中华通草蛉和大草蛉幼虫对黑刺粉虱若虫的捕食功能反应

【目的】为了研究中华通草蛉Chrysoperla sinica(Tjeder)幼虫和大草蛉Chrysopa pallens(Rambur)幼虫对黑刺粉虱Aleurocan spinfetus(Quaintance)若虫的捕食作用。【方法】在室内(25±1)℃条件下对2种草蛉的捕食功能反应模型进行了评估,并对2种草蛉的3龄幼虫的种内干扰作用和自身密度作用的反应方程进行了拟合。【结果】2种草蛉的捕食功能均属于HollingⅡ反应模型,捕食量均随黑刺粉虱若虫密度的增加而增加。中华通草蛉和大草蛉的自身密度方程分别为E=0.753 0×P~(–0.134 8)和E=0.697 5×P~(–0.164 6),种内干扰作用方程分别为A=2.362 6×P~(–0.231 8)和A=2.429 6×P~(–0.225 6)。【结论】中华通草蛉和大草蛉对黑刺粉虱均具有较好的捕食作用。     

黄玛草蛉对两种蚜虫的捕食效能

实验室条件下研究了黄玛草蛉2龄与3龄幼虫对甘蓝蚜以及玉米蚜成虫的捕食功能反应。结果表明:黄玛草蛉2龄与3龄幼虫对2种蚜虫的捕食量均随着猎物密度的增加而增加,寻找效应随着猎物密度的增加而减小。不同龄期幼虫对2种蚜虫的捕食功能反应均符合HollingⅡ模型,黄玛草蛉2龄与3龄幼虫对玉米蚜最大理论日捕食量分别为120.48头、185.18头;黄玛草蛉2龄与3龄幼虫对甘蓝蚜最大理论日捕食量分别为60.60头、86.95头。在相同猎物种类下,黄玛草蛉3龄幼虫对2种蚜虫的捕食量均高于黄玛草蛉2龄幼虫;在相同猎物密度下,黄玛草蛉2龄幼虫与3龄幼虫对玉米蚜的捕食量均高于甘蓝蚜。     

叉角厉蝽对斜纹夜蛾的捕食功能反应

叉角厉蝽Cahtheconidea furcellata是一种重要的捕食性天敌昆虫,为了探明该虫的捕食潜能,在室内条件下研究了叉角厉蝽成虫对斜纹夜蛾Spodoptera litura Fab.二龄和三龄幼虫的捕食作用和种内干扰作用。结果表明,叉角厉蝽成虫的捕食量随着斜纹夜蛾幼虫的密度增加而增大,其捕食功能反应符合HollingⅡ型方程。叉角厉蝽对斜纹夜蛾2龄幼虫的捕食量符合Na=0.7364N/(1+0.0118N),对斜纹夜蛾3龄幼虫的捕食量符合Na=0.7504N/(1+0.0005N),叉角厉蝽的捕食作用有较强的种内干扰反应,捕食率与个体间相互干扰的关系符合Hassell模型。叉角厉蝽的捕食量与害虫密度正相关,寻找效应与害虫密度负相关。     

广重粉蛉对烟粉虱的捕食作用研究

【目的】广重粉蛉Semidalis aleyrodiformis(Stephens)是烟粉虱Bemisia tabaci(Gennadius)的重要天敌昆虫之一,为了明确其控制潜能,本文研究了广重粉蛉对烟粉虱的捕食作用。【方法】在室内温度(26±1)℃,相对湿度75%±5%,光照周期L∶D=14∶10条件下,对广重粉蛉幼虫捕食烟粉虱各个虫态的捕食作用进行研究。并且评估了广重粉蛉幼虫对烟粉虱卵、广重粉蛉成虫对烟粉虱若虫和伪蛹的捕食功能反应模型,同时,对广重粉蛉成虫捕食烟粉虱卵的干扰反应方程进行了拟合。【结果】广重粉蛉幼虫对烟粉虱的捕食量随着广重粉蛉龄期的增大而增大。广重粉蛉幼虫对烟粉虱卵的功能反应和广重粉蛉成虫对烟粉虱各个虫态的捕食功能反应都呈HollingⅡ型。随着广重粉蛉龄期的增加,广重粉蛉对烟粉虱卵的寻找效率(a)逐渐增加,处置时间(Th)依次缩短;而广重粉蛉成虫对不同龄期烟粉虱的功能反应是随着猎物龄期的增加,寻找效率逐渐降低,处置时间(Th)依次延长。广重粉蛉自身密度方程为E=0.127 9×P-0.317 3,干扰系数为0.317 3。【结论】研究表明,广重粉蛉4龄幼虫和雌成虫对烟粉虱有较好的捕食作用,控害潜力最大。     

大草蛉对桃蚜和夹竹桃蚜的捕食作用研究

大草蛉在我国分布广泛,能捕食多种农作物害虫。本试验首先研究了大草蛉一龄幼虫对桃蚜、大草蛉二龄幼虫对桃蚜和夹竹桃蚜的捕食功能反应。三个反应的最大捕食量Namax分别为144．93、303．03和151．51（头）,瞬时攻击率a分别为0．7428、0．8654和0．6644。大草蛉一龄幼虫有较强的种内干扰反应,随着捕食者密度的增加,捕食作用率（E）依次为0．2025、0．1185、0．0866、0．0694和0．0584;对桃蚜的捕食作用率（E）与自身密度（P）的函数关系式为E=0．2025P^-0.7727。在桃蚜和夹竹桃蚜的混合种群中,大草蛉二龄幼虫对桃蚜的选择效应大于夹竹桃蚜。     

温度对中华通草蛉捕食麦长管蚜的影响

为明确温度对中华通草蛉 Chrysoperla sinica 捕食麦蚜能力的影响,充分发挥其控害潜能,本研究利用年龄-龄期两性生命表方法,研究了5个温度下(16℃、19℃、22℃、25℃、28℃)中华通草蛉幼虫对麦长管蚜 Sitobion avenae 的捕食能力。结果发现,1龄幼虫在19℃条件下捕食量最高,16℃条件下捕食量最低,且差异显著。2龄幼虫不同温度处理间捕食量均无显著性差异,3龄幼虫捕食麦长管蚜数量则随处理温度的提高而显著降低,而幼虫期总捕食量除28℃在不同温度间均无显著性差异。2龄幼虫平均捕食率高于1龄幼虫,但显著低于 3龄幼虫。年龄-龄期捕食率结果说明,温度升高缩短了幼虫发育时间,但提高了其捕食能力;虽然不同温度处理总捕食量不变,但高温缩短了幼虫捕食所消耗的时间。22℃条件下中华通草蛉雌成虫期长(96.63 d),产卵期长(55.36 d),繁殖力强(310.36),平均世代周期( T )短(48.99 d),容易产生世代重叠现象;内禀增长率( r )和周限增长率(λ)显示中华通草蛉种群呈正增长趋势。研究结果对于春季田间释放中华通草蛉防治麦长管蚜具有一定参考价值。     

异色瓢虫对白毛蚜捕食作用的研究

试验研究了异色瓢虫Leis axyridis(Pallas)各龄幼虫和戌虫对白毛蚜Chaitophorus po-pulialbae无翅成蚜的捕食功能反应及其成虫的寻找效应。功能反应均属Holling II型。异色瓢虫成虫寻找效应和自身密度之间的关系用Hasell & arley(1969)模型E=QP-m 和Beddington(1975)模型E=aT/［1+btm(P-1)]进行了模拟,Beddington模型更好地反映寻找效应和瓢虫密度之间的 关系。寻找效应与瓢虫成虫自身密度和蚜虫密度之间的关系用Bcddington(1995)模型E＝aT/[1+aT_mN十bt_m(P-1)]进行描述,表明寻找效应(E)随瓢虫密度(P)和猎物蚜虫密度(N)的增大而下降     

利它素对中华通草蛉不同龄期幼虫捕食行为的影响

本文测定了棉蚜及棉花嫩梢不同溶剂提取液对中华通草蛉捕食行为的影响,结果表明,棉花受害嫩梢及未受害嫩梢提取液对中华通草蛉幼虫捕食行为无明显影响;棉蚜虫体浆液、棉蚜水提液,均含有很强的利它素活性物质,而棉蚜无水乙醇提取液利它素活性物质含量甚微,中华通草蛉各龄幼虫对棉蚜水提液均表现有明显的滞留和调转行为.     

不同龄期的大草蛉对桃蚜的捕食作用

大草蛉Chrysopa pallens(Rambur)是我国分布较广、捕食能力较强的天敌昆虫。为明确大草蛉对桃蚜Myzus percicae潜在的控制能力,在室内研究了大草蛉不同龄期幼虫和成虫对桃蚜的捕食作用,以及种内干扰对大草蛉捕食的影响。结果表明：25℃恒温条件下,大草蛉成虫和幼虫对桃蚜的捕食功能反应可拟合HollingⅡ圆盘方程,在24 h内大草蛉成虫、1龄幼虫、2龄幼虫和3龄幼虫对桃蚜理论最大捕食量分别为370.4头、21.5头、112.4头和217.4头。大草蛉成虫和幼虫对桃蚜的捕食量均随着猎物密度的增加而增加,当桃蚜数量增加到150头后,大草蛉成虫和幼虫捕食量的增加速度明显减缓。成虫及幼虫对桃蚜的搜寻效应随着猎物密度的增加而降低,内干扰作用随着大草蛉虫龄的增加而增强。试验结果表明大草蛉对桃蚜具有较强的控害能力,对研究桃蚜生物防治技术有重要参考价值。     

不同龄期异色瓢虫对烟蚜的捕食潜能研究

异色瓢虫是烟田烟蚜的优势天敌种类之一,本文在室内进行了异色瓢虫成虫及各龄幼虫对烟草蚜虫的捕食功能反应试验,采用Holling-Ⅱ型功能反应模型进行拟合以明确其捕食潜能,利用Hassell模型和Watt模型拟合并测定了异色瓢虫种内干扰以及自身密度对烟蚜捕食作用的影响,结果表明:异色瓢虫各虫态对烟蚜的捕食量有明显的差异,在相同的烟蚜密度条件下,异色瓢虫4龄幼虫的日最大捕食量最大,为107.41头;其次是成虫,其日最大捕食量为94.34头;3龄幼虫、2龄幼虫和1龄幼虫的日最大捕食量分别为40.32头、14.25头和12.15头。在一定空间和相同比例猎物存在的条件下,种内干扰作用对1龄异色瓢虫幼虫的捕食量影响最为明显,干扰常数为1.1731,而对4龄幼虫干扰最小。各虫态自身密度对其捕食作用的干扰效应明显,1-4龄异色瓢虫幼虫以及成虫的竞争参数b值分别为0.5199、0.1848、0.1351、0.6757、0.6528。本研究表明异色瓢虫对烟蚜捕食潜力很大,尤其是4龄幼虫及成虫对烟蚜具有较大的捕食潜能。     

THE CHROMOSOMES OF THE SEMPERVIVOIDEAE (CRASSULACEAE)

Uhl , Charles H. (Cornell U., Ithaca, New York.) Chromosomes of the Sempervivoideae (Crassulaceae). Amer. Jour. Bot. 48(2): 114–123. Illus. 1961.—Chromosome numbers are reported for 207 collections representing 68 of the ca. 95 species in this subfamily. Basic numbers are 16, 17, 18, and 19 in Sempervivum, Section Sempervivum (10 species, with many tetraploids and one hexaploid); 19 in Sempervivum, Section Jovisbarba (5 species, all diploid); 15 in Aichryson (9 species, including 1 aneuploid, 1 tetraploid, and 1 aneutetraploid); and strictly 18 in Aeonium (31 species, including 4 wholly and 1 partly tetraploid), Greenovia (3 species, 1 partly tetraploid), and Monanthes (10 species, including 2 wholly and 1 partly tetraploid). The cytological evidence appears decisive in ranking several species of disputed generic position definitely with Aichryson rather than with Aeonium. Possible relationships between various Canarian genera and certain North African species often classed in Sedum are discussed briefly in the light of the scanty morphological and cytological evidence. It is suggested that both these groups may be descended from the same ancestors that were widespread in North Africa before the deserts developed.     

THE EARLY DEVELOPMENT OF THE MARINE PROSOBRANCH NASSARIUS (HINIA) RETICULATUS (LINNAEUS)

The early development up to the end of gastrulation of the marineprosobranch Nassarius (Hinia) reticula-tus (Linnaeus) has beenexamined by scanning and transmission electron microscopy. Thesynchrony of the cleavage divisions ends with the formationof the second quartet. The somatoblast 2d and the mesen-toblast4d appear earlier than the other micromeres of their quartets.From the 16- to the 32-cell stage the turret cells have an outgrowth.At the end of cleavage, Nassarius shows a typical sterroblastula.During gastrulation, the epibolic encirclement of the yolk macromeresby the micromeres is produced by an active flattening of themicromere cap and at the end of gastrulation the blastoporeis completely closed. The nuclei of the four yolk macromeresmigrate from the animal cell regions towards the vegetativepole. The development of Nassarius reticulatus is very similarto that of the related species llyanassa obsoleta (Say). (Received 19 December 1990; accepted 18 August 1991)     

鳜和乌鳢最适温度的研究

研究了体重47.2-540.2g的鳜和45.0-546.2g的乌鳢的最适摄食和生长温度。结果表明,鳜的最大摄食率随温度的上升而增大,在25-35℃之间形成“最适温度平台”,低温（10-25℃）时,乌鳢的最大摄食率随温度的上升而增加,在25-30℃之间形成“最适温度平台”,之后随温度的增加而下降,鳜的特定生长率随温度的增加而加快,在25-35℃“最适温度平台”,乌鳢的特定生长率受体重和温度的交互影响。     

金丝猴(RHINOPITHECUS)脑的外部形态

本文是对三种金丝猴脑的外部形态的观察结果表明:金丝猴的大脑皮层除存在猴科固有的全部沟裂外,还较其他猴科动物具有更多的副沟。大脑的沟型与疣猴亚科的特征完全吻合,但是很多特点都较叶猴更近似于长臂猿。另外,除了蚓叶和蚓结节较小,四叠体的下丘较猕猴发达以外,金丝猴的小脑和脑干均与猴科的一般特征无明显差异。     

NEW CRINOIDS (ECHINODERMATA) FROM THE LLANDOVERY (LOWER SILURIAN) OF THE BRITISH ISLES

Abstract:  British Llandovery crinoids remain poorly known. Three species are documented herein that were originally described, but not published, by W. H. C. Ramsbottom. Clematocrinus ramsbottomi Fearnhead sp. nov. (Tortworth Inlier, Gloucestershire; Telychian) has a heteromorphic column, N434243414342434, radices directed away from the crown, and ten long, uniserial arms with a pustular aboral sculpture and long, slender pinnules. Clematocrinus spp. are widely distributed in the Silurian of England. Ptychocrinus mullochillensis Fearnhead and Donovan sp. nov. (Girvan district, Strathclyde; Rhuddanian) is the second report of this Upper Ordovician–Lower Silurian genus from outside North America. Although incompletely known, this species is distinguished by its hidden infrabasals, 20 arms and sunken interbrachial plates with a strongly stellate sculpture. Petalocrinus bifidus (Bather MS) Donovan and Fearnhead sp. nov. (Woolhope Inlier, Herefordshire; Telychian) is locally common enough to give its name to a mappable lithostratigraphic unit, the Petalocrinus Limestone. Unlike other Petalocrinus species known from the Silurian of China, northern Europe and North America, the fused arms of P. bifidus are divided in two by a proximal adoral ridge and an associated distal notch. Unlike extant crinoids, Petalocrinus probably lived as a rheophobe; the fused arms may have acted to deter predators.