梨园作物间作与生物药剂对梨木虱及其捕食性天敌种群数量动态的协同调控作用

Synergistic Manipulation of Intercrop Combining Biological Medicaments on the Population Dynamics of Psylla Chinensis and Predators in Pear Orchard

中国梨木虱(Psylla chinensis)遍布全国猖獗为害,对梨产量和品质造成极大威胁。梨木虱若虫在其分泌物的保护下生活、为害,药剂很难触及虫体杀死若虫,且对各类农药品种均可产生抗药性。为了减少化学农药用量,本研究定量评价了间作作物与生物药剂相结合生态控制梨木虱的效果。2013年和2014年采用梨园控制实验,系统研究了梨园间作白三叶草、桔梗与生物药剂结合对梨木虱及其捕食性天敌种群数量动态的协同调控作用。2年的实验结果表明:白三叶草、桔梗作物间作区捕食性天敌总数显著高于清耕裸地区。2013年白三叶草间作区优势种捕食性天敌为微小花蝽Orius minutus,桔梗间作区优势种捕食性天敌为梭形毒隐翅甲Paederus fuscipes。2014年三叶草间作区优势种捕食性天敌为草间小黑蛛Erigonidium graminicolum、中华小步甲Tachys chinensis,桔梗间作区优势种捕食性天敌为异色瓢虫Harmonia axyridis、龟纹瓢虫Propylaea japonica、黑带食蚜蝇Episyrphus balteata和草间小黑蛛E.graminicolum。2013年,2种作物间作+生物药剂区梨树上梨木虱若虫种群数量除6月18日显著高于裸地常规施药区外,其余时期与裸地常规施药区均无显著差异。2014年,在梨木虱为害的各个时期2种作物间作+生物药剂区梨树上梨木虱成虫、若虫种群数量均显著低于裸地常规施药区。研究表明梨园间作多年生白三叶草、桔梗一年后与生物药剂SAVONA结合可替代50%化学农药施用量,对全年各代梨木虱成虫、若虫的控制效果显著高于清耕裸地常规施药。

P. chinensis is one of the most harmful pests all over the country which has a serious threat to the production and quality of pears. Nymphae of P. chinensis can live under the protection of its own secretion, pesticide is hard to reach and kill them. Furthermore, nymphae can make resistance to any kinds of pesticides. This research is to estimate quantitatively the effect of intercrop combining with biological medicament controlling the Psylla chinensis ecologically. In 2013 and 2014, the manipulating experiment was established in pear orchard. The synergistic manipulation of pear intercropping Trifolium repens and Platycodon grandiflorum combining with the biological agent on the population dynamics of P. chinensis and their predators were determined systematically. The results showed that the total population size of predators in the areas of intercropping T. repens and P. grandiflorum were higher than that in the bare area by artificial weeding. In 2013, the predator of dominant species was O. minutes in the area of intercropping T. repens and P. fuscipes was in the area of intercropping P. grandi-florum. In 2014, E. graminicolum and T. chinensis dominated in the area of intercropping T. repens;H. axyridis, P. japonica, E. balteata and E. graminicolum dominated in the area of intercropping P. grandiflorum. In 2013, the nymphae populations of P. chinensi in the areas of both intercropping T. repens and P. grandiflorum combining with the biological agent on June 18 were significantly higher and on other dates were not significant difference compared with the bare area with conventional pesticide application. In 2014, the population densities of both adults and nymphae of P. chinensis were significantly lower in the areas of both intercropping T. repens and P. grandiflorum combining with the bio-logical agent than that in the bare area with conventional pesticide application during all the period of P. chinensis occurence. This research demonstrated that the measure of intercropping perennial T. repens and P. grandiflorum in pear orchard one year later combining with application of the biological agent SOVONA could substitute half amount of chemical pesticide usage. The synergistic manipulation effect of this measure was significantly higher relative to conventional pesticide application in the bare area of artificial weeding.