麦红吸浆虫的灾害与成灾规律研究 Ⅱ.灾害出现的影响因子与控制

Studies on Plagues caused by Sitodiplosis mosellana(Gehin) and their Law and ControlⅡ.Factors affecting plague emergence and their control

小麦吸浆虫作为小麦的重要害虫能够成灾,内在条件在于其生活隐蔽、幼虫滞育与多态性、潜伏土壤中隔年或多年羽化、种群数量增长迅速,具r型与k型生态对策的优势特性。小麦作为承灾体,对麦红吸浆虫的危害有一系列防御机制,表现出不选择性、机械抗性、生化抗性等多层次的综合抗性。种植感虫小麦品种,抽穗期与吸浆虫的羽化高峰期相吻合,是出现灾害的基本条件。在半湿润和干旱地区,小麦生态系统的自然环境因子,如地形地势、土壤、温度、降雨、光照、风、天敌,以及农业生产措施如水利工程与灌溉、品种更换、种植制度、土壤耕作、施用农药、施肥、播期等田间管理措施与水平,对麦红吸浆虫发生与暴发成灾有交互影响作用。小麦品种的抗性程度、保持土壤湿度的灌溉条件与雨量、种植制度及农田农药的施用情况是麦红吸浆虫发生与成灾的关键因子,新灌区对麦红吸浆虫的灾害应特别引起注意。麦红吸浆虫灾害发生的过程分为孕育期、潜伏期、预兆期、暴发期、持续期、衰减期、平息期7个阶段。根据灾害出现各阶段的特征,提出了控制策略与监控措施。

Why wheat midge,Sitodiplosis mosellana (Gehin),a serious pest of wheat,can cause heavy damage results from its following characters:it hides most of its life;the larvae have diapause multimorphism and lie in the soil for two to several years before pupating;its population increases rapidly with both r-type and k-type ecological strategies,being capable of out-breaking innately.As the damage receptor,wheat has a series of resistance modes to wheat midge,such as non-escaping physical resistance,and biochemical resistance etc.Planting susceptible wheat cultivars and synchronizing wheat heading with the emergence peak of the wheat midge are the essential conditions to cause plague.In the semi-humid and arid areas,the natural environmental factors in the wheat ecosystem,such as topography,soil composition,temperature,precipitation,light,wind,and natural enemies,and the farming practices,such as irrigation works and irrigation,variety replacement,planting system,pesticide application,fertilizer application,and sowing time,have interactive influences on the occurring and plague of the wheat midge.The key factors influencing the population dynamics and plague of the wheat midge,however,are the resistance of wheat varieties,irrigation condition and precipitation to preserve the moisture content of soil,planting system,and the alternation of pesticides applied in the fields.The plague process of the wheat midge is divided into seven stages:sprouting,incubation,presage,erupting,sustaining,diminishing,and subsiding periods.The strategy and measures to control and forecast its plague are put forward.