文献类型： 外文期刊

作者： Ji, X. -Y. ¹ ; Wan, N. -F. ¹ ; Liu, J. ¹ ; Jiang, J. -X. ¹ ;

作者机构： 1.Shanghai Acad Agr Sci, Ecoenvironm Protect Res Inst, Shanghai Key Lab Protected Hort Technol, Shanghai 201403, Peoples R China

关键词： 20-hydroxyecdysone;haemolymph;Microplitis pallidipes Szepligeti;nucleopolyhedrovirus;Spodoptera exigua (Hubner)

期刊名称：JOURNAL OF APPLIED ENTOMOLOGY （ 影响因子：2.603； 五年影响因子：2.562 ）

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收录情况： SCI

摘要： This study examined the physiological effects of joint and separate parasitism and infection by the endoparasitoid Microplitis pallidipes Szepligeti and the nucleopolyhedrovirus (NPV), respectively, on haemolymph 20-hydroxyecdysone (20-E) titre in Spodoptera exigua (Hubner) larvae. The results indicated that in parasitized larvae, virus-infected larvae (5.7 x 10(3) and 5.7 x 10(5) OB/ml) and parasitized larvae infected with virus at 5.7 x 10(5) OB/ml, compared to healthy larvae, the 20-E all declined during the first 3 days but began to increase from day 4 after treatment, while in jointly parasitized and infected larvae (5.7 x 10(3) OB/ml), the 20-E declined during the first 4 days but began to increase on day 5 after treatment. Meanwhile, compared to parasitized larvae, the 20-E declined during the first 4 days but significantly increased on day 5 in jointly parasitized and infected larvae (5.7 x 10(3) OB/ml), while significantly increased during the first 2 days but began to decrease from day 3 after treatment in jointly parasitized and infected larvae (5.7 x 10(5) OB/ml). Finally, in larvae that were both parasitized and virus infected (5.7 x 10(3) OB/ml), compared to just virus-infected larvae (5.7 x 10(3) OB/ml), the 20-E was lower on days 3 and 4 but higher on other days after treatment; in larvae that were both parasitized and virus infected (5.7 x 10(5) OB/ml), compared to just virus-infected larvae (5.7 x 10(5) OB/ml), the 20-E was significantly higher at the first 2 days but lower from day 3 after treatment. Our results revealed that 2nd instar larval M. pallidipes in host bodies may release 20-E into the haemolymph of S. exigua larvae and that NPV infection may stimulate S. exigua to release more 20-E during its third to fourth instar larval moulting. We found that this stimulatory effect was greater with higher virus concentrations.