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The pine caterpillar is one of the most important pests of pine trees in China. Be-cause there are some disadvantages to apply chemical control of this pest, an urgentneed of using microbial methods as a supplementary measure is evident. The results ofthe preliminary test are very promising. The results are as follows: 1. The application of B. thuringiensis var. thuringiensis to control the pine cater-pillar seems to be very effective. In future it may develop into a new and powerfulweapon in pest control work.... The pine caterpillar is one of the most important pests of pine trees in China. Be-cause there are some disadvantages to apply chemical control of this pest, an urgentneed of using microbial methods as a supplementary measure is evident. The results ofthe preliminary test are very promising. The results are as follows: 1. The application of B. thuringiensis var. thuringiensis to control the pine cater-pillar seems to be very effective. In future it may develop into a new and powerfulweapon in pest control work. 2. The concentrations of the bacterial suspensions should be raised with the in-crease of larval instars. The range is approximately between 15×10~6--2.7×10~8 sporesper c.c. 3. High temperature resulted in a quick infection and death of the larvae. There-fore, the application of this method in June, July and August will give better results,though in cold and wet seasons, for example in March and April in central China, thecontrol is also effective. 4. The applications of B. thuringiensis var. thuringiensis with very dilute concentra-tions of chemical insecticides, such as 666, DDT and Diptrex, will give quicker andbetter results. This is a promising method. Dusting is valuelessly. 本文系应用苏云金杆菌(Bacillus thuringiensis var.thuringiensis)粉制剂防治马尾松毛虫(Dendrolimus Punctatus Walk.)的试验结果,试验表明此菌的致病力高,防治效果好,大有应用的前途。应用时,菌剂的浓度应随幼虫龄期的增加而递增,含孢子数的有效幅度为1,500-27,000万/c.c.死亡率可达90-100%。此菌如与稀浓度化学药剂(如666、DDT、敌百虫)混合使用,防治抵抗力较强的4-7龄幼虫,效果更好。 The European corn borer(Ostrinia nubilalis)is one of the major pest insects of grain crops in Hopei Province.In the past satisfactory control may be achieved by using granulated insecticides at the late whorl stage of the corn.But in recent years the infestation by this pest has aggravated in districts where the cultivation system has changed.This paper reports the occurrence and the integrated control of this insect in Yung-ching County,1974.The results of our study may be summarized as follows.1.Our field... The European corn borer(Ostrinia nubilalis)is one of the major pest insects of grain crops in Hopei Province.In the past satisfactory control may be achieved by using granulated insecticides at the late whorl stage of the corn.But in recent years the infestation by this pest has aggravated in districts where the cultivation system has changed.This paper reports the occurrence and the integrated control of this insect in Yung-ching County,1974.The results of our study may be summarized as follows.1.Our field observations on the development of the European corn borer have shown that when the summer corn is sown between rows of growing wheat,the eggs of the second generation of the pest will be deposited mainly on corn plants at the tasseling-silking stage.When the summer corn is sown after the wheat is harvested as before,the eggs will be equally divided between the corn plants at late whorl stage and those at the tasseling-silking stage.This is the reason why the damage on corn by this insect at tasseling-silking stage is increased in recent years.2.Several insecticides and their mixtures have been tested and some of them are found to be good substitutes for the organochlorine insecticides used before.The effectiveness of 1%,0.5% and even 0.25% granulated E605 were found higher or a little lower than the 5% granulated DDT When 0.5% or 0.1% E605 is added to the soil granules of the white muscardine fungus(Beauveria bassiana)(1:20),the effectiveness is higher or a little lower than the 5% DDT granules respectively.0.1% and 0.2% Phoxim granules are more effective than 0.1% 666 granules.C-9140 soil granules(1:10)are as effective as 5% DDT granules.3.According to our experience the integrated control of the European corn borer in our district may include the following steps:destruction of the host plant debris in the winter,attracting and killing the adult moths by light traps,and the combined use of the fungus and chemical insecticides. 玉米螟是河北省主要粮作害虫。过去在玉米心叶期应用颗粒剂防治已可基本控制为害。近年来一些地区耕作改制后玉米螟的为害又有所回升。我们1974年在永清县对耕作改制后玉米螟的发生进行了系统调查,采用农业、物理、化学、生物等措施,进行综合防治试验、示范,初步明确了以下几个问题: 1.通过对玉米螟发生期及生活史的系统调查,初步澄清耕作改制后,夏玉米由收麦后平播,改变为麦垄套播,玉米螟第二代卵,主要产在抽雄吐丝期,而麦茬平播夏玉米则心叶期和穗期各半。这点是近年穗期螟害加重的主要原因。 2.通过试验、示范,找出代替有机氯治螟的药剂。如1%、0.5%、0.25%1605颗粒剂效果高于或略低于5%DDT颗粒剂;白僵菌20倍加0.5%1605,或白僵菌20倍加0.1%1605颗粒剂,效果分别高于或稍低于5%DDT颗粒剂。0.1%、0.2%辛硫磷颗粒剂效果高于0.1%六六六颗粒剂。2.5%螟铃畏颗粒剂,效果与5%DDT颗粒剂相仿。 3.通过采用农业、物理、化学、生物等综合措施,我们认为本地玉米螟的综合防治概括为:“越冬防治,处理秸秆,诱杀成虫,压低虫源;田间防治,菌药结合,安全经济,控制为害”。 This paper reports the results of studies on the nuclear polyhedrosis virus-of the cotton bollworm Heliothis armigera.The virus was isolated in 1974 from dead boll-worms collected from cotton fields in Chinchow district of Hupeh Province.It was designated as VHA-273.It is observed that the polyhedra are hexagonal,pentahedron,cubical or irregular in shape,varying from 1.25 to 5.0 p in diameter.Serious pathological changes were in the fat-body,epidermis,tracheal matrix and other tissues of the diseased insects... This paper reports the results of studies on the nuclear polyhedrosis virus-of the cotton bollworm Heliothis armigera.The virus was isolated in 1974 from dead boll-worms collected from cotton fields in Chinchow district of Hupeh Province.It was designated as VHA-273.It is observed that the polyhedra are hexagonal,pentahedron,cubical or irregular in shape,varying from 1.25 to 5.0 p in diameter.Serious pathological changes were in the fat-body,epidermis,tracheal matrix and other tissues of the diseased insects and the former two seemed to be the most susceptible tissues.The muscle bundles were not affected.Our bioassay showed that the susceptibility of the larvae to the NPV varied with dosage,larval instar and temperature.The first and second instars were the most susceptible stages;and their mortality rates at 1×106 PIBs/ml were 85% and 80% and the time lasting were 6 and 8 days respectively.Larvae of fifth and sixth instars were not so susceptible,especially when the temperature exceeded 33℃.Cross infections of the NPV with tobacco budworm,Heliothis assulta,was susccessful.In 1975,from July to September,field tests with the NPV to control bollworms were made in cotton fields about 102 mil's at Kung-an County of Hupeh Province.The concentrations used were 1.5×1010 PIBs/mu,3×1010 PIBs/mu and 6×1010 PIBs/mu.The results showed that the NPV was better than the chemical insecticides 1605+DDT.Combined use of the NPV with dilute sevin and Bacillus thurin-giensis suspensions were also tested;and the results were either better or as effective as the NPV or sevin used alone.The application of the NPV VHA-273 to control bollworms in the field seems promising. 自1973—1974年以来,在湖北荆州地区微生物站筛选出一批棉铃虫病毒毒株,其毒力均为80%以上,有的高达100%。其中毒力较强而又比较稳定的VHA-273,经病虫组织切片观察,确定其为核多角体病毒。1974—1975年除对棉铃虫病毒病的组织病理变化作了初步观察外,又继续在室内外对病毒的毒力、剂量与虫龄、温度的关系,及寄主饲料对病毒产量的影响等,进行了一系列的试验,并用VHA-273生产部分病毒,为大田防治试验作了准备。 1975年7—9月,用VHA-273生产的病毒,在湖北公安县雷州公社约102亩的早发棉田进行示范试验,对第2代及第4代棉铃虫的防治效果,先后调查了5次,最后对试验田、对照田及邻田又作了天敌调查,结果均表明试验田的虫口下降率,花、蕾及青铃受害率等,均低于1605+DDT及西维因的对照田,为棉田的生物防治提供了有希望的微生物农药。 VHA-273棉铃虫核多角体病毒,对烟青虫的毒力很强,对两种害虫能交叉感染。因此,它可用于烟青虫的防治。
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