Action of praziquantel on calcium transport in Hymenolepis diminuta

Effect of praziquantel on inward and outward Ca++ fluxes was investigated in Hymenolepis diminuta in glucose supplemented balanced electrolyte solution and under conditions of glucose/Mg++ deficiency. The 45Ca++ uptake in freshly isolated worms presented, generally, a biphasic kinetics. This comprised of an initial fast uptake phase, followed by a continued slower influx. The initial fast kinetics showed insensitivity to or slight stimulation by praziquantel depending on its concentration, and such stimulatory action was particularly prominent under Mg++ deficient condition (P less than 0.01). The subsequent slower 45Ca++ uptake was, however, markedly inhibited by the drug under both these conditions (P less than 0.01). Glucose starvation of the worms resulted in abolition of the fast 45Ca++ influx phase and uniform inhibition by the praziquantel without any indication of initial stimulatory effect (P less than 0.01). The extrusion of 45Ca++ from the label preloaded worms was stimulated by praziquantel under all the conditions investigated (P less than 0.01).     

Ultrastructure of the tail of Echinostoma revolutum cercaria

The ultrastructure of the tail fins and muscles of Echinostoma revolutum cercaria is described. The longitudinal muscles consist of a primitive type of transversely striated muscle fibres with a well-developed sarcoplasmic reticulum in the Z-band. The fins are formed by a longitudinal tegument fold containing the same components as the remaining part of the tail tegument. The difference between the body and tail tegument is discussed.     

暗黑鳃金龟触角超微结构

利用扫描电镜对暗黑鳃金龟(Holotrichia parallela)雌、雄成虫的触角形态和感器进行了观察。结果表明:暗黑鳃金龟触角分为4部分,即柄节、梗节、鞭节棒状部和鳃状部,其中鞭节棒状部由5节组成,鳃状部由鞭节末端3节扩展构成。暗黑鳃金龟触角感器共7种,分别为板形感器、腔锥感器、腔形感器、刺形感器、毛形感器、锥形感器和Bhm氏鬃毛。雌、雄个体之间触角感器的类型、分布均没有明显差异。不同感器在触角各节上的数量与分布各不同。     

Ultrastructure of the digestive tract of Echinostoma revolutum cercaria

The digestive tract of a fully formed free-swimming cercaria of Echinostoma revolutum (Froelich, 1802) Dietz, 1909 was studied by electron microscopy. The oral sucker and pharynx are covered by a tegument. The oesophagus and the caeca are not luminized. They are packed with giant epithelial cells with electron-dense granules of irregular shape, rough endoplasmic reticulum and its cisterns, and Golgi apparatus. The tegument of the oral sucker cavity contains numerous uniciliate receptors.     

Circumventing the diapause of potato cyst nematodes

The diapause of potato cyst nematodes was bypassed by avoiding desiccation of the cysts. Larvae were artificially hatched by cutting the cysts in halves and subsequent incubation in potato root diffusate. Approximately 40% of the cyst content hatched. These treatments had no influence on viability and fecundity as ascertained by rearing nematodes in pots and on roots of sprouts grown on water agar in Petri dishes. With the artificial hatching procedure it is possible to produce five to six generations a year in Petri dishes and three to five generations in pots.Samenvatting De diapauze van aardappelcysteaaltjes kan worden omzeild door te voorkómen dat de cysten uitdrogen. Hiertoe worden de cysten opgekweekt op wortels van aard-appelspruiten in Petrischalen met wateragar of in potten en zorgvuldig vochtig gehouden.De larven worden uit de eieren gelokt door de cysten met een scalpel te halveren of zorgvuldig door te drukken zonder de eieren te beschadigen en deze vervolgens te incuberen in lokstof. Op deze wijze wordt ongeveer 40% van de cysteïnhoud gelokt. Deze behandeling heeft geen nadelige invloeden op de vitaliteit van de larven en de vrucht-baarheid van de hieruit ontwikkelde mannetjes en vrouwtjes. Dit geldt zowel voor eieren uit cysten opgekweekt in Petrischalen als die in potten.Op deze wijze is het mogelijk drie tot vijf generaties per jaar in potten te kweken en vijf tot zes generaties in Petrischalen.     

异色瓢虫幼虫对草地贪夜蛾卵和低龄幼虫的捕食作用

为明确天敌昆虫异色瓢虫Harmonia axyridis对草地贪夜蛾Spodoptera frugiperda的捕食能力,在室内光照培养箱中,于(25±1)℃、L//D=16 h//8 h条件下,研究了异色瓢虫幼虫对草地贪夜蛾卵和低龄幼虫的捕食功能反应与寻找效应。结果表明:异色瓢虫幼虫对草地贪夜蛾卵和低龄幼虫的捕食功能反应符合HollingⅡ模型。异色瓢虫1龄幼虫对草地贪夜蛾卵的日最大捕食量、瞬时攻击率和处理时间分别为25.6粒、1.035和0.039 d;异色瓢虫4龄幼虫对草地贪夜蛾2龄幼虫的日最大捕食量、瞬时攻击率和处理时间分别为33.3头、0.736和0.03 d。异色瓢虫幼虫对草地贪夜蛾卵和低龄幼虫的寻找效应随猎物密度的增加而下降。异色瓢虫幼虫对草地贪夜蛾卵和低龄幼虫具有较好的控制效果,可用于对草地贪夜蛾的防控实践。     

Ultrastructure of the male reproductive system of the trematode Brachylaimus aequans

The transmission electron microscopic studies of the trematode Brachylaimus aequans revealed that the seminal vesicle and ejaculatory duct are lined with syncytial epithelium with numerous lamellate processes. The cirrus and genital pore are covered with a spineless tegument, which is almost identical with the body tegument. The testes contain tailed spermatozoa developing during spermiogenesis from biflagellate spermatids whose flagella (9 + 1) fuse with the median cytoplasmic process. The lumina of seminal vesicle, ejaculatory duct and cirrus are filled with spermatozoa.     

Ultrastructure of the Infection of Sorghum bicolor by Colletotrichum sublineolum

ABSTRACT Ultrastructural studies of the infection of susceptible and resistant cultivars of Sorghum bicolor by Colletotrichum sublineolum were conducted. Initial penetration events were the same on both susceptible and resistant cultivars. Germ tubes originating from germinated conidia formed globose, melanized appressoria, that penetrated host epidermal cells directly. Appressoria did not produce appressorial cones, but each penetration pore was surrounded by an annular wall thickening. Inward deformation of the cuticle and localized changes in staining properties of the host cell wall around the infection peg suggests that penetration involves both mechanical force and enzymic dissolution. In compatible interactions, penetration was followed by formation of biotrophic globular infection vesicles in epidermal cells. Filamentous primary hyphae developed from the vesicles and went on to colonize many other host cells as an intracellular mycelium. Host cells initially survived penetration. The host plasma membrane invaginated around infection vesicles and primary hyphae and was appressed tightly to the fungal cell wall, with no detectable matrix layer at the interface. Necrotrophic secondary hyphae appeared after 66 h and ramified through host tissue both intercellularly and intracellularly, forming hypostromatic acervuli by 114 h. Production of secondary hyphae was accompanied by the appearance of electron-opaque material within infected cells. This was thought to represent the host phytoalexin response. In incompatible interactions, infection vesicles and primary hyphae were formed in epidermal cells by 42 h. However, they were encrusted with electron-opaque material and appeared dead. These observations are discussed in relation to the infection processes of other Colletotrichum spp. and the host phytoalexin response.     

四种Bt毒素蛋白对二点委夜蛾幼虫毒力测定及中肠组织病理学变化

为更好地了解苏云金芽胞杆菌Bacillus thuringiensis毒素蛋白对二点委夜蛾Athetis lepigone的毒力以及作用机理,通过饲喂含有Cry1Ac、Cry1Ab、Cry2Ab和Vip3Aa四种不同Bt毒素蛋白饲料,测定Bt毒素蛋白对二点委夜蛾幼虫的毒力,并观察取食4种毒素蛋白后幼虫中肠组织的病理学变化。结果显示,二点委夜蛾幼虫取食毒素蛋白后72 h,Cry1Ab和Cry1Ac毒素蛋白对二点委夜蛾幼虫的杀虫活性较高,校正死亡率为84.7%和76.4%;Vip3Aa和Cry2Ab毒素蛋白的毒力较弱。二点委夜蛾幼虫取食4种Bt毒素蛋白后,中肠柱状细胞微绒毛脱落,杂乱地分散在肠腔内,杯状细胞变形和腔内微绒毛脱落,线粒体和内质网等变形破裂,细胞核的核膜消失、核质凝聚和形状发生变化,经Cry1Ab和Cry1Ac毒素蛋白处理后中肠细胞的病变症状和速度明显高于Cry2Ab和Vip3Aa毒素蛋白处理。表明Cry1Ab和Cry1Ac毒素蛋白对二点委夜蛾幼虫杀虫活性较高,显著高于Cry2Ab和Vip3Aa毒素蛋白,且对其中肠细胞的破坏作用也较强。     

不同营养元素对小麦禾谷孢囊线虫孵化及二龄幼虫存活的影响

 小麦禾谷孢囊线虫（Cereal Cyst Nematode, CCN）病是一种世界性病害,主要为害小麦（Triticum aestivum）、大麦（Hordeum vulgare）、燕麦（Avena saliva）、黑麦（Secale cereale）等禾本科植物^［1］,近年来该病害在全世界发展迅速并造成严重经济损失,在我国,已证实该线虫在北京、山东、河南、河北、安徽等16个省、市、自治区均有分布,发病面积约200万hm²,在河南省18个省辖市中已有16个市有该病害发生,发病面积达170万hm²以上^［2］,造成严重的经济损失。     

墨西哥斑皮蠹幼虫形态特征识别

墨西哥斑皮蠹是一种危害性很大的杂食性仓库害虫。我国尚无记载。其幼虫形态特征描述目前国内尚无报导。该幼虫与同属常见的谷斑皮蠹、花斑皮蠹、黑斑皮蠹幼虫在形态特征上极为相似,外观难以区别。本文对墨西哥斑皮蠹幼虫形态特征进行较详细的描述,并以检索表形式与同属3个常见的近似种进行鉴别。     

旱稻孢囊线虫（Heterodera elachista）孵化特性研究

为了解旱稻孢囊线虫的孵化特性,从水稻根系及根系附近土壤分离孢囊,在室内离体条件下研究不同温度及水稻根系分泌物、土壤浸液、水稻根汁等因子对2龄幼虫孵化的影响,并观察不同温度下2龄幼虫的存活能力.结果表明:旱稻孢囊线虫孵化的适宜温度范围为28～32℃,且在该温度范围初孵2龄幼虫的存活率高、存活时间相对较长,35℃下孵化率及初孵2龄幼虫的存活率、存活时间均明显下降,40℃下无线虫孵化,20℃下孢囊线虫孵化率仅为0.9％,4℃下可延长2龄幼虫的存活时间.水稻分泌物、水稻土壤浸液和水稻20倍根汁对旱稻孢囊线虫孵化具有刺激作用,5倍根汁和4 mmol/L氯化锌溶液对线虫的孵化有抑制作用.上述结果可为制定旱稻孢囊线虫防治措施提供依据.     

Effects of low temperatures on larvae of the genus Trichinella

We examined the effect of an exposure to -25 degrees C (for 8 days) on the histochemistry and the fine structure of 30-day-old Trichinella larvae from muscle fibres of the diaphragm. The larvae of T. pseudospiralis and T. nelsoni were either destroyed in the muscle fibres, dead, eosinophile, or were not found. The structureless mass of a degenerating, changed sarcoplasm was highly AIP-active, and gave a weak positive reaction for SS-groups of proteins. The wall of the deformed capsule around T. nelsoni, and the cuticle of the larva, stained diffusely; it did not contain AM. In a few muscle fibres exposed to -25 degrees C, histochemical reactions of the capsule surrounding larvae of T. nativa and sometimes of larvae of T. spiralis, and reaction of the changed sarcoplasm, were similar to those of the controls. A few mobile larvae were isolated by digestion only from a diaphragm infected with T. nativa. Deterrent to a prolonged survival of larvae were the formation of ice crystals and a denaturation of proteins by which the sarcoplasm of the infected muscle fibre was changed gradually into both a plasmolytically and karyolytically altered mass. Degenerative changes in the fine structure of infected muscle fibres were demonstrated by the presence of "spheromembranous bodies" in the sarcoplasm resembling myeline formations observed after exposure to poisonous substances, e.g., colchicine.     

亮腹釉小蜂成虫触角感受器的超微结构

为进一步了解柑橘木虱Diaphorina citri若虫的优势寄生蜂亮腹釉小蜂Tamarixia radiata的寄生行为,利用扫描电镜对亮腹釉小蜂雌雄成虫触角感受器的种类、分布和形态进行观察。结果表明,亮腹釉小蜂雌成虫触角上存在5种感受器,分别是刺形感受器、毛形感受器、乳头状感受器、板形感受器和末端指形感受器;亮腹釉小蜂雄成虫触角上存在4种感受器,分别为刺形感受器、毛形感受器、乳头状感受器和板形感受器;其中毛形感受器又可以根据外部形态的差异划分为4个亚型,即毛形感受器类型1、2、3、4。此外,板形感受器、毛形感受器类型2和毛形感受器类型3在亮腹釉小蜂雌成虫触角上的分布数量显著多于雄成虫触角上的分布数量。这些形态学差异有助于深入理解不同性别亮腹釉小蜂的触角感知行为。     

Ultrastructure of the Penetration and Infection of Pansy Roots by Thielaviopsis basicola

ABSTRACT Transmission electron microscopy was used to study the penetration and infection of pansy roots by Thielaviopsis basicola. Events observed in 7- to 10-day-old roots produced on moist filter paper differed slightly from those in roots from 4-week-old plants washed free of potting media prior to inoculation. By 3 h postinoculation (PI), epidermal cells of roots produced on filter paper exhibited aggregated cytoplasm and papilla formation in response to germ tube tips. The presence of callose in papillae was demonstrated using immunogold labeling. Papilla formation was not effective in preventing host cell penetration. A slender infection hypha emerged from a germ tube tip and grew through a papilla. Its tip then expanded to form a globose infection vesicle. By 6 h PI, infection hyphae emerged from infection vesicles, and invaded host cells showed signs of necrosis. By 8 h PI, infection hyphae had grown into cortical cells in spite of papilla formation in these cells. By 24 h PI, distinctive intracellular hyphae were present in necrotic cortical cells. In washed roots, most epidermal cells failed to respond to invasion. Hyphae simply grew through these cells and contacted cortical cells that exhibited aggregated cytoplasm and papillae formation. Infection structures similar to those produced in epidermal cells from roots grown on filter paper then formed in cortical cells of washed roots. The fact that T. basicola formed infection structures only in cells that responded to invasion suggests that T. basicola has a more complex relationship with its host than would be expected in a nectrotrophic pathogen. We believe that T. basicola is best described as a necrotrophic hemibiotroph.     

钩臀蚁蛉头部附器感器的超微结构观察

利用扫描电镜技术对钩臀蚁蛉Myrmeleon bore(Tjeder)雌、雄成虫头部附器感器类型、形态、数量与分布进行观察。结果表明:钩臀蚁蛉成虫触角为棒状,由柄节、梗节和鞭节组成,其中鞭节约由38个亚节组成。成虫触角和口器上共有7类14种感器,分别是B#x00F6;hm氏鬃毛、毛形感器(5种)、锥形感器(4种)、腔乳头形感器、腔形感器、刺形感器及钟形感器。不同感器在触角和口器下颚须、下唇须上的分布与数量各不相同,雌、雄成虫之间无差异。结合感器的形态、分布和已报道感器功能的相关研究等,对钩臀蚁蛉的触角各类型感器的功能进行了分析与推测。     

Serum protein profile of mice during infection with single and repeated doses of Hymenolepis nana eggs

Significant alterations in serum protein of mice following Hymenolepis nana infection were observed. These changes were recorded as decrease in albumin, increase in gamma globulin and a temporary rise in alpha-1, alpha-2 and beta globulins. The decrease in albumin and increase in gamma globulin occurred as early as on 1st day after infection. The alpha-1 and alpha-2 globulins did not show definite profile during infection. The beta globulin predominantly increased till the day 20 post infection and thereafter generally decreased. Repeated infection did not enhance any further alterations in serum protein. There was no significant correlation between infection dose levels and serum protein changes.