The Research Institute of Resource Insects, Chinese Academy of Forestry,The Research Institute of Resource Insects, Chinese Academy of Forestry,The Research Institute of Resource Insects, Chinese Academy of Forestry,,
2009-2011年,在四川峨眉对大棚模拟条件下角倍蚜春季的迁飞数量及其与气象因子的关系进行观察分析,结果表明春迁蚜的迁飞活动与天气条件密切相关,在迁飞期内,当日平均气温≥9 ℃、最高气温≥13 ℃、平均相对湿度≤80%,春迁蚜开始迁飞;当日平均气温≥15 ℃、最高气温≥22 ℃、日照时数≥7 h、平均相对湿度≤65%,春迁蚜大量迁飞.在迁飞初期和中期,春迁蚜迁飞数随气温升高而增加.当天气条件适宜时,春迁蚜日迁飞数量的变化为单峰型,前期和末期低、中期高;当迁飞期内遭遇激烈降温,日迁飞数量波动较大,呈双峰或多峰型,同时迁飞期延长、迁飞率和单位面积迁飞量下降.相关分析与主成分分析结果:春迁蚜日迁飞数与平均气温、日最高气温和日照时数呈极显著正相关(P<0.001),与平均相对湿度、最小相对湿度呈显著负相关(P<0.05),与日最低气温和降水量相关性不显著(P>0.1);表明温度和湿度是影响春迁蚜迁飞的关键因子,日照次之.
The Chinese gallnut, an abnormal plant growth formed by larvae of Pemphigidae aphids, is a local specialty of China that is valued as a commercial product for export. Schlechtendalia chinensis is the main commercial aphid species that induces formation of horned galls, which constitute approximately 75% of the global Chinese gallnut yield. Like other Rhus gall aphids, S. chinensis is host species-specific, and can only induce gall formation on its primary host plant, Rhus chinensis. The life cycle of S. chinensis includes six forms: spring alate migration (sexuparae), sexuale (female and male morphs), fundatrix, apterous virginoparae, alate virginoparae (autumnn alate migration), overwintering nymph; and alternation between R. chinensis and certain secondary hosts (mosses). In early spring, alate aphids (sexuparae) migrate from mosses to R. chinensis and produce male and female sexuales, which mate in cracks on the bark. Each mating female sexuale produces a fundatrix through ovoviviparity. The fundatrix crawls to a tender leaf and inserts her stylets into the upper surface of a leaf-wing or leaflet to feed. This causes a small depression, which soon deepens and finally encloses the fundatrix. The horned gall results from the small globular protuberance appearing on the underside of the leaf-wings, and is usually induced by a single fundatrix. Therefore, the numbers of S. chinensis spring migrants can influence the yield of horned galls in a given year. The migratory habits and quantitative dynamics of S. chinensis were observed in a plastic green house from 2009-2010 in Emei mountains, Sichuan province, where the species is naturally distributed. Results show that the migratory behavior of S. chinensis is closely related to weather conditions. During the migratory period, spring migration began when daily mean temperature was higher than 9 ℃, daily maximum temperature was higher than 13 ℃, and mean relative humidity was below 80%. Massive migration occurred when daily mean temperature was higher than 15 ℃, daily maximum temperature was higher than 22 ℃, daily sunshine was longer than 7 hours, and mean relative humidity was below 65%. The number of migrants increased with increasing daily temperature at early and middle migratory stages. The quantitative dynamics was single peak type, and the number of daily migrants was lower in both early and late migratory stages but higher in the middle migratory stage under suitable weather conditions. The number of daily migrants showed strong fluctuations, which appeared as two or more peaks and a prolonged migratory period. Further, the number of migrants was lower during bad weather conditions. Correlation analysis and principal component analysis showed that the number of daily migrants had high significant positive correlation with daily mean temperature, daily maximum temperature and daily sunshine hours (P<0.001), but had significant negative correlation with mean relative humidity and minimum humidity (P<0.05). The number of daily migrants had no significant correlation with daily minimum temperature and rainfall (P>0.1). Results indicate that the migration of S. chinensis is affected by weather conditions, with principle factors being temperature and humidity, followed by sunshine.