桑褐斑病在桑园的空间分布及抽样技术

桑褐斑病是云南蚕区发生最严重的桑树病害之一,调查该病害在桑园的空间分布和建立相应的抽样技术,可为病害的预测预报和制定防控措施提供科学依据。通过构建3种回归模型(Taylor的幂法则、Iwao m*-m及改进m*-m)和测定5种聚集度指标,确定桑褐斑病病叶在试验桑园内桑树上分布的基本成分是个体群,低密度时个体群相互排斥且呈聚集分布,聚集度随着个体群密度升高而增大,当密度上升到一定程度病叶个体群呈均匀分布。应用Blackith种群聚集均数(λ)解析的结果显示,造成桑褐斑病在桑园大量集中发生的因素主要是外部环境,如气候、桑树栽培条件等。依据Iwao m*-m模型建立桑褐斑病病叶抽样数公式为N=1/D2(0.33/m+0.89),可为桑褐斑病的预测预报和田间防控调查提供参考。     

桑树害虫黄星天牛幼虫的空间分布型与抽样技术

黄星天牛Psacothea hilaris Pascoe是桑树的主要害虫之一。调查黄星天牛种群在云南省蒙自蚕区桑园的空间分布结构和建立相应的抽样技术,有利于对害虫的预测预报及制定防治策略。利用6种聚集度指标以及Taylor的幂法则、Iwao m*-m回归分析法建立的2种回归模型测定黄星天牛幼虫在桑树上呈聚集分布,分布的基本成分是个体群,个体间相互吸引且聚集度随着种群密度升高而增大。利用Blackith种群聚集均数(λ)解析幼虫种群的聚集因素主要由环境因素组成,如气候、食料、桑园周围种植的其他宿主植物等。根据Iwao m*-m回归关系建立了黄星天牛幼虫抽样数公式和序贯抽样模型,在田间应用该模型调查样本的累计虫口数量超过上限时,即判为需要实施防治措施。     

宁夏荒漠草原白星花金龟成虫空间分布型的初步研究

通过对白星花金龟(Potosia brevitaris Lewis)成虫空间分布格局的测定,应用聚集度指标法、Taylor幂法则和Iwao回归法对白星花金龟成虫的空间分布型进行分析和检验,以期对该害虫实施预测预报及防治提供科学依据。结果表明:白星花金龟成虫在盐池荒漠草原呈聚集分布,分布的基本单位是个体群,引起聚集的原因主要是白星花金龟成虫自身习性,与环境因素也有一定关系。种群数量动态研究显示白星花金龟种群数量在6个不同样带表现基本一致,除了撂荒2年后形成的以蒙古冰草(Agropyron mongolicum)为优势植物的样带外其他样地也都出现3次高峰。     

新疆草原脊萤叶甲幼虫空间分布型及抽样技术的研究

研究了新疆荒漠草地害虫脊萤叶甲（Theonesilphoides）幼虫的空间分布型及抽样技术,通过频次分布和聚集度指数的测定以及m＊-m回归和Taylor幂法则分析。结果表明,脊萤叶甲幼虫为聚集型中的负二项分布。m＊-m回归分析表明脊萤叶甲幼虫空间分布的基本成分是个体群,幼虫个体间相互吸引,个体群呈聚集分布。Taylor幂法则分析结果表明,脊萤叶甲幼虫个体的空间分布格局随着虫口密度的升高,其聚集程度增强。通过m＊-m回归检验方程确定脊萤叶甲幼虫最适抽样数为440株,仅为实际抽样数的44%。5种抽样方法中,以Z字形法最好,平行线法次之。     

不同空间分布方式对刺穗藜生长格局的影响

在内蒙古退化草原上一年生植物刺穗藜Chenopodium aristatum呈聚集分布。经过长期进化而形成的聚集分布是否在其个体的生长格局上表现出显著的优势？为探讨此问题,用盆栽控制试验的方法研究了不同空间分布方式（均匀、聚集和随机分布）下刺穗藜种群的生长格局。结果表明,不同空间分布方式对刺穗藜个体的高度（P=0.026）、地上生物量（P=0.004）、地下生物量（P=0.049）以及总生物量（P=0.004）均具有显著影响。刺穗藜个体的高度在均匀分布下最大,并且显著大于聚集分布（P=0.014）和随机分布（P=0.023）下的高度,后两者间无显著差异。相反,在聚集分布和随机分布下各生物量指标都显著大于均匀分布下的指标,而聚集分布和随机分布下比较各指标无显著差异。由此看来,在刺穗藜个体高度上,聚集分布并没有表现出比均匀分布和随机分布显著的优势,但在各生物量指标上,聚集分布表现出比均匀分布显著的优势,而和随机分布相比没有表现出显著优势。因此,刺穗藜的这种自然聚集分布的进化优势只是体现在其个体生长格局的某些指标上,此结果可能是控制试验条件下,人为排除了自然条件下种间相互作用（种间竞争）和各种外界干扰（如动物的直接取食、动物的来回践踏活动等）的原因造成的。     

天山北坡两种退化梯度下伊犁绢蒿种群空间分布的点格局分析

采用Ripley’s K函数对重度和极度退化2个区域的伊犁绢蒿种群进行了空间格局及关联分析。结果表明,在20 m的一系列空间尺度上,重度退化区域的绢蒿种群总体上强烈偏离随机分布呈聚集分布,聚集强度在不同尺度上有所变化,在一系列空间尺度上出现明显的“聚集波”现象。而极度退化区域内绢蒿种群则在小尺度内呈聚集分布,到达聚集分布的临界值时则转入随机分布。进一步对不同大小级绢蒿进行了分析,在重度退化区域内,1、2级大小个体均呈聚集分布,但形体较大的植株聚集程度减弱。在极度退化区域内,1级大小个体在小尺度范围内呈聚集分布,而随着尺度增加转为随机或者均匀分布,2级大小个体则为随机分布。通过不同大小级个体的空间关联分析表明,2种退化梯度下,2个大小级的绢蒿群体在小尺度范围内均表现出正关联,但随着尺度的增加关联性逐渐减弱,且二者在产生正关联的尺度范围上有所差别。     

宁夏荒漠草原不同群落蒙古冰草种群空间格局及种间关联性

为探讨蒙古冰草种群对环境的适应对策,以宁夏盐池县荒漠草原短花针茅+蒙古冰草群落、蒙古冰草+牛枝子群落、蒙古冰草+牛心朴子群落为研究对象,采用点格局分析中的O-ring函数统计方法,分析了不同群落中蒙古冰草种群的数量特征、分布类型及优势种群的种间关联性。结果表明:不同群落生境条件下,蒙古冰草+牛枝子群落中蒙古冰草种群的密度、盖度和地上生物量显著高于短花针茅+蒙古冰草群落和蒙古冰草+牛心朴子群落(P<0.05),3个群落之间蒙古冰草种群的高度差异不显著(P<0.05)。不同群落生境蒙古冰草种群在<4 m尺度范围内主要表现为聚集分布,随尺度增大,聚集强度减弱,逐渐过渡到随机分布和均匀分布。蒙古冰草种群与短花针茅种群、蒙古冰草种群与牛枝子种群在小于4 m尺度上呈显著负关联,随尺度的增大趋于无关联;蒙古冰草种群与牛心朴子种群在整个研究尺度上无关联。     

宁夏荒漠草原不同群落蒙古冰草种群空间格局及种间关联性

为探讨蒙古冰草种群对环境的适应对策,以宁夏盐池县荒漠草原短花针茅+蒙古冰草群落、蒙古冰草+牛枝子群落、蒙古冰草+牛心朴子群落为研究对象,采用点格局分析中的O-ring函数统计方法,分析了不同群落中蒙古冰草种群的数量特征、分布类型及优势种群的种间关联性。结果表明:不同群落生境条件下,蒙古冰草+牛枝子群落中蒙古冰草种群的密度、盖度和地上生物量显著高于短花针茅+蒙古冰草群落和蒙古冰草+牛心朴子群落(P0.05),3个群落之间蒙古冰草种群的高度差异不显著(P0.05)。不同群落生境蒙古冰草种群在4 m尺度范围内主要表现为聚集分布,随尺度增大,聚集强度减弱,逐渐过渡到随机分布和均匀分布。蒙古冰草种群与短花针茅种群、蒙古冰草种群与牛枝子种群在小于4 m尺度上呈显著负关联,随尺度的增大趋于无关联;蒙古冰草种群与牛心朴子种群在整个研究尺度上无关联。     

宁夏东部退化草原群落建群种种群格局

运用方差/均值比率法及聚集强度指数研究宁夏东部退化草原主要植物群落建群种种群分布格局及其动态,结果表明,14个建群种中除老瓜头种群呈随机分布外,其余种群均服从聚集分布.分析表明,影响种群格局的主要因子为物种本身的生物学特性、环境因子以及种内、种间的竞争排斥.     

高山草原蝗虫种群空间格局研究

以１９９３－１９９６年在甘肃省夏河县甘加高山草原蝗虫种群调查资料为基础,了草原蝗虫混合种群的空间格局及其聚集与扩散优势,并用聚块性指标研究了其聚集强度的时序变化。研究结果表明;蝗蝻呈集各随机分布,成虫随随机型分布,近似Ｐｏｉｓｓｏｎ分布、蝗 孵化初期呈现扩散地趋势,孵化盛期聚集趋势,而成虫则主要表现出扩散趋势。     

National occurrence reporting of Trichinella and trichinellosis using a computerized database

Historical and contemporary national data on the occurrence and distribution of Trichinella and trichinellosis in people, domestic animals and wildlife in Canada have been incorporated into a computerized database, the Canada Database of Animal Parasites (CDAP). This database was established in 1998, and contains similar information on several other helminth and protozoan parasites which are of importance in animal health, human health, food safety or trade. The CDAP is a unique assemblage of national information on parasite occurrences, not available from any other single source. This paper describes the CDAP, with emphasis on sources of data, database structure and outputs, logistical issues associated with database development and maintenance, and the application of the CDAP to Trichinella surveillance at a national level. It is suggested that the CDAP, or a similar approach, could be applied in other countries for assembling data on Trichinella and trichinellosis.     

A gel delivery system for coccidiosis vaccine: uniformity of distribution of oocysts

A patented gel delivery system being used to deliver coccidiosis vaccine to poultry hatchlings is assessed. For effective vaccination, the coccidial oocysts must be uniformly suspended before exposure to birds. The uniformity of distribution within the gel was evaluated by incorporating a culture of chicken gut flora into gel sausages, placing sections of the sausage on culture plates, determining the appearance and distribution of bacterial colonies on culture plates after incubation, and verifying by cell counts. The uniformity of distribution of similarly prepared coccidial oocysts was verified by infecting birds with 40,000 Eimeria tenella oocysts delivered via the gel. Gel-inoculated birds were compared with control birds inoculated PO with 40,000 oocysts suspended in water by using cecal lesion scores. Both the appearance and colony counts of chicken gut flora from the gel were uniform. The standard deviation in the lesion scores for the gel-inoculated group and the water-inoculated groups were 0.51 and 0.69, respectively. The results indicate that a gel delivery system can provide uniform distribution of live organisms and vaccine agents to birds.     

贵州中部的鹭鸟群巢

2006年5月,对贵州中部的鹭鸟群巢进行了调查,共记录到11个繁殖群、1587巢,种类包括小白鹭(Egretta garzetta)、牛背鹭(Bubulcus ibis)、池鹭(Ardeola bacchus)、夜鹭(Nycticorax nycticorax)和苍鹭(Ardea cinema).最大的繁殖群在黄平风云崖和赤水宴府.种类以小白鹭为优势种,其巢数量占总巢数的49.7%;而苍鹭最少,仪占0.1%.所有鹭鸟巢均只发现于贵州中、北部,而南部的雷公山地区没有调查到.鹭鸟群巢在贵州中部的分布明显受到农田种植模式(冬天种植小麦和油菜,夏天种植水稻)的影响,繁殖巢主要分布于稻作区.但在贵州南部的主要稻作区却没有发现鹭鸟繁殖群巢,其原因尚待调查.对贵州黄平和赤水这两个较大鹭鸟群巢所在地需重点加以保护.     

Classification Problems of African Muridae

In the Transvaal, Miniopterus schreibersi natalensis forms hibernating colonies during May-July on the highveld where the ambient and cave temperatures are lower than in the lowveld. In two highveld caves, mating and hibernating colonies were resident from January to the end of July, but only one cave was occupied for hibernating during the winter. In the cave selected for hibernation humidity was lower, and fluctuated more, than in the other cave. Temperature also fluctuated more, but tended to average lower, than in the unused cave. It appears that low temperature rather than high humidity determined the choice of a hibernating cave.     

胡蜂对蜜蜂采集行为影响的实验研究

选择云南高原温带型东方蜜蜂和云南低海拔热带型东方蜜蜂各2群,在蜂箱门口用活体黑盾胡蜂(Vespa Velutina)干扰蜜蜂采集活动,干扰的时间分别为3 min,6 min和12 min.每分钟为一计数单位,记录蜜蜂采集蜂飞出的数量.结果发现蜜蜂采集蜂飞出的数量随干扰时间的增加而明显下降,干扰的时间越长,蜜蜂采集蜂恢复到正常数量的时间就越长;高原温带型东方蜜蜂和低海拔热带型东方蜜蜂在胡蜂干扰时,在数量变化上有明显的差异,后者对胡蜂的干扰比前者更为敏感(P＜0.05).     

Demonstration of colonies of Anaplasma marginale in the midgut of Rhipicephalus simus

Rhipicephalus simus nymphs were allowed to feed on a cow experimentally infected with the BW-strain of Anaplasma marginale from Republic of South Africa, and they were studied as adults. Colonies were demonstrated by light microscopy in midgut epithelial cells of adult ticks that were unfed (as adults), incubated, or prefed for 72 hours on a cow. The colonies occurred in 5 different morphologic types (1 to 5) that were similar to those described previously for a Virginia isolate of A marginale in Dermacentor andersoni. The colony density (number of colonies/0.001 mm2 midgut tissue examined) ranged from 0 to 2.0 and was highest in unfed ticks that were not incubated (mean 0.566). Colonies observed by light microscopy were sectioned for study with the electron microscope. The colonies contained both electron-dense forms and reticulated forms. The organisms in type 2 and 3 colonies appeared to be attached to one another, and those in type 4 and 5 colonies occurred separately. Small particles were seen within the limiting membrane of some organisms. A few colonies contained a dense matrix and were surrounded by many small electron-dense particles.     

Preweaning mortality in specific pathogen free kittens

The incidence, causes and age distribution of preweaning deaths in a specific pathogen free (SPF) cat colony are described. The age distribution of kitten mortality is compared with that in one other SPF and four conventionally housed colonies. Almost all preweaning deaths in the SPF colonies occurred within the first week of life. The only infectious agent considered to be a cause of death was Escherichia coli. It is suggested that in the selection of breeding stock the mothering ability of the dam is of particular importance.     

3个地方鸡种的核型及其似近系数分析

运用外周血淋巴细胞培养法，对我国3个地方鸡种(仙居鸡、北京油鸡、狼山鸡)染色体核型进行了研究，结果显示：仙居鸡、北京油鸡、狼山鸡染色体形态十分相似，No．1、No．2、No．8、Z、W染色体都为m型；No．6染色体都为sm型；No．3、No．5、No．7、No．9染色体都为t型，仅在No．4染色体形态和W染色体的相对长度表现出一定的差异。此外，核型似近系数和进化距离聚类分析表明，7个地方鸡种(另收集了鹿苑鸡、寿光鸡、泰和鸡和旧院黑鸡的资料)可分为3个类群，其结果与起源进化，产地分布大致相同。     

Development of infestation with Varroa jacobsoni O. in bee colonies in Tunisia

The mite Varroa jacobsoni, an ectoparasite of the honey bee, was imported to Tunisia probably in 1976. Afterwards, this parasitosis caused severe losses of colonies for several years. The continued examination of the level of infestation in colonies of a "GTZ" project stated a steady number of mites since 1980. Only in a few colonies, the infestation was above the limit of damage. Though the colonies in North West Tunisia did not receive any treatment since 1986 there was no increase of infestation. In order to investigate the reason for this the mites' ability of reproduction was examined during two following years. The portion of infertile female mites in the worker brood in most of the colonies was with 50% considerably higher than in Europe. In Brazil, the adaptation between host and mite produced similar low reproduction rates. As, however, in Tunisia the portion of infertile females in the drone brood of the individual colonies corresponded to the one in the worker brood climatic conditions are supposed to be responsible.     

黄体生成素和褪黑素受体在不同日龄雏鸵鸟睾丸内的分布研究

采用免疫组织化学SABC法对1 d、30 d和90 d雏鸵鸟睾丸内黄体生成素(1uteinizing hormone,LH)和褪黑素受体(melatonin receptor,MR)的分布进行定位,结果显示:LH阳性细胞胞质或胞膜出现棕黄色,胞核无阳性反应;MR阳性反应颗粒呈棕褐色或棕黄色,位于胞质、胞膜或胞核,呈散在...