扬州地区水稻二化螟寄生蜂种类及主要寄生蜂发生动态

本文报道了江苏扬州地区水稻二化螟Chilo suppressalis(Walker)寄生蜂主要有10种,即中华钝唇姬蜂Eriborus sinicus(Holmgren)、二化螟盘绒茧蜂Cotesia chilonis(Munakata)、稻螟小腹茧蜂Microgaster russata Haliday、螟甲腹茧蜂Chelonus munakatae Munakata、中华茧蜂Amyosoma chinensis(Szepligeti)、螟黄足盘绒茧蜂Cotesia flavipes(Cameron)、夹色姬蜂Auberteterus alternecoloratus(Cushman)、桑蟥聚瘤姬蜂Iseropus(Gregopimpla)kuwanae(Viereck)、螟蛉瘤姬蜂Itoplectis naranyae(Ashmead)以及二化螟盘绒茧蜂的重寄生蜂绒茧灿金小蜂Trichomalopsis apanteloctena(Crawford)。田间系统调查表明:扬州地区7-9月水稻二化螟寄生蜂的主要种类为二化螟盘绒茧蜂、中华钝唇姬蜂、螟甲腹茧蜂、稻螟小腹茧蜂、螟蛉瘤姬蜂、桑蟥聚瘤姬蜂,但这些寄生蜂对一代水稻二化螟幼虫的寄生率较低,对二代水稻二化螟幼虫的寄生率高。水稻二化螟越冬期的系统调查表明:扬州地区二化螟越冬幼虫的寄生蜂主要有3种,即二化螟盘绒茧蜂、中华钝唇姬蜂和稻螟小腹茧蜂,其中二化螟盘绒茧蜂和中华钝唇姬蜂是寄生水稻二化螟越冬幼虫的优势种。水稻二化螟越冬幼虫的寄生率调查表明,扬州地区水稻二化螟越冬幼虫的寄生率在不同年份间有一定的波动,但一般都在15%以上,有的甚至高达89.88%,因此寄生蜂对二化螟越冬幼虫具有很好的控制作用,能有效压低来年水稻二化螟的田间越冬基数。此外,3种寄生蜂出茧时间在1月和2月之间达到最长,分别达到19.79 d、17.26 d和27.00 d,该结果表明,在扬州地区这3种寄生蜂可能都存在滞育现象。

Species and occurrence dynamics of parasitic wasps of the rice stem borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae) in Yangzhou

In this study, ten species of parasitic wasps of Chilo suppressalis were found in the field in Yangzhou district in Jiangsu Province. And they were Eriborus sinicus ( Holmgren ) , Cotesia chilonis ( Munakata ) , Microgaster russata Haliday, Chelonus munakatae Munakata, Amyosoma chinensis ( Szepligeti ) , Cotesia flavipes ( Cameron ) , Auberteterus alternecoloratus ( Cushman ) , Iseropus ( Gregopimpla) kuwanae ( Viereck ) , Itoplectis naranyae ( Ashmead ) and Trichomalopsis apanteloctena ( Crawford ) . According to systematical investigation in the field, the result exhibited C. chilonis, M. russata, E. sinicus, I. naranyae, C. munakatae, and I ( G. ) kuwanae were the primarily parasitic wasps of C. suppressalis between July and September. But the parasitic rate of these parasitic wasps to second generation of rice stem borer larvae is higher than the first generation. During overwintering phase of C. suppressalis larvae, our systematical survey indicated C. chilonis, M. russata, and E. sinicus were three main parasitic wasps, furthermore, C. chilonis and E. sinicus were both dominant. The survey shows there are certain fluctuations with the parasitism of overwintering larvae in Yangzhou in different years, The parasitism is often above 15%, some even as high as 89. 88%. Therefore, it helps control the overwintering rice stem borer larvae well. Moreover, average durations of the cocoons of three species of parasitic wasps found from the overwintering larvae of C. suppressalis were the longest between January and February, 19. 79 days for C. chilonis, 17. 26 days for M. russata and 27. 00 days for E. sinicus respectively. These results suggest three parasitic wasps might enter the diapause in Yangzhou district.