甘蓝挥发物对小菜蛾幼虫取食行为的影响

Feeding behavior of Plutella xylostella larvae responding to volatiles from Brassica oleracea L.

[目的]明确寄主植物甘蓝(Brassica oleracea L.)挥发物对小菜蛾(Plutella xylostella)幼虫取食行为反应的影响,为筛选小菜蛾植物源引诱剂提供理论依据。[方法]利用Y型嗅觉仪测定小菜蛾幼虫雌雄虫对甘蓝3种活性挥发物的嗅觉反应,通过田间试验测定在挥发物存在下小菜蛾幼虫对花椰菜植株的取食效果。[结果]甘蓝3种挥发物能够引起小菜蛾幼虫嗅觉反应,但不同浓度下引诱选择率不同。异硫氰酸烯丙酯浓度为1μg·μL;时对雌雄小菜蛾幼虫均表现出极显著引诱效果,引诱率分别为75%和80%;浓度为10μg·μL;的异硫氰酸丁酯对雌、雄幼虫的引诱率分别为75%和80%;顺-3-己烯醇对幼虫雄虫引诱率为70%;在田间取食试验中,3种化合物总体上可以促进小菜蛾幼虫取食,取食指数均显著高于对照,然而浓度为500μg·μL;的异硫氰酸烯丙酯则对雄性幼虫表现出拒食效果。[结论]异硫氰酸烯丙酯、异硫氰酸丁酯和顺-3-己烯醇对小菜蛾幼虫具有较强的引诱作用,这些可为治理小菜蛾为害十字花科植物提供新的思路和方法。

[Objective]This study was to clarify the feeding behavior of Plutella xylostella larvae responding to volatiles from Brassica oleracea,and to provide a theoretical basis for screening the plant-derived attractant of P.xylostella.[Method]The olfactory response of the both male and female larvae to three active volatiles extracted from B.oleracea was determined through Y-tube olfactometer assays,and the feeding activities of larvae on B.aleracea L.var.botrytis L.in the presence of volatiles was determined by field experiments.[Result]The three volatiles induced olfactory response of P.xylostella larvae,but different concentrations of volatiles displayed different attracting rates to larvae.Allyl isothiocyanate showed an extremely significant attracting effect on both female and male larvae at the concentration of 1μg·mL;,and the attracting rates were 75%and 80%,respectively.The attracting rates of butyl isothiocyanate to male and female larvae at a concentration of 10μg·mL;were 75%and 80%,respectively;the attracting rate of cis-3-hexen-1-ol to male larvae was 70%.In the feeding test,the three compounds promoted the feeding of P.xylostella larvae in general,and the feeding indexes were significantly higher than that of the control.However,allyl isothiocyanate showed an anti-feeding effect on male larvae at a dose of 500μg·μL;.[Conclusion]Allyl isothiocyanate,butyl isothiocyanate and cis-3-hexenol have strong attracting effects on P.xylostella larvae,and these results provide new ideas and methods for control P.xylostella on cruciferous plants.