致倦库蚊Culex quinquefasciatus自然种群动态与环境条件的关系

在广州地区致倦库蚊Culex quinquefasciatus自然种群每年有2个密度高峰。第一个高峰出现在1月到5月,最高密度在3月到5月中,第二个高峰出现在11月到12月。本文分析了温度、相对湿度、降雨量、大气压等物理环境因素对各虫态数量动态的影响。结果表明,上述各因素对种群动态起综合性影响,但不同因素作用的强度不同,即使是同一因素在不同时期影响的强度也有差异。在1月到4月,各虫态的密度随着温度升高而增加,5月以后,随着温度增加而下降,以1月到6月收集的种群动态的资料与温度进行相关分析,有的年份呈正关,有的年份呈负相关,在7月到12月,种群的密度随温度下降而增加,呈显著负相关。不同季节收集的卵的孵化率无明显差异。降雨量对幼虫、蛹的密度有很明显影响,呈负相关。降雨对成虫数量呈负相关影响,但未达显著水平。降雨对卵块数量影响不明显。成虫的数量与大气压成明显的正相关。

Seasonal Change of Population Density of Culex quinquefasciatus Relation to the Environmental Factors

There are two density peaks annually for the field population of Culexquinquefasciatus in Guangzhou. The first density. peak occurs in January to May,the highest density falls in March to med-May. The second peak occurs in Novemberto December. The physical environmental factors such as temperature, relativehumidity, rainfall and airpresure affecting the population fluctuation are analysed.The results show that above factors act comprehensively on population butdifferent factor affects various with different acting intensity, even if one factoract at different periods the affecting intensity is different. In early spring, Januaryto April, the population density of egg raft, larvae, pupae and adult increasewith the increase of temperature, after May, they decrease with temperatureincrease, analyses of data taken from January to June show some year positivecorrelation some year negative correlation between the population density andtemperature. In July to December, population density increase with temperautredecrease, negative correlation exsists between the two. Negative correlation,r=0. 5624, p<0. 01, between egg raft size and temperature are also observed.No significant different for the hatch rate of egg rafts collected at differentseasons is recorded. For rainfall, negative correlation to the larval and pupal density and no signi-ficant correlation to the adult density and egg rafts are exsisted. Air presure hasobvious positive correlation to the adult density.