Predicting white peach scale phenology on kiwifruit in Sichuan

White peach scale (<i>Pseudaulacaspis pentagona</i>) is a polyphagous pest of perennial horticulture in Asia and many other warm-temperate and tropical regions. In China, it is a serious pest of kiwifruit. The optimal time to control <i>P. pentagona</i> field populations is at the first instar stage of the first, spring generation. Three methods for predicting the hatching of eggs of the first generation from field populations were tested on kiwifruit in Sichuan, based upon the accumulation of heat units (day-degrees) above a developmental threshold, calculated as 10.75 °C. A method developed for <i>P. pentagona</i> control in tea in Japan gave excellent predictions of 50% hatching in 5 of the 6 years under study (2009–2014). The other two methods also gave acceptable predictions of dates of 50% egg hatching (within 5 days of field observed dates). These models may be used as a basis for forecasting spring insecticide application dates targeting the first instar stage (crawlers and settled ‘white caps’).桃白蚧（*Pseudaulacaspis pentagona*）是一种多食性害虫，可危害亚洲及诸多其他暖温带与热带区域的多年生园艺作物。在中国，该虫是猕猴桃的重要农业害虫。防治田间桃白蚧种群的最佳适期为春季第一代的1龄若虫阶段。本研究以10.75℃为发育起点温度，基于有效积温（日度，day-degrees）的积累原理，在四川猕猴桃种植园开展田间试验，对3种预测田间种群第一代卵孵化进程的方法进行了验证。此前日本针对茶园桃白蚧防治开发的一种预测模型，在本研究涵盖的2009-2014年共6年试验周期中，有5年可精准预测50%卵的孵化时间。其余两种方法对50%卵孵化日期的预测结果同样满足应用要求，与田间实测日期的误差不超过5天。上述模型可作为针对1龄若虫阶段（爬行若虫与已固定的‘白盖’虫体）的春季杀虫剂喷施适期预测的技术依据。