土壤容重对棉铃虫卵发生的影响

棉铃虫卵量的多少直接决定着危害棉花的幼虫的数量，而在新疆以二代幼虫危害最为严重。不同棉区的气候和土壤类型有差异，而土壤是棉铃虫幼虫入土和化蛹的重要媒介，因此弄清土壤对虫卵产生的作用有着理论和现实的意义。此文通过对南疆（麦盖提县）和北疆（沙湾县）两个植保站的多年虫情资料和全疆30个农业气象试验站的实测数据进行回归分析、通径分析和聚类分析，得出影响南疆麦盖提县虫卵的因子较多，其中土壤容重对其虫卵的发生直接作用较小（-0.025），指示作用较小，而影响北疆沙湾县虫卵的因子较少，土壤容重对其虫卵的发生直接作用较大（-0.294），指示作用相对较大。降水对虫卵的影响在南、北疆也不相同。土壤容重对虫卵的影响是负作用，对虫卵的发生起到一定的指示作用。因此，可能运用不同地区的土壤容重，并结合相关的气候和生物因子，可以对棉铃虫卵的发生程度起到一定的指示作用。

Effect of Soil Bulk Density on Eggs of Helicoverpa Armigera Occurrence

The number of eggs of Helicoverpa armigera directly affects the number of larvae which harm the cotton.However,generation two of H.armigera do the severe harm to cotton in Xinjiang.There are differences on climate and soil types among different cotton-planted areas.Soil is important intermedium for larvae to enter soil and pupate and has affected on promoting eggs.Thus,it has theoretic and practical significance that we understand what function of the soil will bring on the eggs.In this study,long term data on H.armigera from two plant stations in south （Maigaiti county） and north （Shawan county） of Xinjiang and experiment data from 30 agricultural meteorology experimentation stations in Xinjiang were employed to conduct path analysis,clustering analysis and regression analysis.The results showed that there were more influence factors on eggs of H.armigera in Maigaiti county than that in Shawan county.Soil bulk density had litter direct effect on eggs of H.armigera in Maigaiti county （-0.025） than that in Shawan county （-0.294）.The indication effect of soil bulk density on occurrence of eggs of H.armigera to the north of Xinjiang was more evidence than that to the south of Xinjiang.The effect of precipitation on H.armigera was different in south and north of Xinjiang.The effect of soil bulk density on eggs of H.armigera was negative and it could have indication effected in some extend.So it can be regarded as indication effect in some extend on occurrence of eggs of H.armigera when use soil bulk density in different regions and combine weather and biological factors.