论文部分内容阅读
在马尾松毛虫二、三代发生区,6年以上有一次高三代分化率,形成初秋虫灾大暴发,致使成片松林死亡。与高三代分化相关显著的气象因子是:8月份平均气温,稳定通过10℃的始日和全年大于10℃的日照时数。而打破松毛虫滞育的关键因子是8月中、下旬4龄幼虫长日照的刺激,使分化三代虫数大量增加,通过林场22年的三代分化率调查数据和7个气象因子的电算,预测出松毛虫三代分化率的数学模型:用时间序列法预测1986、1987年三代分化率与实地调查数字比较接近。
In the second and third generations of Dendrolimus punctatus, there was a high third generation differentiation rate for more than six years, causing a big outbreak of pest disaster in early autumn, resulting in the death of Songlin. The significant meteorological factors related to the differentiation of the third generation are the average temperature in August, the steady passage of 10 ° C and the sunshine duration of more than 10 ° C throughout the year. The key factor to break the diapause of Dendrolimus punctatus was the stimulation of the fourth instar larvae in mid-August by the long-day sunshine, which greatly increased the number of three-generation larvae. Based on the survey data of the third generation differentiation rate and the calculation of seven meteorological factors in the forest farm for 22 years, Predicting the third generation of pine caterpillars differentiation rate of the mathematical model: using time series forecast 1986,1987 third generation differentiation rate and field survey data are relatively close.