间作番茄对花椰菜田主要害虫和天敌的调控作用

Regulation of dominant insect pests and natural enemies by intercropping tomato in cauliflower-based fields

【目的】已有研究表明花椰菜Brassica oleracea var.botrytis田合理间作番茄Lycopersicon esculentum对菜田主要害虫具有抑制作用。本研究旨在进一步探明提高花椰菜田生态系统保益控害服务功能的番茄最佳间作比例。【方法】2014年2-5月,试验在福建省闽清县省级标准农田示范区(26°10'41″N,118°48'10″E)内进行,按番茄株数占花椰菜田总植株数中的比例设置4个梯度小区,分别为0%,10%,30%和50%,小区采用随机区组设计,通过目测法对花椰菜菜田节肢动物的种类和个体数量进行观察并记录。【结果】间作番茄显著降低了花椰菜田中菜蚜Lipaphis erysimi的个体数量,且控制效果随番茄间作比例的上升而增强(50%>30%>10%)。间作30%和50%番茄显著降低了黄曲条跳甲Phyllotreta striolata的个体数量,但2种间作比例的效果差异不显著。间作番茄不影响菜青虫Pieris rapae和蜘蛛的个体数量。3种间作比例都提高了菜蛾绒茧蜂Cotesia plutellae的个体数量和蜂/蛾比,但三者差异不显著。【结论】在花椰菜田中间作30%的番茄,对害虫控制最有利。

【Aim】It has been documented that intercropping with tomato,Lycopersicon esculentum,can suppress populations of the dominant insect pests in cauliflower（ Brassica oleracea var. botrytis） fields.The present study aims to find the optimal ratio of tomato intercropped for protection of natural enemies and suppression of insect pests in cauliflower-based fields. 【Methods】The study was conducted in a provincial standard demonstration site located in Minqing County of central Fujian（ 26°10’41″N,118°48’10″E）. The experiment was designed with scaled-up intercropping ratios of 0%,10%,30% and 50%of tomato plants to the total plants in cauliflower-based fields,using a randomized-block arrangement.The species of arthropods and their numbers of individuals in the cauliflower fields were visually observed and recorded. 【Results 】 The results showed that the number of individuals of Lipaphis erysimi was significantly suppressed in the cauliflower-based intercropping fields and the inhibitory efficacy increased with increasing of the intercropping ratio of tomato（ 50% 〉 30% 〉 10%）. The number of individuals of Phyllotreta striolata decreased significantly in the intercropping fields with 30% and 50% tomato plants as compared to that in the monoculture system of cauliflower,but with no significant difference between the intercropping systems with 30% tomato plants and with 50% tomato plants. Intercropping with tomato had no effects on the numbers of individuals of Pieris rapae and spiders in the cauliflower-based fields.The number of individuals of Cotesia plutellae and the ratio of C. plutellae wasps to Plutella xylostella moths increased in the intercropping fields compared to those in the monoculture system of cauliflower,but with no significant differences among the three intercropping ratios. 【Conclusion 】 The 30%intercropping ratio of tomato plants is most optimal for the control of insect pests in cauliflower-based fields.