核型多角体病毒对不同日龄斜纹夜蛾成虫生殖的影响

Effects of Spodoptera litura Nucleopolyhedrovirus on Reproduction of Host at Different Ages

核型多角体病毒不仅直接感染幼虫,也与宿主成虫的生殖密切相关。本文研究了斜纹夜蛾成虫在不同日龄摄入斜纹夜蛾核型多角体病毒(Sl NPV)时对其生殖力和卵巢发育的影响。结果表明,斜纹夜蛾成虫在不同日龄通过补充营养摄入病毒后,其生殖力所受影响因成虫日龄不同而异,随日龄增加,病毒的影响减弱。羽化后第1天即1日龄成虫摄入病毒,其平均产卵量和残留卵量分别为221.6和163.7粒/雌,均显著低于对照(390.5和237.5粒/雌),交配次数也显著降低;4日龄成虫摄入病毒,生殖力未受影响。成虫寿命均未受到病毒的影响。研究还发现斜纹夜蛾卵巢发育分成5级;病毒对1日龄雌蛾卵巢长度有影响,雌蛾在摄入病毒1 d后时,卵巢管长度显著低于对照,但此后又与对照无差异,病毒对2日龄成虫卵巢管长度无显著影响。

Nucleopolyhedrovirus not only infects the larvae of its hosts, but also affects the reproduc6on of the adult. In the present study, effects of Spodoptera litura nucleopolyhedrovirus （SlNPV） on reproduction and ovarian development of the host were investigated when SIN- PV was ingested by adults at differont ages. Egg production, egg deposition, mating frequency and longevity of adults were compared, be.- sides that, length of ovary was also measured. It was found that the impact of SINPV on reproduction of its host varied with host＇ s ages. The eadier SINPV was in, ted, the heavier the impact on reproduction was. When adult S. litura ingested NPV at 1-day-old, the average num- bers d eggs produced and deposited were 221.6 and 163.7 per female, which were all significantly lower than that of the control （390.5 and 237.5）, while when adult S. litura ingested NPV at 4-day-old, both its egg production and depmition were all not affected by NPV ingest- ion. Though NPV had impact on reproduction, it had no effect on longevity of both female and male adults. Similar to impact on egg production, the copulation of adult ingested NPV at 1-day-old was also negatively affected, mating frequency was sigldficantly lower than that of control. It was also found that ovarian development of S. liutra was divided into 5 stages which was the same as that of S. exigua. NPY ad- versely affected the ovarian length of females ingested SINPV at 1-day-old,ordy ld after NPV ingestion, the length of ovary was significantly shorter than that of the control, but 2 d after NPV ingestion, there was no difference between them.