共查询到19条相似文献，搜索用时 140 毫秒
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低温处理对豆天蛾幼虫越冬以及化蛹的影响 总被引：1，自引：0，他引：1
在0~4℃的冰箱内用木屑土低温保存豆天蛾幼虫,测定其保存时间,模仿豆天蛾幼虫野外生存条件,对豆天蛾老熟幼虫进行不同时间低温处理,并采用梯度降温法处理已入土的豆天蛾幼虫。结果表明:在0~4℃的环境下豆天蛾幼虫的保存时间在60 d以内死亡率较低,当保存时间上升到80 d时死亡率达31.67%,100 d时死亡率达33%;经过5 d的预低温处理,基本没有效果,预低温20 d死亡率大幅度上升,并存在提前化蛹的现象;梯度降温后逐渐升温处理也存在提前化蛹现象,并且死亡率低。 相似文献
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为了研究葛藤扦插育苗中不同基质处理对其发芽率、出苗率、成苗率和株高的影响,试验采用火土、锯末、河沙和壤土（对照）为扦插基质,独山当地野生葛藤苗为插穗进行扦插试验。结果表明：基质为火土、锯末和河沙的发芽率、出苗率、成苗率和株高都高于壤土。 相似文献
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采用大田调查和室内尼龙纱笼、玻璃缸饲养等方法,对桑蓝萤叶甲的形态、生物学特性等进行了研究。结果表明,在诸暨地区桑蓝萤叶甲一年发生一代,2月下旬至4月上旬为蛹期,3月—5月下旬为成虫期,4月—6月下旬为卵期,5月—9月下旬为幼虫生长活动期,10月以后为越冬幼虫休眠期。各虫态发生不整齐。幼虫经3个龄期老熟,钻入深土层筑土室越冬,并化蛹其中。成虫喜食嫩叶,具有假死习性;在原桑地分散产卵,完成生活史。在稀植、管理粗放的桑园中,一般虫口密度较高。 相似文献
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为明确青葙（Celosia argentea Linn.）提取物对槟榔红脉穗螟（Tirathaba rufivena Walker）化蛹和羽化的影响,采用室内生物测定法研究了青葙甲醇和乙醇提取物,对红脉穗螟蛹发育、化蛹率及成虫羽化的干扰作用。结果表明,青葙提取物对红脉穗螟的幼虫化蛹具有一定抑制作用,其中经甲醇提取物处理后7天,化蛹率仅为66.3%,显著低于对照处理(91.70%);红脉穗螟老龄（5龄）幼虫取食经青葙提取物处理后的叶片,蛹重减轻,蛹长缩短;经青葙提取物处理预蛹后,红脉穗螟成虫羽化率降低,羽化时间明显延长,而且能诱导产生畸形个体。青葙提取物具有开发成红脉穗螟防控药剂的潜力。 相似文献
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不同饲养条件对蝇蛆生长发育及蛹虫繁殖性能的影响 总被引：1，自引：0，他引：1
在不同饲养条件下饲养蝇蛆,从而建立蝇蛆养殖的最优环境组合量化标准.选择培养基基料中不同奶粉添加量、培养基湿度及饲养密度3个主要因素,每因素设4个水平,进行交叉组合试验,共有64个处理,每个处理设3个重复,观测每个组合条件下饲养蝇蛆的蛆重、蛆长、蛹重、蛹长等指标,以评价这些因素对蝇蛆生长发育及蛹虫繁殖性能的影响.单因素方差分析结果表明:不同奶粉添加量、培养基湿度及饲养密度对家蝇生长发育及繁殖性状等指标均存在极显著差异(P＜0.01),在奶粉添加量为6 g、培养基含水量为65％～80％、饲养密度为每瓶60～90条时最有利于家蝇生长发育及蛹虫的繁殖.此外,三因素之间对生长性状蛆重和蛆长存在极显著差异(P＜0.01),但在化蛹率指标中表现为任意两因素的交互作用有极显著差异(P＜0.01),而三因素交互却不显著(P＞0.05);繁殖性状蛹重和化蛹率指标的三因素互作效应显著(P＜0.05),而对家蝇蛹长的互作效应不显著(P＞0.05).结果 显示,家蝇幼虫的饲养条件以30 g发酵麦麸+3g红糖的基础培养基中,添加奶粉量为6 g,培养基湿度为80％,饲养密度为60～ 90条/瓶时,生长性状中蛆重、蛆长、化蛹率和繁殖性状中蛹重、蛹长等指标均较为理想;而培养基湿度为50％时,羽化率最高,且随着培养基湿度的增大,羽化率呈下降趋势. 相似文献
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本研究将当年收获的苜蓿（Medicago sativa）种子储存于4个温度条件下,采用定期剖种的方法,调查苜蓿籽蜂（Bruchophagus roddi）的越冬虫态及其存活情况。结果表明,苜蓿籽蜂主要以3龄幼虫在苜蓿种子内滞育越冬。10月从田间将苜蓿种子收回,储存温度在18.0 ℃、平均湿度为27.2%（10―12月）时,越冬幼虫于当年12月下旬开始化蛹;储存温度在9.9 ℃,平均湿度为40.1%（10月―次年2月）时,越冬幼虫于次年2月下旬开始化蛹。不同温度和不同时间梯度处理苜蓿种子结果表明,在50 ℃、-30 ℃条件下处理1 d,籽蜂幼虫的死亡率均达100%,苜蓿种子的发芽率分别为93.33%和88.33%。 相似文献
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Assessing the reasons for death in pig breeding units is the first step in understanding and controlling the factors influencing sow losses due to mortality. From October 1997 to October 2001 in forty-nine indoor (2876 sows died) and sixty-five outdoor breeding units (3451 sows died) sow mortality was evaluated. The average annual mortality rate during the four year evaluation period was 5.1 +/- 1.2% in indoor and 12.2 +/- 2.1% in outdoor production units. Swine urogenital disease (SUGD, 32.4%), heart failure (HF, 21.8%) and locomotor problems (LP, 33.1%) caused deaths were markedly higher in outdoor production, while periparturient diseases (mastitis-metritis-agalactia, MMA, 24.5%) and torsion or distension abdominal organs (TDA, 20.5%) revealed markedly higher losses in indoor units. The annual culling rate was 39.1% in the indoor and 45.2% in the outdoor units. In outdoor units 40.1% of all deaths occurred during the periparturient period of the reproductive cycle, in indoor units the majority of mortality happened during lactation (40.2%). Average parity at death was 3.6 in indoor and 2.5 in outdoor production. 相似文献
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云南热带雨林地区野猪生物学特性与驯养方法 总被引：1，自引：0，他引：1
为了解云南热带雨林地区野猪的生物学特性与驯化技术,探讨野猪的规模化养殖与开发利用。通过野外实地调查和收集2~4个月体重约5~8 kg的16头野猪,按试验要求与同等体重家猪人工混养驯化2年时间,将试验中观察的野猪部分生物学特性和驯化方法进行总结,整理成可供推广应用的野猪驯化管理模式。结果表明:西双版纳热带雨林地区野猪适应性强,喜集群活动,驯化后性情和食性会发生改变,可全年发情,提高繁殖性能和生长速度。在增加防护措施和户外运动场所的基础上,可参照家猪饲养方法,对纯种野猪进行家养或将纯种公野猪与母家猪进行杂交利用,开发生产无公害优质野杂猪。 相似文献
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Anke Heyer H. Kristina Andersson Kerstin Lundström 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(1):55-64
Abstract This study aimed to compare different production systems, i.e., the combined effect of outdoor and indoor rearing of pigs and organic diets fed ad libitum or restrictively. Furthermore, the suitability of two breed crosses for outdoor rearing was studied. The effects on performance, carcass and technological quality traits were investigated. During two years, 240 pigs of Duroc x Large White (D*LW) and Swedish Landrace x Large White (L*LW) were allocated to three production systems: 1) Pigs kept outdoors, fed an organic diluted diet (20% alfalfa roughage) ad libitum; 2) Pigs kept outdoors, strategically fed a diluted organic diet up to a live weight of approximately 80 kg and thereafter an undiluted organic diet ad libitum; 3) Pigs kept indoors, fed an undiluted organic diet restrictively. For outdoor pigs, strategic feeding increased daily weight gain and backfat thickness, compared with feeding a diluted diet throughout (p≤0.01). L*LW pigs in both outdoor systems grew slower than in the indoor system (p≤0.001), whereas for D*LW pigs only outdoor pigs fed the diluted diet had a slower growth rate. Outdoor pigs had lower dressing percentage than indoor pigs. Glycogen content and L* values in M. longissimus dorsi were higher, whereas b* values were lower in meat from pigs in the indoor system. D*LW pigs had higher water-holding capacity (lower drip, thawing and cooking losses), lower shear force and higher intramuscular fat content compared with L*LW pigs. 相似文献
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Culicoides obsoletus (Diptera: Ceratopogondae) is considered as the probable main vector of Bluetongue virus (BTV) in northern Europe. Its breeding sites are poorly documented at the present time. We report numerous emergences of C. obsoletus s. str. from soil samples collected in two holdings between August and September 2010. Specimens were collected regularly in the laboratory during 80 days. In one holding, 1584 C. obsoletus midges emerged from used litter collected inside a dairy cow building and 211 C. obsoletus midges emerged from manure left outside the farm buildings. In the second holding, the number of emergences observed was much lower, especially for indoor samples. We discuss the impact of the farming practices on the abundance of emergence between both holdings on one side and between indoor and outdoor breeding sites on the other side. The observation of a peak in emergence and high emergence rates recorded in the laboratory for indoor samples let us assume that these breeding sites are of great importance, especially when it comes to understand the biology of this widespread species and its role in the transmission of BTV. 相似文献
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26种昆虫体内的1-脱氧野尻霉素含量测定 总被引：3，自引：2，他引：1
为发掘新的富含1-脱氧野尻霉素(DNJ)的昆虫资源,共测定了26种昆虫体内的DNJ含量。除家蚕(Bombyxmori)之外,野桑蚕(Bombyx mandarina)、桑蟥(Rondotia menciana)、桑尺蠖(Phthonandria atrineata)、桑螟(Diaphaniapyloalis)等4种仅取食桑叶的单食性或寡食性昆虫也富含DNJ,其中桑蟥和桑尺蠖幼虫中的DNJ质量分数分别为1.0648%±0.1134%、0.5138%±0.0083%,高于家蚕幼虫中的DNJ含量(0.4238%±0.0108%),并且桑尺蠖春季越冬代幼虫及其室内桑叶饲育的第1代幼虫和蛹、成虫均含有DNJ,具有开发利用价值。从桑园采集的兼性食桑昆虫中,人纹污灯蛾(Spilarectia subcarnea)、美国白蛾(Hlyphantria cunea)、大造桥虫(Ascotissele naria)、黄斑星天牛(Anoplophora nobilis)等4种昆虫的幼虫中含有微量DNJ,而褶翅尺蠖(Zamacra excauvata)、枣尺蠖(Sucra jujuba)、桑毛虫(Euproctis similis xanthocampa)幼虫和桑天牛(Apriona ger-mari)成虫中不含DNJ。豆天蛾幼虫(Clanis bilineata)等13种非食桑昆虫体内均不含DNJ。研究结果也提示取食桑叶的昆虫对DNJ的富集能力存在很大差异。 相似文献
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During the last decade the number of outdoor breeding pig units increased in Northern Europe. With comparable results in reproduction and up to 70 per cent lower capital outlays in relation to the conventional indoor systems the interest of farmers in outdoor breeding grew also in Germany. There are a number of issues that are specific to outdoor systems that need to be considered during winter season. 相似文献