The citrus gall wasp, Bruchophagus fellis, is a serious pest of citrus in southeast Australia and the ability to accurately predict its highly synchronised adult emergence periods is critical for its effective management. We monitored emergence of the citrus gall wasp for six years during 2010–2017 in southern Australia, yielding a total of 22 site-by-year datasets from two citrus production regions and multiple citrus varieties. For each dataset, the proportions of emerged wasps on different monitoring dates were related to the corresponding degree-days using a 2-parameter Weibull function. The two degree-day parameters, the lower development threshold temperature and biofix date, were estimated at 8 °C and August 1 respectively by cross-validation of a series of candidate values using the sum of squared differences between the predicted and observed median emergence dates as the performance indicator. According to the final fitted Weibull function, 5, 50, and 95% emergence occur when 560, 723 and 835 degree-days above 8 °C have accumulated after August 1. The predicted median emergence dates differed from the corresponding observed median emergence dates by an average of 2.8 days across the 22 datasets. The average deviations for 5 and 95% emergence were slightly larger, at five and four days, respectively. Observed degree-days for median emergence did not differ significantly between the two citrus production regions, indicating there is no need for separate degree-day models for different regions. Based on the degree-day model, an interactive, online timing tool has been developed, allowing growers to use local weather station data to predict when the gall wasp is likely to emerge in average, warm, and cool years.

柑橘胆黄蜂，布鲁氏噬菌体，是澳大利亚东南部柑桔的一种严重害虫，准确预测其高度同步的成年期的能力对其有效管理至关重要。我们在2010-2017年期间监测了澳大利亚南部南部柑橘胆黄蜂的出现情况，为期6年，从两个柑橘生产地区和多个柑橘品种中获得了22个逐年站点数据集。对于每个数据集，使用2参数Weibull函数将在不同监测日期出现的黄蜂的比例与相应的度数天相关。两个度日参数，较低的发育阈值温度和生物固定日期，通过将一系列候选值进行交叉验证，分别使用预测的和出现的中值出现日期与观察到的中值出现日期之间的平方差的总和作为性能指标，来对这些元素进行估算。根据最终拟合的威布尔函数，当8月1日之后在8°C以上累积560、723和835度日时，出现5、50和95％的出苗。预测的中位出现日期与相应的观察到的中位出现日期有所不同。在22个数据集中平均需要2.8天。分别在5天和4天时，出现率5％和95％的平均偏差稍大。在两个柑橘生产区域之间，中位数出现的观测天数天数没有显着差异，这表明不需要为不同区域使用单独的观测天数天模型。