aphid in cotton are common in the Mid-South, Texas, and California. Cotton aphid population dynamics data were collected from eight insecticide efficacy trials conducted in Lubbock, TX, over a 4-yr period. Among the field populations in the nontreated plots, the instantaneous rate of population growth averaged 0.56 ± 0.608, and the mean population doubling time was 3.97 ± 2.16 d. For calculating economic injury levels (EIL) and thresholds, control costs were set at US$30.50/ha, market prices were evaluated at US$0.88, US$1.33, US$1.77, and US$2.21 kg-lint, and cotton yield potentials were evaluated at 672, 896, and 1,120 kg-lint/ha. The EIL we calculated ranged from 66 to 272 aphids per leaf, and averaged 137 aphids per leaf. Economic thresholds (ET) were calculated based on lead times of 1, 3, 5, and 7 d before EIL occurs. The mean ET across control cost, market price, and yield potential were 110 ± 48, 70 ± 31, 45 ± 19, and 29 ± 13 aphids per leaf at lead times of 1, 3, 5, and 7 d, respectively. Most curative pest management tactics in cotton are implemented within 3 d of determining need, and the ET at 3 d that we calculated (70 ± 31 aphids per leaf) overlaps the current recommended action threshold in Texas and California of 50 aphids per leaf.
棉蚜，棉蚜属（半翅目：蚜科），是世界上大部分地区棉花的常见害虫。在美国，美国中南部、得克萨斯州和加利福尼亚州针对棉花上棉蚜的杀虫剂应用很普遍。在4年时间里，从得克萨斯州拉伯克进行的8次杀虫剂药效试验中收集了棉蚜种群动态数据。在未处理地块的田间种群中，种群瞬时增长率平均为0.56±0.608，平均种群加倍时间为3.97±2.16天。为了计算经济损害水平（EIL）和阈值，防治成本设定为30.50美元/公顷，市场价格评估为每千克皮棉0.88美元、1.33美元、1.77美元和2.21美元，棉花产量潜力评估为672、896和1120千克皮棉/公顷。我们计算出的EIL范围为每片叶66至272头棉蚜，平均为每片叶137头棉蚜。经济阈值（ET）是根据在EIL出现前1、3、5和7天的提前期计算得出的。在提前期为1、3、5和7天时，综合防治成本、市场价格和产量潜力得出的平均ET分别为每片叶110±48、70±31、45±19和29±13头棉蚜。棉花中大多数治疗性害虫管理策略是在确定需要后的3天内实施的，我们计算出的3天提前期的ET（每片叶70±31头棉蚜）与得克萨斯州和加利福尼亚州目前推荐的每片叶50头棉蚜的行动阈值重叠。
