Abstract: 【Objective】 To study on intraguild predation by adult Hippodamia variegata (Coleoptera:Coccinellidae) on Chrysoperla nipponensis by using molecular gut content analysis.【Method】 Molecular analysis were used to detect the DNA of C. nipponensis in the gut contents of H. variegate. Primers for the C. nipponensis were designed according to cytochrome oxidase subunit I gene in Genbank (accession No.KY806757), and the sensitivity of this primer was tested. Moreover, feeding experiments were performed to determine how long prey DNA remained detectable in the guts of H. variegate.【Result】 Species-specific tests showed that the primers were only used to amplify the DNA of the lacewing in C. nipponensis, and had no effect on other pests and natural enemies occurring in the The specificity tests performed with the primers showed that the single band presented in C. nipponensis, and no amplification to other pest and natural enemy of same ecological system. Primer The band was about 220 bp. The sensitivity tests detected with the primers indicat ed that 0.117 ng/μL of prey DNA can could be detected. Feeding experiments showed the detectability of prey DNA declined with digestion time extended. The half-life for adult H. variegata was estimated to be 8.32 h.【Conclusion】 This method can be used to study quantificationally the IGP by H. variegata on C. nipponensis predators in the field.

Key words: Chrysoperla nipponensis; Cytochrome oxidase subunit I gene; adult Hippodamia variegata; gut content analysis; intraguild predation

摘要： 【目的】研究利用分子检测技术评价棉田多异瓢虫对日本通草蛉的集团内捕食作用。【方法】根据基因库 NCBI 中的日本通草蛉的线粒体细胞色素氧化酶 I(COI)的基因序列(登录号为 KY806757),设计日本通草蛉的特异引物,并测定特异引物的灵敏度。利用 DNA 检测技术,在室内以该引物检测喂食5粒日本通草蛉卵的多异瓢虫成虫中肠内靶标食物的衰变情况,估算多异瓢虫对日本通草蛉的半衰期。【结果】所设计引物只对日本通草蛉DNA具有扩增效果,对与其同域发生的其它害虫和天敌不具扩增作用,其扩增片段大小约为220 bp,其最低检出浓度为0.117 ng/μL。多异瓢虫成虫喂食日本通草蛉卵后,检出率随消化时间呈现逐渐下降的趋势,到16 h检出率为0,多异瓢虫成虫半衰期为8.32 h。【结论】利用该技术可定量评价多异瓢虫与日本通草蛉集团内竞争。

关键词: 日本通草蛉, 细胞色素氧化酶 I 基因, 多异瓢虫成虫, 中肠内容物, 集团内竞争