云南省粘虫发生世代及其迁飞规律的研究

STUDIES ON THE GENERATIONS AND MIGRATIONS OF ARMYWORM (Mythimna Separata WALKER) IN YUNNAN PROVINCE

粘虫(Mythimna separata Walker)在云南省的发生及为害,由于受特殊地理、气候和耕作制度的影响,表现相当复杂、特异。七十年代以来,其发生为害频繁、程度加重,严重影响了本省的粮食增产。因此,查明粘虫在本省的发生及为害规律,不但在农业生产上有很大意义,而且在学术上也有一定价值。昆明动物研究所受云南省科委的委托,于1974年筹备,1975—1979年先后组织了省内部份地,县农业科技单位协作攻关,基本查明粘虫在本省年发生世代数分别有1—8代,可区分为六个发生区;全年有五次迁飞活动,可造成四次为害。

Since 1970,the armyuorm (Mythimna separata Walker) has often damaged rice,corn and wheat in Yunnan Province.After investigation and by the tests of recapturing marking insects at various areas in the province,We divide our province into six regions,1.The region ovre 3,200 meters above sea level,with one generation a year.2.1,500 to 2,400 meters,2 to 3 gcneartions a year;3.1,300 to 2000 meters,3 to 4 generations a year;4.1,000 to 1.600 meters,4 to 5 generations a year;5.700 to 1,300 meters,5 to 6 generations a year;6.Below 700 meters,6 to 8 generations a year.We also studied:1.The phenomena of simultaneous outbreak and sudden drop in moth population during a certain period of the year;2.Anatomy of female genitalia;3.The marking insects recaptured;4.Degree of its damage to the crops.We found that there are five mass migrations in this province every year:1.Migrate from west and south into Yunnan Province’s western and southern part,its altitude under 1,600 meters,from December to January next year;2.From regions below 1,600 meters to regions 1,600-2,400 meters above sea level,from March to April;3.Most moths migrate from regions notheast of Yunnan Province to regions 1,000-3,200 meters,even more than 3,200 meters,in May and June;4.From regions 1,000-over 3,200 meters migrate back to regions below 1,000 meters,in July and August;5.From regions below 1,000 meters the moths fly westward and southward and off the province in October and November.There are three mass migrations from low lying to higher places in December and first half of the year and two reverse migrations from the altitudes to lows from July to November every year.When the temperature is higher than 30℃,moths migrate to the altitudes.When the temperature began to drop in early autumn,moths migrate reversely from the altitudes to lows.The five migrations result in four crop damages;1.From June to March,regions below 1,600 meters,2.April to May,regions 1,300 to 2,000 meters;3.June and July,regions 1,000 to over 3,200 meters;4.August and September,regions below 1,000 meters.It was found that the vertical character featured the pest’ s outbreak,migration and damage to the crops in Yunnan.