松毛虫赤眼蜂对高粱害虫的防效及生态经济效益评估

Evaluation of the effectiveness,environmental benefit and cost-effectiveness,of using Trichogramma dendrolimi as a biological control for sorghum pests

【目的】高粱是我国重要的食用、饲用、制糖及酿酒用作物,其害虫的绿色防控技术手段的应用和推广非常有限。本研究连续2年在河北省衡水高粱种植区,开展了利用松毛虫赤眼蜂Trichogramma dendrolimi Matsumura防治多种鳞翅目害虫的试验示范,以期为减少化学农药的使用、促进高粱产业的绿色可持续发展,提供一种有效、经济和可靠的害虫防治手段。【方法】赤眼蜂防治试验和化学防治试验分别在两个村子的高粱田内进行。通过统计植株被害率、田间捕食性天敌的丰度及高粱产量等参数,进行成本收益分析,比较两种方法对害虫的防治效果,进一步评价其生态和经济效益。【结果】赤眼蜂防治在减轻植株被害率和提高田间捕食性天敌丰度等方面优于化学防治,同时也实现了高粱的增产增收。与化学防治相比,2019年,赤眼蜂防治显著降低了高粱叶片被害率,田间捕食性天敌的丰度提高了3.96倍,产量略有提高,害虫防治成本相对更低,差额净收入增加了305.47元/hm^(2);2020年,赤眼蜂防治显著降低了高粱穗部被害率,田间捕食性天敌的丰度提高了2.66倍,产量增加了1392.5 kg/hm^(2),单位面积防治成本虽略有增高,但综合起来,差额净收入却增加了3644.05元/hm^(2)(19.90%),增收效果显著。【结论】与化学防治相比,松毛虫赤眼蜂不仅防治害虫效果更好,而且增加了田间生物多样性,提高了天敌的丰度,增产、增收效果显著。利用松毛虫赤眼蜂防治高粱害虫是一种可行、高效并极具竞争力的生物防治手段,具有大面积推广应用的前景。

[Objectives]To evaluate the effectiveness,environmental benefit and cost-effectiveness,of using the parasitoid wasp,Trichogramma dendrolimi Matsumura,as a biological control to protect sorghum,an important crop used for food,animal feed,sugar production and wine-making in China.[Methods]An experimental trial of the release of T.dendrolimi to control a variety of lepidopteran pests was carried out in the sorghum planting area of Hengshui county,Hebei province over two consecutive years.Biological control by releasing Trichogramma,and chemical control of pests were conducted in sorghum fields in two different villages.The effectiveness of the two different pest-control methods was assessed by comparing the amount of crop damage,the abundance of predatory natural enemies and sorghum grain yield,between these villages.We also conducted a cost-benefit analysis in order to evaluate the overall ecological and economic benefits of releasing Trichogramma compared to using chemical control.[Results]Fields in which Trichogramma were released had less plant damage,a greater abundance of predatory natural enemies,higher grain yield and greater profit,compared to those that used chemical control.In 2019,fields in which Trichogramma were released had significantly reduced leaf damage,a 3.96 fold greater abundance of predatory natural enemies and a slightly higher grain yield with lower pest control costs than those that used chemical control,resulting in an increase in net differential income of 305.47 yuan/hm^(2).In 2020,fields in which Trichogramma were released had significantly reduced ear damage,a 2.66-fold increase in the abundance of predatory natural enemies and 1392.5 kg/hm^(2) higher grain yield than those that used chemical control,albeit with slightly higher cost,resulting in an increase in net differential income of 3644.05 yuan/hm^(2)(19.90%).[Conclusion]Compared to chemical control,the release of T.dendrolimi not only significantly reduced crop damage,but sustained the biodiversity and abundance of the natural enemies of crop pests,thereby significantly increasing production and income.As a result,releasing Trichogramma to control sorghum pests is a practical and efficient biological control solution for sustainable pest control in sorghum plantations.