螟长距茧蜂、玉米螟与春玉米间相互关系的初步研究

研究表明,螟长距茧蜂发生高峰期比玉米螟成虫高峰期大约推迟6-9天,与春玉米抽雄期相一致。玉米抽雄开花时绝大部分玉米螟幼虫处在易被螟长距茧蜂寄生的Ⅲ、Ⅳ龄。玉米开花后雄穗的形态结构和营养成分发生改变,致使幼虫下垂转移寻找更适宜的食物。螟长距茧蜂被取食玉米雄穗的玉米螟幼虫所吸引。其寄生与玉米螟幼虫的发育和玉米生育期密切相关。     

螟长距茧蜂、玉米螟与春玉米间相互关系的初步研究

研究表明,螟长距茧蜂发生高峰期比玉米螟成虫高峰期大约推迟6-9天,与春玉米抽雄期相一致。玉米抽雄开花时绝大部分玉米螟幼虫处在易被螟长距茧蜂寄生的Ⅲ、Ⅳ龄。玉米开花后雄穗的形态结构和营养成分发生改变,致使幼虫下垂转移寻找更适宜的食物。螟长距茧蜂被取食玉米雄穗的玉米螟幼虫所吸引。其寄生与玉米螟幼虫的发育和玉米生育期密切相关。     

螟长距茧峰,玉米螟与春玉米间相互关系的初步研究

研究表明,螟长距茧蜂发生主高峰期比玉米螟成虫高峰期大约推迟６－９天,与春玉米抽雄期相一致。玉米抽雄开花时绝大部分玉米螟幼虫处在易被螟长距茧蜂寄生的Ⅲ、Ⅳ龄。玉米开花后雄穗的形态结构和营养成分发生改变,致使幼虫下垂转移寻找更适宜的食物。螟长距茧蜂被取食玉米雄穗的玉米螟幼虫所吸引,其寄生与玉米螟幼虫的发育和玉米生育期密切相关。     

玉米螟生物防治措施的复合应用研究

为探索玉米螟Ostrinia furnacalis Guenée生物防治新技术,春季应用白僵菌(Beauveriabassiana)封玉米秸秆垛加夏季田间释放松毛虫赤眼蜂Trichogramma dendrolimi Matsumura的方法,实施了大面积玉米螟生物防治技术。结果表明,利用白僵菌封垛加释放松毛虫赤眼蜂的复合技术防治玉米螟,平均防治效果达70.95%,挽回玉米产量损失率6.45%。这种复合生物防治技术减少了田间玉米螟成虫和幼虫的数量,延长了控制玉米螟的时间,可以根据玉米螟的发生情况和玉米生产的需要而应用。     

颗粒剂防治玉米螟试验初报

一、玉米螟发生简况 1962年,百色地区玉米螟越冬代蛾始见在3月中旬,下旬发现第1代低龄幼虫为害早玉米,被害率58％,蛀茎的植株占14.5％;雄花被害的植株占25％。曾先后调查18坵早、中玉米,其中在心叶期的平均被害率14.07％,抽雄授粉期为17.85％;乳熟期为     

亚洲玉米螟与欧洲玉米螟混生区的研究

生殖隔离试验、形态鉴定、网室内性信息素活性反应和食性试验的结果表明 :张家口苍耳中的玉米螟与新疆伊宁的欧洲玉米螟同种 ,而为害玉米的优势种与广东阳山的亚洲玉米螟同种。张家口为害玉米的种群中 ,有部分雄蛾对欧洲玉米螟性信息素及苍耳中的雌处女蛾具有反应。苍耳和玉米中的种群在玉米、谷子、高梁、苍耳、草和大马蓼等 6种寄主上均可产卵和取食为害 ,并能正常完成生活史。研究结果证实张家口为亚洲玉米螟和欧洲玉米螟混生区 ,而且在玉米中很可能有少量欧洲玉米螟与亚洲玉米螟混生。     

利用自然界害虫卵复壮繁殖赤眼蜂兼治棉田害虫

1975年我们利用赤眼蜂防治棉田三代玉米螟兼治四代棉铃虫获得了良好效果,1976年全大队放蜂面积扩大为1,160亩,其中防治棉田三代玉米螟兼治四代棉铃虫600亩,1977年又增达1,416亩,防治棉田三代玉米螟兼治四代棉铃虫为757亩,先后放蜂三次,每次每亩放蜂一万头左右。在三代玉米螟发生期放蜂于玉米诱集带上,第二、三次放蜂于棉花上,每隔三天放蜂一次。经调查夏玉米诱集带上玉米螟的卵寄生率达100％,棉花上玉米螟的卵寄生率为91％。1976年     

北京地区玉米螟系统防治的研究初报

玉米螟是北京郊区玉米的主要害虫,近几年随着田间管理技术和复种指数的提高,玉米螟的发生数量有所增多,春玉米的穗期防治及夏玉米的控制螟害问题,都成了突出要解决的问题。1971年作者随中国科学院动物研究所杂粮害虫研究组在大兴县礼贤公社蹲点,在紫各庄大队二、四生产队科学实验小组的协助下,进行了此项研究,兹将其中的部分初步结果,整理出来,供有关方面参考。     

耕作改制后玉米螟的发生及综合防治

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”。     

河北省衡水地区玉米螟越冬寄主处理调查

一、前言 玉米螟是我省玉米、谷、高粱作物的主要害虫。在冬、春处理其越冬寄主,消灭越冬幼虫是防治玉米螟的一项重要措施。苏联把处理越冬寄主消灭越冬期的幼虫、低茬收获作为预防玉米螟为害的主要措施;罗马尼亚、匈牙利也大力推行处理玉米螟越冬寄主的方法,并且曾有在一定时期内处理完的规定。山西省长治专区曾因处理越冬寄主使玉米螟为害大为减轻。在河北省对这一措施虽然推广已久,在部分地区     

Volatiles induced by the larvae of the Asian corn borer (Ostrinia furnacalis) in maize plants affect behavior of conspecific larvae and female adults

Abstract  Effects of maize ( Zea mays L.) volatiles induced by larvae of the Asian corn borer, Ostrinia furnacalis (Guenée), on the orientation behaviors of Asian corn borer larvae and oviposition of the females were investigated. Nineteen volatile chemicals, with terpenes being the major components, were identified from maize plants attacked by third instar Asian corn borer larvae. Coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses revealed some electroantennographic differences between female and male Asian corn borer antennae in response to larvae-induced maize volatiles; female responded to ( E )-2-hexenal, nonanal, ( Z )-3-hexen-1-ol and three unknown compounds while the male only responded to ( E )-2-hexenal, nonanal and one unknown compound. In laboratory orientation bioassays, Asian corn borer neonate larvae were attracted to extracts collected from Asian corn borer-damaged plants as well as to synthetic farnesene, but were repelled by ( Z )-3-hexen-1-ol. In laboratory oviposition bioassays, gravid females laid fewer eggs on plants damaged by larvae than on mechanically damaged plants or undamaged plants. Adult Asian corn borer females deposited fewer eggs on wax paper treated with ( E )-2-hexenal or ( Z )-3-hexen-1-ol than on wax paper treated with hexane (control). The results suggest that Asian corn borer can affect the behaviors of conspecific larvae and adults by changing host plant volatiles.     

Evaluation of the European Union Maize Landrace Core Collection for resistance to Sesamia nonagrioides (Lepidoptera: Noctuidae) and Ostrinia nubilalis (Lepidoptera: Crambidae)

Two corn borer species are the principal maize insect pests in Europe, the European corn borer, Ostrinia nubilalis (Hübner), and the pink stem borer, Sesamia nonagrioides (Lefebvre). Hence, it would be advisable to evaluate the European maize germplasm for corn borer resistance to generate European varieties resistant to corn borer attack. The creation of the European Union Maize Landrace Core Collection (EUMLCC) allowed the screening of most of the variability for European corn borer resistance present among European maize local populations from France, Germany, Greece, Italy, Portugal, and Spain, testing a representative sample. The objective of this study was the evaluation of stem and ear resistance of the EUMLCC to European corn borer and pink stem borer attack. Trials were made at two Spanish locations that represent two very different maize-growing areas. Populations that performed relatively well under corn borer infestation for stem and ear damage were 'PRT0010008' and'GRC0010085', among very early landraces; 'PRT00100120' and 'PRT00100186', among early landraces; 'GRC0010174', among midseason landraces; and 'ESP0070441', among late landraces. Either the selection that could have happen under high insect pressure or the singular origin of determined maize populations would be possible explanations for the higher corn borer resistance of some landraces. Landraces 'PRT0010008', 'FRA0410090', 'PRT00100186', and 'ESP0090214' would be selected to constitute a composite population resistant to corn borers and adapted to short season, whereas populations 'ESP0090033', 'PRT00100530', 'GRC0010174', and 'ITA0370005' would be used to make a resistant composite adapted to longer season.     

Evaluation of conventional resistance to European corn borer (Lepidoptera: Crambidae) and western corn rootworm (Coleoptera: Chrysomelidae) in experimental maize lines developed from a backcross breeding program

Plant resistance is a promising control method for the two most damaging insect pests of maize, Zea mays L.: the European corn borer, Ostrinia nubilalis (Hübner), and the western corn rootworm Diabrotica virgifera virgifera LeConte. Fifteen experimental lines of maize, derived from a backcross breeding program designed to introgress resistance to European corn borer from Peruvian maize into two U.S. Corn Belt adapted inbred lines, were evaluated for resistance to European corn borer and western corn rootwonrm. The experimental lines were in the second generation of backcrossing. All experimental lines were resistant to leaf blade feeding by European corn borer. These lines had low levels of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one, a chemical commonly associated with leaf blade feeding resistance, indicating that this was not the mechanism of resistance to leaf blade feeding in these lines. Eleven experimental lines were resistant to leaf sheath and collar feeding by European corn borer. Useful sources of European corn borer ovipositional nonpreference and root feeding resistance to western corn rootworm were not identified. Some of the lines evaluated in this study may provide useful sources of resistance to both leaf blade and leaf sheath and collar feeding by European corn borer.     

Biodetrimental effects of the Corn hybrids,Neemazal-T/S and Chlorphan 48% on the pink corn borer Sesamia cretica Led.

The aim of this study was to investigate influence of transgenic and commercial corn hybrids on the behaviour and feeding activity of the pink corn borer (Sesamia cretica Led.). Food consumption was different according to feeding period and hybrids. The feeding ratio of S. cretica on maize hybrids was significantly different between transgenic and commercial hybrids. It appears from the results of this experiment that the antifeeeding activity of transgenic hybrids had greater effect than commercial hybrids one. Thus, it is apparent from these results that transgenic maize was unsuitable because larvae were dead, but the other commercial hybrids were preferable. It can be concluded from the data that the feeding on different maize hybrids had different effects on certain biological aspects of pink corn borer. The impact of untreated Bt. Corn; 0.5% water emulsion of Neem-Azal-T/S and 0.005% water emulsion of Chlorpyrifos insecticides on the behaviour and feeding activity of the pink corn borer S. cretica has been studied. The data showed that larvae stopped feeding from the time when it was fed on untreated Bt. corn or/and non Bt. Corn treated with NeemAzal-T/S 0.5%. The results indicated that Bt. corn, NeemAzal-T/S 0.5% and Chlorphan 48% (0.005%) possessed the toxic effect on pink corn borer S. cretica. According to results, it could be stated that the tested compounds can play an important role in controlling the pink corn borer.     

Transgenic maize hybrids as a tool to control Sesamia cretica Led. compared by conventional method of control on normal hybrids

This study was conducted on Bt and normal maize hybrids during two successive sowing dates, early and late summer plantation. The Sesamia cretica larvae were observed for the first time on first week of April on different commercial maize hybrids. While there was no larva/plant on transgenic maize hybrids, YieldGard and Ageeb-YG, while larvae were found on last week of July by a very little number on maize hybrids for late one. In Early summer planting date showed highly significant differences in reduction percent, between tested compounds and control one, in the pink corn borer population. The bio-residual activity of the NeemAzal-T/S 0.5% on TWC310 was significantly less pronounced, i.e. 75.5%, than other tested ones; the highest percentage of reduction, 86.6%, was achieved by Chlorophan 0.005% on SC2031, followed by NeemAzal-T/S 0.5% on SC2031 83.5% and Chlorophan 0.005% on SC2030 83.4%, respectively. Also the average reduction percentage of S. cretica larvae differed significantly from 69.6%, on NeemAzal-T/S SC2031, to 83.0%, on Chlorophan SC2031, in the late summer planting. The different treatments had positive effects on maize yield in the two planting dates. In the first plantation date, the increased rate of control ranged from 1.04 to 1.24, when NeemAzal-T/S acted on TWC310 and transgenic IYG, respectively. And in the second plantation date, rate of control obtained was 1.06–1.30, when NeemAzal-T/S acted on SC 2031 and transgenic IYG, respectively. The tested compounds played an important role in controlling the pink corn borer insect, S. cretica, and this study suggests that Cry 1Ab-expressing corn hybrids would provide a great value as a component of corn IPM in Egypt.     

Effects of selection for resistance to Sesamia nonagrioides on maize yield,performance and stability under infestation with Sesamia nonagrioides and Ostrinia nubilalis in Spain

A maize synthetic population was improved for resistance to the Mediterranean corn borer (MCB, Sesamia nonagrioides) while maintaining yield. The objectives of this research were to investigate whether yield and yield stability of the maize synthetic population named EPS12 were affected by selection for MCB resistance; also to determine which genotypic and environmental covariates could explain the genotype (G), environment (E) and genotype × environment (GE) effects for yield under corn borer infestation. Plants from three cycles of selection and their testcrosses to three inbred testers (A639, B93 and EP42) were evaluated at two locations in 2 years, under MCB and European corn borer infestations. After selection EPS12 was a more stable genotype. Hybrids derived from crosses between B93 and inbreds obtained from the initial cycles of selection could be recommended for cultivation in northern Spain. The yield of crosses between cycles of selection and testers increased when there were fewer days with temperatures >25°C and higher mean maximum temperatures. Differences in yield among these genotypes were mostly explained by resistance to corn borer attack. In general, among EPS12-derived materials, genetic characteristics that contribute to increased grain yield were also responsible for increased abiotic stress tolerance.     

Effect of environment on resistance to the European corn borer (Lepidoptera: Crambidae) in maize

The European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), is a major pest of maize, Zea mays L., in many temperate parts of the world. Genotype-by-environment interaction effects can make relative performance unpredictable and may hamper selection for resistance to European corn borer. The objective of this study was to determine the effect of environment on genotypic reaction to European corn borer resistance in maize. A set of 12 maize inbred lines was chosen to represent a range of European corn borer responses. Eleven testing environments ranged from Delaware, Ohio, Illinois, Iowa, Nebraska, Missouri, to Mississippi. For length of stalk tunneling, environmental and genotypic main effects (estimated by restricted maximum likelihood) were >20- and 10-fold larger than their interaction effect, respectively. Length of tunneling means for genotypes (across environments) ranged from 10.1 to 35.4 cm. Several putatively resistant genotypes grouped with the susceptible checks, B73 and Mol7. By breaking factors and the interaction into single degree of freedom components, we observed that GEMS-0001 had significant crossover interactions toward less susceptibility in both Mississippi and the Nebraska environments. Environments displaying several crossover interactions indicated that European corn borer screening at these sites would not necessarily apply to other locations, whether due to small differences in experimental conduct and/or environmental effects. The five most resistant genotypes were fairly consistent across environments. Because all environments except Illinois used larvae from the same insectary, and these environments differed in damage intensity and rankings, it is unlikely that insect biotype was a factor contributing to genotype-by-environment effects.     

Conventional resistance of experimental maize lines to corn earworm (Lepidoptera: Noctuidae), fall armyworm (Lepidoptera: Noctuidae), southwestern corn borer (Lepidoptera: Crambidae), and sugarcane borer (Lepidoptera: Crambidae)

Plant resistance is a useful component of integrated pest management for several insects that are economically damaging to maize, Zea mays L. In this study, 15 experimental lines of maize derived from a backcross breeding program were evaluated for resistance to corn earworm, Helicoverpa zea (Boddie); fall armyworm, Spodoptera frugiperda (J. E. Smith); southwestern corn borer, Diatraea grandiosella Dyar; and sugarcane borer, Diatraea saccharalis (F.). Experimental line 100-R-3 was resistant in the field to leaf feeding by fall armyworm and line 116-B-10 was resistant in the field to leaf feeding by fall armyworm and leaf and stalk feeding by southwestern corn borer. When corn earworm larvae were fed field harvested silks from experimental line 81-9-B in the laboratory, their pupal weights were significantly lower than the pupal weights of larvae that were fed silks from the resistant control, Zapalote Chico. Maysin levels lower than those commonly associated with corn earworm resistance were present in the resistant experimental line, 107-8-7, indicating a new basis confers resistance to corn earworm in this line. These resistant experimental lines will provide plant breeders with new sources of resistance to lepidopterous insects for the development of improved maize breeding populations.     

Simulation models for European corn borer postdiapause morphogenesis and early infestation of maize in Missouri, USA

 The European corn borer is one of the most damaging insect pests to maize in the United States. Different methods exist for the estimation of time of damage to corn by first generation European corn borer. The most commonly used method is the linear thermal constant concept of phenology which by convention calculates cumulative thermal units from January 1 or another arbitrary date. Linear and nonlinear models based on the thermal units concept developed were to predict and simulate postdiapause development of the European corn borer and subsequent infestation of the maize crop using early spring temperatures (May 1–15) in central Missouri. The developmental rates of European corn borer were obtained from growth chamber investigations that simulated those temperatures, the operational temperatures being selected from a compilation of archival meteorological data from 1948 to 1989. The linear and polynomial regression models were developed to predict phenological stages of the European corn borer using thermal units as developmental rates. The models were compared against each other to determine the better predictor of estimation values: each explained 94 and 98% of the variation in developmental stages, respectively. In addition, the models were tested against independent field data and both models gave good predictions of developmental stages, indicating that either model would be a good predictor. Received: 9 September 1994 / Revised: 28 December 1995 / Accepted: 8 August 1996