关键词: 白背飞虱, 缨小蜂, 卵被寄生率, 水稻品种, 施肥时间

Abstract: To understand the effect of rice variety and fertilization timing on egg parasitism of the white-backed planthopper, Sogatella furcifera (Homoptera: Delphacidae) by parasitoids, experiments with “trap” rice plants of two varieties (indica-japonica hybrid combination Xieyou 413 and japonica Xiushui 11) were set up in the habitats created by the combinations of the two rice varieties and fertilizations at two different dates in the single-cropping season rice plots in Hangzhou, China. The location of egg masses of S. furcifera laid in plants of Xieyou 413 were higher and the clutch size of egg masses was larger than that of those laid in plants of Xiushiu 11. The parasitism of S. furcifera eggs by Anagrus spp. (Hymenoptera: Mymaridae) was significantly affected by rice varieties used as traps, but not by rice varieties and nitrogen fertilization timing in the field. The parasitism (24%) in Xieyou 413 as trap was significantly higher than that (12%) in Xiushui 11 as trap. The parasitism in the plants (Xieyou 413 vs Xiushui 11: 17% vs 9%) grown in the field was more significantly influenced by rice varieties than by fertilization timing. The results implied that rice variety was an important factor in enhancing the biocontrol of the planthopper. Additionally, the estimation of egg parasitism by trapping approach was significantly correlated with that by dissection of rice plants sampled from fields.

Key words: Sogatella furcifera, Anagrus spp., egg parasitism, rice variety, fertilization time