家蚕血液型脓病流行规律及其与气象因子的相关性

Epidemic law of Bombyx mori nuclear polyhedrosis and its correlation with meteorological factors

【目的】摸清广西家蚕血液型脓病流行规律,并研究其与气象因子的相关性,建立病虫害预测预报的动态数学模型,为精准防控蚕病提供科学依据。【方法】以广西2008-2018年的蚕病调查数据和气象数据为基础,将家蚕血液型脓病危害情况与主要气象因子进行相关性分析和通径分析,构建回归预测模型。【结果】2008-2018年广西家蚕血液型脓病呈波动发生态势,年均发生率为11.35%,危害等级为重度(Ⅲ级)和超重度(Ⅳ级)的出现频率达55.56%;月均发病趋势呈正态分布,7月发病率最高(18.04%),其次是6和8月,发病率分别为16.00%和15.36%。夏蚕期(6-8月)广西蚕区家蚕血液型脓病危害等级大部分达Ⅳ级,占比为62.79%,各蚕区发病率由高至低排序为贵港(18.15%)>南宁(17.89%)>河池(16.27%)>百色(15.82%)>柳州(14.16%);春蚕期(3-5月)发病率绝大部分在中度(Ⅱ级)以内,发病率由高至低排序为柳州(10.13%)>河池(9.65%)>百色(7.43%)>贵港(7.00%)>南宁(6.68%);秋蚕期(9-10月)各蚕区发病率均在Ⅱ级以内,差异不显著(P>0.05)。降雨量和气温是影响广西蚕区家蚕血液型脓病发病率的最主要气象因子,据此建立的预测预报模型为y=0.15116+0.0037371x1+0.00018527x2+0.000051826x3-0.0000030415x4-0.00000082702x5+0.00063798x6(y为家蚕血液型脓病发病率,x1为旬平均气温与23.75℃差值的二次方,x2为上一旬降水量,x3为上两旬平均气温的二次方,x4为上两旬日照时数的二次方,x5为前三旬降雨量之和的二次方,x6为近四旬降雨量之和),发病等级的建模拟合准确率为78.89%,对2018年9批监测数据的预测准确率为66.67%。【结论】广西家蚕血液型脓病危害较严重,夏蚕期(6-8月)是发病高峰期。建立的预测模型可用于广西蚕桑生产中家蚕血液型脓病发生危害的预测预报。

【Objective】In order to provide scientific basis for the accurate prevention and control of silkworm disease,the epidemic law of Bombyx mori nuclear polyhedrosis in Guangxi and the correlation between it and meteorological factors was studied,and a regional dynamic warning model was established.【Method】Based on the survey data of silkworm diseases and meteorological data in Guangxi from 2008 to 2018,the correlation analysis and path analysis between the damage of B.mori nuclear polyhedrosis and the main meteorological factors were carried out,and a regression prediction model was built.【Result】The results showed that the incidence of B.mori nuclear polyhedrosis in Guangxi was fluctuating from 2008 to 2018,with an average annual rate of 11.35%,and the frequency of serious(gradeⅢ)and highly severe(gradeⅣ)was 55.56%.The monthly incidence was normally distributed in a year,with the highest incidence rate of 18.04%in July,followed by 16.00%and 15.36%in June and August,respectively.The rate of incidence of B.mori nuclear polyhedrosis in Guangxi was mostly gradeⅣin summer(June-August),accounting for 62.79%,and the incidence of nuclear polyhedrosis in different sericultural areas ranged from high to low was Guigang(18.15%)>Nanning(17.89%)>Hechi(16.27%)>Baise(15.82%)>Liuzhou(14.16%).And the incidence grade of spring(March-May)was mostly in moderate level(grade II),and the incidence for different areas was Liuzhou(10.13%)>Hechi(9.65%)>Baise(7.43%)>Guigang(7.00%)>Nanning(6.68%).While autumn silkworm rearing season(September-October)were below grade II and no significant difference(P>0.05).The main factors that influenced the incidence rate of nuclear polyhedrosis of silkworm in Guangxi were rainfall and temperature.Based on this,the prediction model of the harm degree of B.mori nuclear polyhedrosis in Guangxi was y=0.15116+0.0037371x1+0.00018527x2+0.000051826x3-0.0000030415x4-0.00000082702x5+0.00063798x6(y was the incidence rate of B.mori nuclear polyhedrosis,x1 was the quadratic power of the difference between the average temperature of ten-day period and the 23.75℃,the x2 was the previous ten-day period precipitation,x3 was the square of the previous twenty-day period average temperature,x4 was the square of previous twenty-day period sunshine hours,x5 was the square of the rainfall of previous thirty-day period,and x6 was the sum of the rainfall in the past forty days),from which the fitting accuracy rate of the incidence grade of nuclear polyhedrosis in silkworm was 78.89%and the prediction accuracy of nine batches of monitoring data in 2018 was 66.67%.【Conclusion】The B.mori nuclear polyhedrosis is serious in Guangxi,and its incidence peak period is in summer silkworn rearing season(June-August).Finally,the prediction model can be used in the production of sericulture to predict the occurrence and damage of B.mori nuclear polyhedrosis in Guangxi.