两种稻田摇蚊采集方法的比较

本文介绍了一种较为简便和节省人工的稻田摇蚊田间取样方法:笼罩法,并将笼罩法得到的稻田摇蚊群落结构和发生动态和吸虫器法得到的结果进行了比较。研究结果表明:在水稻的4个生育期中,笼罩法和吸虫器法均采集到了中华摇蚊Chironomus sinicus Kiknadze,Wang,Istomina&Gunderina;台湾长跗摇蚊Tanytarsus formosanus Kieffer;云集多足摇蚊Polypedilum nubifer Skuse和刺铗长足摇蚊Tanypus puncitpennis Meigen,而吸虫器法还采集到微小沼摇蚊Limnophyes minimus Meigen。其中中华摇蚊和台湾长跗摇蚊为优势类群,笼罩法取样得到的两种优势种种群密度均高于吸虫器法的,例如在拔节期时笼罩法取样得到台湾长跗摇蚊的种群密度是吸虫器法的22倍。通过取样变异系数的比较发现,两种方法精确性都并不理想,在今后的试验中可以通过增加取样的样点量或取样面积来提高精确度。相比较而言吸虫器法操作复杂,而且较为耗时,在实际操作中往往受到一定条件的限制,而笼罩法则具有操作简便、准确度高等优点,试验安排可以进行高频率取样,能够更准确地反映田间摇蚊的种群动态。因此,笼罩法为以后研究与摇蚊生活习性相似的稻田节肢动物类群(如蚊科昆虫)提供了一种新的取样方案。

Comparison of two sampling methods for chironomid midges in rice fields

The nature, operation and operator time requirements for emergence traps as a method for studying rice field- dwelling, non-biting midges are introduced. The bio-community structure and major aspects of population dynamics of non-biting midges determined using emergence traps are compared with those determined using the classical sampling method, a motorised suetion trap. We found that both methods collected four species, namely Chironomus sinicus Kiknadze, Wang, Istomina ＆ Gunderina; Tanytarsus formosanus Kieffer; Polypedilum nubifer Skuse and Tanypus punctipennis Meigen. In addition, Limnophyes minimus Meigen was collected by the motorized suction method only. Both methods demonstrated C. sinicus and T. formosanus to be the dominant species in rice fields, but the emergence trap collected significantly more midges than the motorised suction trap. For example, the estimated density of T. formosanus collected by the emergence trap was 22 times as high as that for the motorized suction method at the rice elongation stage. The comparison of variation coefficients shows that neither method has a marked advantage over the other. We suspect that both methods require the taking of more samples to increase accuracy. In comparison with the emergence trap, the motorized suction trap requires is much more labor intensive and time consuming in the field and laboratory. Therefore, sampling frequency can be more readily increased by use of the emergence trap providing much better information on population dynamics. We consider that the emergence trap is also a suitable method for studying mosquitoes in rice fieldsas mosquitoes have similar biological characteristics to non-biting midges.