共查询到20条相似文献，搜索用时 15 毫秒
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粤北桑芽瘿蚊的世代及生活史和习性调查 总被引：1，自引：0，他引：1
调查表明 :粤北桑芽瘿蚊 1年发生 10代 ,世代重叠现象明显 ,从 5月初一直为害至 11月 ,11月底以结成囊包休眠体的老熟幼虫在桑田土表层中进行越冬 ,但从 6月下旬开始各代均有部分老熟幼虫结成囊包休眠体在桑田土表层中进行越夏、越冬 ;全年以第 1～ 3代发生量最大。各虫态历期 :卵 1～ 2d ,幼虫 5～ 12d ,蛹 5～ 12d ,成虫 1～3d ,完成 1个世代需 15～ 2 6d ,大多要 2 0d左右。雌雄成虫比例 (性比 )约为 2 5 1∶1。 相似文献
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N-甲基-N-亚硝基脲(MNU)是一种能诱导生物体产生随机点突变的烷化剂。为了完善利用MNU诱导家蚕突变的实验体系,用MNU处理家蚕品种大造的5龄第3天幼虫、化蛹第5天蛹、羽化当天的雄蛾及产后4～6 h的受精卵,通过Bliss法计算MNU对家蚕的半致死剂量(LD50)。结果显示MNU对不同发育时期家蚕的LD50值存在一定的差异:MNU对家蚕5龄第3天幼虫雌雄个体的LD50分别为28.735、20.157μg/头;对化蛹第5天蛹雌雄个体的LD50分别为56.466、54.672μg/头;对羽化当天的雄蛾的LD50为273.94μg/头;对产后4～6 h的受精卵的LD50为7 288.8μg/mL。实验数据表明,家蚕幼虫对MNU的毒性耐受能力差,蛾和卵的耐受能力较强;雌性个体对MNU毒性的耐受能力比雄性个体更强。 相似文献
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硫酸二乙酯(DES)是一种能诱导生物体产生随机点突变的烷化剂。为了完善利用DES诱导家蚕突变的实验技术,采用不同剂量DES分别处理家蚕蛹、蛾、卵,检测DES对不同发育时期家蚕毒性的半致死剂量(LD50),结果表明DES对不同发育时期家蚕的LD50值存在显著差异:化蛹第5天的雌雄蛹分别为2 333.90μg/头和2 369.50μg/头;刚羽化雄蛾为156.39μg/头;蚕卵为13.23 mg/mL。研究结果可作为DES对家蚕的最适诱变剂量和家蚕诱变最佳发育时期选择的参考依据。 相似文献
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R A Ogunsusi 《Research in veterinary science》1979,26(2):189-192
Monthly worm counts of groups of ewes and lambs that grazed continuously and tracer lambs revealed that under the conditions existing in northern Nigeria, most of the Haemonchus contortus in sheep between November and March were arrested larvae. During the months of April and May, almost equal proportions of adults, developmental stages and arrested larvae were recovered and, by June, only adults and developmental stages were recovered in high numbers. The proportion of arrested larvae had diminished considerably. A similar pattern was recorded for Trichostrongylus spp, except that fewer larvae were involved in arrested development and very large numbers of adults were recovered throughout the duration of the study. Maturation of arrested larvae occurs in April. 相似文献
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粤北桑芽瘿蚊Giadomyiasp是粤北桑树的主要害虫之一，其形态特征主要表现在成虫触角、前翅、外生殖器的形态，卵、幼虫胸骨片的形状，蛹胸足长短等方面，与广东老蚕区（顺德）的桑吸浆虫（Contariniasp．）有着明显差异。 相似文献
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高温对家蚕蛹期生殖细胞与产卵质量的影响 总被引：2，自引：0，他引：2
<正> 蚕种生产过程中,蛹期的保护温度与产卵质量的关系极为密切。过去国内外学者从保护目的温度与产不良卵,不受精卵数量方面研究,至于高温对蛹期的雌雄生殖细胞的影响与产卵质量方面的研究甚少。因此,本试验进一步研究了不同蛹期接触高温后,引起生殖细胞的变化与产卵质量的关系,并调查其内外生殖器官是否正常,俾能更确切地了解蚕种生产过程中雌雄蛹不宜接触高温的发育阶段及其原因。 广东6—9月,自然温度常超过32℃,特别是7月有时超过36℃。因此,在蚕种生产过程中,经常因遇到高温的冲击而影响蚕种的质量。所以,采用35℃为接触温度。 相似文献
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Field efficacy of phoxim 50% (ByeMite) against the poultry red mite Dermanyssus gallinae in battery cages stocked with laying hens 总被引：2，自引：0，他引：2
Infestations with the poultry red mite Dermanyssus gallinae represent a major ectoparasite problem in poultry and can affect egg layers worldwide. There is presently a lack of an ectoparasiticide in Europe for poultry which can assure a 0-day withholding period for eggs. In this study, ByeMite (phoxim 50%, Bayer HealthCare, Animal Health Division) was administered to treat a D. gallinae infestation in a poultry house stocked with egg-laying hens kept in a cage system. A layer house was sprayed twice within a 7-day interval using a solution containing 2000 ppm phoxim and a similar layer house was used as an untreated control unit. Specially developed D. gallinae traps made of cardboard were used to assess the mite density in both layer houses during a 49-day period after the treatment. In order to collect mites, the traps were placed on days--1, 2, 6, 9, 13, 20, 34 and 48 and always removed after 24 h. The collected mites were counted and differentiated according to their developmental stage (mite eggs, larvae, nymphs, adults). Three days after the first spray treatment, the efficacy against all mite stages (larvae, nymphs, adults) was 96.1%, and from day 7 post-treatment until the end of the trial (day 49) the efficacy exceeded 99%. In contrast, in the untreated layer house (negative control group) the mite population showed a 400% increase. No treatment-related side effects in chickens were detectable. It is concluded that two administrations of ByeMite within a 7-day interval are highly effective against D. gallinae infestations in a stocked poultry house. 相似文献
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本文探讨昆虫保幼激素类似物(JHA)和蜕皮激素(MH)对家蚕蛹的生殖效应。结果表明:(1)两种激素在蛹期使用的生物活性与其在幼虫期的作用效果完全相反。JHA具有缩短蛹期经过的作用,最大效应值出现在蛹中期使用。高剂量的MH具有显著延长蛹期经过的作用。最大效应值出现在蛹前期和蛹后期处理。(2)蛹期注射适当剂量的MH,对生殖生物量具有一定的增值效应,处理时间以蛹前期和蛹后期为准。(3)激素类似物在蛹期使用,其生殖效应主要改变百粒卵重,MH具有正效应,JHA具有负效应。中、低剂量的MH和JHA不显著改变成熟卵粒数,而高剂量的MH和JHA均使成熟卵数大幅度下降。 相似文献
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The capacity of various developmental stages of Ascaris suum to induce a protective immune response in the guinea pig model was evaluated. Larvated eggs, second, third or fourth stage larvae were injected into guinea pigs by either the suncutaneous, intramuscular, ear vein or mesenteric vein route. Animals were challenged with a mesenteric vein injection of artificially hatched infective larvae of A. suum. Second stage larvae produced the highest degree of immunity and fourth stage larvae produced the least protection comparing all routes of administration. The most effective route of immunization for all the developmental stages was the mesenteric vein. Antibody titer as assessed by indirect hemagglutination was not correlated with the degree of protection. 相似文献
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催青温度对家蚕二化性品种滞育激素受体基因表达的影响及基因的结构特征 总被引：1，自引：0，他引：1
家蚕二化性品种的卵滞育与否受上代环境影响,25℃高温明催青将产滞育卵,而15℃低温暗催青将产非滞育卵。为探究催青温度调控二化性家蚕滞育的分子机制,对从家蚕卵巢细胞中克隆的家蚕滞育激素受体基因(Bmdhr)的5种cDNA进行生物信息学分析,结果表明Bmdhr基因的5种cDNA由相同的mRNA转录本通过不同的剪接方式而来,其中Bmdhr mR-NA-1与Bmdhr mRNA-2编码的氨基酸序列相同,Bmdhr mRNA-4编码的氨基酸序列与家蚕滞育激素BmDHR-1的序列相似度达99.2%。将家蚕二化性品种秋丰的蚕卵用蛾区半分法分成2组,分别以15℃暗催青和25℃明催青,利用实时荧光定量PCR分析催青温度对家蚕不同发育时期及蚕体组织中Bmdhr基因mRNA转录的影响。结果显示:Bmdhr mRNA-1主要在蛹期卵巢中表达,在对滞育激素最敏感的化蛹后4 d时,其转录水平急速上升至峰值,并且高温催青的转录水平高于低温催青;Bm-dhr mRNA-4主要在各发育时期的蚕体血液中表达,特别是在高温明催青条件下,其在蛹期血液中的转录水平是低温暗催青的7.7倍,说明BmDHR-4可能是决定家蚕二化性品种卵滞育与否的关键因子之一;Bmdhr mRNA-5在化蛹后2～3 d的卵巢中转录水平高,且低温催青的转录水平高于高温催青,化蛹后3 d其转录水平开始下降,至化蛹后4～5 d 2种催青处理间的转录水平无显著差异。研究结果为阐明家蚕滞育的分子机制积累了实验数据。 相似文献
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在云南省西双版纳种植区发现为害澳洲坚果的新害虫——脊胸露尾甲,为准确掌握其生物学习性,在室内以澳洲坚果果仁为食对其进行了饲养,并对各虫态的形态、成虫交配习性、产卵习性、卵的孵化率、各虫态的存活率进行了观察。结果表明：脊胸露尾甲的发育经历卵、幼虫、蛹、成虫四个虫态,其中幼虫分为3个龄期,随着龄期的增长,幼虫体长、体宽和头壳宽度逐渐增加。成虫羽化后不会立即交配,交配前期为（4.65±0.04）d,交配时长不等,初次交配时长为（13.78±0.29）min,雄成虫存在争夺交配权的行为。雌成虫产卵前期为（8.65±0.03）d,初次产卵量为(1.94±0.06)粒,在15:00-18:00时间段的产卵量/小时最高;雌成虫对产卵位置具有选择性,背光面的着卵率极显著高于向光面。卵的孵化率随着湿度的增加而不断提高。常规饲养条件下,卵、1龄幼虫、2龄幼虫、3龄幼虫、蛹的存活率分别为(86.50±0.69)%、(83.31±2.99)%、(94.85±0.71)%、(97.09±1.46)%、(98.77±1.23)%。本研究为脊胸露尾甲的生物学及防治提供参考依据。 相似文献
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为筛选与线虫感染性相关的基因,本研究以猪蛔虫为对象,构建猪蛔虫感染期幼虫差异表达消减cDNA文库,为研究线虫期特异性发育的分子机制奠定基础。分别提取感染期幼虫和其它各期幼虫及成虫的总RNA,纯化mRNA后,采用Clontech公司PCR-selectTM试剂盒进行反转录合成cDNA并进行抑制消减杂交(SSH),构建猪蛔虫感染期幼虫差异表达的消减cDNA文库,并采用Southern斑点杂交进行消减效率的检测。随机从文库中抽取45个克隆进行测序及在线BLAST分析。试验结果表明,感染期幼虫差异表达的消减cDNA文库具有较强的特异性;在得到的41个表达序列标签(ESTs)中,有40个ESTs与已报道的基因有较高的相似性,主要代表猪蛔虫第三期幼虫基因和成虫头部基因,有1个cDNA片段可能代表新基因。猪蛔虫感染期幼虫差异表达消减cDNA文库的成功构建,为进一步研究幼虫发育差异表达基因的功能奠定了基础。 相似文献
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滞育激素(DH)是导致家蚕滞育生理现象出现的关键因素。研究卵期不同温度和光照节律引起家蚕滞育激素基因Dh表达的变化,探讨温度和光照对家蚕滞育调控的机制。催青期25℃持续光照(25LL)条件下,蚕卵中Dh基因mRNA高水平稳定转录;而在15℃持续黑暗(15DD)条件下,蚕卵中只有痕迹量Dh基因mRNA存在;25LL或者20℃、光照与黑暗12h交替(20LD)条件下,胚胎发育至单眼着色后(有效积温2160℃.h以后)Dh基因mRNA转录水平显著上调,与此时期胚胎对诱导滞育的温度和光照节律更加敏感一致。从催青期开始整个世代的保护温度和光照节律,呈现高温25℃显著上调整个胚后时期Dh基因mRNA转录水平,光照上调蛹期与蛾期Dh基因mRNA转录水平,且高温的作用强于光照。5龄第3天幼虫的基因芯片表达谱显示,Dh基因mRNA转录水平存在显著的性别与组织差异,雌蚕多个组织中的Dh基因mRNA转录水平都显著低于雄蚕,卵巢中的Dh基因mRNA只有痕迹量。亲代卵的催青温度与光照节律决定子代卵的滞育性,也影响到Dh基因mRNA的转录水平;但子代卵内Dh基因mRNA转录水平高低不是蚕卵滞育与否的关键。推测家蚕Dh基因表达的性别差异及在早期蚕卵中表达特征与滞育性不一致的现象,可能与Dh基因的前体多肽翻译产物剪切有关。 相似文献
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蓖麻蚕蛹的冷藏试验研究 总被引：2，自引：0，他引：2
本报告了笔在巴西工作期间，针对蓖麻蚕种茧玲藏这一重要技术环节做的一系列试验。试验结果表明：在常规饲养的情况下，种茧在最适宜的发育阶段．用5℃冷藏在90天以内时，只要技术措施得当，羽化、交尾、产孵情况基本正常。冷藏90天以上，上述各项指标的变化十分明显，显示出有不良的影响。蓖麻蚕蛹在冷藏过程中蛹体重量的减轻程度与冷藏时间的长短、蛹的性别、冷藏容器的密闭程度有关，这些因素也直接影响到羽化、交尾及产卵。蓖麻蚕品种、饲料种类、饲养和结茧的温湿度以及饲养水平对蛹的冷藏期限都有显的影响。 相似文献
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The cat flea, Ctenocephalides felis, is the most important ectoparasite of cats and dogs worldwide as a cause of irritation and health problems. Most products to control these pests in the household environment rely upon a combination of neurotoxic insecticides and insect growth regulators to inhibit development of flea eggs and larvae into adults. However, some of these are affected by problems of insecticide resistance as well as public concerns about their potential for toxicity in domestic use. Heavy synthetic oils, like the siloxane dimeticone, are currently widely used to treat human ectoparasite infestations, acting by a physical mode of action, and have been used in a variety of presentations for killing all life stages of fleas. We have investigated the activity of low concentrations of high molecular weight dimeticone in a volatile silicone base for ability to immobilise flea life stages without asphyxiating them. We found that cat flea adults and larvae were immobilised by a surface film of dimeticone that inhibited movement of cuticular joints, apparently forming an effective sticky trap. When cocoons were treated the fleas continued to develop within the pupae but failed to emerge. An aerosol spray incorporating 0.4% concentration of dimeticone, for use as a residual household treatment, showed no significant difference in knock down capability compared with that of a widely used pyriproxifen/permethrin spray in a repeat challenge test, with effects persisting to inhibit adult flea emergence in the test arena area for more than 3 weeks after application. 相似文献
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桑大象(Episomus kwanhsiensis Heller)成虫取食桑叶,幼虫取食桑根,可以造成整株桑树和整片桑园死亡。近年来,在四川蚕区的许多地方已成为主要害虫。桑大象分一年一代和二年一代两个类型。以幼虫和成虫在地下越冬,成虫出土为害的高峰期在4—5月和8一9月。卵产在杂草或桑叶上,卵的发育起点温度为12.8℃,发育有效积温为142日·度,幼虫期约300天,蛹期24—28天。桑大象的天敌,主要有卵寄生啮小蜂(Tetrastichus sp.)寄生率可达60—80％。 相似文献
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选择柞蚕5龄幼虫以及前滞育期、滞育期和解除滞育后发育前期、中期、后期的柞蚕蛹分离卵巢细胞,利用新研制的柞蚕细胞培养基MLM-45,在不同温度、pH值及渗透压条件下进行柞蚕卵巢细胞的体外培养,探究最佳培养条件及卵巢细胞取材的最佳发育时期。用台盼蓝染色活细胞计数方法,测定不同条件下用MLM-45培养基培养的不同发育时期柞蚕卵巢细胞的活力,当在27℃、pH 6.3、渗透压325 mOsm/kg的条件下培养30 d时,上述各发育时期柞蚕卵巢细胞的存活率最高,并且5龄幼虫、前滞育期和解除滞育后发育前期的卵巢细胞出现了增殖,其增殖率分别为54%、64%和2%,滞育期及解除滞育后发育中期和后期的卵巢细胞存活率也分别达到99.6%、96.6%和92.4%。在此最佳培养条件下,各发育时期柞蚕卵巢细胞培养2个月后其形态以圆形和椭圆形为主,尤以5龄幼虫和前滞育期蛹卵巢细胞的培养效果最好,细胞增殖7～8倍,是适于以MLM-45培养基培养的最佳发育时期柞蚕卵巢细胞。 相似文献