光周期对异色瓢虫卵巢和脂肪体发育的影响

Influence of photoperiod on ovarian and fat body development of Harmonia axyridis (Pallas)

为探究光周期在异色瓢虫雌虫卵巢和脂肪体发育过程中的作用以及明确二者之间关系,研究了20℃条件下异色瓢虫雌虫在13个光周期组合下卵巢和脂肪体发育情况,结果表明:在光照时间多于14h(包括14h)时,76%以上的雌虫卵巢发育集中在Ⅳ级、Ⅴ级,全部脂肪体发育为1级或2级,此时卵巢管长度为962.42~1 095.76μm,显著长于短光照下的卵巢管长度;在光周期为10L∶14D时,94.12%雌虫卵巢发育为Ⅰ级、Ⅱ级,卵巢管长度最短,为213.33μm,88.2%的脂肪体发育等级为3级,脂肪体发育水平最高;在光周期为2L∶22D、4L∶20D、6L∶18D、8L∶16D、12L∶12D时,卵巢的5个发育等级同时出现,且发育为Ⅲ级的个体占到了总体的40%;卡方检验显示,异色瓢虫雌虫卵巢与脂肪体发育呈负相关。

In order to figure out the influence of photoperiod on the female ovarian and fat body development of Harrnonia axyrids （Pallas） and to determine the relationship between them, the current experiment investigated the effect of photoperiod on the development of o- vary and fat body of female H. axyridis under 13 photoperiods at 20℃. Results indicated that the ovarian development of over 76% female adults were at stage IV and V when photo- period was more than 14 h（14 h included）, and the fat body development of H. axyridis were all at stages 1 or 2. Besides, the length of ovariole under these photoperiods were 962.42-1 095.76 μm, which was significantly longer than those under short photoperiods. Under the photoperiod of 10L - 14D, the ovarian development of 94.12% female individuals were at stages Ⅰ or Ⅱ , of which the length of ovariole was the shortest as 213.33μm, and the fat body development of 88.2 % female individuals were at stage Ⅲ, which was the highest development level. Under photoperiods of 2L ＂ 22D, 4I. ＂ 20D, 6I. ＂ 18D, 8I. ＂ 16D and 12L ＂ 12D, five ovarian developmental grades all appeared, and around 40% of female ovavies developed into grade Ⅲ. Chi-square test showed that ovarian development of female H. axyridis was negetively correlated with the development of fat body.