低温贮存罗索线虫寄生前期幼虫效果观察

OBSERVATION ON EFFECT OF LOW TEMPERATURE PRESERVATION OF PREPARASITIC LARVAE OF ROMANOMERMIS SP.

本文报道不同温度下罗索线虫寄生前期幼虫可存活的时间。试验表明，在－２～２℃温度下贮存５天，９０％以上的线虫幼虫能保持其感染蚊幼虫的能力。而在２６～２８℃和１６～１８℃下，９０％的线虫仅能存活１天和２天。低温贮存方法可延长线虫的寿命并保持其感染力。

Romanomermis sp. was found in Henan, China. It has a broad host range in Anopheles and has been successfully tested for control of A.sinensis and A.anthropophagus in the field. This study attempts to determine the viability and infectivity of parasitic larvae of R. sp. at various temperature. The culture containing R. sp. eggs were flooded 2h with distilled water, filtered and blocked with 1% agarose. Put the filter paper into water, then the motile preparasites separated from the unhatched eggs and got into water. About 200ml water containing the preparasites free from eggs were held at 26～28℃, 16～18℃ and -2～2℃ for test. The motility or lack of motility was used as the criterion to distinguish the living and dead nematodes. The rate of infection of mosquitoes and the parasitism of nematodes were used to show the infectivity of the preserved preparasites. The results of this study showed that at -2～2℃, more than 90% of preparasitic larvae of R. sp. could live for 5d, but at 26～28℃ and 16～18℃ the 90% survival time of preparasites only 1d and 2d respectively. It indicated that low temperature preservation may prolong the survival time and keep the infectivity of this preparasitic larvae.