红火蚁觅食活动的气象因子相关性及其等级划分

背景]气象因子是制约害虫种群动态的重要因素，也是昆虫觅食活动的影响因子。【方法】通过系统的田间调查分析了红火蚁在华南地区的觅食活动年变动规律及其与气象因子的关系。结果]红火蚁在12和1月份时觅食活动最弱，3—6月出现一个觅食高峰，在下半年的9—11月出现另一个高峰，7、8月份受高温的影响觅食活动有一定程度的回落现象。红火蚁工蚁觅食活动的年变化规律又因不同生境类型呈现一定的差异。相关分析结果表明，红火蚁觅食工蚁数与降水量、月平均气温、月最低气温、月最高气温、月最小相对湿度呈正相关，而与月平均气压呈负相关，且各相关性均达显著水平。逐步回归分析表明，月平均气温、日照时数、月最低气温综合影响红火蚁觅食活动的变化。其中，月平均气温可以作为一个非常重要的直接影响红火蚁觅食活动的参数。对荔枝园内全年红火蚁觅食活动进行分级，对方程进行求导得到红火蚁在荔枝园中觅食活动的5个活动级别所对应的月平均温度、日照时数和月平均最低气温实际临界值。结论与意义]气象因子与红火蚁的觅食活动存在密切的相关性，研究结果可为红火蚁的监测与控制提供依据。

Climate correlation analysis and grade partition of foraging activity of Solenopsis invicta Buren

Background] Climatic factors are important for restricting foraging activities as well as population dynamics of insects. Method] Annual monitoring was conducted on the dynamics of the Solenopsis invicta colony in south China. Result] The results showed the foraging activities of the fire ant occurred all the year round. The foraging activity of S. invicta slowed down in December and January, steadily increased from February until it peaked from March to June, and then declined in July and August. Another foraging activity peak appeared from September to November. Habitat affected the foraging activity of the fire ant to some extent. The correlation analysis indicated that monthly rainfall, mean monthly temperature, mean monthly minimum temperature and monthly minimum relative humidity had significant positive correlations with the number of foraging workers. Monthly atmospheric pressure showed a negative correlation with activity. The results of stepwise regression analysis showed that mean monthly temperature, monthly sunlight hours and mean monthly minimum temperature were the major climatic factors influencing foraging activity of the fire ant. Using a path and decision coefficient analysis, it was found that mean monthly temperature was the most significant factor influencing foraging activity. 1tle levels of damage from S. invicta workers in the lychee （Litchi chinensis） orchard was estimated and showed that mean monthly temperatures, monthly sunlight hours and mean monthly minimum temperatures were the variables. Con- clusion and significance ] This study showed the climatic factors were closely related to the foraging activities of the red imported fire ant. The results provided a scientific basis for monitoring and control of the fire ants.