云南省微小按蚊A、C种群密度高峰及嗜血习性的观察

目的研究云南省勐腊县微小按蚊A、C种群密度高峰及其与当地疟疾发病的相关性,并比较微小按蚊A、C的嗜血习性。方法在云南省勐腊县选取人房,逐月收集微小按蚊,以复合PCR方法分子鉴别其为微小按蚊A或C,观察密度高峰;收集当地疟疾发病情况,分析其与微小按蚊A或C密度高峰的相关性。对勐腊和元江县人房和牛栏采集的吸血蚊经复合PCR方法分子鉴别后,以ELISA方法检测胃血来源。结果微小按蚊A的密度高峰出现在9月,微小按蚊C则在7月,两者密度高峰的出现均会引起当地疟疾发病人数的增加。微小按蚊A的吸人血率(19 .1 %)略高于微小按蚊C的(12 .8 %) ,但无统计学意义。结论微小按蚊A、C的的种群密度高峰略有不同,两者均嗜吸牛血,尚不能认为微小按蚊A、C的嗜血习性存在差异。

罗葵地区大劣按蚊成蚊调查

大劣按蚊是海南省山林及山麓地区的主要传疟媒介，1991年6月─1992年6月，连续13个月在保亭县罗葵地区什故村对大劣按蚊成蚊进行了调查，发现当地大劣按蚊构成比为60％（207／345），4、5、6、7、8月份均有，5月为密度高峰（8．3只／人工小时）；平均密度为2．4只／人工小时；半通宵观察平均叮人率为2．96;经产蚊比率为0．646，日存活率为0．88；预期寿命为7．8天，恶性疟原虫孢子增殖需要11．3天；传染性蚊虫比率为0．272，预期传染性寿命为2．06天；媒介能量为6．2。

A Mechanism for Biological Control-Tempo-Spatial Synchronization of Natural Enemy and Insect Pest Population Dynamics at the Peak by Increase of Biodiversity

To reveal the mechanism of control of the Woolly Apple Aphid （Eriosoma lanigerum Hausm, WAA） by increase of biodiversity in the apple orchard, a consecutive two-year field trials were conducted in Yurman province, China. The results showed that the peak of natural enemy density curve in the cover cropping orchard was well temporally synchronized with that of the WAA density on trees, but did not synchronize with that of WAA density on trees in clean orchard. In addition, the frequency of natural enemies and WAA within a same sample in cover cropping orchard was obviously higher than that in clean cultivated orchard during the peak of population curves, indicating that natural enemies spatially synchronized with aphids. The density of WAA for the whole growing season in cover cropping orchard was much less than that in clean orchard. Therefore, the temporal-spatial synchrony of natural enemy and aphid populations was proposed as one of the mechanisms for aphid control in cover cropped orchards.