向日葵螟对不同向日葵品种的寄主选择性

Selection of sunflower moths for different sunflower cultivars

通过田间选择性试验结合室内黑色素鉴定,研究向日葵螟Homoeosoma nebulellum Denis et Schiffermüller对35个不同向日葵品种的寄主选择性。向日葵螟对不同供试向日葵品种的选择性存在显著差异,选择性最强的是大黑片,其次是S47,再则是5135和RH316,选择性较弱的有T25和天葵503等18个品种,对TO12244和GT110等13个品种无选择性。寄主选择性可以用开花盛期的花盘被害率、每盘可见幼虫数、每盘虫粪指数与籽粒成熟期的籽粒被害率、籽粒被害虫情指数5个指标中的任何一个来评价。相关性分析表明,向日葵螟的寄主选择性与向日葵花盘直径呈显著正相关关系。

Host plant selection of the sunflower moth,Homoeosoma nebulellum Denis et Schiffermüller,by 35 different sunflower cultivars was evaluated in the field in combination with identification of phytomelanin in the laboratory.There was evidence of significant selection for different sunflower cultivars,with the strongest preference for Daheipian,followed by S47,5135 and RH316.Selection to T25,Tiankui503 and 16 other cultivars was weaker,and there was no apparent preference for TO12244,GT110 and the 11 other cultivars.The selection of the sunflower moth for different sunflower cultivars can be evaluated by any of the following criteria,percent infestation of the flower head,the mean number of visible larva per head,fecal index per head during the blooming stage,percent infestation of seeds and infestation index of seeds during the seed maturing stage.There was a significant positive correlation between the degree of host plant selection and flower head diameter.