首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 78 毫秒
1.
粘虫是莱西县小麦的主要害虫之一,多年来已成为小麦的常发性害虫,在水浇丰产田发生尤为严重,影响产量很大。二代粘虫主要为害麦田套种玉米,如防治不好玉米苗则会全部被吃光。为了摸清麦田二代粘虫发生规律,搞好测报,笔者在一代粘虫成虫大发生的年份里对一代蛾嗉囊液的含糖量每年都进行测定,如发现含糖量高,一代蛾则留在当地产卵;如含糖量达6％以下,则一代蛾就会飞走,蛾量再大也不会造成二代幼虫的大发生。笔者从1966年起历年都于一代成虫发蛾盛期在麦田进行观察,发现一代蛾量虽大,二代幼虫密度也不一定准大的规律。 方法是,在黑光灯和杨树枝把中一代粘虫蛾量“激增”(大田小麦灌浆乳熟时期),黄昏时分麦田中有大量粘虫蛾取食时目测1平方米小麦穗部蛾数;再于翌晨取杨树枝把上的粘虫蛾10头取其嗉囊液用日本产补正糖度计,逐头进行测定。  相似文献   

2.
空气相对湿度对粘虫飞翔活动的影响   总被引：8，自引：0，他引：8  
在室内条件下，系统研究了粘早蛾飞翔活动与温度的关系，试验结果表明，空气相对湿度对粘虫蛾的翔活动具有显著影响，干燥或极端潮湿的条件均不利于粘虫飞翔活动，适宜的空气相对湿度为７０％－８５％。在蛾龄或温度不同的情况下，湿度对其飞翔活动的影响是一致的。在不同相对温度下由飞翔活动造成的体重和水分损失随温度的增加而减少，且蛾龄越低其损耗愈重。另外，根据测试结果讨论了粘虫在自然情况下迁悦时的空间位置等问题。  相似文献   

3.
以广西大学东校园内糖胶树上的绿翅绢野螟[Diaphania angustalis(Snellen)]4龄幼虫为研究对象,研究了氰戊·辛硫磷处理后不同时间(10、30、60、90 min和120 min)对绿翅绢野螟4龄幼虫呼吸代谢、解毒酶和保护酶活性的影响。结果表明,在25℃时,氰戊·辛硫磷药液浓度128.35 mg/L处理绿翅绢野螟4龄幼虫30 min后出现明显的呼吸峰,CO_2释放率达到15.68μL/h,随后迅速降到对照水平。绿翅绢野螟4龄幼虫的乙酰胆碱酯酶和超氧化物歧化酶活性在氰戊·辛硫磷处理初期显著升高,分别达到5.57×10~(-2) n mol/s和12.3 n mol/s,60 min后迅速下降到对照水平,分别为1.87×10~(-2) nmol/s和9.42 nmol/s;过氧化物酶活性变化初期与乙酰胆碱酯酶和超氧化物歧化酶相似,但在60 min后酶活性开始升高,120 min时达到307 n mol/s,极显著高于对照。  相似文献   

4.
为了明确短期低温和高温对草地贪夜蛾蛹和成虫生长发育的影响, 设置低温10?13?16?19℃和高温35?38?41?44℃共8个温度梯度, 将初化蛹和新羽化成虫分别处理2 d和4 d, 之后置于28℃下继续饲养, 观察了不同处理下蛹的发育历期?羽化率?成虫寿命?成虫产卵期及繁殖力等生物学指标?结果表明, 草地贪夜蛾蛹经10~19℃低温2 d和4 d处理, 羽化率随着温度和时间的增加而逐渐增加, 最高达到100.0%, 而经35~38℃高温2 d和4 d, 其羽化率降至30%~60%?发育历期随温度的升高逐渐缩短, 41℃以上高温处理2 d时蛹全部死亡, 即蛹的致死高温≤41℃?在10~19℃时, 成虫寿命随着温度升高表现为先增加后减少的趋势, 在16℃处理4 d时雄成虫和雌成虫寿命达到最高值, 分别为10.2 d和11.1 d, 44℃处理2 d成虫不能存活, 即成虫的致死高温≤44℃?雌蛾产卵量随温度升高而增加, 19℃处理4 d的产卵量最高, 为984.5粒?35~41℃处理2 d或4 d, 雌蛾不产卵或产卵量显著降低?综上所述, 16~19℃短期低温有利于草地贪夜蛾雌成虫产卵, 而16℃以下短期低温或35℃以上短期高温对草地贪夜蛾蛹和成虫的生长发育有抑制作用?  相似文献   

5.
环境温度变化对异色瓢虫的飞行与运动能力的影响   总被引：1，自引：0，他引：1  
研究环境温度变化对异色瓢虫Harmonia axyridis(Pallas)飞行与爬行搜索能力的影响,对合理利用异色瓢虫进行生防控害有重要意义。本研究设置15、25和35℃恒温处理,以及15~35℃连续线性变温和15℃—25℃—35℃跳跃变温处理,利用飞行磨和昆虫行为记录仪测定异色瓢虫成虫对上述温度处理的行为响应。结果表明,异色瓢虫在15℃平均飞行(14.2±1.9)次、累计飞行(1089.6±112.3)m、(98.3±11.6)min,平均飞行速度为(11.2±1.1)m/min,显著高于其他温度;而在35℃平均爬行(26.1±2.1)次,共爬行(719.6±73.2)cm、平均爬行速度为(2.6±0.7)cm/s,且方向改变(101.3±11.2)次,均显著大于其他处理。异色瓢虫在连续跳跃变温条件下的飞行能力与运动搜索能力均显著大于连续线性变温及恒定常温(25℃)对照。本研究表明异色瓢虫在较低温度下的飞行能力较强,而在较高温度下的爬行搜索能力较强。此外,扰动型环境波动可以显著提升异色瓢虫飞行和爬行能力。  相似文献   

6.
采用水浴法,对离体咖啡短体线虫、薯蓣块根内咖啡短体线虫以及薯蓣块根在不同温度条件下的敏感性进行测定。结果表明,在47、50、52、55 ℃处理条件下,杀死100%离体咖啡短体线虫的处理时间分别为6、2.5、1.5、1.5 min,而杀死100%薯蓣块根内线虫的处理时间分别为19、15、11、10 min;同时在上述温度下,分别处理35、30、25 min和25 min对薯蓣发芽没有影响。在同一温度处理中,随着处理时间延长,线虫的死亡率增加;而在不同温度处理中,随着温度升高,杀死线虫的时间逐渐缩短。综合上述试验结果,建议生产上防治薯蓣种薯内咖啡短体线虫的处理方法以52～55 ℃处理15～20 min为宜。  相似文献   

7.
溴甲烷熏蒸对桃蛀果蛾的毒力作用   总被引：1，自引：0，他引：1  
对溴甲烷熏蒸处理桃蛀果蛾结果进行机率值法分析,推算出在25℃温度条件下溴甲烷熏蒸处理1.5h和2h,达到桃蛀果蛾Carposina sasakii Matsumura幼虫死亡率99%的浓度时间乘积(CT值)分别为43.79g·h/m3和46.77 g·h/m3;15℃和10℃温度条件下熏蒸处理3h,达到桃蛀果蛾幼虫死亡率99%的溴甲烷浓度分别为50.84 g·h/m3和118.55 g·h/m3.研究表明,溴甲烷熏蒸对桃蛀果蛾幼虫的毒性作用随着溴甲烷熏蒸浓度的增加而增加,相同熏蒸剂浓度条件下,随着温度升高,溴甲烷熏蒸效果明显增加.  相似文献   

8.
本文对气流场与粘虫迁飞关系作了分析,表明在900—950mb 层(即400—900米高度)气流场中有适于携虫的气流存在。在各类气象条件下,粘虫蛾发生突增的条件概率,其结果(在气流有利于携虫的前提下):无条件概率值为0.1665;各条件概率值分别为:在雷暴状况下发生突增的条件概率为 0.4000;在降雨状况下发生突增的条件概率为 0.2812;在冷锋区发生突增的条件概率为 0.3720;在暖锋区发生突增的条件概率为 0.2222;在气旋中心区发生突增的条件概率为 0.4000;在“一般性天气”发生突增的条件概率为 0.1166;因此,初步结论是:气旋中心区、冷锋区、与雷暴均显著地有利于扩迁粘虫蛾的降落,而降雨、暖锋区、虽然也有或多或少的有利倾向,但是不够显著。由于在“一般性天气”条件下亦有相对多的蛾量突增的现象发生,这表明很可能降落过程与运转过程不同,在一定程度上与粘虫本身的自主性降落有关。估计这很可能与粘虫蛾的“生物钟”反应有所联系。在本文中亦对各种气象物理事件对于扩迁粘虫蛾降落过程的可能作用机制作了讨论。  相似文献   

9.
为阐明草地贪夜蛾起飞蛾龄以及迁飞在种群成灾中的作用, 本文研究了草地贪夜蛾不同蛾龄飞行对其生殖及寿命的影响, 为草地贪夜蛾迁飞规律和致灾机制的解析提供理论依据。通过对不同日龄的雌蛾进行吊飞飞行试验, 测定其飞行能力的变化以及对雌蛾后续生殖和寿命的影响。结果表明, 羽化后不同日龄的雌蛾吊飞8 h的飞行能力差异显著(P<0.05)。1日龄雌蛾即具有较快的飞行速度, 但飞行时间和距离最短。随着蛾龄的增加雌蛾飞行能力增强, 3~6日龄时飞行能力达到最强(4日龄飞行速度除外), 7日龄时飞行能力下降。与未飞行的对照相比, 1、2日龄雌蛾吊飞8 h处理的产卵前期无显著变化(P>0.05), 但3日龄吊飞8 h后产卵前期则显著延长(P<0.05); 1日龄吊飞后产卵量显著增加, 3日龄吊飞后则显著减少(P<0.05); 1~3日龄雌蛾吊飞后产卵历期、交配率和寿命均无显著变化(P>0.05); 种群产卵同步性(PFO)在2日龄吊飞后显著加强, 且1~3日龄吊飞后PFO四分位间距均小于对照。这表明, 草地贪夜蛾雌蛾可能在羽化后1~2日龄起飞, 此时飞行不仅不会付出生殖代价, 而且还会一定程度地促进成虫快速产卵、提高产卵量并增强种群产卵同步性, 从而容易造成田间迁入种群快速、集中产卵, 导致孵化的幼虫数量同时急剧上升, 引起迁飞成灾。  相似文献   

10.
以渭干河-库车河三角洲绿洲连作5、10、15、20 a和25 a的棉田土壤为研究对象,对棉田土壤的理化性质和酶活性进行分析。结果表明： 随着棉花连作年限的增长棉田土壤容重增大、孔隙度下降,粗砂和细沙含量增加,粘粒含 量下降,其变化连作15 a极为明显; 随着连作年限的增长盐分含量和pH值逐渐降低,有机质和碱解氮含量大幅度升高,速效磷比较稳定或略有减小,而钾的含量显著下降,致使氮、磷、钾比例失调,其增减变化连作15 a极为显著; 随着连作年限的增长脲酶、过氧化氢酶和转化酶的活性呈现先升后降的趋势,连作15 a都达到最高值,蛋白酶和磷酸酶活性也呈现先升后降的趋势,但其活性连作20 a达到最高值。 由研究结果可以得出研究区棉花连作年限不宜超过15 a,棉花连作年限超过15 a时,会导致土壤容重增大、孔隙度下降,土体紧实板结,结构性差,土壤养分含量失衡,酶活性降低,土壤质量下降等连作障碍,使得棉花产出和效益受到影响。  相似文献   

11.
The epidemiology ofSitobion avenae and its natural enemies in winter wheat was studied in 1975, 1976 and 1977. Immigration was important until the end of flowering. The alate immigrants had apterous offspring. These became the driving force in population growth. Their offspring were mostly alatae which usually left the field. A model of the epidemic was developed. Quantitative relations between the aphids and their environment were obtained from literature or established in laboratory trials. The model simulated population development and population composition from the beginning of June till the population peak at the end of June or early in July. Because quantitative data on relations between aphids and their natural enemies and pathogens are scarce, and since the knowledge on wing formation is still limited, the population collapse could not be predicted. In the future, prognosis over a period of three weeks seems possible.Samenvatting De toenemende betekenis van graanbladluizen (vooralSitobion avenae) gepaard gaande met een sterke toename van het gebruik van insecticiden op granen maakte verbetering van de prognose over het schadelijk optreden wenselijk. Door gedetailleerde tellingen in het veld (Fig. 1–7) werden gegevens verkregen over het verloop van de epidemie en het optreden van natuurlijke vijanden in 1975, 1976 en 1977.Een immigratieperiode tot in de bloei kon worden vastgesteld. Daarna lijkt de aantrekkelijkheid van het gewas voor alate luizen te verminderen. De alate immigranten krijgen aptere nakomelingen. Deze vormen de stuwende kracht van de populatiegroei. De nakomelingen van apteren zijn merendeels alaat. Zij verlaten het gewas.Een model van de populatieontwikkeling gedurende de epidemie werd opgesteld. De relatiediagrammen Fig. 9 en 10 laten groei en ontwikkeling vanS. avenae en een predator (Syrphus corollae) zien. Kwantificering van de betrekkingen werd mogelijk door literatuurgegevens en laboratoriumexperimenten.Met het model kon de populatieontwikkeling vanS. avenae vanaf begin juni tot aan de populatiepiek in 1975, 1976 en 1977 vrij goed worden gesimuleerd (Fig. 12). Ook de populatieopbouw kon worden gesimuleerd (Fig. 14). De teruggang van de populatiedichtheid blijkt moeilijker te voorspellen door het ontbreken van gegevens over natuurlijke vijanden.Het lijkt waarschijnlijk dat in de toekomst met het model een prognose over de piek van de bladluispopulatie circa 3 weken tevoren mogelijk zal zijn.  相似文献   

12.
In 1975 many tumours were observed in plants ofBegonia Schwabenland grown in Aalsmeer. Submersion of the roots ofNicotiana megalosiphon seedlings in a homogenate of tumorous tissue, induced tumours after two weeks. Short periods of submergence yielded results similar to those obtained after longer periods. Tumour homogenates lost their infectivity after ten min at 50°C. Aphids transmitted the infectious agent.Treatment with propylene oxide did not inhibit infectivity completely. Filtration through a 450 nm filter removed the infectious agent.Tobacco tumor virus or a viroid could not be isolated. Cultures ofCorynebacterium fascians, isolated from tumours ofN. megalosiphon were highly infectious and induced tumours in healthyN. megalosiphon andBegonia. Tumorous tissue homogenates ofPelargonium zonale, Dahlia sp.,Gladiolus sp., andLilium sp. also caused tumours inN. megalosiphon, from whichC. fascians was isolated. It was not possible to produce tumours inN. megalosiphon with homogenates from roses with symptoms of bud proliferation.Samenvatting In 1975 werden vele tumoren waargenomen inBegonia Schwabenland op Aalsmeerse bedrijven (Fig. 1). De infectiositeit van tumorweefsel kon goed en snel worden vastgesteld door de wortels van zaailingen vanNicotiana megalosiphon in een homogenaat van tumorweefsel te dompelen. Tumoren ontstonden na twee weken, de eindbeoordeling geschiedde na een maand (Fig. 2). Ook verschillende andereNicotiana spp.,Melilotus officinalis (Fig. 3) enPisum odoratum (Fig. 4) werden aangetast.Bij de infectiositeitstoets gaven zeer korte dompeltijden even goede resultaten als langere (Tabel 1). Infectieus sap verloor zijn infectievermogen na 10 min verhitting bij 50°C. Bladluizen brachten de smetstof over. Propyleenoxide verminderde de infectiositeit wel, doch onderdrukte deze niet totaal. Bij filtratie door een 450 nm filter bleef het infectieuse agens op het filter achter. Het tumor-inducerende agens was ook aanwezig in die delen van planten met tumoren welke gezond leken en het ging voor een gering deel over met zaad (Tabel 2).Uit tumoren konden wij geen tabakstumorvirus of een viroïde isoleren. Culturen vanCorynebacterium fascians, geïsoleerd uit tumoren vanN. megalosiphon bleken zeer infectieus en veroorzaakten tumoren inN. megalosiphon enBegonia. Homogenaten van tumorweefsel vanPelargonium zonale, dahlia (Fig. 5), gladiool (Fig. 6) enLilium Mid Century Hybrid Enchantment (Fig. 7) veroorzaakten ook tumoren opN. megalosiphon, waaruitC. fascians werd geïsoleerd. Met sap van kroeskopzieke rozen konden wijN. megalosiphon niet besmetten.  相似文献   

13.
Organic amendments and green manure are potential alternatives to the harmful chemical control means currently used against plant-parasitic nematodes. In this work, Chrysanthemum coronarium was applied to the soil as a green manure to control the root-knot nematodes Meloidogyne incognita and M. javanica. Chrysanthemum coronarium significantly reduced nematode infection of tomato roots and improved plant-top fresh weight, both in the greenhouse and in microplots. Other green manures, derived from Anthemis pseudocotula, wild chickpea (Cicer pinnatifidum), Geranium spp. and wheat, were not as effective as C. coronarium. Chrysanthemum coronarium, retained its nematicidal activity even when applied as a dried material. Only mature C. coronarium plants, in their flowering stage, exhibited nematode control activity, but the green plant parts were more effective than the flowers. An aqueous extract of C. coronarium exhibited in vitro, nematostatic activity towards M. incognita and M. javanica second-stage juveniles and inhibited their hatching from eggs and egg-masses; its nematostatic activity was expressed also against other phytonematode species such as Heterodera avenae and Pratylenchus mediterraneus, but did not affect the beneficial entomopathogenic nematode Steinernema feltiae.  相似文献   

14.
Samples of heavily infested crop residues were incorporated in static compost heaps (2.5–4.6 m3) of the Indore type. Temperature increased to 50–70°C within 6 days depending on the type of crop residues used and the location within the heap. The heat phase (>40 °C) lasted 2–3 weeks and was followed by a c. 5-months maturation phase (<40 °c).=" among=" the=" 17=" pathogens=" tested,=">Olpidium brassicae and one of the four formae speciales ofFusarium oxysporum that were tested survived composting, but also their inoculum was greatly reduced.Survival during specific phases of composting was studied by incorporation and retrieval of samples at various stages of the process.F. oxysporum f. sp.melonis was completely inactivated andO. brassicae andPlasmodiophora brassicae were almost completely inactivated during the short heat phase. The three pathogens survived the long-lasting maturation phase without loss of viability. Heat evolved during composting was found to be the most important factor involved with sanitation of crop residues. The possible involvement of fungitoxic conversion products and microbial antagonism is discussed.  相似文献   

15.
浅黄恩蚜小蜂和丽蚜小蜂对温室白粉虱的寄生潜能分析   总被引：1，自引：1，他引：0  
浅黄恩蚜小蜂Encarsia sophia GiraultDodd和丽蚜小蜂Encarsia formosa Gahan是防治粉虱类害虫的优势寄生蜂,通过生命表技术方法分析了2种寄生蜂对温室白粉虱Trialeurodes vaporariorum(Westwood)的防治潜能。结果表明,丽蚜小蜂在羽化第3天和第10天出现2次寄生高峰,占其总寄生量的13.7%和8.0%,在2次高峰之间逐日寄生粉虱数量比较平稳,单雌逐日平均产雌数保持在10.6~13.4头,10 d后寄生量呈明显的下降趋势;而浅黄恩蚜小蜂羽化10 d内逐日寄生粉虱量变化不大,单雌逐日产雌数稳定在4.2~5.4头,羽化14 d后寄生量呈明显下降趋势。丽蚜小蜂和浅黄恩蚜小蜂的R0、T、rm、λ值分别为171.5、18.0、0.2854、1.3303和61.6、16.2、0.2544、1.2897;粉虱若虫充足时,丽蚜小蜂平均单雌寄生若虫数是浅黄恩蚜小蜂的2.7倍,而后者平均单雌取食若虫数为60.6头,明显高于前者42.7头,总的来看,丽蚜小蜂通过寄生和取食杀死粉虱总量220.8头,明显高于浅黄恩蚜小蜂的127.9头。表明在应用寄生蜂防治温室白粉虱时,单独释放丽蚜小蜂比浅黄恩蚜小蜂显示出更好的防治潜能。  相似文献   

16.
Five Pythium species (Pythium irregulare, P. mamillatum, P. myriotylum, P. spinosum and P. ultimum var. ultimum) were isolated from the hypocotyls and roots of kidney bean plants with damping-off from a commercial field and from experimental plots that have undergone either continuous cropping with kidney bean or rotational cropping with arable crops. In inoculation tests, all five Pythium species were pathogenic to kidney bean. This is the first report of damping-off of kidney bean caused by Pythium species; we named this disease damping-off of kidney bean. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession numbers AB291811, AB291944 and AB291945.  相似文献   

17.
Research on root rot pathogens of peas in the Netherlands has confirmed the prevalence ofFusarium solani, F. oxysporum, Pythium spp.,Mycosphaerella pinodes andPhoma medicaginis var.pinodella. Aphanomyces euteiches andThielaviopsis basicola were identified for the first time as pea pathogens in the Netherlands. Other pathogens such asRhizoctonia solani andCylindrocarpon destructans were also found on diseased parts of roots. F. solani existed in different degrees of pathogenicity, and was sometimes highly specific to pea, dwarf bean of field bean, depending on the cropping history of the field.A. euteiches was specific to peas, whereasT. basicola showed some degree of physiological specialization.  相似文献   

18.
Botryodiplodia theobromae, Colletotrichum gloeosporioides andGliocephalotrichum microchlamydosporum are the causal fungi of the rambutan postharvest diseases stem-end rot, anthracnose and brown spot, respectively. Two different treatments of rambutan fruits(Nephelium lappaceum) against the three pathogens were compared: potassium metabisulphite (250 ppm) or cinnamaldehyde (30 ppm), each combined withTrichoderma harzianum (TrH 40). The application of TrH 40 and potassium metabisulphite effectively controlled the incidence and severity of the three postharvest diseases and maintained the overall quality and color of the fruit under low temperature storage at 13.5°C and 95% r.h. for 18 days. The greatest effect of this treatment was shown onG. microchlamydosporum. Cinnamaldehyde affected the growth and germination of TrH 40, whereas potassium metabisulphite did not. http://www.phytoparasitica.org posting Nov. 4, 2001.  相似文献   

19.
Several pathovars of Pseudomonas syringae produce the phytotoxin coronatine (COR)in vitro, and the availability of purified toxin has facilitated development of immunological detection methods. A modified, indirect competitive ELISA using the COR-specific monoclonal antibody 11B8 was developed to detect COR in various host plants infected by P. syringae. The estimated detection limit for COR was 50 pg per well, and COR could be reliably quantified from 5 to 40 ng ml−1. The subcellular localization of COR within infected tomato tissue was investigated using the COR-specific antibody MAb 8H3G2. Immunofluorescence microscopy and immunogold labelling showed that COR was present inside tomato cells and was associated with chloroplasts and particles of proteinase inhibitor I. Localization studies indicated that COR is mobile in infected plant tissue and can be detected in healthy tissue adjacent to the bacterial lesions.  相似文献   

20.
The effects of the saprophytic mycoflora and its interference with cereal aphids on growth and yield of winter and spring wheat was studied in field experiments in 1980, 1981 and 1982.Yields varied between 5000 and 8000 kg dry matter of kernels per ha. The effect of the saprophytic mycoflora on yield was determined in different treatments: A) no control measures against cereal aphids and saprophytic and necrotrophic fungi, B) no control of cereal aphids, control of saprophytic and necrotrophic fungi, C) control of cereal aphids and control of saprophytic and necrotrophic fungi, D) control of cereal aphids and stimulation of saprophytic mycoflora and E) control of cereal aphids, no control of saprophytic and necrotrophic fungi nor stimulation of saprophytic mycoflora.Considerable differences in top densities of saprophytic mycoflora (10 times as large in A and D as in B and C) were determined. The consequences of these differences for the growth and productivity of wheat were minor. A negative effect of saprophytic mycoflora on the yield could not be detected in 1981 and 1982, whereas a small positive significant effect was found in 1980. This stimulation may have been due to competition between necrotrophic fungal pathogens and saprophytic mycoflora. As a result of favourable weather conditions necrotrophic fungal pathogens were very numerous in 1980 and could form an important yield reducing factor. Yield levels may effect the importance of the necrotrophic and saprophytic mycoflora as yield reducing factors. Additionally, in the presence of aphid honeydew captafol was found to be relatively ineffective against saprophytic fungi.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号