摘要
苜蓿籽蜂是沙打旺上重要的害虫之一,其蛀食种子,严重影响沙打旺的种子生产。为了确定籽蜂在田间寄生于种子内的时间,以便适时防治,减少危害,本研究于11月初沙打旺成熟期采集了8个品种沙打旺的早花穗(已成熟果穗)和晚花穗(未完全成熟果穗),将每个品种早花穗和晚花穗的单穗脱粒后分别放置于室内用自封袋封闭的玻璃培养皿中,同时将每个品种的3个果穗放置于室外有细小网孔可防止成虫逃逸的尼伦纱网中,每周统计1次羽化成虫数直至羽化结束。室内、外试验均测定籽蜂的整体羽化进度以及在不同品种、不同花穗上的寄生水平等。结果显示,籽蜂对沙打旺种子的寄生率为0(辽宁阜新晚花穗)～20.71%(固原早花穗),随着花穗早晚和品种不同而不同,其中内蒙早熟、宁夏彭阳、固原、辽宁阜新、河南沙打旺的早花穗种子中籽蜂的寄生率显著高于晚花穗(P<0.05)。籽蜂在室内与室外羽化的进度不同,在室内羽化历时167 d,而在室外羽化历时仅77 d;在室内与室外最早羽化时间分别为2月3日和5月5日左右,在室内比在室外提前91 d;羽化高峰期分别为3月31日和5月26日左右,在室内比在室外提前56 d,但羽化末期相同,均为7月21日。早花穗和晚花穗均有2个羽化高峰期,说明收集的果穗中的籽蜂有2个寄生高峰期。籽蜂在不同品种上的羽化进度也不同,意味着籽蜂寄生种子的时期与品种有关。由此可知,籽蜂的幼虫无冬季休眠习性,只要温度适宜就可继续生长取食、发育并完成羽化。室外放置的沙打旺果穗和室内存放的种子中的籽蜂均可成为田间沙打旺的虫源,由本研究得出田间防治籽蜂应在沙打旺始花期至7月下旬左右进行。
Alfalfa seed chalcid(Bruchophagus roddi) is an important insect pests in milk-vetch(Astragalus adsurgens) as it bores into seeds, and seriously affects the yield of viable seed. In order to obtain relevant information for timely control and reduction of this pest, in this study mature inflorescences(early flowering, EF) and immature inflorescences(late flowering, LF) were collected from 8 regionally sourced germplasm lines(Inner Mongolia, Guyuan, Ningxia, Liaoning, Shanxi, Ordos, Henan, Zhongsha) of A. adsurgens, beginning in early November when plants were at a mature stage of growth. Three inflorescences of each variety were enclosed in nylon bags with fine mesh and placed outdoors in order to capture and count emerging adults. At the same time, seeds of each enclosed inflorescence were harvested and put into glass petri dishes in the laboratory at room temperature. The number of emerging adults in each treatment were then counted weekly, until no further emergence of adults occurred. The objectives of these tests were to determine the timing of emergence of B. roddi and the levels of parasitism of different varieties and different categories of spikes. The percentage of parasitized seeds ranged from 0 in late flowering inflorescences of the Liaoning line, to 20.71% in early flowering inflorescences of the Guyuan line. Generally, parasitism of late flowering inflorescences was low. Only the Shanxi line had significant parasitism of late flowering inflorescences, while the Ordos line was notable, compared to other lines, for low parasitism of early flowering inflorescences. The emergence timing of B. roddi differed between the indoor and outdoor samples with adults first appearing on February 3 rd and May 5 th, respectively(91 day difference);and peak emergence on March 31 st and May 26 th, respectively(56 day difference). Hence, the indoor adult emergence period lasted for 167 days, while the outdoor feathering lasted only 77 days. However, the date of complete emergence for both indoor and outdoor conditions was all on July 21 st. There were two emergence peaks in both EF and LF inflorescences, indicating that the B. roddi in the collected spikes had two egg-laying periods. In addition, emergence timing differed between varieties meaning that the date of egg-laying was affected by the plant variety. In conclusion, the larvae of B. roddi have no winter dormancy, and can continue to grow, feed, and develop to adults as long as the temperature is appropriate. All the emerging adults counted, both indoors and outdoors, would have been able to fly and attack other plants in the field. It is concluded that the optimal time to control B. roddi adults in A. adsurgens field crops would be from the beginning of flowering to late July.
作者
刘慧
NZABANITA Clement
李彦忠
LIU Hui;LI Yan-zhong(State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China;Institute of Grassland Research, Chinese Academy of Agricultural Sciences (CAAS), Hohhot 010010, China)
出处
《草业学报》
CSCD
北大核心
2019年第4期146-156,共11页
Acta Prataculturae Sinica
基金
兰州大学中央高校基本科研业务费专项资金(lzujbky-2017-k02)
公益性行业(农业)科研专项经费项目(201303057)
国家现代农业产业技术体系(CARS-34)
南志标院士工作站(2018IC074)
高等学校学科创新引智计划(B12002)
创新人才培养项目计划(lzujbky-2017-it10)资助
关键词
豆科牧草
种子产量
产卵
生活史
越冬
Leguminous forage
seed yield
lay egg
life history
overwintering
