Siebert M Willrich, Leonard B R, Gable R H, LaMotte L R
Department of Entomology, LSU AgCenter, Baton Rouge, LA 70803, USA.
J Econ Entomol. 2005 Feb;98(1):82-7. doi: 10.1093/jee/98.1.82.
Cotton plants were infested with brown stink bug, Euschistus servus (Say), to define cotton boll age classes (based on heat unit accumulation beyond anthesis) that are most frequently injured during each of the initial 5 wk of flowering. Bolls from each week were grouped into discrete age classes and evaluated for the presence of stink bug injury. Brown stink bug injured significantly more bolls of age class B (approximately 165-336 heat units), age class C (approximately 330-504 heat units), and age class D (approximately 495-672 heat units) during the initial 3 wk in both years and in week 5 in 2002 compared with other boll ages. Generally, the frequency of injured bolls was lowest in age class A (< or = 168 heat units) during these periods. The preference by brown stink bug for boll age classes B, C, and D within a week was similar when ages were combined across all 5 wk. Based on these data, bolls that have accumulated 165.2 through 672 heat units beyond anthesis (approximately 7-27-d-old) are more frequently injured by brown stink bug when a range of boll ages are available. The boll ages in our studies corresponded to a boll diameter of 1.161-3.586 cm with a mid-range of 2.375 cm. A general protocol for initiating treatments against stink bugs is to sample bolls for evidence of injury as an indicator of presence of infestations in cotton. Sampling bolls within a defined range, which is most likely to be injured, should improve the precision of this method in detecting economic stink bug infestations in cotton.
用褐蝽（Euschistus servus (Say)）侵染棉花植株，以确定在开花初期的前5周中，每周最常受到伤害的棉铃年龄类别（基于开花后热量单位的积累）。将每周的棉铃分组为不同的年龄类别，并评估是否存在蝽象伤害。在两年的最初3周以及2002年的第5周，与其他棉铃年龄相比，褐蝽对B龄期棉铃（约165 - 336热量单位）、C龄期棉铃（约330 - 504热量单位）和D龄期棉铃（约495 - 672热量单位）的伤害显著更多。在这些时期，A龄期棉铃（≤168热量单位）的受害频率通常最低。当将所有5周的棉铃年龄合并时，褐蝽在一周内对B、C和D龄期棉铃的偏好相似。基于这些数据，当有一系列棉铃年龄可供选择时，开花后积累了165.2至672热量单位（约7 - 27日龄）的棉铃更常受到褐蝽的伤害。我们研究中的棉铃年龄对应于直径为1.161 - 3.586厘米、中间值为2.375厘米的棉铃。启动防治蝽象处理的一般方案是对棉铃进行取样，以寻找伤害证据，作为棉花中存在虫害的指标。在最有可能受到伤害的限定范围内对棉铃进行取样，应能提高该方法在检测棉花中经济蝽象虫害时的精度。
