桔小实蝇在黄瓜上连代饲养的种群适合度研究

Study on Experimental Population Fitness of Bactrocera dorsalis Reared Continuously on Cucumbers

为评估桔小实蝇(Bactrocera dorsalis)对北方蔬菜的为害风险,本研究以北方温室内大面积种植瓜类作物的黄瓜为桔小实蝇的寄主,人工饲料为对照,采用年龄-龄期两性生命表的方法研究了该虫在黄瓜上连代饲养的适合度.结果表明,桔小实蝇可以在黄瓜上造成为害,但连续多代在黄瓜上为害的可能性小,对黄瓜的适合度逐代降低.黄瓜种群的桔小实蝇在成虫前存活率、雌雄虫寿命、产卵天数、繁殖力和种群数量等方面均低于人工饲料种群,从适合度较高的寄主转移到黄瓜上连续取食繁殖180 d后,桔小实蝇数量增长倍数(F1:216 624.2;F2:24 387.4;F3:4 459.7)呈现逐代下降趋势.综上所述,桔小实蝇在黄瓜上连代饲养的适合度逐渐降低,在瓜类作物上连代为害的可能性较低,但极可能在嗜食寄主缺乏时成为替代寄主,维持种群数量.因此,黄瓜等瓜类作物种植区应远离果园,并加强其在瓜类作物上的监测,为桔小实蝇的预测预报和全面精准防控奠定坚实基础.

Bactrocera dorsalis is a quarantine fruit and vegetable pest in many countries and regions in the world.In China,under the influence of climate and trade,B.dorsalis(Hendel)has been gradually spreading from south to north.Current studies have shown that B.dorsalis will cause serious damage to the main fruits production in northern China.In order to assess the risk of B.dorsalis on northern vegetables,this study took cucumbers,which are one of melon crops cultivated in a large area in greenhouses in northern China as the host and artificial diet as the control,and studied the fitness of B.dorsalis cultured in successive generations on cucumbers by age-stage two-sex life table method.The results showed that B.dorsalis could cause harm to cucumber,but the possibility of harm to cucumber by multiple generations was small and the fitness of B.dorsalis to cucumber decreased at each generation.The pre-adult survival rate,longevity of male and female,oviposition days,fecundity and population number of B.dorsalis of cucumber population were lower than those of artificial diet population.After 180 days of continuous feeding and reproduction on cucumber from a host with higher fitness,the multiples of number of B.dorsalis increased(F1:216624.2;F2:24387.4;F3:4459.7)showed a decreasing trend of generation to generation.In conclusion,the fitness of B.dorsalis in successive generations on cucumber gradually decreased,therefore,the possibility of damage by successive generations of B.dorsalis in melon crops was low.However,the melon crops were highly likely to become the substitute hosts of B.dorsalis to maintain the population in the absence of feeding host.Therefore,cucumber and other melon crops growing areas should be far away from orchards,and monitoring B.dorsalis on melon crops should be strengthened.This study laid a solid foundation for the prediction,forecast and comprehensive and accurate prevention and control of B.dorsalis.