韭菜根蛆的发生危害及综合防治技术研究——公益性行业(农业)科研专项“作物根蛆类害虫综合防治技术研究与示范”进展

针对我国根蛆类害虫严重危害葱蒜类蔬菜作物,特别在韭菜上问题突出的现状,项目开展了根蛆的生物学和生态学、种群规律、单项防治技术及综合防治技术的研究与示范工作。明确了我国大部分地区韭菜上的根蛆主要是韭菜迟眼蕈蚊Bradysiaodoriphaga Yang et Zhang,在甘肃和辽宁地区的优势种为异迟眼蕈蚊B.difformis Frey。采用黄板诱集成虫结合挖根查幼虫的方法,明确了华北、东北、西北和华东地区根蛆在田间的发生规律。根蛆不耐高温耐低温,春、秋和冬季发生严重,在夏季有转主危害的趋势,冬季以老熟幼虫在0~5 cm土层中越冬。蕈蚊成虫对黑色和棕色趋性最强,研发出特异性的黑色粘虫板。覆盖50~60目防虫网对根蛆的防效最佳,且对韭菜生长有促进作用。建立了蕈蚊成虫的优势捕食性天敌——瘦弱秽蝇Coenosia attenuata的饲养技术和田间应用技术,筛选出了对蕈蚊幼虫高致病力的昆虫病原线虫和Bt菌株,田间防效达60%以上。研发出保护地灌溉臭氧水、减量施药和喷淋施药等轻简化的根蛆防治技术10项。根据不同地区韭菜的种植习惯和根蛆的发生特点,在辽宁、河北、山东、甘肃等地建立了区域性的根蛆类害虫综合防治技术,建立核心示范区10个,进行技术培训5 000人次,取得了一定的经济、社会和生态效益。

The occurrence of,and damage caused by,root maggots on Chinese chives and integrated management techniques to control these pests

Root maggots are serious pests of Allium vegetable crops, particularly Chinese chives. A national project approved in 2013 to address this problem included research on the biological and ecological characteristics of root maggots, their population dynamics, control methods, and integrated management strategies. With the exception of Gansu and Liaoning Provinces where B. difformis is the most common species, the predominant root maggot on Chinese chives is Bradysia odoriphaga Yang et Zhang. The population dynamics of root maggots in northern, northeastern, northwestern and eastern China were clarified using the yellow sticky trap method combined with investigating larvae in soil. Root maggots have strong cold tolerance but relatively weak heat tolerance and cause the greatest damage to crops in spring, autumn and winter. In summer, root maggots move to different crops and overwinter at a depth of 0-5 cm in soil as mature larvae. Because adults prefer black and brown, a black sticky trap was invented. Covering insect-proof nets with 50-60 mesh was effective in protecting chives against root maggots, moreover the growth of chives was also promoted. Methods for rearing the dominant natural enemy of root maggots, Coenosia attenuata Stein, in laboratories and releasing it in the field, were established. Entomopathogenic nematodes and Bacillus thuringiensis strains with high toxicity to root maggots and a control efficacy in the field of>60%were identified. Ten relatively easy techniques, such as irrigating with ozonized water, reducing the application of insecticides, particularly the drench application of insecticides, were investigated. Technologies for the integrated management of root maggots were established according to local production methods and timing of infestation of chive crops. More than 5 000 farmers and agricultural technicians were trained. Obvious economic, ecological and social benefits followed.