伞裙追寄蝇滞育诱导的温光周期条件和低温贮藏

Diapause Induction and Cold Storage of Exorista civilis Rondani(Diptera, Tachinidae)

伞裙追寄蝇是草地螟的优势寄生天敌,是对草地螟进行防控的有效手段之一。为了提高天敌防控效果,本试验在室内条件下通过温度和光周期的设定,研究了伞裙追寄蝇的外源滞育诱导条件和低温储藏。结果表明,17℃下光照时间小于12 h,伞裙追寄蝇滞育率为100%,随着温度的升高,滞育率逐渐下降,29℃时,伞裙追寄蝇不发生滞育;不同温度(4～25℃)储藏后伞裙追寄蝇羽化性比为1.38～1.63(P>0.05);16℃时伞裙追寄蝇滞育诱导临界光周期为12.53 h,18℃时临界光周期为11.12 h;越冬虫茧低温储藏后羽化率随着储藏时间的延长而下降。结果说明,温度对伞裙追寄蝇滞育起主导作用,在伞裙追寄蝇幼虫期施以低温处理,可以有效的诱导滞育,4℃低温贮藏最佳时间为50 d。

As one of the efficient control measures of meadow moth, Exorista civilis Rondani is the preponderant parasitic natural enemy of meadow moth. In order to improve the efficiency of the effect of natural enemy control, this study conducted the research on the effect of exogenous diapause induced condition and low temperature storage on E. civilis by setting cycles of temperature and illumination time indoors. The results showed that the ratio of diapause was 100% if the illumination time was less than 12 h at 17℃. With the increased temperature, the ratio of diapause decreased gradually, which reached to top at 29℃. The sexual ratio were various from 1.38 to 1.63 （P〉0.05） after different temperature storage（4-25℃）. The critical photoperiod was 12.53 h at 16℃ and 11.12 h at 18℃. The parasitoid accepted the signal for diapause at the larval stages, the ratio of diapause can reach to 94.3%. For the low temperature storage of overwintering chrysalis. Adult emergence rate was decreased with the extension of the storage period, which was 56.79% at 90 d. This study demonstrated that the temperature played a key role in the diapause of E. civilis. The low temperature treatment can induce the diapause of E. civilis efficiently at larval. The optimum low temperature storage period was 50 d at 4℃.