Evaluation of the acaricidal activity of 63 commercialized pesticides against Haemaphysalis longicornis (Acari: Ixodidae)

The acaricidal activity and residual effects of 63 commercialized pesticides against the Cheongju strain of Haemaphysalis longicornis in Korea were examined. Twenty‐two pesticides (4 carbamates, 5 organophosphates, 10 pyrethroids, 1 amitraz, 1 diamide, and 1 unclassified pesticide) caused greater than 80% mortality in H. longicornis adults under laboratory conditions using the spray method. These 22 pesticides were used to treat grassland under field conditions for investigation of the residual effects, and 100% mortality in H. longicornis adults was observed with all the carbamates (carbosulfan, benfuracarb, fenobucarb, and carbaryl) and γ‐cyhalothrin after 3 days of pesticide treatment. γ‐Cyhalothrin exhibited 56.7% mortality after 10 days of treatment, which was the longest residual effect of treated grass on H. longicornis adults. With regard to the residual effects on H. longicornis under field conditions, most of the 22 pesticides exhibited higher mortality in nymphs than in adults. In particular, benfuracarb exhibited 96.7% acaricidal activity until 10 days after treatment. These results indicate that carbamates are highly likely to be available under field conditions and, based on this preliminary data, could be used for the control of H. longicornis adults and nymphs.     

Ultrastructure of the tubular accessory gland in Haemaphysalis longicornis (Acari: Ixodidae)

The paired tubular accessory glands in Haemaphysalis longicornis open at the junction of the cervical and the vestibular parts of vagina via short and narrow ducts. The pseudostratified columnar glandular epithelium covered by the muscle layer consists of both secretory and supporting cells. As feeding proceeds, the secretory cells increase in volume. In ovipositing females, well-developed rough endoplasmic reticulum, the Golgi complex, and membranebound granules that are undergoing exocytosis suggest that the secretory cells are involved in protein synthesis. However, in virgin females that fed 10 days, only small dense granules and no secretion activity were observed. The secretions from the tubular accessory gland may be released into the genital tract during the egg passage through the vagina. However, the supporting cells located between the secretory cells become slender during feeding, cohere to each other at the luminal side, and have a very narrow attachment at the basement membrane. Supporting cells probably help maintain secretory cell shape especially during granular discharge into the lumen. © 1994 Wiley-Liss, Inc.     

Proteomic Screening of Antigenic Proteins from the Hard Tick,Haemaphysalis longicornis (Acari: Ixodidae)

Proteomic tools allow large-scale, high-throughput analyses for the detection, identification, and functional investigation of proteome. For detection of antigens from Haemaphysalis longicornis, 1-dimensional electrophoresis (1-DE) quantitative immunoblotting technique combined with 2-dimensional electrophoresis (2-DE) immunoblotting was used for whole body proteins from unfed and partially fed female ticks. Reactivity bands and 2-DE immunoblotting were performed following 2-DE electrophoresis to identify protein spots. The proteome of the partially fed female had a larger number of lower molecular weight proteins than that of the unfed female tick. The total number of detected spots was 818 for unfed and 670 for partially fed female ticks. The 2-DE immunoblotting identified 10 antigenic spots from unfed females and 8 antigenic spots from partially fed females. Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF) of relevant spots identified calreticulin, putative secreted WC salivary protein, and a conserved hypothetical protein from the National Center for Biotechnology Information and Swiss Prot protein sequence databases. These findings indicate that most of the whole body components of these ticks are non-immunogenic. The data reported here will provide guidance in the identification of antigenic proteins to prevent infestation and diseases transmitted by H. longicornis.     

孤雌生殖长角血蜱的哈氏器超微结构与发育

为阐明长角血蜱Haemaphysalis longicornis孤雌生殖种群的哈氏器结构及发育特征, 用扫描电镜对其各虫期哈氏器进行了观察, 分析了血餐对哈氏器发育的影响。结果表明： 该种群幼蜱、 若蜱和成蜱哈氏器形态结构基本相同, 均由前窝和后囊构成。幼蜱前窝感毛6根, 位于同一基盘; 若蜱和成蜱哈氏器相似, 前窝感毛7根, 其中1根孔毛位于外侧基盘, 另6根感毛位于内侧基盘。各虫期饱血后哈氏器大小均比饥饿状态下显著增大（P<0.05）。幼蜱前窝与后囊面积比值与若蜱相比无显著差异（P>0.05）, 若蜱前窝与后囊面积比值与成蜱相比差异显著（P<0.05）。各虫期哈氏器均在发育, 且血餐对哈氏器发育有重要影响。幼蜱至若蜱期哈氏器前窝与后囊的发育速度相似, 若蜱至成蜱期哈氏器前窝发育快于后囊。本研究结果在一定程度上揭示了孤雌生殖长角血蜱的哈氏器发育规律。     

No distributional association between the tick Haemaphysalis longicornis (Acari: Ixodidae) and plant surface area

The questing height of the tick Haemaphysalis longicornis Neumann was studied on the plant species Solidago altissima L., Pteridium aquilinum Kuhn, Miscanthus sinensis Anderss, and Pleioblastus chino Makino in an abandoned rice field and in an ume (Japanese Apricot) orchard in a forest. On all plant species, the vertical distribution of tick adults and nymphs was not significantly correlated with the distribution of plant surface area. This result suggests that the questing height of this tick is related to the body height of its main animal host, the sika deer.     

Ultrastructure of receptaculum seminis in Haemaphysalis longicornis (Acari: Ixodidae) in relation to inserted endospermatophore

The receptaculum seminis, opening into the female genital tract, is found only in the metastriate ixodid ticks. An endospermatophore that has been inserted into the female genital aperture at copulation is first stored in the receptaculum seminis, where spermiogenesis is completed before the sperm ascend the oviducts. The receptaculum seminis consists of a simple cuticularized epithelium. Epithelial cells in sexually matured females develop during feeding and become active in secretion. Secretions discharged from epithelial cells are released into the lumen of this organ through the cuticle and may act on the wall of the inserted endospermatophore. The fact that resumption of spermiogenesis (spermateleosis) has already occurred before destruction of the endospermatophore just after copulation suggests that secretions from epithelial cells of the receptaculum seminis are not the trigger of spermateleosis, but a destructive agent of the endospermatophore wall. J Morphol 231:143–147, 1997. © 1997 Wiley-Liss, Inc.     

Studies on in vitro Extrusion and Ultrastructure of the Spermatophore in Haemaphysalis longicornis (Acari: Ixodidae)

Copulation in ticks is completed by the insertion of the spermatophore into the female genital aperture by a male. The endospermatophore, a cord-like structure and contents are packed in the ectospermatophore of the completed spermatophore. The endospermatophore extrudes just after insertion of the tip of the spermatophore. Only the endospermatophore enters the female genital tract, and the ectospermatophore remains outside the female body. The extrusion is observed in vitro in Haemaphysalis longicornis at various concentrations of NaCl solution: the process is accelerated in less concentrated solutions. The cord-like structure and the endospermatophore finally receive contents extruded from the ectospermatophore. The tip of the cord-like structure connects to the surface of the endospermatophore, and together form a loop after extrusion. Ultrastructural observations confirmed that the ectospermatophore wall is composed of four layers, and the contents consist of male germ cells and three types of secretions from the male accessory genital glands. As in other ticks the male germ cells are elongated spermatids in spermatophores just after formation and extrusion. Adlerocysts described in other ticks are not found in the spermatophore of H. longicornis.     

Seasonal abundance and activity of the hard tick Haemaphysalis longicornis (Acari: Ixodidae) in North China

Seasonal abundance and activity of all the three post-embryogenic stages of Haemaphysalis longicornis, both feeding and free-living phases, were evaluated over a period of 2 years, from February 2008 to January 2010, in North China. Feeding ticks were removed weekly from head and ears of domestic sheep and the attachment sites of this tick were assessed coinstantaneously; free-living ticks were collected weekly in four habitat types by flag-dragging. The results suggested that H. longicornis mainly resides in shrubs and completes one generation per year with population attrition between stages. Infestation of nymphs was detected from March to September with highest peak between late April and early May; adults were detected from April to September with highest peak between late June and July, and an overwintering male population was found during late September to March; infestation of larvae was observed from June to October and peaked between middle August and early September. Most of this tick (91%) attached to head and ears of hosts. Additionally, we captured rodents from April to September 2008, but only a negligible number of nymphs were detected. This result suggested that rodents are not the principal hosts for this tick in the study area.     

长角血蜱不同发育期盾窝超微结构的比较研究

为阐明蜱类盾窝及其发育特点,用扫描电镜观察了长角血蜱Haemaphysalis longicornis不同发育期盾窝的结构,并分析了血餐对盾窝发育的影响.结果表明：幼蜱仅具1对盾窝原基,且每个盾窝原基有1个盾窝孔;若蜱盾窝有了一定的发育,面积（长径×短径）增大且盾窝孔数增多（2~6个）;成蜱盾窝面积最大,且盾窝孔数达21~35个.盾窝的发育主要在幼蜱蜕皮阶段及若蜱的吸血和蜕皮阶段,雌蜱盾窝孔径显著大于雄蜱（P<0.01）,成蜱、若蜱和幼蜱的盾窝孔孔径在吸血过程中（交配雌蜱除外）各虫期均无显著变化 （P>0.05）.综合分析成蜱与未成熟蜱盾窝孔径,发现它们之间无显著差异 （P>0.05）,这在一定程度上说明蜱类的盾窝孔径在未成熟期可能已经有了雌雄分化.     

昆虫病原线虫斯氏线虫和异小杆线虫对长角血蜱雌蜱的致病力

用昆虫病原线虫小卷蛾斯氏线虫（Sc BJ）、夜蛾斯氏线虫（Sf Otio）、拟双角斯氏线虫（Sc D43）、格氏斯氏线虫（Sg NC32）和嗜菌异小杆线虫（Hb E-6-7）对长角血蜱雌蜱进行感染试验,所用线虫剂量为4 000 Ijs/dish。结果表明,5种线虫均对长角血蜱雌蜱有致死效应。Hb E-6-7和Sc BJ两种线虫对雌蜱各发育期致病力最强,导致雌蜱的累积死亡率和半致死时间分别为饥饿雌蜱82.5%,9.0天和75.0%,8.8天;吸血雌蜱90.0%,8.0天和82.5%,8.0天;饱血雌蜱93.3%,7.3天和86.7%,7.3天。Sc D43对饱血雌蜱有较高的致死效应,为80.0%,但半致死时间较长,为11.7天。Sf Otio和Sg NC32对长角血蜱雌蜱的致死效应较低。饱血雌蜱较饥饿雌蜱和吸血雌蜱更易被线虫感染。     

The significance of feeding for reproduction in a male Metastriata tick, Haemaphysalis longicornis (Acari: Ixodidae)

In Haemaphysalis longicornis , secretions of the male accessory genital glands were regenerated by re-feeding for 3 or 4 days, although the secretions were almost completely released during the first copulation. It was also shown that spermatogenesis continued during re-feeding, since prospermia (elongated spermatids) were deposited in the seminal vesicle. A potent male seeks a receptive female on the host for copulation. The movement of males to different attachment sites occurred between the third and fourth day of re-feeding, and completely re-fed males (for 4 days) were able to copulate successfully. Spermatogenic cells, ranging from spermatogonia at the anterior end to prospermia at the posterior end, were found in fed males. Degeneration of spermatocytes at the great growth phase and developing spermatids prior to final development of prospermia were seen in virgin males without re-feeding after the first meal. Fully elongated spermatids (prospermia) appeared morphologically normal up to 10 days after the first feeding. Degeneration of spermatocytes and developing spermatids occurred from the second day and was almost complete by the fourth day. The degenerating cells shrank, became electron-dense, and finally died. A reduction in secretions of the four lobes of the accessory glands occurred during the 10 days after feeding.     

Influence of aggregation and relative humidity on longevity of unfed bush tick, Haemaphysalis longicornis Neumann (Acari: Ixodidae)

The survival of all stages of Haemaphysalis longicornis was investigated at different densities and at 3 levels of relative humidity. Larvae survived longer when the density was higher, or the size of a cluster was larger, or both. However, in nymphs and adults, there was no significant relationship between the density and the survival period. Moreover, in nymphs and adults, there was no positive relationship between the size of the aggregation and tick longevity, except for 2 nymphs/vial in high humidity. These results suggest that the advantage gained from a higher density, or from taking part in a cluster, or both, differed between stages. Furthermore, the fact that the survival period of larvae and nymphs was influenced by cohort suggests that a maternal effect, as well as aggregation, influences the survival of immature ticks.     

长角血蜱雌蜱感染嗜菌异小杆线虫后血淋巴的变化

用嗜菌异小杆线虫Heterorhabditis bacteriophora E-6-7(Hb E-6-7)感染长角血蜱Haemaphysalis longicornis雌蜱,测定感染后雌蜱血淋巴总蛋白含量、酯酶活性及酯酶同工酶的变化,以探讨昆虫病原线虫对蜱的致病机理。结果显示,雌蜱血淋巴总蛋白含量在Hb E-6-7感染后12 h显著增加,达到最大值92.21 μg/μL;在感染后24 h明显下降（49.06 μg/μL）;至感染后48 h降至34.25 μg/μL。雌蜱血淋巴酯酶活性在线虫感染后0～12 h内无显著变化;在感染24 h后迅速增加（OD_24h=0.1840,OD_36h=0.1940,OD_48h=0.2165）,与对照组差异显著。PAGE结果表明,线虫感染后导致雌蜱血淋巴酯酶同工酶电泳图谱发生变化,主要为电泳图谱两端a带和b带的消失以及一条c带的增加。上述结果表明,长角血蜱雌蜱被Hb E-6-7感染后其血淋巴总蛋白含量和酯酶发生变化,这种变化可能与蜱的防御和对昆虫病原线虫的适应有关。     

Immunization effect of recombinant P27/30 protein expressed in Escherichia coli against the hard tick Haemaphysalis longicornis (Acari: Ixodidae) in rabbits

We investigated the induction of resistance to Haemaphysalis longicornis infestation in rabbits that had been immunized with recombinant H. longicornis P27/30 protein. The success of immunological control methods is dependent upon the use of potential key antigens as tick vaccine candidates. Previously, we cloned a gene encoding 27 kDa and 30 kDa proteins (P27/30) of H. longicornis, and identified P27/30 as a troponin I-like protein. In this study, rabbits that were immunized with recombinant P27/30 expressed in Escherichia coli showed the statistically significant longer feeding duration for larval and adult ticks (P<0.05), low engorgement rates in larval ticks (64.4%), and an apparent reduction in egg weights, which suggest that H. longicornis P27/30 protein is a potential candidate antigen for a tick vaccine. These results demonstrated that the recombinant P27/30 protein might be a useful vaccine candidate antigen for biological control of H. longicornis.     

长角血蜱卵黄蛋白的纯化及其性质

用凝胶过滤与离子交换层析、蛋白质电泳和糖脂蛋白染色等方法提取纯化长角血蜱Haemaphysalis longicornis卵黄蛋白,并对其性质进行了研究。PAGE和SDS-PAGE分析表明,长角血蜱的卵黄蛋白只有一种,由8个亚基组成,亚基的相对分子质量分别为112 kD, 103 kD, 80 kD, 78 kD, 71 kD, 68 kD, 62 kD和52 kD,卵黄蛋白经苏丹黑B和希夫试剂染色呈阳性,表明是一种含血红素的糖脂蛋白。     

Effect of of methoprene and retinoic acid on characteristics of Haller's organ regeneration in the tick Haemaphysalis longicornis (Acari, Ixodidae)

The results of experiments on regeneration of the Haller's sensory organ in the metastriate ixodid tick Haemaphysalis longicornis Neumann in the presence of the juvenoid methoprene and retinoic acid and of studies of its structural changes by SEM confirmed the similarity of prostriate and metastriate ixodids as concerns the juvenalizing effect of the above morphogens on regenerative processes during nymphal-imaginal metamorphosis. However, the metastriate ticks (Haemaphysalis and earlier studied Hyalomma) are well behind the prostriate ticks (Ixodes) as concerns the extent of changes induced by juvenoids and retinoids in the sensillar sets of Haller's organ regenerates.