豚草卷蛾的寄主专一性测定

HOST SPECIFICITY OF EPIBLEMA STRENUANA [LEPIDOPTERA: TORTRICIDAE]: A POTENTIAL BIO-CONTROL AGENT FOR AMBROSIA ARTEMISIIFOLLA AND A. TRIFIDA [COMPOSITAE]

1990～1992年在北京对从澳大利亚引进原产地为北美的豚草卷娥,对有代表性的15科37种主要经济作物、粮食作物、观赏植物及与豚草近缘或形态上相似的植物,进行了食性测定,特别对菊科植物中有经济价值的作物向日葵,在特定环境条件下进行了多种选择、诱导、强迫性等产卵、取食试验。结果表明:(1)常规方法的测定:无论选择性试验还是非选择性试验,豚草卷蛾只在豚草、三裂叶豚草、银胶菊和苍耳上产卵,并完成发育;而在供试的其它寄主上均未发现成虫产卵,也未发现幼虫企图咬食或钻蛀的痕迹。(2)特定方法的测定:豚草卷蛾不选择向日葵植株产卵;仅在混栽区诱导实验中,发现低龄幼虫可转移到茎秆较细或倒伏的向日葵上蛀食并形成虫瘿,并能完成发育,但向日葵不是豚草卷蛾的适口寄主植物。对影响豚草卷蛾取食行为的各种因素综合分析后,作者认为该天敌可在我国长江以南非向日葵作物区释放,在北方向日葵作物区能否释放,尚需进一步研究。

Epiblema strenuana, a native North American gall-former on ragweeds, Ambrosia spp., was introduced from Australia to China in 1990. Tests with the conventional methods, choice as well as no-choice starvation and negative oviposition tests in the out-door cages, and more specific inducing and inoculative tests with 60 sunflower varieties or strains, were performed in different environmental conditions in Beijing during 1990-1992,.to determine the host range of the moth The results showed that the moth had a restricted host range. In the conventional tests, in which 37 species of economical crops, ornamental plants and species closely related with the ragwecd representing 15 families were included, E. strenuana only attacked and completed its life cycle on Ambrosia artemisiifolia, A. trifida, Parthenium hysterophorus and Xianthium sp. In the specific tests where sunflower (Helianthus annuus L.) was planted in mixture with the ragweeds, however, larvae of E. strenuana were found to form galls on dwarf, fallen down or weakened sunflower plants and had completed a life cycle. Yet no oviposition by the moth was ever found on the sunflowers. A total of 36 galls were found on 262 sunflower plants, with only 5 adults emerged. Prolonged larval and pupal development and a high mortality of the larvae fed on the sunflowers were observed. To confirm the possible feeding and development of the insect on sunflower, newly emerged moths were released in a field cage of 10×8×3 m planted with only sunflower. Eggs and a small proportion of hatched larvae were found on the sunflower plants, but no feeding nor gall forming was discovered. It is concluded that sunflower is not a suitable host for the moth and the insect may not attack sunflower in natural conditions. The authors suggested that it is safe to release the moth in areas, such as south of the Yangtze River where sunflower is not a major crop, for the control of the ragweeds.