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1.
新疆菜蝽在新疆发生普通,是油菜和蔬菜的重要害虫。该虫在南疆沙雅地区一年发生三代,世代重迭,主要以第三代成虫在田边、田埂、青苔落叶下面越冬,翌年四月下旬迁飞至田间为害油菜幼苗,以第一、二代为害油菜最烈。 越冬成虫和第一代成虫交配期,平均分别为30.5天及2.4天。产卵前期的越冬成虫为3.8天;第一代为10.2天;第二代为4.7天。越冬成虫每雌产卵平均103.8粒;第一代32.0粒;第二代10.3粒。产卵期的长短因世代而异,第三代、第一代、第二代平均分别为35.9天、2.6天、2.9天。第一代卵主要产于地面的土块上,第二代主要产于植株的中下部叶面上。第一代与第二代成虫寿命平均分别为13天及71.3天。当平均温度在24.4℃时,第一代卵期平均9天,在27.5℃时,第二代卵期平均5.8天。若虫共五龄,若虫期第一代平均31.5天,第二代平均26.9天。 有一种卵蜂在田间平均寄生率达55.0%,有利用价值。防治时,消灭田内的杂草,结合人工捕采成虫和卵块以及浸水淹杀第一代卵。田间化学防治可用6%可湿性666的200-400倍液,对若虫及成虫效果很好。  相似文献   

2.
据室内观察,星豹蛛在安徽省芜湖市(12.7—29.8℃)一年发生不完全的二代,以若蛛和成蛛越冬。雌蛛一生只交配一次,多次产卵。越冬代雌蛛平均产卵囊2.4个,每个卵囊平均具卵52粒;第一代雌蛛平均产卵囊2.2个,每个卵囊平均具卵39粒。卵粒孵化率最低为65%,最高达100%。从若蛛发育至成蛛,一般蜕皮5—6次,少为7次,雌雄性比为1.5:1,成蛛平均寿命为133.2天。  相似文献   

3.
前齿肖蛸(Tetragnatha praedonia)在湖北省武汉地区一年可发生五代,以低龄幼蛛在杂草丛中越冬。雌蛛一生最多可产5个卵袋,单雌平均产卵量第一代为155.43粒,第二代260.20粒,第三代213.01粒,第四代62.50粒。卵的孵化率各代均在88%以上。各代幼蛛期、产卵前期、全代历期以及成蛛寿命均不相同。能捕食蚊子以及棉田和稻田的多种害虫。  相似文献   

4.
对棉大卷叶螟Sylepta derogata Fabricius第5代、第6代室内种群饲养结果显示,该虫的有效越冬虫源为第5代滞育的老熟幼虫,滞育率24.4%~33.1%,第6代棉大卷叶螟的发生对第2年的种群基数影响不大。滞育老熟幼虫的越冬存活率为60.0%~71.9%。次年越冬代羽化的成虫雌虫少,雄虫多,单雌产卵量平均为163.4~198.8粒。  相似文献   

5.
蝶蛹金小蜂在杭州的年生活史   总被引:4,自引:1,他引:3  
胡萃 《昆虫学报》1984,(3):302-307
蝶蛹金小蜂是菜粉蝶蛹期的主要寄生蜂。在杭州,绝大多数以老熟幼虫在寄主蛹内越冬。田间养虫室内饲养结果:1979年发生11—12代;1981年早、中、迟三组分别为12—13代、10—11代以及9—10代,三组合计,非越冬代成虫自5月上旬至12月初始终不断,一年之内,前后(连续或不连续)两代成虫重叠发生的天数至少175天,前后(连续或不连续)三代成虫重叠发生的天数至少49天。 2、3月间小蜂即可羽化,远远早于田阔第一代菜粉蝶蛹的出现,惟不能寄生越冬后的越冬代菜粉蝶蛹,但越冬代蜂的羽化盛期仍处于田间第一代菜粉蝶蛹初见至化蛹始盛期之间,且喂食后寿命很长,故越冬代蜂与第一代菜粉蝶蛹之间的发生期基本上是吻合的。其后,两者代数既多(菜粉蝶一年发生9代),发生又都不整齐,小蜂成虫与菜粉蝶蛹均连绵不断,时间上彼此也是吻合的。这是此蜂自然寄生率高并成为其重要天敌的一个主要原因。 对发生代数多、世代重叠的重要天敌建议分期分批饲养,以深入掌握其生活史及与寄主发生的关系。  相似文献   

6.
白翅叶蝉(Thaia subrufa Motschulsky)在浙江省东阳县,一年大部发生二代。第一、二代成虫分别于6月下旬至7月上、中旬和8月下旬至9月中旬盛发于早稻和双季晚稻,第二代成虫大部分越冬,少数早发的才能发生第三代。第一、二和三代卵历期分别为17—19、11—12和15一19天,若虫历期分别为19、16和24天。成虫4℃开始活动,10℃开始取食,15℃开始羽化和产卵。卵开始发育温度在20℃左右。成虫无孤雌生殖现象,产卵前期在第一、二代分别为23和17天,越冬成虫则长达6—8月之久。每雌产卵量以越冬代最高,以后各代急剧下降。越冬后成虫在4月下旬几乎全部集中于早、中稻秧田,产卵盛期在5月即早稻本田分蘗期。繁殖寄主仅限于水稻。 因白翅叶蝉具有这些生物学特性,所以防治适期为早季秧田。1964—1965年在东阳县早季秧田大面积防治结果,可减低早、中稻本田虫口90%以上,且能压低双季晚稻田的虫口密度。  相似文献   

7.
<正> 黄地老虎Euxoa segetum(Schiffermuller)在山东省普遍发生,是农业生产的一大害虫。 一、生物学特性 1.年生活史 黄地老虎一年发生4代,以第四代幼虫越冬,各代发生期见表1。 第一代幼虫发生于5月上旬至6月下旬,第二代为6月下旬至9月上旬,第三代发生于8月中旬,11月中、下旬进入越冬期,翌年3  相似文献   

8.
梁兴善 《昆虫学报》1966,(4):327-332
1.榆毒蛾在北京地区,一年两代,每代的历期与季节性气候变化有关。第—代在夏季完成,卵期,约在7月上中旬,幼虫于7月中下旬孵化,至8月下旬化蛹,9月上旬羽化,历期约50日;第二代从秋末到次年春末夏初,卵期在9月上旬至下旬,幼虫9月中下旬孵化至10月中旬前后进入越冬,次年4月中下旬活动至6月下旬化蛹,7月上旬羽化,除越冬期外,历期约120日。 2.榆毒蛾的雌雄性比,1956年统计:第一代雌雄比例(%)为68:32,第二代为56.5:43.5。其产卵量,每雌最多215粒,少为26粒,平均79.1粒。成虫期遇天气晴朗,卵量较多,阴雨天气,产卵量减少。卵的孵化率,在自然条件下,每代都在90%以上。 3.榆毒蛾在北京地区,以2龄幼虫越冬。越冬场所主要在榆树洞穴、裂皮和树下的堆积物内。榆毒蛾成虫不取食,幼虫取食叶片;幼虫1-3龄,趋光性弱,大部在榆树下层,叶片背面,5-7龄,趋光性增强,栖居于榆树上部、叶片表面;成虫夜晚有趋光习性,白天在晴朗的中午前后飞翔数量较多,阴雨和风速在3级以上的夭气停止飞翔。 4.榆毒蛾虫口数量的变化与降雨量及其分布有关。少雨的世代,榆毒蛾数量上升,多雨的世代,其数量下降。如1955年第一代幼虫初期降雨125.5毫米。蛾量较越冬代增长11.8倍,1956年第一代幼虫期降雨529.0毫米,其蛾量较越冬代却有所下降。  相似文献   

9.
小波分析二点委夜蛾发生规律   总被引:2,自引:0,他引:2  
二点委夜蛾Proxenus lepigone(Moschler),属鳞翅目夜蛾科,主要分布于日本、朝鲜、俄罗斯和欧洲等地。我国于2005年7月在河北省夏玉米田首次发现。近年来,该虫发生范围不断扩大,为害程度日益加重。2011年二点委夜蛾在我国夏玉米产区严重暴发,虫情涉及6省47市302个区(县),面积近220万hm2。山东省2007年首次在德州市发现该虫为害玉米,2011年全省17个地市普遍为害严重。为更准确地确定该虫的发生代次、每代各虫态发生历期、发生盛期、发生高峰日等信息,适时准确监控发生时期,本文采用symlets小波函数变换滤除高频信息,对山东省多地点二点委夜蛾成虫诱虫数据进行分析,结果显示,二点委夜蛾在山东省一年发生4代,越冬代、1代、2代、3代,始见蛾日在3月底—4月上旬,越冬代成虫发生期在3月底至4月上中旬,1代发生期在4月上旬至6月中下旬,2代发生期在6月中旬至8月上中旬,3代发生期在8月上旬至9月中下旬,越冬代幼虫发生期在9月中旬至10月中下旬,10月下旬左右老熟幼虫做茧越冬。另外,通过调查和室内观察还发现高温环境不利于二点委夜蛾幼虫生长发育,7—8月份高温期,成虫致畸率较高。  相似文献   

10.
哈尔滨地区大猿叶虫发育历期与生物学特性   总被引:4,自引:0,他引:4  
在哈尔滨对白菜上的大猿叶虫Colaphellus bowringi Baly的生活史和生物学习性进行观察研究。结果表明,大猿叶虫在哈尔滨地区绝大多数个体1年发生1代,少部分个体1年发生2代。主要以成虫入土在2~27cm土层中滞育越冬。越冬成虫翌年4月下旬开始出土活动。第1代发生在5上旬至7月上旬,第2代发生于6月中旬至7月中旬。所有成虫在7月下旬以后均滞育越冬。在25℃条件下,雌虫产卵期为6~55d,平均为30.95d,单雌平均产卵量为454.9粒。在25℃各虫态的发育历期为:卵(4.46±0.33)d,幼虫(8.22±0.26)d,蛹(4.17±0.22)d。各虫态发育起点温度卵为10.80℃,幼虫为10.95℃,蛹为9.79℃;有效积温卵为64.82日.度,幼虫为117.37日.度,蛹为64.36日.度。  相似文献   

11.
Although the importance of cell adhesion in morphogenesis is already known for quite some time, there are remarkably few studies on the distribution and function of adhesion molecules in tooth development. We have chosen the zebrafish to study the role of specific cell adhesion molecules in the development and renewal of teeth. Zebrafish lack an oral dentition but have pharyngeal teeth which are renewed throughout life. Here we focus on the expression of E (epithelial)‐cadherin during the development of the first tooth to develop in the dentition, ‘initiator tooth’ 4V1. E‐cadherin is expressed exclusively in the pharyngeal epithelium and in the enamel organ throughout all stages of development of this first‐generation tooth. Further studies are needed to compare this expression pattern with protein distribution, both in this and other first‐generation teeth as well as in replacement teeth.  相似文献   

12.
紫胶虫的生物学研究   总被引:3,自引:0,他引:3  
紫胶虫Laccifer lacca(Kerr)Targ.在云南自然分布区一年发生两代,各世代有涌散、固定、泌胶、泌蜡和排泄蜜露等活动。由于幼虫在饥饿状态下的存活期较短,迁移能力较差,必须及时实行人工放养和科学管理,才能获得紫胶高产。本文报道了紫胶虫各世代的泌胶量、生殖力和性比,并提出发展紫胶生产的建议。  相似文献   

13.
报道中国弹尾目钩圆跳科1新纪录属和1新纪录种,即钩圆跳属Bourletiella和原野钩圆跳Bourletiella arvalis(Fitch)。共计1头雄性和8头雌性采自新疆伊犁,对其进行了再描述。该虫已知分布于欧洲、北美洲和澳洲,目前仅在中国西部地区发现。  相似文献   

14.
G. G. Ganf 《Oecologia》1974,16(1):9-29
Summary Lake George, a shallow lake in western Uganda, supports a permanent and dense crop of phytoplankton, and may be regarded as eutrophic although the ambient concentrations of inorganic nitrogen and phosphorus are low. The figures for the annual nutrient loadings (Viner and Smith, 1973) would suggest, however, a eutrophic lake when analysed on the scheme of eutrophication proposed by Vollenweider (1968).The horizontal distribution of chlorophyll a shows a concentric pattern, with the maximum values occurring towards the center. This horizontal variation is thought to reflect water movements, and a general pattern of water flow is proposed.The majority of the species show no seasonal variation but populations of both Anabaena and Melosira show annual variations. These two species also have a horizontal distribution pattern which is the reverse of other species. This pattern is used to support the proposed movements of water.Phytoplankton generation times are discussed in relation to the diurnal cycle occurring in Lake George.  相似文献   

15.
斜纹拟木蠹蛾在广州发生的生物学特征   总被引:1,自引:0,他引:1       下载免费PDF全文
马骏  林莉  梁帆 《环境昆虫学报》2020,42(2):493-498
本文报道了斜纹拟木蠹蛾Indarbela obliquifasciata在广州的发生和为害特征,对其形态和生物学特征做了阐述,表明该虫在广州一年发生一代,其取食寄主达18种,但主要寄主植物为羊蹄甲,其幼虫共6龄并以幼虫越冬。并对该虫的防治提出了建议。  相似文献   

16.
Genetic control of blood pressure in spontaneously hypertensive rats (SHR)   总被引:1,自引:0,他引:1  
H Tanase 《Jikken dobutsu》1979,28(4):519-530
Genetic control of blood pressure in the SHR strain was studied by three separate experiments which consist of cross analysis between the SHR and Donryu, two-way selecton for high and low blood pressure levels, and successive backcrosses to the parental strains. The results obtained were as follows. 1. The data from genetic crosses between the SHR and Donryu showed the phenotype segregation ratio of 1:1 at the backcross and 1:2:1 at the F2 generation. 2. Two-way selection for high and low blood pressure levels was performed from the F2 generation onward. The separation between the two lines occurred immediately after the first selection. Thereafter, the difference increased gradually with generation. The blood pressure level at the seventh generation of selection became approximately equal to those of the parental strains. 3. Two types of the successive backcross were performed from the F1 hybrids by mating the males showing the highest blood pressure level to Donryu females and the females showing the lowest blood pressure level to SHR males on the other. Bimodality was observed in the distribution of blood pressure levels at each generation. Their phenotypic segregation ratios were accordant with 1:1 on the whole. At the intercross generation during successive backcrosses, a trimodal distribution was observed. 4. These results confirmed that the hypertensive trait of the SHR is regulated by a single major gene and other several genes with minor effect. A gene symbol ht was proposed for this major gene. Concurrently, a congenic strain having the ht gene on the genetic background of the Donryu was developed by the successive backcross system.  相似文献   

17.
Anopheles cruzii is a small sylvatic mosquito and primary human Plasmodium vector in Southern Brazil. The distribution of this bromeliad-breeding mosquito follows the Atlantic forest coastal distribution, where bromeliads are abundant. Morphological, genetic, and molecular polymorphisms among different populations have been reported and it has recently been suggested that An. cruzii is a complex of cryptic species. The aim of this work is to analyze the gene flow between different populations of An. cruzii collected in four localities within the geographic distribution range of the species, and to examine if An. cruzii is a complex of cryptic species. The genetic distances show that populations of the states of Santa Catarina, Sao Paulo, and Rio de Janeiro are genetically closer (0.032 to 0.083) than populations of Bahia (0.364 to 0.853) based on profiles from 10 distinct isoenzyme loci. The Fst was lower (0.077) when the Bahia population was excluded than when it was included (0.300) in the analyses. The inferred number of migrants per generation was 2.99 individuals among populations from the states of Santa Catarina, Sao Paulo, and Rio de Janeiro and 0.58 migrants per generation among all populations. Results suggest that An. cruzii is a complex of species and that the specimens of state of Bahia can be considered as belonging to a species that is distinct from other three closely-related populations studied.  相似文献   

18.
栌菊木属及白菊木属的细胞学研究   总被引:6,自引:3,他引:3  
对栌菊木属及白菊木属的染色体数目进行了首次报道,对栌菊木(Nouelia insignis Franch.)分布区内的10个居群进行了细胞学研究,染色体数目均为2n=54。白菊木属在中国分布的仅白菊木(Leucomeris decora Kurz)一种,对漾濞这个居群的细胞学研究表明,染色体也为2n=54。这两个属的基数可能x=9,它们可能为6倍体,结合帚木菊族已有染色体报道及形态特征,地理分布等初步分析表明:栌菊木种内分化程度小,是一自然类群;栌菊木和白菊木可能有着较近缘的联系;栌菊木可能是古老孑遗植物的后裔,为适应环境而多倍体化,得以保存下来。  相似文献   

19.
The external morphology, osteology, and distribution of a rare fish species Psychrolutes pustulosus (Scorpaeniformes: Psychrolutidae) is examined based on an extensive material for the first time. P. pustulosus shows an extreme degree of reduction of the skeleton among the Psychrolutidae. The comparative morphological analysis confirms the placement of this species in the genus Psychrolutes rather than in Gilbertidia. The new data show that P. pustulosus is widespread in the Sea of Okhotsk. The occurrence of this species in the Sea of Japan (Tatar Strait, Peter the Great Bay) is recorded for the first time. Reports on the findings of P. pustulosus in the Bering Sea are erroneous.  相似文献   

20.
P. E. Smouse  T. R. Meagher 《Genetics》1994,136(1):313-322
Genealogical analysis is a powerful tool for analysis of reproductive performance in both natural and captive populations, but assignment of paternity has always been a stumbling block for this sort of work. Statistical methods for determining paternity have undergone several phases of development, ranging from straightforward genetic exclusion to assignment of paternity based on genetic likelihood criteria. In the present study, we present a genetic likelihood-based iterative procedure for fractional allocation of paternity within a progeny pool and apply this method to a population of Chamaelirium luteum, a dioecious member of the Liliaceae. Results from this analysis clearly demonstrate that different males make unequal contributions to the overall progeny pool, with many males contributing essentially nothing to the next generation. Furthermore, the distribution of paternal success among males shows a highly significant departure from (Poisson) randomness. The results from the present analysis were compared with earlier results obtained from the same data set, using likelihood-based categorical paternity assignments. The general biological pattern revealed by the two analyses is the same, but the estimates of reproductive success are only modestly (though significantly) correlated. The iterative procedure makes more complete use of the data and generates a more sharply resolved distribution of male reproductive success.  相似文献   

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