荔枝园红火蚁觅食活动的时序动态及影响因子

Temporal food searching dynamics of red imported fire ant (RIFA) in litchi orchard and their influential factors

红火蚁轻度发生荔枝园与红火蚁重度发生荔枝园的红火蚁种群数量全年的波动均较大，红火蚁的取食活动受天气和季节的影响明显。温度是影响红火蚁取食的重要因素，不同月份因气温等环境因子的不同，工蚁的取食也表现各异。12月份和1月份时觅食活动最弱，诱集的红火蚁也最少，3～6月随着气温的回升，出现一个觅食高峰，诱集的红火蚁逐渐增多，7、8月份受高温和降雨的影响，觅食活动有一定程度的回落，9月中旬以后，红火蚁的觅食活动出现另一个高峰，外出活动的红火蚁数量又有所回升。对影响红火蚁种群波动主要因子的通径分析结果表明，无论是轻度发生，还是重度发生，环境温度对荔枝园红火蚁种群的直接作用较大，且其直接作用大于间接作用，环境温度变化直接影响到红火蚁种群的数量变动。环境湿度对红火蚁种群的间接作用大于其直接作用，且这种间接效应主要是通过环境温度的影响而产生的。

The population dynamics of red imported fire ant （RIFA） was monitored with bait traps between 2005 and 2006 in litchi orchard, and its relationships to the temperature and relative humidity were also discussed. The result showed that the food searching activity of RIFA occurred all the year round in litchi orchard. However, the food searching activity remained at low level during December to the coming January,then at high level during March to November with two peaks in May and October, and a shallow eoncavity in the other months. The effects of temperature and relative humidity on the RIFA population dynamics were estimated with the path analysis. Monthly temperature was the key factor influencing directly RIFA population, while monthly relative humidity influenced indirectly RIFA population development through influencing the environmental temperature.