USDA-ARS, Arid Land Agricultural Research Center, 21881 N. Cardon Lane, Maricopa, AZ 85138, USA.
J Insect Sci. 2012;12:136. doi: 10.1673/031.012.13601.
Recent studies on adult diapause in the western tarnished plant bug, Lygus hesperus Knight (Heteroptera: Miridae), have highlighted the need to identify a reliable external marker for the internal changes that differentiate a normal animal from one that is overwintering. To test the efficacy of a color based discrimination system, L. hesperus of both genders were reared from eggs through day 10 of adulthood under a 10 hour photophase at a constant temperature. They were separated into three color groups (yellow, pale green, dark green), then dissected for diapause categorization based on internal development. Most yellow individuals were in diapause, dark green individuals were not, and pale green ones were mixed. A group of 25 assessors, naïve with regard to L. hesperus development, were then asked to use a simplified color criteria (yellow = diapause, green = non-diapause) to estimate the status of a mixture of diapausing and non-diapausing adults of both genders aged two to seven days post-eclosion. After dissection to verify diapause status, assessor accuracy was found to be ineffective for assessing adults of both sexes younger than four days because color differences, which increased with age, were subtle or non-existent at this stage. For four to seven-day-old bugs, 84% of females and 67% of males were correctly categorized, on average. Incorrect assessments in all but the youngest males over-identified diapause, but for females there was no trend in miscategorizations. Overall, the results indicate that diapause status can be adequately discriminated by color assessment, and with greatest accuracy when sampling older females. However, factors other than photoperiod appear to also influence coloration.
最近对西方玷污叶蝉（Lygus hesperus Knight）成虫滞育的研究强调需要识别一种可靠的外部标记，以区分正常动物和越冬动物内部的变化。为了测试基于颜色的区分系统的效果，将雌雄两性玷污叶蝉的卵从孵育到成虫期第 10 天在恒定温度下的 10 小时光周期下进行饲养。将它们分为三组颜色（黄色、浅绿色、深绿色），然后根据内部发育情况进行滞育分类。大多数黄色个体处于滞育状态，深绿色个体未处于滞育状态，浅绿色个体处于混合状态。然后，一组 25 名对玷污叶蝉发育一无所知的评估员被要求使用简化的颜色标准（黄色=滞育，绿色=非滞育）来估计混合有雌雄两性 2 至 7 天龄出蛰成虫的滞育和非滞育状态。在对滞育状态进行解剖验证后，发现评估员的准确率对于评估年龄小于 4 天的雌雄两性成虫效果不佳，因为颜色差异随着年龄的增长而增加，但在这个阶段非常细微或不存在。对于 4 至 7 天龄的虫子，84%的雌性和 67%的雄性平均被正确分类。除了最年轻的雄性外，所有其他年龄的雄性都过度识别了滞育，但对于雌性，误分类没有趋势。总体而言，结果表明可以通过颜色评估充分区分滞育状态，而且在取样较年长的雌性时准确率最高。然而，除了光周期之外，其他因素似乎也会影响颜色。
