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1.
多异瓢虫生物学的研究   总被引:3,自引:0,他引:3  
多异瓢虫在山东省德州地区一年发生4代,部分个体5代,以成虫在杂草丛内、残枝落叶及土块下越冬。在自然变温下,卵、幼虫、预蛹、蛹、成虫产卵前期和全世代的发育始点和有效积温分别为18.8±0.52℃和15.0日度、16.97±0.03℃和73.3日度、15.97±0.01℃和10.23日度、15.47±0.05℃和23.05日度、17.6±0.04℃和34.1日度、18.2±0.10℃和170.3日度。据Holing圆盘方程测定,1─4龄幼虫和产卵前期成虫日最大捕食棉蚜量依次力6.7头、36.4头、77.5头、81.3头和68.0头。  相似文献   

2.
牟秀林 《生态学报》1994,14(3):318-322
辽东半岛水利建设造成洄游型香鱼资源下降,并在碧流河水库、转角楼水库形成了陆封型香鱼。陆封型香鱼发生了①个体小型化:体长和体重由洄游型香鱼的20─25cm(平均22.6cm),150─250g(平均204g),分别下降到10─18cm(平均13.6cm),和13─73g(平均36.5g)。②性状变异:洄游型香鱼体长为体高的3.7─4.7倍,为头长的4.5─5.3倍,而陆封型香鱼体长为体高的4.3─6.5倍,为头长的3.9─4.3倍。③怀卵量减少,产卵期提前:洄游型香鱼怀卵量为1.0─8.5万粒(平均3.1万位).产卵盛期为9月底至10月上旬,而陆封型香鱼的怀卵量为0.32─0.61万粒(平均0.40万粒),产卵盛期为9月上旬至下旬,提前20d左右。  相似文献   

3.
考氏把盾蚧的生物学特性及防治   总被引:2,自引:0,他引:2  
通过1986-1989年室内外饲养观察,该虫在广州1年发生6代,以雌成虫在被害枝上越冬。1月下旬越冬成虫开始产卵。田间若虫于2月上中旬、4月下旬、8月上旬、10月上旬出现5次高峰。该虫捕食性优势种天敌主要有中华草岭、尼氏钝绥螨。寄生性优势种天敌主要为跳小蜂科的一种小蜂(学名特定),对雌成虫的寄虫生率高达63%~76%。加强观赏植物管理,保护和利用自然天敌,适时施用40%氧乐果、25%喹硫磷、40%  相似文献   

4.
草兔繁殖生物学的初步研究   总被引:4,自引:0,他引:4  
卢欣 《兽类学报》1995,15(2):122-127
本文分析了1991年1-10月获自山西省东南部丘陵山区以及1990-1993年10月至翌年1月获自该省各地草兔的有关繁殖特征。草兔的繁殖季节为1-9月,雄性进入性活动的时间早于雌性。生殖腺测度有明显的季节变化,其峰值在4月和5月。当年兔3-4月龄时性可成熟,但达到性成熟月龄的当年兔只有51.7%在7、8月参加繁殖。怀孕个体见于2-9月,3月怀孕率最高,此后逐渐下降。胎仔数1-7只,5月最多,年均值3.6只,每只雌兔年产幼兔12.9只。  相似文献   

5.
小鼠卵慢速和快速降温及玻璃化冻存的比较研究   总被引:3,自引:0,他引:3  
本文用4种冷冻模式:慢速降温(SL),超快速降温(Q1)和防冻剂组成不同的玻璃化法(R-FVM和MVM)对昆明小鼠卵进行冷冻保存的比较研究,并用体外受精技术检测冷冻复苏卵的受精能力。SL和R-FVM的存活率分别为55.1±1.2和65.9±7.9,显著高于Q1(24.2±7.3)和MVM(4.5±2.4)其受精率分别为72.8±1.8和73.9±0.4显著高于Q1(58.6±11.2)和MVM(41.5±8.5),而与对照组(77.5±3.9)相似。结果表明:1)慢速降温程序(SL)和同时含有渗透性和非渗透性防冻剂的玻璃化法(F—RVM)较适宜昆明小鼠卵的冻存;2)同时考虑冻存过程中的冰晶损伤和渗透压损伤是获得较好冻存结果的关键。  相似文献   

6.
为探讨温度对胸腺激素促NK活性的影响,用胸腺因子D、胸腺素和胸腺肽与白介素2联合诱导LAK细胞,以LDH释放法检测其NK活性,发现:140℃以下加热处理的胸腺激素与未加热者活性无明显差异,当加热150℃以上时,其所诱导的NK活性,胸腺因子D、胸腺素和胸腺肽分别由62.4±5.4%降至48.2±7.6%%、53.3±3.1%降至44.4±2.6%和由60.5±4.4%降至46.7±2.9%,结果表明,150℃以上温度可使胸腺激素促NK活性丧失。  相似文献   

7.
极北鲵繁殖习性的研究   总被引:7,自引:0,他引:7  
1987-1991年4-10月对极北鲵的调查,试验结果表明,每年4月中,下旬出蛰,繁殖后休眠在5月上旬结束,9月中旬开始入蛰。孵化期15-20天,孵化率95.20%,孵化起点温度为1.53℃,孵化有效积温为263.16日度。变态期80-90天,人工饲养下的变态率为87.5%。  相似文献   

8.
甘薯天蛾又名旋花天蛾,是本地区间断性大害虫。常为人们所忽视,一到大发生年,出于不备的蒙受灾害,使薯叶全被吃光,减产甚巨。据当地群众说,此虫除1961年猖獗发生以外,1948年也曾成灾。为了摸清此虫在本地区的发生代数、时间以及各代与天敌之关系,供今后防治时的参考,我所于1962年对甘薯天蛾进行了初步观察,结果如下。 一、发生代数及时间 甘薯天蛾在襄北地区一年可发生三—四代,如为三代,主要是以第二代的部分蛹(占第二代总蛹数的46.6%)在土室内越冬。越冬代成虫5月上旬开始发生,中旬达产卵盛期,幼虫盛发期在5月下旬;第二代成虫8月上旬开始发生,卵于8月上旬初见,中旬达产卵盛期,幼虫发生盛期在8月中下旬;第三代成虫于9月中旬出现,此期由于气温渐低,幼虫生活期也相应延  相似文献   

9.
逐步回归模型在早稻白背飞虱预报上的应用   总被引:1,自引:0,他引:1  
刘俊魁 《昆虫知识》1999,36(1):40-40
作者自1987年开始利用灯下4~7月200瓦白炽灯诱虫资料、田间定点系统调查资料,结合气象资料,对湖南武冈地区白背飞虱Sogatella furcifera(Horvath)的发生规律进行了统计整理。用逐步回归方法,建立了早稻白背飞虱发生程度的模型和发生期模型。早稻白背飞虱发生程度的模型:其中,X5:4月下旬雨日,X11:5月下旬温度,X13:6月上旬温度,X14:6月上中旬雨日,X15:6月下旬湿度。早稻白背飞虱发生期模型:其中,X6:6月下旬温度,X16:6月下旬湿度。经对1995、1996…  相似文献   

10.
祁诚进  刘贤铭 《昆虫知识》1999,36(5):288-292
无忧花茸毒蛾(Dasychira horsfieldi Saunders)在山东1年发生3代,以蛹越冬。翌年4月中、下旬成虫羽化、产卵,幼虫6~7龄,一生可食泡桐叶片1~2.6片(250-650cm~2)。各虫态历期分别为:卵10~22天;幼虫25~50天;蛹8~15天(越冬蛹160-180天)。其生长发育受寄主植物,空气温、湿度的影响,种群数量的消长则受天敌、降雨和冬季低温的制约。防治可采用在树干基部打孔注入内吸农药,既不伤害天敌,也可减少对环境的污染。  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

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正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases  相似文献   

16.
Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

20.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

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