Life cycle and reproduction of house-dust mites: environmental factors influencing mite populations.

Science.gov (United States)

Hart, B J

1998-01-01

An understanding of the life cycle of house-dust mites, as well as environmental factors influencing mite populations, can be exploited in mite control. The most important limiting factor for house-dust-mite populations is air humidity. House-dust mites osmoregulate through the cuticle and therefore require a high ambient air humidity to prevent excessive water loss. In addition, the supracoxal glands actively take up ambient water vapour, and the protonynph stage of the life cycle is resistant to desiccation. Larger house-dust-mite populations are found when the absolute indoor air humidity is above 7 g/kg (45% relative humidity at 20 degrees C). Consequently, ventilation by air-conditioning systems is being developed as a means of control. A number of other aspects of the domestic environment are also being manipulated in an integrated approach to render the habitat less suitable for mites. The potential exists for developing models for house-dust mite populations, environmental characteristics, and the effects of various approaches to control.

Genetic diversity within and among two-spotted spider mite resistant and susceptible common bean genotypes

Directory of Open Access Journals (Sweden)

Zeinab YOUSEFI

2017-12-01

Full Text Available Two-spotted spider mite (Tetranychus urticae C. L. Koch, 1836, is one of the most destructive herbivores of common bean. Very little is known about the diversity among resistant sources in this crop. The present study was conducted to characterize 22 resistant and susceptible common bean genotypes by 8 Simple Sequence Repeats (SSRs and 8 Random Amplified Polymorphic DNA (RAPD markers. These SSR and RAPD primers produced 100 % and 81.8 % polymorphic bands. Based on RAPD fingerprints and SSR profiles, pairwise genetic similarity ranged from 0.0 to 0.857 and from 0.125 to 1, respectively. The resistant and susceptible common bean accessions were grouped together in the dendrograms generated from RAPD and SSR clustering analyses. The results indicate that RAPD and SSR analysis could be successfully used for the estimation of genetic diversity among genotypes. SSR markers could group genotypes according to their resistibility and susceptibility to the spotted spider mite but RAPD could not. Therefore, the SSR markers can facilitate the development of resistant common bean cultivars through breeding programs against T. urticae.

Engineering cotton (Gossypium hirsutum L.) for resistance to cotton leaf curl disease using viral truncated AC1 DNA sequences.

Science.gov (United States)

Hashmi, Jamil A; Zafar, Yusuf; Arshad, Muhammad; Mansoor, Shahid; Asad, Shaheen

2011-04-01

Several important biological processes are performed by distinct functional domains found on replication-associated protein (Rep) encoded by AC1 of geminiviruses. Two truncated forms of replicase (tAC1) gene, capable of expressing only the N-terminal 669 bp (5'AC1) and C-terminal 783 bp (3'AC1) nucleotides cloned under transcriptional control of the CaMV35S were introduced into cotton (Gossypium hirsutum L.) using LBA4404 strain of Agrobacterium tumefaciens to make use of an interference strategy for impairing cotton leaf curl virus (CLCuV) infection in transgenic cotton. Compared with nontransformed control, we observed that transgenic cotton plants overexpressing either N-terminal (5'AC1) or C-terminal (3'AC1) sequences confer resistance to CLCuV by inhibiting replication of viral genomic and β satellite DNA components. Molecular analysis by Northern blot hybridization revealed high transgene expression in early and late growth stages associated with inhibition of CLCuV replication. Of the eight T(1) transgenic lines tested, six had delayed and minor symptoms as compared to nontransformed control lines which developed disease symptoms after 2-3 weeks of whitefly-mediated viral delivery. Virus biological assay and growth of T(2) plants proved that transgenic cotton plants overexpressing 5'- and 3'AC1 displayed high resistance level up to 72, 81%, respectively, as compared to non-transformed control plants following inoculation with viruliferous whiteflies giving significantly high cotton seed yield. Progeny analysis of these plants by polymerase chain reaction (PCR), Southern blotting and virus biological assay showed stable transgene, integration, inheritance and cotton leaf curl disease (CLCuD) resistance in two of the eight transgenic lines having single or two transgene insertions. Transgenic cotton expressing partial AC1 gene of CLCuV can be used as virus resistance source in cotton breeding programs aiming to improve virus resistance in cotton crop.

Curling for Confidence: Psychophysical Benefits of Curling for Older Adults.

Science.gov (United States)

Stone, Rachael C; Rakhamilova, Zina; Gage, William H; Baker, Joseph

2018-04-01

While physical activity is increasingly promoted for older adults, there is a paucity of sport promotion, which has distinct benefits from exercise and remains stereotypically associated with younger age. Curling is a moderately intense and safe sport that continues to gain popularity; however, no research has investigated psychophysical benefits of curling for older adults. The present study compares high-experience (20+ years; n = 63) and low-experience (<20 years; n = 53) curlers (aged 60+ years) with older adult noncurlers (n = 44) on measures of daily functionality, balance confidence, and perceptions of the aging process. While no significant differences were found between high- and low-experience curlers, any level of experience reported significantly better functionality, physical confidence, and aging attitudes compared to noncurlers (p ≤ .05). Although further research is necessary, the results suggest that any level of curling experience can enhance older adult psychophysical well-being, and warrants consideration for physical activity promotion and falls prevention programs.

Cotton leaf curl Burewala virus with intact or mutant transcriptional activator proteins: complexity of cotton leaf curl disease.

Science.gov (United States)

Kumar, Jitendra; Gunapati, Samatha; Alok, Anshu; Lalit, Adarsh; Gadre, Rekha; Sharma, Naresh C; Roy, Joy K; Singh, Sudhir P

2015-05-01

Cotton leaf curl disease (CLCuD) is a serious disease of cotton on the Indian subcontinent. In the present study, three cotton leaf curl viruses, cotton leaf curl Burewala virus (CLCuBuV), cotton leaf curl Kokhran virus (CLCuKoV) and cotton leaf curl Multan virus (CLCuMV), and their associated satellites, cotton leaf curl Multan betasatellite (CLCuMB) and cotton leaf curl Multan alphasatellite (CLCuMA), were detected. CLCuBuV with either intact (CLCuBuV-1) or mutant (CLCuBuV-2) transcriptional activator protein (TrAP) were detected in different plants. Agroinoculation with CLCuBuV-1 or CLCuBuV-2 together with CLCuMB and CLCuMA, resulted in typical leaf curling and stunting of tobacco plants. Inoculation with CLCuKoV or an isolate of CLCuMV (CLCuMV-2), together with CLCuMB and CLCuMA, induced severe leaf curling, while the other isolate of CLCuMV (CLCuMV-1), which was recombinant in origin, showed mild leaf curling in tobacco. To investigate the effect of intact or mutant TrAP and also the recombination events, CLCuBuV-1, CLCuBuV-2, CLCuMV-1 or CLCuMV-2 together with the satellites (CLCuMA and CLCuMB) were transferred to cotton via whitefly-mediated transmission. Cotton plants containing CLCuBuV-1, CLCuBuV-2 or CLCuMV-2 together with satellites showed curling and stunting, whereas the plants having CLCuMV-1 and the satellites showed only mild and indistinguishable symptoms. CLCuBuV-1 (intact TrAP) showed severe symptoms in comparison to CLCuBuV-2 (mutant TrAP). The present study reveals that two types of CLCuBuV, one with an intact TrAP and the other with a mutant TrAP, exist in natural infection of cotton in India. Additionally, CLCuMuV-1, which has a recombinant origin, induces mild symptoms in comparison to the other CLCuMV isolates.

Deformation behavior of curling strips on tearing tubes

Energy Technology Data Exchange (ETDEWEB)

Choi, Ji Won; Kwon, Tae Soo; Jung, Hyun Seung; Kim, Jin Sung [Dept. of Robotics and Virtual Engineering, Korea University of Science and Technology, Seoul (Korea, Republic of)

2015-10-15

This paper discusses the analysis of the curl deformation behavior when a dynamic force is applied to a tearing tube installed on a flat die to predict the energy absorption capacity and deformation behavior. The deformation of the tips of the curling strips was obtained when the curl tips and tube body are in contact with each other, and a formula describing the energy dissipation rate caused by the deformation of the curl tips is proposed. To improve this formula, we focused on the variation of the curl radius and the reduced thickness of the tube. A formula describing the mean curl radius is proposed and verified using the curl radius measurement data of collision test specimens. These improved formulas are added to the theoretical model previously proposed by Huang et al. and verified from the collision test results of a tearing tube.

Hygienic Activity Toward Varroa Mites in Capped Brood is not Dependent on Mite Reproductive Status

Science.gov (United States)

- The varroa resistance of bees selectively bred for high levels of varroa sensitive hygiene (VSH) is characterized by a reduction of (1) the mite infestation rate (Harris 2007 J. Apic. Res. / Bee World 46: 134-139) and (2) the percentage of fertile mites (Harris and Harbo 1999 J. Econ. Entomol. 92:...

Engineering resistance against Tomato yellow leaf curl virus via the CRISPR/Cas9 system in tomato

KAUST Repository

Mahfouz, Magdy M.

2017-12-22

CRISPR/Cas systems confer molecular immunity against phages and conjugative plasmids in prokaryotes. Recently, CRISPR/Cas9 systems have been used to confer interference against eukaryotic viruses. Here, we engineered Nicotiana benthamiana and tomato (Solanum lycopersicum) plants with the CRISPR/Cas9 system to confer immunity against the Tomato yellow leaf curl virus (TYLCV). Targeting the TYLCV genome with Cas9-single guide RNA at the sequences encoding the coat protein (CP) or replicase (Rep) resulted in efficient virus interference, as evidenced by low accumulation of the TYLCV DNA genome in the transgenic plants. The CRISPR/Cas9-based immunity remained active across multiple generations in the N. benthamiana and tomato plants. Together, our results confirmed the efficiency of the CRISPR/Cas9 system for stable engineering of TYLCV resistance in N. benthamiana and tomato, and opens the possibilities of engineering virus resistance against single and multiple infectious viruses in other crops.

Analysis of insecticide resistance-related genes of the Carmine spider mite Tetranychus cinnabarinus based on a de novo assembled transcriptome.

Science.gov (United States)

Xu, Zhifeng; Zhu, Wenyi; Liu, Yanchao; Liu, Xing; Chen, Qiushuang; Peng, Miao; Wang, Xiangzun; Shen, Guangmao; He, Lin

2014-01-01

The carmine spider mite (CSM), Tetranychus cinnabarinus, is an important pest mite in agriculture, because it can develop insecticide resistance easily. To gain valuable gene information and molecular basis for the future insecticide resistance study of CSM, the first transcriptome analysis of CSM was conducted. A total of 45,016 contigs and 25,519 unigenes were generated from the de novo transcriptome assembly, and 15,167 unigenes were annotated via BLAST querying against current databases, including nr, SwissProt, the Clusters of Orthologous Groups (COGs), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO). Aligning the transcript to Tetranychus urticae genome, the 19255 (75.45%) of the transcripts had significant (e-value insecticide resistance in arthropod were generated from CSM transcriptome, including 53 P450-, 22 GSTs-, 23 CarEs-, 1 AChE-, 7 GluCls-, 9 nAChRs-, 8 GABA receptor-, 1 sodium channel-, 6 ATPase- and 12 Cyt b genes. We developed significant molecular resources for T. cinnabarinus putatively involved in insecticide resistance. The transcriptome assembly analysis will significantly facilitate our study on the mechanism of adapting environmental stress (including insecticide) in CSM at the molecular level, and will be very important for developing new control strategies against this pest mite.

Genetic diversity/impurity estimation in sources of natural resistance against cotton leaf curl disease in pakistan

International Nuclear Information System (INIS)

Sarwar, G.

2007-01-01

Cotton accounts for more than 60% of Pakistan's export earnings through the export of both raw cotton and cotton products. An epidemic of cotton leaf curl disease (CLCuD) in Pakistan during the 1990s led to the withdrawal of high yielding cotton cultivars. Due of their susceptibility to the disease. The identification of natural resistance in some genotypes provided a means to manage reduce losses due to the disease. But it has been an adversity that almost all these resistant varieties have ultimately 'lost' their resistance. There are also reports that the original sources of resistance, as well as the varieties developed from them, are now susceptible to the disease when grafted with infected scion. For the present studies. Seed of two resistant varieties (LRA-5166 and (CP-152) was obtained from six different research organizations. Plants raised from these seed were grafted with symptomatic scion and used for morphological comparisons. Our results indicated that the genetic pool of these cultivars is not well maintained and that an unacceptable diversity impurity is present within and among the genetic stock of both these lines. There is thus a requirement for screening of these elite lines at the molecular level to ensure the purity of these varieties for future development. The virus causing CLCuD showed change by recombination making the search for new sources of resistance, as well as the maintenance of established sources, indispensable for the sustainable cotton production in Pakistan. (author)

Role of cucurbitacin C in resistance to spider mite (Tetranychus urticae) in cucumber (Cucumber sativus L.)

NARCIS (Netherlands)

Balkema-Boomstra, A.G.; Zijlstra, S.; Verstappen, F.W.A.; Inggamer, H.; Mercke, P.

2003-01-01

Cucurbitacins are bitter triterpenoid compounds that are toxic to most organisms and occur widely in wild and cultivated Cucurbitaceae. The only cucurbitacin identified in Cucumis sativus is cucurbitacin C. The bitter taste of cucumber has been correlated with resistance to the spider mite

Engineered disease resistance in cotton using RNA-interference to knock down cotton leaf curl kokhran virus-Burewala and cotton leaf curl Multan betasatellite

Science.gov (United States)

Cotton Leaf Curl virus Disease (CLCuD) has caused enormous losses in cotton (Gossypium hirsutum) production in Pakistan. RNA interference (RNAi) is an emerging technique that could knock out CLCuD by targeting different regions of the pathogen genome that are important for replication, transcription...

Analysis of transcriptome differences between resistant and susceptible strains of the citrus red mite Panonychus citri (Acari: Tetranychidae.

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Bin Liu

Full Text Available BACKGROUND: The citrus red mite is a worldwide citrus pest and a common sensitizing allergen of asthma and rhinitis. It has developed strong resistance to many registered acaricides, However, the molecular mechanisms of resistance remain unknown. we therefore used next generation sequencing technology to investigate the global transcriptomes between resistant strains and susceptible strains. RESULTS: We obtained 34,159, 30,466 and 32,217 unigenes by assembling the SS reads, RS reads and SS&RS reads respectively. There are total 17,581 annotated unigenes from SS&RS reads by BLAST searching databases of nr, the Clusters of Orthologous Groups (COGs and Kyoto Encyclopedia of Genes and Genomes (KEGG with an E-value ≤ 1e-5, in which 7,075 unigenes were annotated in the COG database, 12, 712 unigenes were found in the KEGG database and 3,812 unigenes were assigned to Gene ontology (GO. Moreover, 2,701 unigenes were judged to be the differentially expressed genes (DEGs based on the uniquely mapped reads. There are 219 pathways in all annotated unigenes and 198 pathways in DEGs that mapped to the KEGG database. We identified 211 metabolism genes and target genes related to general insecticide resistance such as P450 and Cytochrome b, and further compared their differences between RS and SS. Meanwhile, we identified 105 and 194 genes related to growth and reproduction, respectively, based on the mode of action of Hexythiazox. After further analyses, we found variation in sequences but not in gene expression related to mite growth and reproduction between different strains. CONCLUSION: To our knowledge, this is the first comparative transcriptome study to discover candidate genes involved in phytophagous mite resistance. This study identified differential unigenes related to general pesticide resistance and organism growth and reproduction in P. citri. The assembled, annotated transcriptomes provide a valuable genomic resource for further understanding

Computed tomography of ball pythons (Python regius) in curled recumbency.

Science.gov (United States)

Hedley, Joanna; Eatwell, Kevin; Schwarz, Tobias

2014-01-01

Anesthesia and tube restraint methods are often required for computed tomography (CT) of snakes due to their natural tendency to curl up. However, these restraint methods may cause animal stress. The aim of this study was to determine whether the CT appearance of the lungs differs for ball pythons in a curled position vs. tube restraint. Whole body CT was performed on ten clinically healthy ball pythons, first in curled and then in straight positions restrained in a tube. Curved multiplanar reformatted (MPR) lung images from curled position scans were compared with standard MPR lung images from straight position scans. Lung attenuation and thickness were measured at three locations for each scan. Time for positioning and scanning was 12 ± 5 min shorter for curled snakes compared to tube restraint. Lung parenchyma thickness and attenuation declined from cranial to caudal on both straight and curled position images. Mean lung parenchyma thickness was greater in curled images at locations 1 (P = 0.048) and 3 (P = 0.044). Mean lung parenchyma thickness decreased between location 1 and 2 by 86-87% (straight: curled) and between location 1 and 3 by 51-50% (straight: curled). Mean lung attenuation at location 1 was significantly greater on curled position images than tube restraint images (P = 0.043). Findings indicated that CT evaluation of the lungs is feasible for ball pythons positioned in curled recumbency if curved MPR is available. However, lung parenchyma thickness and attenuation in some locations may vary from those acquired using tube restraint. © 2014 American College of Veterinary Radiology.

The sports science of curling: a practical review.

Science.gov (United States)

Bradley, John L

2009-01-01

Curling is a sport played on ice in which two teams each deliver 8 granite stones towards a target, or 'house'. It is the only sport in which the trajectory of the projectile can be influenced after it has been released by the athlete. This is achieved by sweeping the ice in front of the stone to change the stone-ice friction and thereby enable to stone to travel further, curl more or stay straight. Hard sweeping is physically demanding. Different techniques of sweeping can also have different effects on the stone. This paper will review the current research behind sweeping a curling stone, outline the physiological demands of sweeping, the associated performance effects and suggest potential strategies of sweeping that can be used by both coaches and curling teams. Key pointsSweeping a curling stone can be highly physically demanding.Effective sweeping requires a combination of downward force and brush head speed, determined by the stone velocity.Sweeping on the left or right of a stone can help the stone to remain straight or curl more depending on the rotation of the stone.This can lead to the development of sweeping and playing tactics and contribute to team selection.

Analysis of insecticide resistance-related genes of the Carmine spider mite Tetranychus cinnabarinus based on a de novo assembled transcriptome.

Directory of Open Access Journals (Sweden)

Zhifeng Xu

Full Text Available The carmine spider mite (CSM, Tetranychus cinnabarinus, is an important pest mite in agriculture, because it can develop insecticide resistance easily. To gain valuable gene information and molecular basis for the future insecticide resistance study of CSM, the first transcriptome analysis of CSM was conducted. A total of 45,016 contigs and 25,519 unigenes were generated from the de novo transcriptome assembly, and 15,167 unigenes were annotated via BLAST querying against current databases, including nr, SwissProt, the Clusters of Orthologous Groups (COGs, Kyoto Encyclopedia of Genes and Genomes (KEGG and Gene Ontology (GO. Aligning the transcript to Tetranychus urticae genome, the 19255 (75.45% of the transcripts had significant (e-value <10-5 matches to T. urticae DNA genome, 19111 sequences matched to T. urticae proteome with an average protein length coverage of 42.55%. Core Eukaryotic Genes Mapping Approach (CEGMA analysis identified 435 core eukaryotic genes (CEGs in the CSM dataset corresponding to 95% coverage. Ten gene categories that relate to insecticide resistance in arthropod were generated from CSM transcriptome, including 53 P450-, 22 GSTs-, 23 CarEs-, 1 AChE-, 7 GluCls-, 9 nAChRs-, 8 GABA receptor-, 1 sodium channel-, 6 ATPase- and 12 Cyt b genes. We developed significant molecular resources for T. cinnabarinus putatively involved in insecticide resistance. The transcriptome assembly analysis will significantly facilitate our study on the mechanism of adapting environmental stress (including insecticide in CSM at the molecular level, and will be very important for developing new control strategies against this pest mite.

An analysis of potential resistance of the phytophagous mite, Tetranychus urticae Koch (Acari: Tetranychidae to four botanical pesticides

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Attia, S.

2015-01-01

Full Text Available Description of the subject. Synthetic acaricides have been widely used to manage Tetranychus urticae. Due to the excessive use of biocide and the associated problems of pesticide resistance and environmental pollution, there is an increasing demand for sustainable, environmentally-friendly control methods. Among the current alternative strategies aimed at decreasing the pest populations, the pesticides based on plant extracts are currently one of the most promising methods. Essential oils with acaricidal properties have been categorized as green pesticides because they are biodegradable and predominantly non-toxic to vertebrates. Objectives. With an aim to reduce the use of synthetic pesticides, they represent a promising approach for eco-chemical control of mites. Method. The aim of the present work was to analyze the risk of resistance emergence of T. urticae to repeated treatments with four plant extracts: Deverra scoparia Coss. & Durieu (Araliales: Apiaceae, Hertia cheirifolia (L. Kuntze (Asterales: Ateraceae, Santolina africana Jord. & Fourr. (Asterales: Asteraceae essential oils and garlic distillate Allium sativum L. (Asparagales: Alliaceae after 20 generations. Results. Repeated treatments with S. africana essential oil during 20 generations did not provoke an emergence of resistance while a low development of resistance was observed with H. cheirifolia, A. sativum and D. scoparia extracts. Conclusions. The efficacy of these extracts against the two spotted spider mite and their low development of resistance make them a promising use for pest management.

MicroRNA profiling of tomato leaf curl new delhi virus (tolcndv infected tomato leaves indicates that deregulation of mir159/319 and mir172 might be linked with leaf curl disease

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Haq Qazi MR

2010-10-01

Full Text Available Abstract Background Tomato leaf curl virus (ToLCV, a constituent of the genus Begomovirus, infects tomato and other plants with a hallmark disease symptom of upward leaf curling. Since microRNAs (miRs are known to control plants developmental processes, we evaluated the roles of miRNAs in Tomato leaf curl New Delhi virus (ToLCNDV induced leaf curling. Results Microarray analyses of miRNAs, isolated from the leaves of both healthy and ToLCNDV agroinfected tomato cv Pusa Ruby, revealed that ToLCNDV infection significantly deregulated various miRNAs representing ~13 different conserved families (e.g., miR319, miR172, etc.. The precursors of these miRNAs showed similar deregulated patterns, indicating that the transcription regulation of respective miRNA genes was perhaps the cause of deregulation. The expression levels of the miRNA-targeted genes were antagonistic with respect to the amount of corresponding miRNA. Such deregulation was tissue-specific in nature as no analogous misexpression was found in flowers. The accumulation of miR159/319 and miR172 was observed to increase with the days post inoculation (dpi of ToLCNDV agroinfection in tomato cv Pusa Ruby. Similarly, these miRs were also induced in ToLCNDV agroinfected tomato cv JK Asha and chilli plants, both exhibiting leaf curl symptoms. Our results indicate that miR159/319 and miR172 might be associated with leaf curl symptoms. This report raises the possibility of using miRNA(s as potential signature molecules for ToLCNDV infection. Conclusions The expression of several host miRNAs is affected in response to viral infection. The levels of the corresponding pre-miRs and the predicted targets were also deregulated. This change in miRNA expression levels was specific to leaf tissues and observed to be associated with disease progression. Thus, certain host miRs are likely indicator of viral infection and could be potentially employed to develop viral resistance strategies.

Swept Away: Exploring the Physics of Curling

Science.gov (United States)

Esser, Liza

2011-01-01

Studying the Olympic sport of curling is a fun and engaging way to learn about the concepts of friction, forces, momentum, and Newton's laws. Each winter, the author takes her eighth-grade physical science class on a field trip to experience curling firsthand. This field trip has become a favorite of the eighth graders at Capitol Hill Day School…

Beyond Predation: The Zoophytophagous Predator Macrolophus pygmaeus Induces Tomato Resistance against Spider Mites.

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Maria L Pappas

Full Text Available Many predatory insects that prey on herbivores also feed on the plant, but it is unknown whether plants affect the performance of herbivores by responding to this phytophagy with defence induction. We investigate whether the prior presence of the omnivorous predator Macrolophus pygmaeus (Rambur on tomato plants affects plant resistance against two different herbivore species. Besides plant-mediated effects of M. pygmaeus on herbivore performance, we examined whether a plant defence trait that is known to be inducible by herbivory, proteinase inhibitors (PI, may also be activated in response to the interactions of this predator with the tomato plant. We show that exposing tomato plants to the omnivorous predator M. pygmaeus reduced performance of a subsequently infesting herbivore, the two-spotted spider mite Tetranychus urticae Koch, but not of the greenhouse whitefly Trialeurodes vaporariorum (Westwood. The spider-mite infested tomato plants experience a lower herbivore load, i.e., number of eggs deposited and individuals present, when previously exposed to the zoophytophagous predator. This effect is not restricted to the exposed leaf and persists on exposed plants for at least two weeks after the removal of the predators. The decreased performance of spider mites as a result of prior exposure of the plant to M. pygmaeus is accompanied by a locally and systemically increased accumulation of transcripts and activity of proteinase inhibitors that are known to be involved in plant defence. Our results demonstrate that zoophytophagous predators can induce plant defence responses and reduce herbivore performance. Hence, the suppression of populations of certain herbivores via consumption may be strengthened by the induction of plant defences by zoophytophagous predators.

Comparative transcriptome profiling of a resistant vs. susceptible tomato (Solanum lycopersicum cultivar in response to infection by tomato yellow leaf curl virus.

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Tianzi Chen

Full Text Available Tomato yellow leaf curl virus (TYLCV threatens tomato production worldwide by causing leaf yellowing, leaf curling, plant stunting and flower abscission. The current understanding of the host plant defense response to this virus is very limited. Using whole transcriptome sequencing, we analyzed the differential gene expression in response to TYLCV infection in the TYLCV-resistant tomato breeding line CLN2777A (R and TYLCV-susceptible tomato breeding line TMXA48-4-0 (S. The mixed inoculated samples from 3, 5 and 7 day post inoculation (dpi were compared to non-inoculated samples at 0 dpi. Of the total of 34831 mapped transcripts, 209 and 809 genes were differentially expressed in the R and S tomato line, respectively. The proportion of up-regulated differentially expressed genes (DEGs in the R tomato line (58.37% was higher than that in the S line (9.17%. Gene ontology (GO analyses revealed that similar GO terms existed in both DEGs of R and S lines; however, some sets of defense related genes and their expression levels were not similar between the two tomato lines. Genes encoding for WRKY transcriptional factors, R genes, protein kinases and receptor (-like kinases which were identified as down-regulated DEGs in the S line were up-regulated or not differentially expressed in the R line. The up-regulated DEGs in the R tomato line revealed the defense response of tomato to TYLCV infection was characterized by the induction and regulation of a series of genes involved in cell wall reorganization, transcriptional regulation, defense response, ubiquitination, metabolite synthesis and so on. The present study provides insights into various reactions underlining the successful establishment of resistance to TYLCV in the R tomato line, and helps in the identification of important defense-related genes in tomato for TYLCV disease management.

Curls of My Dreams.

Science.gov (United States)

Greenman, Geri

2001-01-01

Describes an art activity in which students draw ribbons (thin watercolor paper that, when torn, will stand up in a curling fashion). Explains in detail the assignment in which students used pencil rendering or charcoal pencil depending on the type of paper used for the assignment. (CMK)

Classical dynamics with curl forces, and motion driven by time-dependent flux

International Nuclear Information System (INIS)

Berry, M V; Shukla, Pragya

2012-01-01

For position-dependent forces whose curl is non-zero (‘curl forces’), there is no associated scalar potential and therefore no obvious Hamiltonian or Lagrangean and, except in special cases, no obvious conserved quantities. Nevertheless, the motion is nondissipative (measure-preserving in position and velocity). In a class of planar motions, some of which are exactly solvable, the curl force is directed azimuthally with a magnitude varying with radius, and the orbits are usually spirals. If the curl is concentrated at the origin (for example, the curl force could be an electric field generated by a changing localized magnetic flux, as in the betatron), a Hamiltonian does exist but violates the rotational symmetry of the force. In this case, reminiscent of the Aharonov–Bohm effect, the spiralling is extraordinarily slow. (paper)

The Curl of a Vector Field: Beyond the Formula

Science.gov (United States)

Burch, Kimberly Jordan; Choi, Youngna

2006-01-01

It has been widely acknowledged that there is some discrepancy in the teaching of vector calculus in mathematics courses and other applied fields. The curl of a vector field is one topic many students can calculate without understanding its significance. In this paper, we explain the origin of the curl after presenting the standard mathematical…

Protocols for the delivery of small molecules to the two-spotted spider mite, Tetranychus urticae.

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Takeshi Suzuki

Full Text Available The two-spotted spider mite, Tetranychus urticae, is a chelicerate herbivore with an extremely wide host range and an extraordinary ability to develop pesticide resistance. Due to its responsiveness to natural and synthetic xenobiotics, the spider mite is becoming a prime pest herbivore model for studies of the evolution of host range, plant-herbivore interactions and mechanisms of xenobiotic resistance. The spider mite genome has been sequenced and its transcriptional responses to developmental and various biotic and abiotic cues have been documented. However, to identify biological and evolutionary roles of T. urticae genes and proteins, it is necessary to develop methods for the efficient manipulation of mite gene function or protein activity. Here, we describe protocols developed for the delivery of small molecules into spider mites. Starting with mite maintenance and the preparation of the experimental mite populations of developmentally synchronized larvae and adults, we describe 3 methods for delivery of small molecules including artificial diet, leaf coating, and soaking. The presented results define critical steps in these methods and demonstrate that they can successfully deliver tracer dyes into mites. Described protocols provide guidelines for high-throughput setups for delivery of experimental compounds that could be used in reverse genetics platforms to modulate gene expression or protein activity, or for screens focused on discovery of new molecules for mite control. In addition, described protocols could be adapted for other Tetranychidae and related species of economic importance such as Varroa, dust and poultry mites.

Suppressors of RNA silencing encoded by tomato leaf curl

Indian Academy of Sciences (India)

Whitefly-transmitted begomoviruses infecting tomato crop code for five different proteins, ORF AC4, ORF AC2 and ORF AV2 in DNA-A component, ORF BV1 in DNA-B ... In the present study suppressor function of ORF C1 of three betasatellites Tomato leaf curl Bangalore betasatellite ToLCBB-[IN:Hess:08], Cotton leaf curl ...

Age and reproductive status of adult Varroa mites affect grooming success of honey bees.

Science.gov (United States)

Kirrane, Maria J; de Guzman, Lilia I; Rinderer, Thomas E; Frake, Amanda M; Wagnitz, Jeremy; Whelan, Pádraig M

2012-12-01

This study evaluated for the first time the grooming response of honey bees to Varroa mites of different ages and reproductive statuses in the laboratory. Plastic cages containing a section of dark comb and about 200 bees were inoculated with groups of four classes of mites: gravid, phoretic foundresses, phoretic daughters and a combination of gravid and phoretic foundress mites. Each cage received 20 mites belonging to one of these classes. Our results showed that, 1 day after mite inoculation, phoretic daughter mites were the most prone to grooming by honey bees with an average mite drop of 49.8 ± 2.6 %. The lowest mite drop was recorded for bees inoculated with phoretic foundresses (30.3 ± 3.6 %) but was comparable to bees inoculated with gravid mites (31.8 ± 3.8 %) and the combination of gravid and phoretic foundress mites (34.2 ± 3.2 %). No differences among mite types were detected during the second and third days of observation. Regardless of mite type, the highest mite drop was recorded on the first day (35 ± 2.1 %) compared to the drop for any subsequent day (grooming behaviour may increase our insight into the importance of grooming in mite resistance.

Assessing hygienic behavior and attraction to Varroa mite (Acari ...

African Journals Online (AJOL)

Three days later, the number of female Varroa in the capped cells were counted as attraction criteria for each treatment separately. ... The negative correlation between 2 major resistance traits (hygienic behavior and attraction traits) in the breeding stock deems that selection for resistance against Varroa mite and improved ...

Performance of cotton leaf curl virus resistant intrahirsutum f/sub 1/ hybrids

International Nuclear Information System (INIS)

Baloch, M.J.

2004-01-01

The first and foremost effort to combat the devastating cotton leaf curl virus (clcv) disease would be to utilize those clcv resistant germplasm in a hybridization programme which can enhance the possibilities of selecting desirable progenies from segregating populations. In this connection, 16 clcv intrahirsutum F1 hybrids were developed and evaluated for their performance. The hybrids, on an average gave an increase of 26.02 % in seed cotton yield; 11.52 % in bolls per plant; 14.23 % in boll weight; 4.28 % in lint; 3.89 % in fibre length and 8.21 % in earliness against the average of parents. However, among the hybrids, the top three scoring for yield were, BH.121 x Cyto.9/91, Cyto.9/91 x CRIS-226 and VH-137 x CRIS-226. The number of bolls per plant was found to be a major contributing factor for increased yield because the hybrids which set higher bolls correspondingly gave higher yields. Boll weight was not regarded as an important attribute to increase yield because hybrids with moderate boll sizes were among the top three high yielders. For lint %, the hybrids CRIS-129 x LRA-5166 and FH-901 x VH-137 were first for fibre length, whereas CRIS-121 x Cyto.51 and BH-124 x CIM-448 were among the top two rankers. Regarding earliness, the hybrids CRIS-121 x Cyto. 51 gave the highest boll opening percent and next in order was the hybrid VH-137 x DNH-49. Our results thus generally suggest that although the best three hybrids were desirable for other traits, the choice of the hybrids may be made on the priority for characters to be bred. (author)

Inactivation of dust mites, dust mite allergen, and mold from carpet.

Science.gov (United States)

Ong, Kee-Hean; Lewis, Roger D; Dixit, Anupma; MacDonald, Maureen; Yang, Mingan; Qian, Zhengmin

2014-01-01

Carpet is known to be a reservoir for biological contaminants, such as dust mites, dust mite allergen, and mold, if it is not kept clean. The accumulation of these contaminants in carpet might trigger allergies or asthma symptoms in both children and adults. The purpose of this study is to compare methods for removal of dust mites, dust mite allergens, and mold from carpet. Carpets were artificially worn to simulate 1 to 2 years of wear in a four-person household. The worn carpets were inoculated together with a common indoor mold (Cladosporium species) and house dust mites and incubated for 6 weeks to allow time for dust mite growth on the carpet. The carpets were randomly assigned to one of the four treatment groups. Available treatment regimens for controlling carpet contaminants were evaluated through a literature review and experimentation. Four moderately low-hazard, nondestructive methods were selected as treatments: vacuuming, steam-vapor, Neem oil (a natural tree extract), and benzalkonium chloride (a quaternary ammonium compound). Steam vapor treatment demonstrated the greatest dust mite population reduction (p 0.05) for both physical and chemical methods. The steam-vapor treatment effectively killed dust mites and denatured dust mite allergen in the laboratory environment.

Field Trial and Molecular Characterization of RNAi-Transgenic Tomato Plants That Exhibit Resistance to Tomato Yellow Leaf Curl Geminivirus.

Science.gov (United States)

Fuentes, Alejandro; Carlos, Natacha; Ruiz, Yoslaine; Callard, Danay; Sánchez, Yadira; Ochagavía, María Elena; Seguin, Jonathan; Malpica-López, Nachelli; Hohn, Thomas; Lecca, Maria Rita; Pérez, Rosabel; Doreste, Vivian; Rehrauer, Hubert; Farinelli, Laurent; Pujol, Merardo; Pooggin, Mikhail M

2016-03-01

RNA interference (RNAi) is a widely used approach to generate virus-resistant transgenic crops. However, issues of agricultural importance like the long-term durability of RNAi-mediated resistance under field conditions and the potential side effects provoked in the plant by the stable RNAi expression remain poorly investigated. Here, we performed field trials and molecular characterization studies of two homozygous transgenic tomato lines, with different selection markers, expressing an intron-hairpin RNA cognate to the Tomato yellow leaf curl virus (TYLCV) C1 gene. The tested F6 and F4 progenies of the respective kanamycin- and basta-resistant plants exhibited unchanged field resistance to TYLCV and stably expressed the transgene-derived short interfering RNA (siRNAs) to represent 6 to 8% of the total plant small RNAs. This value outnumbered the average percentage of viral siRNAs in the nontransformed plants exposed to TYLCV-infested whiteflies. As a result of the RNAi transgene expression, a common set of up- and downregulated genes was revealed in the transcriptome profile of the plants selected from either of the two transgenic events. A previously unidentified geminivirus causing no symptoms of viral disease was detected in some of the transgenic plants. The novel virus acquired V1 and V2 genes from TYLCV and C1, C2, C3, and C4 genes from a distantly related geminivirus and, thereby, it could evade the repressive sequence-specific action of transgene-derived siRNAs. Our findings shed light on the mechanisms of siRNA-directed antiviral silencing in transgenic plants and highlight the applicability limitations of this technology as it may alter the transcriptional pattern of nontarget genes.

Determinación del límite de rotura de un cable por Método de los Elementos Finitos. // Determination of resistance load on steel wire rope by Finite Elements Method.

Directory of Open Access Journals (Sweden)

F. Aguilar Parés

2008-09-01

Full Text Available En ocasiones, se desconocen las características originales de un cable de acero. En estos casos, generalmente se estima ellímite de rotura de un cable a partir del límite de rotura de un alambre del cable. En el presente trabajo, se propone emplearun método para estimar el límite de rotura del cable en base al modelado del cordón mediante elementos finitos. En elcontenido se explica detalladamente el procedimiento y es ejemplificado. El procedimiento es iniciado con el dibujo delcable en un programa de diseño gráfico parámetrico y posteriormente se describen las características generales delmodelado con un programa especializado en el Método de Elementos Finitos. En el análisis se incluye la influencia delcontacto entre los alambres que forman el cordón. Por último, se comparan los resultados obtenidos para el límite de roturadel cable con los datos declarados por el fabricante. Con este procedimiento fueron obtenidos valores mediante modeladodel cable con diferencias entre el 11% al 2,5% en relación al límite de rotura declarado por los fabricantes. Las diferenciasfueron evidenciadas en dependencia de la calidad del mallado empleado.Palabras claves: Cables de acero, elementos finitos, carga límite de rotura._________________________________________________________________________Abstract:In occasions, the original characteristics of steel wire rope are unknown. In these cases, could be estimated the resistanceof the wire rope knowing the wire resistance. In this proposal method for estimating the resistance load of steel wire thecord of the wire rope is modelling using finite elements. Procedure is explained and a sample with a selected wire rope ispresented. It is started with the drawing of the wire rope by professional software. General characteristics of themodelling are described with FEM software. In the analysis, the contact influence in the wires of the cord is included.Lastly, the obtained results of the resistance

Higher glandular trichome density in tomato leaflets and repellence to spider mites

International Nuclear Information System (INIS)

Maluf, Wilson Roberto; Inoue, Irene Fumi; Ferreira, Raphael de Paula Duarte; Gomes, Luiz Antonio Augusto; Castro, Evaristo Mauro de; Cardoso, Maria das Gracas

2007-01-01

The objective of this work was to evaluate the feasibility of selection for higher glandular trichome densities, as an indirect criterion of selection for increasing repellence to spider mites Tetranychus urticae, in tomato populations derived from an interspecific cross between Lycopersicon esculentum x L. hirsutum var. glabratum PI 134417. Trichome densities were evaluated in 19 genotypes, including 12 from advanced backcross populations, derived from the original cross L. esculentum x L. hirsutum var. glabratum PI 134417. Counts were made both on the adaxial and abaxial leaf surfaces, and trichomes were classified into glandular types IV and VI, other glandular types (types I+VII), and nonglandular types. Mite repellence was measured by distances walked by mites onto the tomato leaf surface after 20, 40 and 60 min. Spider mite repellence biotests indicated that higher densities of glandular trichomes (especially type VI) decreased the distances walked by the mites onto the tomato leaf surface. Selection of plants with higher densities of glandular trichomes can be an efficient criterion to obtain tomato genotypes with higher resistance (repellence) to spider mites. (author)

Population growth of Varroa destructor (Acari: Varroidae) in colonies of Russian and unselected honey bee (Hymenoptera: Apidae) stock as related to numbers of foragers with mites

Science.gov (United States)

Varroa mites are an external parasite of honey bees and a leading cause of colony losses worldwide. Varroa populations can be controlled with miticides, but mite resistant stocks such as the Russian honey bee (RHB) also are available. RHB and other mite resistant stock limit Varroa population growth...

Tetranychus urticae mites do not mount an induced immune response against bacteria.

Science.gov (United States)

Santos-Matos, Gonçalo; Wybouw, Nicky; Martins, Nelson E; Zélé, Flore; Riga, Maria; Leitão, Alexandre B; Vontas, John; Grbić, Miodrag; Van Leeuwen, Thomas; Magalhães, Sara; Sucena, Élio

2017-06-14

The genome of the spider mite Tetranychus urticae , a herbivore, is missing important elements of the canonical Drosophila immune pathways necessary to fight bacterial infections. However, it is not known whether spider mites can mount an immune response and survive bacterial infection. In other chelicerates, bacterial infection elicits a response mediated by immune effectors leading to the survival of infected organisms. In T. urticae , infection by either Escherichia coli or Bacillus megaterium did not elicit a response as assessed through genome-wide transcriptomic analysis. In line with this, spider mites died within days even upon injection with low doses of bacteria that are non-pathogenic to Drosophila Moreover, bacterial populations grew exponentially inside the infected spider mites. By contrast, Sancassania berlesei , a litter-dwelling mite, controlled bacterial proliferation and resisted infections with both Gram-negative and Gram-positive bacteria lethal to T. urticae This differential mortality between mite species was absent when mites were infected with heat-killed bacteria. Also, we found that spider mites harbour in their gut 1000-fold less bacteria than S. berlesei We show that T. urticae has lost the capacity to mount an induced immune response against bacteria, in contrast to other mites and chelicerates but similarly to the phloem feeding aphid Acyrthosiphon pisum Hence, our results reinforce the putative evolutionary link between ecological conditions regarding exposure to bacteria and the architecture of the immune response. © 2017 The Authors.

Flange Curling in Cold Formed Profiles

DEFF Research Database (Denmark)

Jönsson, Jeppe; Ramonas, Gediminas

2012-01-01

The non-linear flange curling phenomenon in cold formed profiles is the tendency of slender flanges to deform towards the neutral axis for increasing flexural curvature. Based on Braziers work, Winter proposed a simple engineering formula for determination of the local flange deformation towards...

Stored product mites (Acari: Astigmata) infesting food in various types of packaging.

Science.gov (United States)

Hubert, Jan; Nesvorna, Marta; Volek, Vlado

2015-02-01

From 2008 to 2014, stored product mites have been reported from prepackaged dried food on the market in the Czech Republic. The infestation was by Carpoglyphus lactis (L.) in dried fruits and Tyrophagus putrescentiae (Schrank) in dog feed. The infestation is presumably caused by poor protection of the packages. We compared various packaging methods for their resistance to mites using dried apricots and dog feed in laboratory experiments. The trial packages included nine different plastic films, monofilm, duplex and triplex, and one type of plastic cup (ten replicates per packaging type). All packaging materials are available on the Czech market for dried food products. The samples of dried food were professionally packed in a factory and packaged dried apricots were exposed to C. lactis and dog food to T. putrescentiae. After 3 months of exposure, the infestation and mite density of the prepackaged food was assessed. Mites were found to infest six types of packages. Of the packaging types with mites, 1-5 samples were infested and the maximum abundance was 1,900 mites g(-1) of dried food. Mites entered the prepackaged food by faulty sealing. Inadequate sealing is suggested to be the major cause of the emerged infestation of dried food.

Increased tolerance and resistance to virus infections: a possible factor in the survival of Varroa destructor-resistant honey bees (Apis mellifera.

Directory of Open Access Journals (Sweden)

Barbara Locke

Full Text Available The honey bee ectoparasitic mite, Varroa destructor, has a world-wide distribution and inflicts more damage than all other known apicultural diseases. However, Varroa-induced colony mortality is more accurately a result of secondary virus infections vectored by the mite. This means that honey bee resistance to Varroa may include resistance or tolerance to virus infections. The aim of this study was to see if this is the case for a unique population of mite-resistant (MR European honey bees on the island of Gotland, Sweden. This population has survived uncontrolled mite infestation for over a decade, developing specific mite-related resistance traits to do so. Using RT-qPCR techniques, we monitored late season virus infections, Varroa mite infestation and honey bee colony population dynamics in the Gotland MR population and compared this to mite-susceptible (MS colonies in a close by apiary. From summer to autumn the deformed wing virus (DWV titres increased similarly between the MR and MS populations, while the black queen cell virus (BQCV and sacbrood virus (SBV titres decreased substantially in the MR population compared to the MS population by several orders of magnitude. The MR colonies all survived the following winter with high mite infestation, high DWV infection, small colony size and low proportions of autumn brood, while the MS colonies all perished. Possible explanations for these changes in virus titres and their relevance to Varroa resistance and colony winter survival are discussed.

EFFECT OF THE SHOULDER POSITION ON THE BICEPS BRACHII EMG IN DIFFERENT DUMBBELL CURLS

Directory of Open Access Journals (Sweden)

Taian M.M. Vieira

2009-03-01

Full Text Available Incline Dumbbell Curl (IDC and Dumbbell Preacher Curl (DPC are two variations of the standard Dumbbell Biceps Curl (DBC, generally applied to optimize biceps brachii contribution for elbow flexion by fixing shoulder at a specific angle. The aim of this study is to identify changes in the neuromuscular activity of biceps brachii long head for IDC, DPC and DBC exercises, by taking into account the changes in load moment arm and muscle length elicited by each dumbbell curl protocol. A single cycle (concentric-eccentric of DBC, IDC and DPC, was applied to 22 subjects using a submaximal load of 40% estimated from an isometric MVC test. The neuromuscular activity of biceps brachii long head was compared by further partitioning each contraction into three phases, according to individual elbow joint range of motion. Although all protocols elicited a considerable level of activation of the biceps brachii muscle (at least 50% of maximum RMS, the contribution of this muscle for elbow flexion/extension varied among exercises. The submaximal elbow flexion (concentric elicited neuro muscular activity up to 95% of the maximum RMS value during the final phase of IDC and DBC and 80% for DPC at the beginning of the movement. All exercises showed significant less muscle activity for the elbow extension (eccentric. The Incline Dumbbell Curl and the classical Dumbbell Biceps Curl resulted in similar patterns of biceps brachii activation for the whole range of motion, whereas Dumbbell Preacher Curl elicited high muscle activation only for a short range of elbow joint angle

Using an in vitro system for maintaining Varroa destructor mites on Apis mellifera hosts: Studies of mite longevity and feeding behavior

Science.gov (United States)

Varroa destructor mites (Vd) are ectoparasites of Apis mellifera honey bees, and the damage they inflict on hosts is a likely causative factor of recent poor honey bee colony performance. Much research has produced an arsenal of control agents against Vd, which have become resistant to many chemical...

Beyond insects: current status, achievements and future perspectives of RNAi in mite pests.

Science.gov (United States)

Niu, Jinzhi; Shen, Guangmao; Christiaens, Olivier; Smagghe, Guy; He, Lin; Wang, Jinjun

2018-05-11

Mites comprise a group of key agricultural pests on a wide range of crops. They cause harm through feeding on the plant and transferring dangerous pathogens, and the rapid evolution of pesticide resistance in mites highlights the need for novel control methods. Currently, RNA interference (RNAi) shows a great potential for insect pest control. Here, we review the literature associated with RNAi in mite pests. We discuss different target genes and RNAi efficiency in various mite species, a promising Varroa control program through RNAi, the synergy of RNAi with plant defense mechanisms and microorganisms, and the current understandings of systemic movement of dsRNA. Based on this, we can conclude that there is a clear potential for an RNAi-based mite control application but further research on several aspects is needed, including: (i) the factors influencing the RNAi efficiency, (ii) the mechanism of environmental RNAi and cross-kingdom dsRNA trafficking, (iii) the mechanism of possible systemic and parental RNAi, and (iv) non-target effects, specifically in predatory mites, should be considered during the RNAi target selection. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Population Growth of Varroa destructor (Acari: Varroidae) in Colonies of Russian and Unselected Honey Bee (Hymenoptera: Apidae) Stocks as Related to Numbers of Foragers With Mites.

Science.gov (United States)

DeGrandi-Hoffman, Gloria; Ahumada, Fabiana; Danka, Robert; Chambers, Mona; DeJong, Emily Watkins; Hidalgo, Geoff

2017-06-01

Varroa (Varroa destructor Anderson and Trueman) is an external parasite of honey bees (Apis mellifera L.) and a leading cause of colony losses worldwide. Varroa populations can be controlled with miticides, but mite-resistant stocks such as the Russian honey bee (RHB) also are available. Russian honey bee and other mite-resistant stocks limit Varroa population growth by affecting factors that contribute to mite reproduction. However, mite population growth is not entirely due to reproduction. Numbers of foragers with mites (FWM) entering and leaving hives also affect the growth of mite populations. If FWM significantly contribute to Varroa population growth, mite numbers in RHB colonies might not differ from unselected lines (USL). Foragers with mites were monitored at the entrances of RHB and USL hives from August to November, 2015, at two apiary sites. At site 1, RHB colonies had fewer FWM than USL and smaller phoretic mite populations. Russian honey bee also had fewer infested brood cells and lower percentages with Varroa offspring than USL. At site 2, FWM did not differ between RHB and USL, and phoretic mite populations were not significantly different. At both sites, there were sharp increases in phoretic mite populations from September to November that corresponded with increasing numbers of FWM. Under conditions where FWM populations are similar between RHB and USL, attributes that contribute to mite resistance in RHB may not keep Varroa population levels below that of USL. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

Mite Pests in Plant Crops – Current Issues, Inovative Approaches and Possibilities for Controlling Them (2

Directory of Open Access Journals (Sweden)

Radmila Petanović

2010-01-01

Full Text Available Part one discusses some principal mite pests in agroecosystems and urban horticulturein European countries, Serbia and its neighbouring countries focusing primarily on issueswith regard to plant production, novel methods and approaches in applied acaralogy. Parttwo displays some major properties of acaricides inhibiting respiration, growth and developmentand other synthetic substances with acaricide action on the market in the last decadeof the 20th century and the first decade of the 21st century. Also some products of naturalorigin (azadirachtin, oils, micoacaricides are said to be gaining in importance. Issues withregard to the fact that mites can readily develop resistance to acardicides are discussed anda survey on the results of biochemical, physiological and genetical causes of resistance areanalyzed. Some basic principles of biological control of phytophagous mites and modernadvances and approaches are discussed as well as current knowledge on host plant resistanceto mites. Eventually, the possibility of using a combination of selective acaricides andbiological control agents is discussed but also the inclusion of other modes of control (agriculturalpractices and physical measures expected to contribute to an integrated managementof pest populations.

The economic importance of acaricides in the control of phytophagous mites and an update on recent acaricide mode of action research.

Science.gov (United States)

Van Leeuwen, Thomas; Tirry, Luc; Yamamoto, Atsushi; Nauen, Ralf; Dermauw, Wannes

2015-06-01

Acaricides are one of the cornerstones of an efficient control program for phytophagous mites. An analysis of the global acaricide market reveals that spider mites such as Tetranychus urticae, Panonychus citri and Panonychus ulmi are by far the most economically important species, representing more than 80% of the market. Other relevant mite groups are false spider mites (mainly Brevipalpus), rust and gall mites and tarsonemid mites. Acaricides are most frequently used in vegetables and fruits (74% of the market), including grape vines and citrus. However, their use is increasing in major crops where spider mites are becoming more important, such as soybean, cotton and corn. As revealed by a detailed case study of the Japanese market, major shifts in acaricide use are partially driven by resistance development and the commercial availability of compounds with novel mode of action. The importance of the latter cannot be underestimated, although some compounds are successfully used for more than 30 years. A review of recent developments in mode of action research is presented, as such knowledge is important for devising resistance management programs. This includes spirocyclic keto-enols as inhibitors of acetyl-CoA carboxylase, the carbazate bifenazate as a mitochondrial complex III inhibitor, a novel class of complex II inhibitors, and the mite growth inhibitors hexythiazox, clofentezine and etoxazole that interact with chitin synthase I. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparison of cultivars of ornamental crop Gerbera jamesonii on production of spider mite-induced volatiles, and their attractiveness to the predator Phytoseiulus persimilis.

Science.gov (United States)

Krips, O E; Willems, P E; Gols, R; Posthumus, M A; Gort, G; Dicke, M

2001-07-01

We investigated whether volatiles produced by spider mite-damaged plants of four gerbera cultivars differ in attractiveness to Phytoseiulus persimilis, a specialist predator of spider mites, and how the mite-induced odor blends differ in chemical composition. The gerbera cultivars differed in resistance, as expressed in terms of spider mite intrinsic rate of population increase (rm). In order of increasing resistance these were Sirtaki, Rondena, Fame, and Bianca. To correct for differences in damage inflicted on the cultivars, we developed a method to compare the attractiveness of the blends, based on the assumption that a larger amount of spider mite damage leads to higher attraction of P persimilis. Spider mite-induced volatiles of cultivars Rondena and Bianca were preferred over those of cultivar Sirtaki. Spider mite-induced volatiles of cultivars Sirtaki and Fame did not differ in attractiveness to P. persimilis. Sirtaki plants had a lower relative production of terpenes than the other three cultivars. This was attributed to a low production of cis-alpha-bergamotene, trans-alpha-bergamotene, trans-beta-bergamotene, and (E)-beta-farnesene. The emission of (E)-beta-ocimene and linalool was lower in Sirtaki and Fame leaves than in Bianca and Rondena. The importance of these chemical differences in the differential attraction of predatory mites is discussed.

Apparatus and method for transfer of information by means of a curl-free magnetic vector potential field

International Nuclear Information System (INIS)

Gelinas, R.C.

1984-01-01

A system for transmission of information using a curl-free magnetic vector potential radiation field. The system includes current-carrying apparatus for generating a magnetic vector potential field with a curl-free component coupled to apparatus for modulating the current applied to the field generating apparatus. Receiving apparatus includes a detector with observable properties that vary with the application of an applied curl-free magnetic vector potential field. Analyzing apparatus for determining the information content of modulation imposed on the curl-free vector potential field can be established in materials that are not capable of transmitting more common electromagnetic radiation

Biology and interactions of two distinct monopartite begomoviruses and betasatellites associated with radish leaf curl disease in India

Directory of Open Access Journals (Sweden)

Singh AK

2012-02-01

Full Text Available Abstract Background Emerging whitefly transmitted begomoviruses are major pathogens of vegetable and fibre crops throughout the world, particularly in tropical and sub-tropical regions. Mutation, pseudorecombination and recombination are driving forces for the emergence and evolution of new crop-infecting begomoviruses. Leaf curl disease of field grown radish plants was noticed in Varanasi and Pataudi region of northern India. We have identified and characterized two distinct monopartite begomoviruses and associated beta satellite DNA causing leaf curl disease of radish (Raphanus sativus in India. Results We demonstrate that RaLCD is caused by a complex of two Old World begomoviruses and their associated betasatellites. Radish leaf curl virus-Varanasi is identified as a new recombinant species, Radish leaf curl virus (RaLCV sharing maximum nucleotide identity of 87.7% with Tomato leaf curl Bangladesh virus-[Bangladesh:2] (Accession number AF188481 while the virus causing radish leaf curl disease-Pataudi is an isolate of Croton yellow vein mosaic virus-[India] (CYVMV-IN (Accession number AJ507777 sharing 95.8% nucleotide identity. Further, RDP analysis revealed that the RaLCV has a hybrid genome, a putative recombinant between Euphorbia leaf curl virus and Papaya leaf curl virus. Cloned DNA of either RaLCV or CYVMV induced mild leaf curl symptoms in radish plants. However, when these clones (RaLCV or CYVMV were individually co-inoculated with their associated cloned DNA betasatellite, symptom severity and viral DNA levels were increased in radish plants and induced typical RaLCD symptoms. To further extend these studies, we carried out an investigation of the interaction of these radish-infecting begomoviruses and their associated satellite, with two tomato infecting begomoviruses (Tomato leaf curl Gujarat virus and Tomato leaf curl New Delhi virus. Both of the tomato-infecting begomoviruses showed a contrasting and differential interaction with

Antigenic relationship between the house dust mite Dermatophagoides farinae and the predacious mite Phytoseiulus persimilis.

Science.gov (United States)

Homma, R; Ando, T; Miyahara, A; Kimura, H; Ito, G; Uesato, N; Ino, Y; Iwaki, M

1994-12-01

We have examined the antigenic relationship between the house dust mite Dermatophagoides farinae and the predacious mite Phytoseiulus persimilis. Immunoblotting analysis demonstrated that there was a very weak antigenic cross-reactivity between these different suborder of mites but that this cross-reactivity was not attributed to D. farinaes major allergen's, Der fI and Der fII. These results suggest that P. persimilis might scarcely provoke allergic symptoms in patients sensitized to house dust mites.

Population survey of phytoseiid mites and spider mites on peach leaves and wild plants in Japanese peach orchard.

Science.gov (United States)

Wari, David; Yamashita, Jun; Kataoka, Yoko; Kohara, Yoko; Hinomoto, Norihide; Kishimoto, Hidenari; Toyoshima, Shingo; Sonoda, Shoji

2014-07-01

A population survey of phytoseiid mites and spider mites was conducted on peach leaves and wild plants in Japanese peach orchards having different pesticide practices. The phytoseiid mite species composition on peach leaves and wild plants, as estimated using quantitative sequencing, changed during the survey period. Moreover, it varied among study sites. The phytoseiid mite species compositions were similar between peach leaves and some wild plants, such as Veronica persica, Paederia foetida, Persicaria longiseta, and Oxalis corniculata with larger quantities of phytoseiid mites, especially after mid-summer. A PCR-based method to detect the ribosomal ITS sequences of Tetranychus kanzawai and Panonychus mori from phytoseiid mites was developed. Results showed that Euseius sojaensis (specialized pollen feeder/generalist predator) uses both spider mites as prey in the field.

Scales of North Atlantic wind stress curl determined from the comprehensive ocean-atmosphere data set

Science.gov (United States)

Ehret, Laura L.; O'Brien, James J.

1989-01-01

Nineteen years of wind data over the North Atlantic are used to calculate a field of wind stress curl. An empirical orthogonal function (EOF) analysis is performed on this field, resulting in spatial patterns of wind stress curl and associated time series. A Monte Carlo technique is used to establish the statistical significance of each spatial pattern, and the associated time series are spectrally analyzed. The first four statistically significant EOF modes represent more than 50 percent of the curl variance, and the spatial patterns of curl associated with these modes exhibit the major elements of North Atlantic climatology. Most of the time series spectral variance is contained in annual and semiannual frequencies. The features observed include the individual annual variation of the subtropical high and the subpolar low, the annual oscillation of intensity between pressure centers, the influence of localized strong SST gradients and associated cyclogenesis regions, and the constant nature of the trades.

Seed storage protein components are associated with curled ...

African Journals Online (AJOL)

PRECIOUS

2009-11-16

Nov 16, 2009 ... analysis suggests that the two increased protein spots in mutants were ... The main objective of this work was to gain further understanding of the influence of curled cotyledon on the seed storage protein components in soybean by com- .... cotyledon formation during Arabidopsis embryogenesis: interaction.

Evaluation of predatory mites and Acramite for control of twospotted spider mites in strawberries in north central Florida.

Science.gov (United States)

Rhodes, Elena M; Liburd, Oscar E

2006-08-01

Greenhouse and field experiments were conducted from 2003 to 2005 to determine the effectiveness of two predatory mite species, Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus (McGregor), and a reduced-risk miticide, Acramite 50 WP (bifenazate), for control of twospotted spider mite, Tetranychus urticae Koch, in strawberries (Fragaria x ananassa Duchesne). In greenhouse tests, three treatments consisting of releases of P. persimilis, N. californicus, and an untreated control were evaluated. Both species of predatory mites significantly reduced twospotted spider mite numbers below those found in the control during the first 3 wk of evaluation. However, during week 4, twospotted spider mite numbers on the plants treated with P. persimilis increased and did not differ significantly from the control. Field studies used releases of P. persimilis and N. californicus, applications of Acramite, and untreated control plots. Both N. californicus and P. persimilis significantly reduced populations of twospotted spider mite below numbers recorded in the control plots. During the 2003-2004 field season P. persimilis took longer than N. californicus to bring the twospotted spider mite population under control (< 10 mites per leaflet). Acramite was effective in reducing twospotted spider mite populations below 10 mites per leaflet during the 2003-2004 field season but not during the 2004-2005 field season, possibly because of a late application. These findings indicate that N. californicus releases and properly timed Acramite applications are promising options for twospotted spider mite control in strawberries for growers in north Florida and other areas of the southeast.

Reliability of Arm Curl and Chair Stand tests for assessing muscular endurance in older people

Directory of Open Access Journals (Sweden)

Boneth M

2012-05-01

Full Text Available Objective: to assess the test-retest reliability and level of agreement between measures of the 30 second (30-s Arm Curl and 30-s Chair Stand test in a sample of older adults from Bucaramanga. Materials and methods: a study of evaluation of diagnostic technology was done. Both tests were administered by the same evaluator to 111 adults older than 59 year-old (70,4 ± 7,3, on two occasions, with an interval of time between measures of 4 to 8 days. In the analysis, test-retest reliability was determined using the Intraclass Correlation Coefficient ICC= 2,1 with their confidence interval 95% (CI 95% respective. The agreement level was established by the Bland and Altman method. Results: the test-retest reproducibility of the 30-s Arm Curl test was very good ICC= 0,88 and to the Chair Stand test was good ICC= 0,78. The agreement was very good for both tests of muscle endurance. The CI 95% were between -3,8 and 3,2 stands to 30-s Chair Stand test and between -3,1 and 2,8 curls to 30-s Arm Curl test. Conclusion: the 30-s Arm Curl and 30-s Chair Stand test have good reliability and agreement to assess muscle endurance in older adults functionally independent.

Characterization of a novel curled-cotyledons mutant in soybean ...

African Journals Online (AJOL)

ARL

different stages. Protein and amino acid contents in seeds of mutant are higher than those of the wild .... curled shape, from seedling to maturation phase (Figure. 1D-1F). ..... Arabidopsis seed dermination by stimulating abscisic acid synthesis.

Genome wide identification of cotton (Gossypium hirsutum)-encoded microRNA targets against Cotton leaf curl Burewala virus.

Science.gov (United States)

Shweta; Akhter, Yusuf; Khan, Jawaid Ahmad

2018-01-05

Cotton leaf curl Burewala virus (CLCuBV, genus Begomovirus) causes devastating cotton leaf curl disease. Among various known virus controlling strategies, RNAi-mediated one has shown potential to protect host crop plants. Micro(mi) RNAs, are the endogenous small RNAs and play a key role in plant development and stress resistance. In the present study we have identified cotton (Gossypium hirsutum)-encoded miRNAs targeting the CLCuBV. Based on threshold free energy and maximum complementarity scores of host miRNA-viral mRNA target pairs, a number of potential miRNAs were annotated. Among them, ghr-miR168 was selected as the most potent candidate, capable of targeting several vital genes namely C1, C3, C4, V1 and V2 of CLCuBV genome. In addition, ghr-miR395a and ghr-miR395d were observed to target the overlapping transcripts of C1 and C4 genes. We have verified the efficacy of these miRNA targets against CLCuBV following suppression of RNAi-mediated virus control through translational inhibition or cleavage of viral mRNA. Copyright © 2017 Elsevier B.V. All rights reserved.

Qualitative investigation into students' use of divergence and curl in electromagnetism

Science.gov (United States)

Bollen, Laurens; van Kampen, Paul; Baily, Charles; De Cock, Mieke

2016-12-01

Many students struggle with the use of mathematics in physics courses. Although typically well trained in rote mathematical calculation, they often lack the ability to apply their acquired skills to physical contexts. Such student difficulties are particularly apparent in undergraduate electrodynamics, which relies heavily on the use of vector calculus. To gain insight into student reasoning when solving problems involving divergence and curl, we conducted eight semistructured individual student interviews. During these interviews, students discussed the divergence and curl of electromagnetic fields using graphical representations, mathematical calculations, and the differential form of Maxwell's equations. We observed that while many students attempt to clarify the problem by making a sketch of the electromagnetic field, they struggle to interpret graphical representations of vector fields in terms of divergence and curl. In addition, some students confuse the characteristics of field line diagrams and field vector plots. By interpreting our results within the conceptual blending framework, we show how a lack of conceptual understanding of the vector operators and difficulties with graphical representations can account for an improper understanding of Maxwell's equations in differential form. Consequently, specific learning materials based on a multiple representation approach are required to clarify Maxwell's equations.

Gamma irradiation as a quarantine treatment for spider mites (Acarina: tetranychidae) in horticultural products

International Nuclear Information System (INIS)

Ignatowicz, S.; Banasik-Solgala, K.

1999-01-01

The carmine spider mite, Tetranychus cinnabarinus (Boisd.), and the two-spotted spider mite, Tetranychus urticae Koch, are closely related species of tetranychid mites (Acarina, Tetranychidae) that respond to gamma irradiation in a similar way. Eggs of both species exposed to gamma radiation early in embryonic development were considerably more susceptible to irradiation than older eggs. The tolerance of eggs to gamma radiation increased in 3-4-day-old eggs, when eye-spots were formed. Nymphs were more resistant to gamma radiation than eggs and larvae. Deteriorative effects of irradiation treatment were reflected in the immatures by their mortality in subsequent developmental stages. A positive relationship between dosage and the percent egg mortality or the mortality of subsequent stages was usually found when the immature stages were irradiated. The sex ratio of adults developed from irradiated eggs, larvae, and nymphs was affected by the irradiation treatment; the ratio was usually skewed towards males. Irradiation of females resulted in increased mortality, lowered fecundity, reduced egg viability, and sex ratio distortion in their progeny. Two-day-old females of the carmine spider mite and the two-spotted spider mite irradiated with 200 or 300 Gy lived as long as the controls. Mortality occurred after 3 weeks. The number of eggs laid by irradiated females of spider mites was considerably lower than in the control, and it decreased as the absorbed dose increased. The higher the dose of gamma radiation applied to adults of the spider mites (the parental generation, P), the higher the mortality of the F1 mites during their embryonic development. Viability of eggs laid by irradiated females of spider mites mated with irradiated males was significantly reduced. Young females treated with a dose of 0.2 kGy produced 40-50% nonviable eggs, while control mites produced only 6.0-6.6% nonviable eggs. A dose of 0.3 kGy caused high mortality of eggs; 88% and 97% nonviable

Allergens of mites

Directory of Open Access Journals (Sweden)

Emilia Siwak

2014-04-01

Full Text Available Mite allergens belong to the group of inhalant allergens and represent antigenic substances which are particutlarly important in the pathogenesis of respiratory system diseases and skin diseases. The most common diseases associated with chronic exposure to these aeroallergens include: allergic rhinitis, bronchial asthma and atopic dermatitis. Mite allergens are simple proteins or glycoproteins with different molecular structures and various biochemical functions. The sensitizing capacity of these proteins is connected from their physicochemical properties. Individual allergens perform, among others, the functions of structural proteins, act as enzymes, transport lipids, bind metal ions, and are capable of glycosylation. In addition, mite allergenic proteases degrade proteins of the skin epithelium-resulting in a weakening of its natural protective barrier-and induce the immune response. The proteases also induce the release of pro-inflammatory cytokines: interleukin-4 (IL-4, interleukin 6 (IL-6, interleukin 8 (IL-8, eotaxin, and granulocyte-macrophage colony-stimulating factor-GM-CSF. The article presents the tertiary structure of major and mid-range mite allergens and their classification. Based on literature reports concerning the chemical structure of allergenic proteins, it was emphasized that the structural differences between homologous proteins with allergenic pozoproperties relate to the distribution of amino acid residues on the surface of the molecule. IgE binding affinity and the similarities and differences in the amino acid sequence of the allergens were also the basis for determining cross-reactivity of allergenic proteins. The paper shows an example of this phenomenon, describing the existence of common allergens for various mite species.

Regular dorsal dimples and damaged mites of Varroa destructor in some Iranian honey bees (Apis mellifera)

OpenAIRE

Ardestani, Masoud M.; Ebadi, Rahim; Tahmasbi, Gholamhossein

2011-01-01

The frequency of damaged Varroa destructor Anderson and Trueman (Mesostigmata: Varroidae) found on the bottom board of hives of the honey bee, Apis mellifera L. (Hymenoptera: Apidae) has been used as an indicator of the degree of tolerance or resistance of honey bee colonies against mites. However, it is not clear that this measure is adequate. These injuries should be separated from regular dorsal dimples that have a developmental origin. To investigate damage to Varroa mites and regular dor...

Learned predation risk management by spider mites

Directory of Open Access Journals (Sweden)

Thomas eHackl

2014-09-01

Full Text Available Predation is a prime selective force shaping prey behavior. Investment in anti-predator behavior is traded-off against time and energy for other fitness-enhancing activities such as foraging or reproduction. To optimize this benefit/cost trade-off, prey should be able to innately and/or by experience modulate their behavior to the level of predation risk. Here, we assessed learned predation risk management in the herbivorous two-spotted spider mite Tetranychus urticae. We exposed spider mites coming from benign (naïve or high immediate predation risk (experienced environments to latent and/or no risk and assessed their site choice, activity and oviposition. Benign environments were characterized by the absence of any predator cues, high immediate risk environments by killed spider mites, physical presence of the predatory mite Phytoseiulus persimilis and associated chemosensory traces left on the surface, and latent risk environments by only predator traces. In the no-choice experiment both naïve and experienced spider mites laid their first egg later on leaves with than without predator traces. Irrespective of predator traces presence/absence, experienced mites laid their first egg earlier than naïve ones did. Naïve spider mites were more active, indicating higher restlessness, and laid fewer eggs on leaves with predator traces, whereas experienced mites were less active and laid similar numbers of eggs on leaves with and without predator traces. In the choice experiment both naïve and experienced spider mites preferentially resided and oviposited on leaves without predator traces but experienced mites were less active than naïve ones. Overall, our study suggests that spider mites experienced with high predation risk behave bolder under latent risk than naïve spider mites. Since predator traces alone do not indicate immediate risk, we argue that the attenuated anti-predator response of experienced spider mites represents adaptive learned

Injuries in recreational curling include head injuries and may be prevented by using proper footwear.

Science.gov (United States)

Ting, D K; Brison, R J

2015-04-01

Our study examines a recreational curling population to describe patterns of injury occurrence, estimate risk of injury and to gauge attitudes towards equipment-based prevention strategies. In a retrospective case series, we queried the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP), a national injury surveillance database, for curling injuries entered between 1993 and 2011. Kingston General Hospital and Hotel Dieu Hospital provide the two Kingston, Ontario, sites for emergency department (ED) care and participate in CHIRPP. Each retrieved entry underwent a chart review. A secondary survey was mailed to select individuals who had experienced curling injuries to solicit details on their injury and attitudes towards equipment to prevent injury. We used descriptive statistics for rates and proportions. Over 90% of acute curling injuries resulted from a fall, and 31.7% were head impacts. We found that acute injuries requiring ED presentation occur at a rate of approximately 0.17 per 1000 athlete-exposures (95% CI: 0.12-0.22). The secondary survey was completed by 54% of potential respondents. Of survey respondents, 41.3% attributed their fall to a lack of proper footwear and 73.5% of respondents agreed with mandatory sport-specific footwear as a prevention strategy, but only 8% agreed with mandatory helmet wear. Although curling injuries requiring medical care are not common, head injuries make up a large proportion. Mandated use of appropriate footwear appears to be the most effective prevention strategy, as well as the measure deemed most acceptable by players.

[Role of the poultry red mite (Dermanyssus gallinae) in the transmission of avian influenza A virus].

Science.gov (United States)

Sommer, D; Heffels-Redmann, U; Köhler, K; Lierz, M; Kaleta, E F

2016-01-01

The aim of this study was to investigate the role of the poultry red mite (Dermanyssus [D.] gallinae) in the horizontal transmission of avian influenza A virus (AIV) to chickens. This mite is the most common ectoparasite in poultry worldwide, and may play a role in the spread of infectious agents including AIV. Currently, the control of mites is difficult due to frequently developed resistance to many acaricides, their nocturnality and their ability to survive hidden without feeding for months. D. gallinae were collected in a commercial layer farm and housed in self-made fibreboard boxes. SPF chickens were intravenously infected with AIV strain A/turkey/Ontario/7732/1966 (H5N9). The viraemia in chickens was monitored and at an appropriate time point about 1000 mites were allowed to suck on the AIV infected chickens. Re-isolation of the virus from blood-filled mites was tried daily for 14 days using chicken embryo fibroblast cultures and embryonated chicken eggs. Subsequently, the virus containing mites were placed into boxes that contained naïve SPF chickens to enable virus transmission from mites to chickens. Possible transmission to the chickens was examined using clinical signs, serology, gross lesions, histopathology and immunohistochemistry. Chickens developed a dose-dependent viraemia one day after infection, therefore this day was chosen for the bloodmeal of the mites. AIV was detected in mites after bloodsucking on AIV-infected chickens over a 10-day period. Naïve SPF chickens were infected during bloodsucking of AIV carrying mites. AIV isolates in mites and in chickens were undistinguishable from the original AIV inoculum by RT-PCR. D. gallinae ingested AIV during bloodmeals on AIV infected chickens and are able to transmit AIV to SPF chickens. Therefore, mites serve as mechanical vector of AIV and may play a major role in the circulation of AIV within a facility or area although the life span of infectious virus in the mite is limited. The proven

House dust mite control measures for asthma

DEFF Research Database (Denmark)

Gøtzsche, Peter C.; Johansen, Helle Krogh

2008-01-01

BACKGROUND: The major allergen in house dust comes from mites. Chemical, physical and combined methods of reducing mite allergen levels are intended to reduce asthma symptoms in people who are sensitive to house dust mites. OBJECTIVES: To assess the effects of reducing exposure to house dust mite...... antigens in the homes of people with mite-sensitive asthma. SEARCH STRATEGY: PubMed and The Cochrane Library (last searches Nov 2007), reference lists. SELECTION CRITERIA: Randomised trials of mite control measures vs placebo or no treatment in people with asthma known to be sensitive to house dust mites......), the standardised mean difference was 0.00 (95% confidence interval (CI) -0.10 to 0.10). There were no statistically significant differences either in number of patients improved (relative risk 1.01, 95% CI 0.80 to 1.27), asthma symptom scores (standardised mean difference -0.04, 95% CI -0.15 to 0...

House dust mite allergen causes certain features of steroid resistant asthma in high fat fed obese mice.

Science.gov (United States)

Singh, Vijay Pal; Mabalirajan, Ulaganathan; Pratap, Kunal; Bahal, Devika; Maheswari, Deepanshu; Gheware, Atish; Bajaj, Aabha; Panda, Lipsa; Jaiswal, Ashish; Ram, Arjun; Agrawal, Anurag

2018-02-01

Obesity is a high risk factor for diseases such as cardiovascular, metabolic syndrome and asthma. Obese-asthma is another emerging phenotype in asthma which is typically refractive to steroid treatment due to its non-classical features such as non-eosinophilic cellular inflammation. The overall increased morbidity, mortality and economical burden in asthma is mainly due to steroid resistant asthma. In the present study, we used high fat diet induced obese mice which when sensitized with house dust mite (HDM) showed steroid resistant features. While the steroid, dexamethasone (DEX), treatment to high fat fed naïve mice could not reduce the airway hyperresponsiveness (AHR) induced by high fat, DEX treatment to high fat fed allergic mice could not reduce the HDM allergen induced airway remodeling features though it reduced airway inflammation. Further, these HDM induced high fat fed mice with or without DEX treatment had shown the increased activity and expression of arginase as well as the inducible nitric oxide synthase (iNOS) expression. However, DEX treatment had reduced the expressions of high iNOS and arginase I in control chow diet fed mice. Thus, we speculate that the steroid resistance seen in human obese asthmatics could be stemming from altered NO metabolism and its induced airway remodeling and with further investigations, it would encourage new treatments specific to obese-asthma phenotype. Copyright © 2017 Elsevier B.V. All rights reserved.

Anti-mite measurements in mite-sensitive adult asthma. A controlled trial.

Science.gov (United States)

Burr, M L; St Leger, A S; Neale, E

1976-02-14

A cross-over controlled trial has been conducted among 32 adult patients with mite-sensitive asthma. The bedclothes and pillows of each subject were laundered and vacuum-cleaned and a plastic cover applied to the mattress for six weeks in an attempt to reduce exposure to mites. No improvement in daily peak-flow reading or drug usage was found in comparison with a control period.

Spectral response of spider mite infested cotton: Mite density and miticide rate study

Science.gov (United States)

Two-spotted spider mites are important pests in many agricultural systems. Spider mites (Acari: Tetranychidae) have been found to cause economic damage in corn, cotton, and sorghum. Adult glass vial bioassays indicate that Temprano™ (abamectin) is the most toxic technical miticide for adult two-spot...

Predicting hand function in older adults: evaluations of grip strength, arm curl strength, and manual dexterity.

Science.gov (United States)

Liu, Chiung-Ju; Marie, Deana; Fredrick, Aaron; Bertram, Jessica; Utley, Kristen; Fess, Elaine Ewing

2017-08-01

Hand function is critical for independence in activities of daily living for older adults. The purpose of this study was to examine how grip strength, arm curl strength, and manual dexterous coordination contributed to time-based versus self-report assessment of hand function in community-dwelling older adults. Adults aged ≥60 years without low vision or neurological disorders were recruited. Purdue Pegboard Test, Jamar hand dynamometer, 30-second arm curl test, Jebsen-Taylor Hand Function Test, and the Late-Life Function and Disability Instrument were administered to assess manual dexterous coordination, grip strength, arm curl strength, time-based hand function, and self-report of hand function, respectively. Eighty-four adults (mean age = 72 years) completed the study. Hierarchical multiple regressions show that older adults with better arm curl strength (β = -.25, p function test. In comparison, older adults with better grip strength (β = .40, p function. The relationship between grip strength and hand function may be test-specific. Grip strength becomes a significant factor when the test requires grip strength to successfully complete the test tasks. Arm curl strength independently contributed to hand function in both time-based and self-report assessments, indicating that strength of extrinsic muscles of the hand are essential for hand function.

Correlation of proteome-wide changes with social immunity behaviors provides insight into resistance to the parasitic mite, Varroa destructor, in the honey bee (Apis mellifera).

Science.gov (United States)

Parker, Robert; Guarna, M Marta; Melathopoulos, Andony P; Moon, Kyung-Mee; White, Rick; Huxter, Elizabeth; Pernal, Stephen F; Foster, Leonard J

2012-06-29

Disease is a major factor driving the evolution of many organisms. In honey bees, selection for social behavioral responses is the primary adaptive process facilitating disease resistance. One such process, hygienic behavior, enables bees to resist multiple diseases, including the damaging parasitic mite Varroa destructor. The genetic elements and biochemical factors that drive the expression of these adaptations are currently unknown. Proteomics provides a tool to identify proteins that control behavioral processes, and these proteins can be used as biomarkers to aid identification of disease tolerant colonies. We sampled a large cohort of commercial queen lineages, recording overall mite infestation, hygiene, and the specific hygienic response to V. destructor. We performed proteome-wide correlation analyses in larval integument and adult antennae, identifying several proteins highly predictive of behavior and reduced hive infestation. In the larva, response to wounding was identified as a key adaptive process leading to reduced infestation, and chitin biosynthesis and immune responses appear to represent important disease resistant adaptations. The speed of hygienic behavior may be underpinned by changes in the antenna proteome, and chemosensory and neurological processes could also provide specificity for detection of V. destructor in antennae. Our results provide, for the first time, some insight into how complex behavioural adaptations manifest in the proteome of honey bees. The most important biochemical correlations provide clues as to the underlying molecular mechanisms of social and innate immunity of honey bees. Such changes are indicative of potential divergence in processes controlling the hive-worker maturation.

Computation of Surface Integrals of Curl Vector Fields

Science.gov (United States)

Hu, Chenglie

2007-01-01

This article presents a way of computing a surface integral when the vector field of the integrand is a curl field. Presented in some advanced calculus textbooks such as [1], the technique, as the author experienced, is simple and applicable. The computation is based on Stokes' theorem in 3-space calculus, and thus provides not only a means to…

Effect of morphological fin curl on the swimming performance and station-holding ability of juvenile shovelnose sturgeon

Science.gov (United States)

Deslauriers, David; Johnston, Ryan; Chipps, Steven R.

2016-01-01

We assessed the effect of fin-curl on the swimming and station-holding ability of juvenile shovelnose sturgeon Scaphirhynchus platorynchus (mean fork length = 17 cm; mean weight = 16 g; n = 21) using a critical swimming speed test performed in a small swim chamber (90 L) at 20°C. We quantified fin-curl severity using the pectoral fin index. Results showed a positive relationship between pectoral fin index and critical swimming speed indicative of reduced swimming performance displayed by fish afflicted with a pectoral fin index < 8%. Fin-curl severity, however, did not affect the station-holding ability of individual fish. Rather, fish affected with severe fin-curl were likely unable to use their pectoral fins to position their body adequately in the water column, which led to the early onset of fatigue. Results generated from this study should serve as an important consideration for future stocking practices.

Association between KIR genes and dust mite sensitization in a Brazilian population.

Science.gov (United States)

Caniatti, Marcela Caleffi da Costa Lima; Borelli, Sueli Donizete; Guilherme, Ana Lúcia Falavigna; Franzener, Soraya Barrionuevo; Tsuneto, Luiza Tamie

2018-01-01

Killer cell immunoglobulin-like receptors (KIRs), found on the surface of natural killer (NK) cells, play a key role in controlling the innate response. Such response depends on a series of cellular interactions between these receptors and HLA activating/inhibiting ligands. Atopic diseases have been associated with genes that regulate cytokine production and HLA genes, which may either protect or predispose to hypersensitivity. To verify an association study of KIR genes with sensitization to the following mites: Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Blomia tropicalis. A total of 341 children aged up to 14 years, were classified as mite-sensitive or mite-insensitive after undergoing a skin prick test for immediate allergic reactions. The presence/absence of KIR genes and their human leukocyte antigen (HLA) ligands was determined by polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) with the commercial kit LabType™ using Luminex™. The frequencies of KIR genes and their respective class I HLA ligands and the frequency of haplotypes were performed in sensitive and insensitive individuals, and no significant differences were found. Our results suggest no influence of KIR genes on resistance/susceptibility to sensitization to dust mites. Copyright © 2017 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Foliar nectar enhances plant-mite mutualisms: the effect of leaf sugar on the control of powdery mildew by domatia-inhabiting mites.

Science.gov (United States)

Weber, Marjorie G; Porturas, Laura D; Taylor, Scott A

2016-09-01

Mite domatia are small structures on the underside of plant leaves that provide homes for predacious or fungivorous mites. In turn, mites inhabiting domatia defend the plant by consuming leaf herbivores and pathogens, which can result in a domatia-mediated, plant-mite defence mutualism. Several recent studies have suggested that plants receive enhanced benefits when they provide a foliar food source, such as sugars secreted from extrafloral nectaries, to mite mutualists alongside mite domatia. However, the effect of foliar sugar on reducing leaf pathogen load via domatia-inhabiting mites has not been directly investigated. To fill this gap, the links between foliar sugar addition, domatia-inhabiting mite abundance, and pathogen load were experimentally evaluated in wild grape. Furthermore, because the proposed combined benefits of providing food and housing have been hypothesized to select for the evolutionary correlation of extrafloral nectaries and domatia across plant lineages, a literature survey aimed at determining the overlap of mite domatia and extrafloral nectaries across plant groups was also conducted. It was found that leaves with artificial addition of foliar sugar had 58-80 % more mites than leaves without foliar sugar addition, and that higher mite abundances translated to reduced powdery mildew (Erysiphe necator) loads on leaves. It was found that mite domatia and extrafloral nectaries occur non-randomly in the same clades across Eudicots. Genera with both traits are reported to highlight candidate lineages for future studies. Together, the results demonstrate that foliar sugar can indeed enhance the efficacy of domatia-mediated plant-mite mutualisms, and suggest that this synergism has the potential to influence the co-distribution of foliar nectar and mite domatia across plants. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Resistance in Cucumis sativus L. to Tetranychus urticae Koch

OpenAIRE

Ponti, de, O.M.B.

1980-01-01

Chapter 1
The role of plant breeding and particularly of host plant resistance in integrated control is discussed. Host plant resistance to insects and mites, especially to Tetranychus urticae is reviewed. A standard terminology for disease and pest resistance is recommended.

Chapter 2
The relationship between the twospotted spider mite and cucumber has been studied on plants and on leaf disks of a number of varieties with different...

Resistance mutation conserved between insects and mites unravels the benzoylurea insecticide mode of action on chitin biosynthesis.

Science.gov (United States)

Douris, Vassilis; Steinbach, Denise; Panteleri, Rafaela; Livadaras, Ioannis; Pickett, John Anthony; Van Leeuwen, Thomas; Nauen, Ralf; Vontas, John

2016-12-20

Despite the major role of chitin biosynthesis inhibitors such as benzoylureas (BPUs) in the control of pests in agricultural and public health for almost four decades, their molecular mode of action (MoA) has in most cases remained elusive. BPUs interfere with chitin biosynthesis and were thought to interact with sulfonylurea receptors that mediate chitin vesicle transport. Here, we uncover a mutation (I1042M) in the chitin synthase 1 (CHS1) gene of BPU-resistant Plutella xylostella at the same position as the I1017F mutation reported in spider mites that confers etoxazole resistance. Using a genome-editing CRISPR/Cas9 approach coupled with homology-directed repair (HDR) in Drosophila melanogaster, we introduced both substitutions (I1056M/F) in the corresponding fly CHS1 gene (kkv). Homozygous lines bearing either of these mutations were highly resistant to etoxazole and all tested BPUs, as well as buprofezin-an important hemipteran chitin biosynthesis inhibitor. This provides compelling evidence that BPUs, etoxazole, and buprofezin share in fact the same molecular MoA and directly interact with CHS. This finding has immediate effects on resistance management strategies of major agricultural pests but also on mosquito vectors of serious human diseases such as Dengue and Zika, as diflubenzuron, the standard BPU, is one of the few effective larvicides in use. The study elaborates on how genome editing can directly, rapidly, and convincingly elucidate the MoA of bioactive molecules, especially when target sites are complex and hard to reconstitute in vitro.

Injuries in recreational curling include head injuries and may be prevented by using proper footwear

Directory of Open Access Journals (Sweden)

D. K. Ting

2015-04-01

Full Text Available Introduction: Our study examines a recreational curling population to describe patterns of injury occurrence, estimate risk of injury and to gauge attitudes towards equipment-based prevention strategies. Methods: In a retrospective case series, we queried the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP, a national injury surveillance database, for curling injuries entered between 1993 and 2011. Kingston General Hospital and Hotel Dieu Hospital provide the two Kingston, Ontario, sites for emergency department (ED care and participate in CHIRPP. Each retrieved entry underwent a chart review. A secondary survey was mailed to select individuals who had experienced curling injuries to solicit details on their injury and attitudes towards equipment to prevent injury. We used descriptive statistics for rates and proportions. Results: Over 90% of acute curling injuries resulted from a fall, and 31.7% were head impacts. We found that acute injuries requiring ED presentation occur at a rate of approximately 0.17 per 1000 athlete-exposures (95% CI: 0.12–0.22. The secondary survey was completed by 54% of potential respondents. Of survey respondents, 41.3% attributed their fall to a lack of proper footwear and 73.5% of respondents agreed with mandatory sport-specific footwear as a prevention strategy, but only 8% agreed with mandatory helmet wear. Conclusions: Although curling injuries requiring medical care are not common, head injuries make up a large proportion. Mandated use of appropriate footwear appears to be the most effective prevention strategy, as well as the measure deemed most acceptable by players.

A Scott bench with ergonomic thorax stabilisation pad improves body posture during preacher arm curl exercise.

Science.gov (United States)

Biscarini, Andrea; Benvenuti, Paolo; Busti, Daniele; Zanuso, Silvano

2016-05-01

We assessed whether the use of an ergonomic thorax stabilisation pad, during the preacher arm curl exercise, could significantly reduce the excessive shoulder protraction and thoracic kyphosis induced by the standard flat pad built into the existing preacher arm curl equipment. A 3D motion capture system and inclinometers were used to measure shoulder protraction and thoracic kyphosis in 15 subjects performing preacher arm curl with a plate-loaded machine provided with the standard flat pad. The same measures were repeated after replacing the flat pad with a new ergonomic pad, specifically designed to accommodate the thorax profile and improve body posture. Pad replacement significantly (p ergonomic pad may potentially allow a more effective training, prevent musculoskeletal discomfort and reduce the risk of injury. Practitioner summary: We have designed an ergonomic thorax stabilisation pad for the preacher arm curl exercise. The new ergonomic pad improves the poor posture conditions induced by the standard flat pad and may potentially allow a more effective training, prevent musculoskeletal discomfort, improve the breathing function and reduce the risk of injury.

Development and application of triple antibody sandwich enzyme-linked immunosorbent assays for begomovirus detection using monoclonal antibodies against Tomato yellow leaf curl Thailand virus.

Science.gov (United States)

Seepiban, Channarong; Charoenvilaisiri, Saengsoon; Warin, Nuchnard; Bhunchoth, Anjana; Phironrit, Namthip; Phuangrat, Bencharong; Chatchawankanphanich, Orawan; Attathom, Supat; Gajanandana, Oraprapai

2017-05-30

Tomato yellow leaf curl Thailand virus, TYLCTHV, is a begomovirus that causes severe losses of tomato crops in Thailand as well as several countries in Southeast and East Asia. The development of monoclonal antibodies (MAbs) and serological methods for detecting TYLCTHV is essential for epidemiological studies and screening for virus-resistant cultivars. The recombinant coat protein (CP) of TYLCTHV was expressed in Escherichia coli and used to generate MAbs against TYLCTHV through hybridoma technology. The MAbs were characterized and optimized to develop triple antibody sandwich enzyme-linked immunosorbent assays (TAS-ELISAs) for begomovirus detection. The efficiency of TAS-ELISAs for begomovirus detection was evaluated with tomato, pepper, eggplant, okra and cucurbit plants collected from several provinces in Thailand. Molecular identification of begomoviruses in these samples was also performed through PCR and DNA sequence analysis of the CP gene. Two MAbs (M1 and D2) were generated and used to develop TAS-ELISAs for begomovirus detection. The results of begomovirus detection in 147 field samples indicated that MAb M1 reacted with 2 begomovirus species, TYLCTHV and Tobacco leaf curl Yunnan virus (TbLCYnV), whereas MAb D2 reacted with 4 begomovirus species, TYLCTHV, TbLCYnV, Tomato leaf curl New Delhi virus (ToLCNDV) and Squash leaf curl China virus (SLCCNV). Phylogenetic analyses of CP amino acid sequences from these begomoviruses revealed that the CP sequences of begomoviruses recognized by the narrow-spectrum MAb M1 were highly conserved, sharing 93% identity with each other but only 72-81% identity with MAb M1-negative begomoviruses. The CP sequences of begomoviruses recognized by the broad-spectrum MAb D2 demonstrated a wider range of amino acid sequence identity, sharing 78-96% identity with each other and 72-91% identity with those that were not detected by MAb D2. TAS-ELISAs using the narrow-specificity MAb M1 proved highly efficient for the detection of

Differential gene expression associated with honey bee grooming behavior in response to varroa mites

Science.gov (United States)

Honey bee (Apis mellifera) grooming behavior is an important mechanism of resistance against the parasitic mite Varroa destructor. This research was conducted to study associations between grooming behavior and the expression of selected immune, neural, detoxification, developmental and health-relat...

Mites as selective fungal carriers in stored grain habitats.

Science.gov (United States)

Hubert, Jan; Stejskal, Václav; Kubátová, Alena; Munzbergová, Zuzana; Vánová, Marie; Zd'árková, Eva

2003-01-01

Mites are well documented as vectors of micromycetes in stored products. Since their vectoring capacity is low due to their small size, they can be serious vectors only where there is selective transfer of a high load of specific fungal species. Therefore the aim of our work was to find out whether the transfer of fungi is selective. Four kinds of stored seeds (wheat, poppy, lettuce, mustard) infested by storage mites were subjected to mycological analysis. We compared the spectrum of micromycete species isolated from different species of mites (Acarus siro, Lepidoglyphus destructor, Tyrophagus putrescentiae, Caloglyphus rhizoglyphoides and Cheyletus malaccensis) and various kinds of stored seeds. Fungi were separately isolated from (a) the surface of mites, (b) the mites' digestive tract (= faeces), and (c) stored seeds and were then cultivated and determined. The fungal transport via mites is selective. This conclusion is supported by (i) lower numbers of isolated fungal species from mites than from seeds; (ii) lower Shannon-Weaver diversity index in the fungal communities isolated from mites than from seeds; (iii) significant effect of mites/seeds as environmental variables on fungal presence in a redundancy analysis (RDA); (iv) differences in composition of isolated fungi between mite species shown by RDA. The results of our work support the hypothesis that mite-fungal interactions are dependent on mite species. The fungi attractive to mites seem to be dispersed more than others. The selectivity of fungal transport via mites enhances their pest importance.

Diversity, Mutation and Recombination Analysis of Cotton Leaf Curl Geminiviruses.

Directory of Open Access Journals (Sweden)

Huma Saleem

Full Text Available The spread of cotton leaf curl disease in China, India and Pakistan is a recent phenomenon. Analysis of available sequence data determined that there is a substantial diversity of cotton-infecting geminiviruses in Pakistan. Phylogenetic analyses indicated that recombination between two major groups of viruses, cotton leaf curl Multan virus (CLCuMuV and cotton leaf curl Kokhran virus (CLCuKoV, led to the emergence of several new viruses. Recombination detection programs and phylogenetic analyses showed that CLCuMuV and CLCuKoV are highly recombinant viruses. Indeed, CLCuKoV appeared to be a major donor virus for the coat protein (CP gene, while CLCuMuV donated the Rep gene in the majority of recombination events. Using recombination free nucleotide datasets the substitution rates for CP and Rep genes were determined. We inferred similar nucleotide substitution rates for the CLCuMuV-Rep gene (4.96X10-4 and CLCuKoV-CP gene (2.706X10-4, whereas relatively higher substitution rates were observed for CLCuMuV-CP and CLCuKoV-Rep genes. The combination of sequences with equal and relatively low substitution rates, seemed to result in the emergence of viral isolates that caused epidemics in Pakistan and India. Our findings also suggest that CLCuMuV is spreading at an alarming rate, which can potentially be a threat to cotton production in the Indian subcontinent.

Thermal and curl properties of PET/PP blend fibers compatibilized ...

Indian Academy of Sciences (India)

67

blend fibers were prepared using a melt-spinning system, and their curl properties were investigated. ... by extrusion and injection molding processes. ..... Inuwa I M, Hassan A, Samsudin S A, Kassim M H M and Jawaid M 2014. Polym.

Molecular Characterization of Tomato Yellow Leaf Curl Virus in Korea and the Construction of an Infectious Clone

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Bong Choon Lee

2015-06-01

Full Text Available Several tomato production regions in Korea were surveyed for tomato yellow leaf curl disease (TYLCD. Tomato leaf samples showing TYLCD-like symptoms were collected from Tongyeong (To, Geoje (Gi, and Gimhae (Gh cities of the southern part of Korea. Tomato yellow leaf curl virus (TYLCV was detected and the full-length genomes of the isolates were sequenced. The TYLCV isolates found in Korea shared high sequence identity (> 99% with TYLCV-IL [JR:Omu:Ng] (AB110217. Phylogenetic relationship analysis revealed that they formed two groups (with little genetic variability, and the To, Gj, and Gh isolates belonged to the TYLCV-IL group. An infectious clone of TYLCV-To (JQ013089 was constructed and agroinoculated into Nicotiana benthamiana, Nicotiana tabacum var. Xanthi, Petunia hybrida, Capsicum annuum, and Lycopersicon esculentum cv. Hausumomotaro. Agroinfection with a dimeric infectious clone of TYLCV-To induced severe leaf curling and stunting symptoms in these plants, excluding C. annuum. Tomato plants then developed typical yellow leaf curl symptoms.

Spectral mimetic least-squares method for div-curl systems

NARCIS (Netherlands)

Gerritsma, Marc; Palha, Artur; Lirkov, I.; Margenov, S.

2018-01-01

In this paper the spectral mimetic least-squares method is applied to a two-dimensional div-curl system. A test problem is solved on orthogonal and curvilinear meshes and both h- and p-convergence results are presented. The resulting solutions will be pointwise divergence-free for these test

Transcript mapping of Cotton leaf curl Burewala virus and its cognate betasatellite, Cotton leaf curl Multan betasatellite

Directory of Open Access Journals (Sweden)

Akbar Fazal

2012-10-01

Full Text Available Abstract Background Whitefly-transmitted geminiviruses (family Geminiviridae, genus Begomovirus are major limiting factors for the production of numerous dicotyledonous crops throughout the warmer regions of the world. In the Old World a small number of begomoviruses have genomes consisting of two components whereas the majority have single-component genomes. Most of the monopartite begomoviruses associate with satellite DNA molecules, the most important of which are the betasatellites. Cotton leaf curl disease (CLCuD is one of the major problems for cotton production on the Indian sub-continent. Across Pakistan, CLCuD is currently associated with a single begomovirus (Cotton leaf curl Burewala virus [CLCuBuV] and the cotton-specific betasatellite Cotton leaf curl Multan betasatellite (CLCuMuB, both of which have recombinant origins. Surprisingly, CLCuBuV lacks C2, one of the genes present in all previously characterized begomoviruses. Virus-specific transcripts have only been mapped for few begomoviruses, including one monopartite begomovirus that does not associate with betasatellites. Similarly, the transcripts of only two betasatellites have been mapped so far. The study described has investigated whether the recombination/mutation events involved in the evolution of CLCuBuV and its associated CLCuMuB have affected their transcription strategies. Results The major transcripts of CLCuBuV and its associated betasatellite (CLCuMuB from infected Nicotiana benthamiana plants have been determined. Two complementary-sense transcripts of ~1.7 and ~0.7 kb were identified for CLCuBuV. The ~1.7 kb transcript appears similar in position and size to that of several begomoviruses and likely directs the translation of C1 and C4 proteins. Both complementary-sense transcripts can potentially direct the translation of C2 and C3 proteins. A single virion-sense transcript of ~1 kb, suitable for translation of the V1 and V2 genes was identified. A predominant

Oral mite anaphylaxis caused by mite-contaminated okonomiyaki/ pancake-mix in Japan: 8 case reports and a review of 28 reported cases.

Science.gov (United States)

Takahashi, Kentaro; Taniguchi, Masami; Fukutomi, Yuma; Sekiya, Kiyoshi; Watai, Kentaro; Mitsui, Chihiro; Tanimoto, Hidenori; Oshikata, Chiyako; Tsuburai, Takahiro; Tsurikisawa, Naomi; Minoguchi, Kenji; Nakajima, Hiroshi; Akiyama, Kazuo

2014-03-01

Anaphylaxis after the ingestion of foods contaminated with mites has recently been recognized. Case series and case reports thus far have shown that mite-contaminated wheat flour is the major cause of oral mite anaphylaxis. However, we have found 8 cases of oral mite anaphylaxis which were caused by mite-contaminated okonomiyaki-mix, a savory Japanese style pancake mix, in our hospital. In addition to our 8 cases, the databases of MEDLINE and ICHUSHI were systematically searched for patients with oral mite anaphylaxis in Japan. Thirty-six patients including our 8 cases with oral mite anaphylaxis were identified. Thirty-four out of 36 cases (94%) ingested okonomiyaki or takoyaki, prepared at home using okonomiyaki-mix or takoyaki-mix which was previously opened and stored for months at ambient temperature. Microscopic examination of culprit mixes of 16 cases including our 1 case revealed contamination of mites such as Dermatophagoides farina (Der f) (5 cases), Tyrophagus putrescentiae (Tyr p) (4 cases), and Dermatophagoides pteronyssinus (Der p) (3 cases). The specific IgE to each mite is generally upregulated in these patients. Especially, the titers of specific IgE to Der p and Der f were more than class 2 in all cases. Mite-contaminated flavored flour is the major cause of oral mite anaphylaxis in Japan.

Toxicity of bifenazate and its principal active metabolite, diazene, to Tetranychus urticae and Panonychus citri and their relative toxicity to the predaceous mites, Phytoseiulus persimilis and Neoseiulus californicus.

Science.gov (United States)

Ochiai, Noriaki; Mizuno, Masayuki; Mimori, Norihiko; Miyake, Toshihiko; Dekeyser, Mark; Canlas, Liza Jara; Takeda, Makio

2007-01-01

Bifenazate is a novel carbazate acaricide discovered by Uniroyal Chemical (now Chemtura Corporation) for the control of phytophagous mites infesting agricultural and ornamental crops. Its acaricidal activity and that of its principal active metabolite, diazene, were characterized. Bifenazate and diazene had high toxicity and specificity both orally and topically to all life stages of Tetranychus urticae and Panonychus citri. Acute poisoning was observed with no temperature dependency. No cross-resistance was found to mites resistant to several other classes of acaricides, such as tebufenpyrad, etoxazole, fenbutatin oxide and dicofol. Bifenazate remained effective for a long time with only about a 10% loss of efficacy on T. urticae after 1 month of application in the field. All stages of development of the predatory mites, Phytoseiulus persimilis and Neoseiulus californicus, survived treatment by both bifenazate and diazene. When adult females of the two predatory mite species were treated with either bifenazate or diazene, they showed a normal level of fecundity and predatory activity in the laboratory, effectively suppressing spider mite population growth. Even when the predators were fed spider mite eggs that had been treated previously with bifenazate, they survived. These findings indicate that bifenazate is a very useful acaricide giving high efficacy, long-lasting activity and excellent selectivity for spider mites. It is, therefore, concluded that bifenazate is an ideal compound for controlling these pest mites.

Injuries in recreational curling include head injuries and may be prevented by using proper footwear

OpenAIRE

D. K. Ting; R. J. Brison

2015-01-01

Introduction: Our study examines a recreational curling population to describe patterns of injury occurrence, estimate risk of injury and to gauge attitudes towards equipment-based prevention strategies. Methods: In a retrospective case series, we queried the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP), a national injury surveillance database, for curling injuries entered between 1993 and 2011. Kingston General Hospital and Hotel Dieu Hospital provide the two Kingston,...

Molecular characterization of two isolates of sweet potato leaf curl ...

African Journals Online (AJOL)

Jane

2011-08-17

Aug 17, 2011 ... related to that of sweet potato leaf curl virus (SPLCV) from United States with nucleotide sequence identity of ... species including Ipomoea indica, are grown orna- mentally all .... and AC4 were closely related to that of SPLCV-.

Detection of pepper leaf curl virus through PCR amplification and ...

African Journals Online (AJOL)

Administrator

2011-04-25

Apr 25, 2011 ... crop. Among the five domesticated species of the genus. Capsicum, C. annuum is the most widely cultivated all over the world ... In India, PepLCV has been an emerging ... virus-vector relationship of chilli leaf curl disease was.

Influence of Varroa Mite (Varroa destructor Management Practices on Insecticide Sensitivity in the Honey Bee (Apis mellifera

Directory of Open Access Journals (Sweden)

Frank D. Rinkevich

2017-01-01

Full Text Available Since Varroa mites may cause devastating losses of honey bees through direct feeding, transmitting diseases, and increasing pathogen susceptibility, chemical and mechanical practices commonly are used to reduce mite infestation. While miticide applications are typically the most consistent and efficacious Varroa mite management method, miticide-induced insecticide synergism in honey bees, and the evolution of resistance in Varroa mites are reasonable concerns. We treated colonies with the miticide amitraz (Apivar®, used IPM practices, or left some colonies untreated, and then measured the effect of different levels of mite infestations on the sensitivity of bees to phenothrin, amitraz, and clothianidin. Sensitivity to all insecticides varied throughout the year among and within treatment groups. Clothianidin sensitivity decreased with increasing mite levels, but no such correlation was seen with phenothrin or amitraz. These results show that insecticide sensitivity is dynamic throughout the 5 months test. In-hive amitraz treatment according to the labeled use did not synergize sensitivity to the pesticides tested and this should alleviate concern over potential synergistic effects. Since IPM practices were largely ineffective at reducing Varroa mite infestation, reliance on chemical methods of Varroa mite management is likely to continue. However, miticides must be used judiciously so the long term effectiveness of these compounds can be maximized. These data demonstrate the complex and dynamic variables that contribute to honey bee colony health. The results underscore the importance of controlling for as many of these variables as possible in order to accurately determine the effects of each of these factors as they act alone or in concert with others.

Edge curling that has plagued scrolls for millenniums

Science.gov (United States)

Chou, Ming-Han; Shen, Wei-Chao; Wang, Yi-Ping; Hung, Sun-Hsin; Hong, Tzay-Ming; Department of Registration and Conservation, National Palace Museum Collaboration; Department of Physics, National Tsing Hua University Team

2014-03-01

Qi-Wa refers to the up curl on the lengths of handscrolls and hanging scrolls, which has troubled Chinese artisans and emperors for as long as the art of painting and calligraphy exists. This warp is unwelcome not only for aesthetic reasons, but its potential damage to the fiber and ink. Although it is generally treated as a part of the cockling and curling due to moisture, consistency of paste, and defects from the mounting procedures, we demonstrate that the spontaneous extrinsic curvature incurred from the storage is in fact more essential to understanding and curing Qi-Wa. In contrast to the former factors whose effects are less predictable, the plastic deformation and strain distribution on a membrane are a well-defined mechanical problem. We study this phenomenon by experiments, theoretical models, and Molecular Dynamics Simulation, and obtain consistent scaling relations for the Qi-Wa height. This knowledge enables us to propose modifications on the traditional mounting techniques, that are tested on real mounted paper to be effective at mitigating Qi-Wa. By experimenting on polymer-based films, we demonstrate possible relevance of our study to the modern development of flexible electronic paper.

Effect of Performance Speed on Trunk Movement Control During the Curl-Up Exercise

Directory of Open Access Journals (Sweden)

Barbado David

2015-06-01

Full Text Available Trunk exercise speed has significant effects on neuro-mechanical demands; however, the influence of a variety of exercise speeds on motor control of the trunk displacement remains unknown. The aim of this study was to assess the effect of performance speed on trunk motion control during the curl-up exercise by analyzing the kinematic variance about the sagittal trajectory. Seventeen subjects volunteered to perform curl-ups at different cadences controlled by a metronome. Standard deviation (SD and range (RG of shoulder girdle medial-lateral displacement (SGML and detrended fluctuation analysis (DFA of SGML were calculated to examine linear variability and long range autocorrelation of medial-lateral upper trunk displacements, respectively. In addition, SD, RG and DFA of centre of pressure medial-lateral displacement (COPML were performed to analyze the behavior of the motor system while controlling trunk displacement. Although SD and RG of COPML increased as speed increased, the curl-up cadence did not have significant effects on SD and RG of SGML. These results suggest that although high speed curl-ups challenged participants’ ability to carry out medial-lateral adjustments, an increase of performance speed did not modify the linear variability about the sagittal trajectory. Regarding DFA, the scaling exponent α of SGML and COPML was higher for the fastest movements, mainly in long term fluctuations. Therefore, to maintain the target trajectory, participants used different strategies depending on performance speed. This is to say, there were less trajectory changes when participants performed the fastest exercises.

Control of poultry red mites

DEFF Research Database (Denmark)

Kilpinen, Ole; Steenberg, Tove

2008-01-01

The poultry red mite (PRM), Dermanyssus gallinae, is the most important ectoparasite in European egg production. The mites hide in cracks and crevices in the near vicinity of the resting places of the birds, coming out to feed mainly during the night. Under favourable conditions the population can...... grow rapidly, leading to serious problems. Large mite populations may cause anaemia or even death to the poultry, but also in lower numbers mites may be a nuisance to the birds causing decreased egg production and egg quality. Furthermore, they may have the potential of acting as reservoir......-pathogenic fungi and desiccant dust. The dust is diatomaceous earth (of natural origin), synthetic silica products or combinations of the two. The progress of the work with desiccant dusts will be reported. So far, 7 different products have been tested in the laboratory with regard to their efficacy, speed...

[Investigation of Acaroid mites breeding in stored dry fruits].

Science.gov (United States)

Tao, Ning; Zhan, Xiao-dong; Sun, En-tao; Li, Chao-pin

2015-12-01

To study the species and density of Acaroid mites breeding in stored dry fruits. The samples from the dried fruit stores and warehouses were collected, and the mites breeding in them were separated, then the slides with mites were prepared and observed by a light microscope for species identification and counting. The indexes such as the breeding density, species richness index, diversity index and evenness index were calculated. Totally 12 species of Acaroid mites belonging to 6 families and 10 genera were obtained from the total 49 samples. The dominant mite species were Carpoglyphus lactis, Tyrophagus putrescentiae, Acarus siro, and Caloglyphus berlesei. The breeding densities of mites in longans, filberts and plum candies were 79.78, 48.91, 35.73 mites/g, respectively, which were higher than those in other dry fruits. The seasonal variation experiment of mites found that the average breeding density of acaroid mites was higher in July and October, the richness index and diversity index reached the highest value in July, and the evenness index was higher in January and April. The observation of the growth and decline of Acaroid mites under the artificial condition found the number of Caloglyphus berlesei declined sharply and Tyrophagus putrescentiae first increased and then decreased. The pollution of Acaroid mites is serious in the stored dried fruits, for which the positive prevention and control measures to the mite breeding should be taken to reduce the harm.

Amplicon based RNA interference targeting V2 gene of cotton leaf curl Kokhran virus-Burewala strain can provide resistance in transgenic cotton plants

Science.gov (United States)

An RNAi based gene construct designated “C2” was used to target the V2 region of the cotton leaf curl virus (CLCuV) genome which is responsible for virus movement. The construct was transformed into two elite cotton varieties MNH-786 and VH-289. A shoot apex method of plant transformation using Agr...

The NRL MITE Air Vehicle

National Research Council Canada - National Science Library

Kellogg, James; Bovais, Christopher; Dahlburg, Jill; Foch, Richard; Gardner, John; Gordon, Diana; Hartley, Ralph; Kamgar-Parsi, Behrooz; McFarlane, Hugh; Pipitone, Frank; Ramamurti, Ravi; Sciambi, Adam; Spears, William; Srull, Donald; Sullivan, Carol

2001-01-01

.... The NRL Micro Tactical Expendable "MITE" air vehicle is a result of this research. The operational MITE is a hand-launched, dual-propeller, fixed-wing air vehicle, with a 9-inch chord and a wingspan of 8 to 18 inches, depending on payload weight...

Clinical evaluation of a double-blind dust mite avoidance trial with mite-allergic rhinitic patients

NARCIS (Netherlands)

Kniest, F.M.; Young, E.; Praag, van M.C.G.; Vos, H.; Kort, H.S.M.; Koers, W.J.; Maat-Bleeker, de F.; Bronswijk, van J.E.M.H.

1991-01-01

Inheritance and allergen exposure are key factors in the development and the course of atopic allergy, expressed as conjunctivitis, rhinitis, asthma or dermatitis. This study concerns the clinical significance of mite and mite-allergen avoidance measures based on intensive cleaning with acaricide

Recent evolution of a novel begomovirus causing tomato leaf curl disease in the Al-Batinah region of Oman.

Science.gov (United States)

Khan, Akhtar J; Akhtar, Sohail; Singh, Achuit K; Al-Shehi, Adel A; Al-Matrushi, Abdulrahman M; Ammara, Ume; Briddon, Rob W

2014-03-01

For last two decades, begomoviruses (family Geminiviridae) have been a major constraint for tomato production in Oman, particularly in the Al-Batinah region, the major agricultural area of Oman. Farms in the Al-Batinah region were surveyed during January-March and November-December in 2012 and January-February in 2013. Leaf samples of tomato plants showing typical leaf curl disease symptoms were collected and analyzed for begomoviruses. Out of fifteen begomovirus clones sequenced, seven were shown to be tomato yellow leaf curl virus strain Oman (TYLCV-OM); three, chili leaf curl virus strain Oman (ChLCV-OM); and one, tomato leaf curl Oman virus (ToLCOMV) - viruses that have previously been shown to occur in Oman. Four sequences were shown to have relatively low percent identity values to known begomoviruses, with the highest (86 %) to isolates of pepper leaf curl Lahore virus, indicating that these should be included in a new species, for which the name "Tomato leaf curl Al Batinah virus" (ToLCABV) is proposed. Although the betasatellite tomato leaf curl betasatellite (ToLCB; 7 full-length sequences isolated) was identified with some isolates of ChLCV-OM, TYLCV-OM and ToLCOMV, it was not identified in association with any of the ToLCABV isolates. Analysis of the sequences of the TYLCV-OM and ToLCOMV isolates characterized here did not show them to differ significantly from previously characterized isolates of these viruses. The three isolates of ChLCV-OM characterized were shown to have a recombination pattern distinct from earlier characterized isolates. ToLCABV was shown to have resulted from recombination between ChLCV-OM and ToLCOMV. A clone of ToLCABV was infectious by Agrobacterium-mediated inoculation to Nicotiana benthamiana and tomato, inducing symptoms typical of those seen in tomato in the field. Additionally, ToLCABV was shown to be able to interact in planta with ToLCB, resulting in a change in symptom phenotype, although the betasatellite did not

Clinical benefits of treatment with SQ house dust mite sublingual tablet in house dust mite allergic rhinitis.

Science.gov (United States)

Demoly, P; Kleine-Tebbe, J; Rehm, D

2017-10-01

Treatment with SQ (standardised quality) house dust mite sublingual tablet for 1 year resulted in a decreased probability of having an allergic rhinitis (AR) exacerbation day (from 11% [placebo] to 5% [SQ house dust mite sublingual tablet]) and an increased probability of having a mild AR day (from 16% [placebo] to 34% [SQ house dust mite sublingual tablet]). © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Predictive 3D modelling of the interactions of pyrethroids with the voltage-gated sodium channels of ticks and mites.

Science.gov (United States)

O'Reilly, Andrias O; Williamson, Martin S; González-Cabrera, Joel; Turberg, Andreas; Field, Linda M; Wallace, B A; Davies, T G Emyr

2014-03-01

The pyrethroid insecticides are a very successful group of compounds that target invertebrate voltage-gated sodium channels and are widely used in the control of insects, ticks and mites. It is well established that some pyrethroids are good insecticides whereas others are more effective as acaricides. This species specificity is advantageous for controlling particular pest(s) in the presence of another non-target invertebrate, for example controlling the Varroa mite in honeybee colonies. We applied in silico techniques to compare the voltage-gated sodium channels of insects versus ticks and mites and their interactions with a range of pyrethroids and DDT analogues. We identified a single amino acid difference within the pyrethroid binding pocket of ticks/mites that may have significant impact on the effectiveness of pyrethroids as acaricides. Other individual amino acid differences within the binding pocket in distinct tick and mite species may provide a basis for future acaricidal selectivity. Three-dimensional modelling of the pyrethroid/DDT receptor site has led to a new hypothesis to explain the preferential binding of acaricidal pyrethroids to the sodium channels of ticks/mites. This is important for understanding pyrethroid selectivity and the potential effects of mutations that can give rise to resistance to pyrethroids in commercially-important pest species. © 2013 Society of Chemical Industry.

Virulence and site of infection of the fungus, Hirsutella thompsonii, to the honey bee ectoparasitic mite, Varroa destructor.

Science.gov (United States)

Peng, Christine Y S; Zhou, Xinsheng; Kaya, Harry K

2002-11-01

The Varroa mite, Varroa destructor, is recognized as the most serious pest of both managed and feral Western honey bee (Apis mellifera) in the world. The mite has developed resistance to fluvalinate, an acaricide used to control it in beehives, and fluvalinate residues have been found in the beeswax, necessitating an urgent need to find alternative control measures to suppress this pest. Accordingly, we investigated the possibility of using the fungus, Hirsutella thompsonii, as a biocontrol agent of the Varroa mite. Among the 9 isolates of H. thompsonii obtained from the University of Florida and the USDA, only the 3 USDA isolates (ARSEF 257, 1947 and 3323) were infectious to the Varroa mite in laboratory tests. The mite became infected when it was allowed to walk on a sporulating H. thompsonii culture for 5 min. Scanning electron micrographs revealed that the membranous arolium of the mite leg sucker is the focus of infection where the fungal conidia adhered and germinated. The infected mites died from mycosis, with the lethal times to kill 50% (LT(50)s) dependent on the fungal isolates. Thus, the LT(50)s were 52.7, 77.2, and 96.7h for isolates 3323, 257, and 1947, respectively. Passage of H. thompsonii through Varroa mite three times significantly reduced the LT(50)s of isolates 257 and 1947 (P<0.05) but not the LT(50) of isolate 3323. The fungus did not infect the honey bee in larval, prepupal, pupal, and adult stages under our laboratory rearing conditions. Our encouraging results suggest that some isolates of H. thompsonii have the potential to be developed as a biocontrol agent for V. destructor. However, fungal infectivity against the mites under beehive conditions needs to be studied before any conclusion can be made.

The merging of two dynasties--identification of an African cotton leaf curl disease-associated begomovirus with cotton in Pakistan.

Directory of Open Access Journals (Sweden)

Muhammad Nouman Tahir

Full Text Available Cotton leaf curl disease (CLCuD is a severe disease of cotton that occurs in Africa and Pakistan/northwestern India. The disease is caused by begomoviruses in association with specific betasatellites that differ between Africa and Asia. During survey of symptomatic cotton in Sindh (southern Pakistan Cotton leaf curl Gezira virus (CLCuGV, the begomovirus associated with CLCuD in Africa, was identified. However, the cognate African betasatellite (Cotton leaf curl Gezira betasatellite was not found. Instead, two Asian betasatellites, the CLCuD-associated Cotton leaf curl Multan betasatellite (CLCuMB and Chilli leaf curl betasatellite (ChLCB were identified. Inoculation of the experimental plant species Nicotiana benthamiana showed that CLCuGV was competent to maintain both CLCuMB and ChLCB. Interestingly, the enations typical of CLCuD were only induced by CLCuGV in the presence of CLCuMB. Also in infections involving both CLCuMB and ChLCB the enations typical of CLCuMB were less evident. This is the first time an African begomovirus has been identified on the Indian sub-continent, highlight the growing threat of begomoviruses and particularly the threat of CLCuD causing viruses to cotton cultivation in the rest of the world.

Alfalfa Leaf Curl Virus: an Aphid-Transmitted Geminivirus.

Science.gov (United States)

Roumagnac, Philippe; Granier, Martine; Bernardo, Pauline; Deshoux, Maëlle; Ferdinand, Romain; Galzi, Serge; Fernandez, Emmanuel; Julian, Charlotte; Abt, Isabelle; Filloux, Denis; Mesléard, François; Varsani, Arvind; Blanc, Stéphane; Martin, Darren P; Peterschmitt, Michel

2015-09-01

The family Geminiviridae comprises seven genera differentiated by genome organization, sequence similarity, and insect vector. Capulavirus, an eighth genus, has been proposed to accommodate two newly discovered highly divergent geminiviruses that presently have no known vector. Alfalfa leaf curl virus, identified here as a third capulavirus, is shown to be transmitted by Aphis craccivora. This is the first report of an aphid-transmitted geminivirus. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Mechanisms and patient compliance of dust-mite avoidance regimens in dwellings of mite-allergic rhinitic patients

NARCIS (Netherlands)

Kniest, F.M.; Wolfs, B.G.; Vos, H.; Ducheine, B.O.I.; Schayk-Bakker, M.J.; de Lange, P.J.P.; Vos, E.M.P.; Bronswijk, van J.E.M.H.

1992-01-01

We report on the mechanisms, the environmental changes and patient compliance with regard to conventional and new dust and mite avoidance measures to prevent allergic symptoms caused by mite allergens, taking into account both allergen contamination and the developmental success of pyroglyphid

An amino acid substitution (L925V associated with resistance to pyrethroids in Varroa destructor.

Directory of Open Access Journals (Sweden)

Joel González-Cabrera

Full Text Available The Varroa mite, Varroa destructor, is an important pest of honeybees and has played a prominent role in the decline in bee colony numbers over recent years. Although pyrethroids such as tau-fluvalinate and flumethrin can be highly effective in removing the mites from hives, their intensive use has led to many reports of resistance. To investigate the mechanism of resistance in UK Varroa samples, the transmembrane domain regions of the V. destructor voltage-gated sodium channel (the main target site for pyrethroids were PCR amplified and sequenced from pyrethroid treated/untreated mites collected at several locations in Central/Southern England. A novel amino acid substitution, L925V, was identified that maps to a known hot spot for resistance within the domain IIS5 helix of the channel protein; a region that has also been proposed to form part of the pyrethroid binding site. Using a high throughput diagnostic assay capable of detecting the mutation in individual mites, the L925V substitution was found to correlate well with resistance, being present in all mites that had survived tau-fluvalinate treatment but in only 8 % of control, untreated samples. The potential for using this assay to detect and manage resistance in Varroa-infected hives is discussed.

Evaluation of dry-adapted strains of the predatory mite Neoseiulus californicus for spider mite control on cucumber, strawberry and pepper.

Science.gov (United States)

Palevsky, E; Walzer, A; Gal, S; Schausberger, P

2008-06-01

The goal of this study was to evaluate spider mite control efficacy of two dry-adapted strains of Neoseiulus californicus. Performance of these strains were compared to a commercial strain of Phytoseiulus persimilis on whole cucumber, pepper and strawberry plants infested with Tetranychus urticae at 50 +/- 5% RH. Under these dry conditions predators' performance was very different on each host plant. On cucumber, spider mite suppression was not attained by any of the three predators, plants 'burnt out' within 4 weeks of spider mite infestation. On strawberry, all predators satisfactorily suppressed spider mites yet they differed in short term efficacy and persistence. Phytoseiulus persimilis suppressed the spider mites more rapidly than did the BOKU and SI N. californicus strains. Both N. californicus strains persisted longer than did P. persimilis. The BOKU strain was superior to SI in population density reached, efficacy in spider mite suppression and persistence. On pepper, in the first 2 weeks of the experiment the BOKU strain was similar to P. persimilis and more efficacious in spider mite suppression than strain SI. Four weeks into the experiment the efficacy of P. persimilis dropped dramatically and was inferior to the SI and BOKU strains. Overall, mean predator density was highest on plants harbouring the BOKU strain, lowest on plants with P. persimilis and intermediate on plants with the SI strain. Implications for biocontrol of spider mites using phytoseiid species under dry conditions are discussed.

Large-bodied Demodex mite infestation in 4 dogs.

Science.gov (United States)

Hillier, Andrew; Desch, Clifford E

2002-03-01

Large-bodied Demodex mites were detected in 4 dogs. The mites were readily detected in material obtained via deep skin scrapings and were most commonly found on the trunk. The mites were distinguishable from D. canis, because adult males were approximately 100% longer and adult females were approximately 50% longer than adult male and female D. canis mites, respectively. The large-bodied mites were found in the hair follicles, sebaceous ducts, and sebaceous glands in histologic sections of skin from 2 dogs. All dogs had adult-onset generalized demodicosis. Two dogs had coexistent iatrogenic hypercortisolism, 1 dog had hypothyroidism, and 1 dog did not have coexistent disease. Infestations responded to miticidal therapy, control of the coexistent disease, or both.

Below-ground plant parts emit herbivore-induced volatiles: olfactory responses of a predatory mite to tulip bulbs infested by rust mites

NARCIS (Netherlands)

Aratchige, N.S.; Lesna, I.; Sabelis, M.W.

2004-01-01

Although odour-mediated interactions among plants, spider mites and predatory mites have been extensively studied above-ground, belowground studies are in their infancy. In this paper, we investigate whether feeding by rust mites (Aceria tulipae) cause tulip bulbs to produce odours that attract

PARASITIC MITES IN BACKYARD TURKEYS

Directory of Open Access Journals (Sweden)

Marco Antonio Camacho-Escobar

2010-02-01

Full Text Available To describe the parasitic mites in backyard turkeys, was did this work. The mites were obtain by hand for 30 backyard turkeys in Oaxaca’s Coast region, Mexico; the mites were mount in adhesive paper and wash with the 200X lent in a computer optical microscopy, the parasites size were determinate in the pictures obtained by the microscopy software, the images were sized using a specialist software for it, which relate the number of pixels in the picture with the size of the observation field. Were indentified the species Dermanyssus gallinae, Megninia ginglymura and Ornithonyssus sylviarum, the last two described for first time in backyard turkeys in Mexico. Â

Induction of direct and indirect plant responses by jasmonic acid, low spider mite densities, or a combination of jasmonic acid treatment and spider mite infestation.

Science.gov (United States)

Gols, Rieta; Roosjen, Mara; Dijkman, Herman; Dicke, Marcel

2003-12-01

Jasmonic acid (JA) and the octadecanoid pathway are involved in both induced direct and induced indirect plant responses. In this study, the herbivorous mite, Tetranychus urticae, and its predator, Phytoseiulus persimilis, were given a choice between Lima bean plants induced by JA or spider mites and uninduced control plants. Infestation densities resulting in the induction of predator attractants were much lower than thus far assumed, i.e., predatory mites were significantly attracted to plants that were infested for 2 days with only one or four spider mites per plant. Phytoseiulus persimilis showed a density-dependent response to volatiles from plants that were infested with different numbers of spider mites. Similarly, treating plants with increasing concentrations of JA also led to increased attraction of P. persimilis. Moreover, the duration of spider mite infestation was positively correlated with the proportion of predators that were attracted to mite-infested plants. A pretreatment of the plants with JA followed by a spider mite infestation enhanced the attraction of P. persimilis to plant volatiles compared to attraction to volatiles from plants that were only infested with spider mites and did not receive a pretreatment with JA. The herbivore, T. urticae preferred leaf tissue that previously had been infested with conspecifics to uninfested leaf tissue. In the case of choice tests with JA-induced and control leaf tissue, spider mites slightly preferred control leaf tissue. When spider mites were given a choice between leaf discs induced by JA and leaf discs damaged by spider mite feeding, they preferred the latter. The presence of herbivore induced chemicals and/or spider mite products enhanced settlement of the mites, whereas treatment with JA seemed to impede settlement.

The typical RB76 recombination breakpoint of the invasive recombinant tomato yellow leaf curl virus of Morocco can be generated experimentally but is not positively selected in tomato.

Science.gov (United States)

Belabess, Z; Urbino, C; Granier, M; Tahiri, A; Blenzar, A; Peterschmitt, M

2018-01-02

TYLCV-IS76 is an unusual recombinant between the highly recombinogenic tomato yellow leaf curl virus (TYLCV) and tomato yellow leaf curl Sardinia virus (TYLCSV), two Mediterranean begomoviruses (Geminiviridae). In contrast with the previously reported TYLCV/TYLCSV recombinants, it has a TYLCSV derived fragment of only 76 nucleotides, and has replaced its parental viruses in natural conditions (Morocco, Souss region). The viral population shift coincided with the deployment of the popular Ty-1 resistant tomato cultivars, and according to experimental studies, has been driven by a strong positive selection in such resistant plants. However, although Ty-1 cultivars were extensively used in Mediterranean countries, TYLCV-IS76 was not reported outside Morocco. This, in combination with its unusual recombination pattern suggests that it was generated through a rare and possibly multistep process. The potential generation of a recombination breakpoint (RB) at locus 76 (RB76) was investigated over time in 10 Ty-1 resistant and 10 nearly isogenic susceptible tomato plants co-inoculated with TYLCV and TYLCSV clones. RB76 could not be detected in the recombinant progeny using the standard PCR/sequencing approach that was previously designed to monitor the emergence of TYLCV-IS76 in Morocco. Using a more sensitive PCR test, RB76 was detected in one resistant and five susceptible plants. The results are consistent with a very low intra-plant frequency of RB76 bearing recombinants throughout the test and support the hypothesis of a rare emergence of TYLCV-IS76. More generally, RBs were more scattered in resistant than in susceptible plants and an unusual RB at position 141 (RB141) was positively selected in the resistant cultivar; interestingly, RB141 bearing recombinants were detected in resistant tomato plants from the field. Scenarios of TYLCV-IS76 pre-emergence are proposed. Copyright © 2017 Elsevier B.V. All rights reserved.

Pyroglyphid mites as a source of work-related allergens.

Science.gov (United States)

Macan, Jelena; Kanceljak-Macan, Božica; Milković-Kraus, Sanja

2012-01-01

Pyroglyphid mites are primarily associated with allergen exposure at home; hence the name house dust mites. However, we have found numerous studies reporting pyroglyhid mite levels in public and occupational settings. This review presents the findings of house dust mite allergens (family Pyroglyphidae, species Dermatophagoides) as potential work-related risk factors and proposes occupations at risk of house dust mite-related diseases. Pyroglyphid mites or their allergens are found in various workplaces, but clinically relevant exposures have been observed in hotels, cinemas, schools, day-care centres, libraries, public transportation (buses, trains, taxies, and airplanes), fishing-boats, submarines, poultry farms, and churches. Here we propose a classification of occupational risk as low (occasional exposure to mite allergen levels up to 2 μg g(-1)), moderate (exposure between 2 μg g(-1) and 10 μg g(-1)), and high (exposure >10 μg g(-1)). The classification of risk should include factors relevant for indoor mite population (climate, building characteristics, and cleaning schedule). To avoid development or aggravation of allergies associated with exposure to house dust mites at work, occupational physicians should assess exposure risk at work, propose proper protection, provide vocational guidance to persons at risk and conduct pre-employment and periodic examinations to diagnose new allergy cases. Protection at work should aim to control dust mite levels at work. Measures may include proper interior design and regular cleaning and building maintenance.

Effectiveness of Hamstring Knee Rehabilitation Exercise Performed in Training Machine vs. Elastic Resistance Electromyography Evaluation Study

DEFF Research Database (Denmark)

Jakobsen, M. D.; Sundstrup, E.; Andersen, C. H.

2014-01-01

Objective The aim of this study was to evaluate muscle activity during hamstring rehabilitation exercises performed in training machine compared with elastic resistance. Design Six women and 13 men aged 28-67 yrs participated in a crossover study. Electromyographic (EMG) activity was recorded...... inclinometers. Results Training machines and elastic resistance showed similar high levels of muscle activity (biceps femoris and semitendinosus peak normalized EMG >80%). EMG during the concentric phase was higher than during the eccentric phase regardless of exercise and muscle. However, compared with machine.......001) during hamstring curl performed with elastic resistance (7.58 +/- 0.08) compared with hamstring curl performed in a machine (5.92 +/- 0.03). Conclusions Hamstring rehabilitation exercise performed with elastic resistance induces similar peak hamstring muscle activity but slightly lower EMG values at more...

The role of epistatic interactions underpinning resistance to parasitic Varroa mites in haploid honey bee (Apis mellifera) drones.

Science.gov (United States)

Conlon, Benjamin H; Frey, Eva; Rosenkranz, Peter; Locke, Barbara; Moritz, Robin F A; Routtu, Jarkko

2018-06-01

The Red Queen hypothesis predicts that host-parasite coevolutionary dynamics can select for host resistance through increased genetic diversity, recombination and evolutionary rates. However, in haplodiploid organisms such as the honeybee (Apis mellifera), models suggest the selective pressure is weaker than in diploids. Haplodiploid sex determination, found in A. mellifera, can allow deleterious recessive alleles to persist in the population through the diploid sex with negative effects predominantly expressed in the haploid sex. To overcome these negative effects in haploid genomes, epistatic interactions have been hypothesized to play an important role. Here, we use the interaction between A. mellifera and the parasitic mite Varroa destructor to test epistasis in the expression of resistance, through the inhibition of parasite reproduction, in haploid drones. We find novel loci on three chromosomes which explain over 45% of the resistance phenotype. Two of these loci interact only additively, suggesting their expression is independent of each other, but both loci interact epistatically with the third locus. With drone offspring inheriting only one copy of the queen's chromosomes, the drones will only possess one of two queen alleles throughout the years-long lifetime of the honeybee colony. Varroa, in comparison, completes its highly inbred reproductive cycle in a matter of weeks, allowing it to rapidly evolve resistance. Faced with the rapidly evolving Varroa, a diversity of pathways and epistatic interactions for the inhibition of Varroa reproduction could therefore provide a selective advantage to the high levels of recombination seen in A. mellifera. This allows for the remixing of phenotypes despite a fixed queen genotype. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

Haematophagus Mites in Poultry Farms of Iran

Directory of Open Access Journals (Sweden)

S Rahbari

2009-12-01

Full Text Available Background: Blood sucking mites are important avian ectoparasites which being found on bird species worldwide. Their presence are problematic for the producers either through potential direct effects on weight gain, egg produc­tion, sperm production in roosters or as nuisance pests on worker handle hens and eggs. The aim of this study was pointing out of the status of haematophagus mites.Methods: Eight caged layer and four breeder flocks were visited, monitoring for the presence of chicken mites per­formed by removing and examining debris from poultry house, infested nesting material collected into zip lock plas­tic bags and at least 20 birds were also randomly selected to examine the presence of chicken mites. Mites obtained from each population were mounted in Hoyer,s medium on microscope slides and identified. All eight caged layer and four breeder flocks were inspected, which were infested with chicken blood feeding mites.Results: Massive infestations of Dermanyssus gallinae were common with huge numbers of parasites on birds, cages and the conveyor belts for egg. Only one farm from Mazandaran Province was infested to Ornithonyssus bursa.Conclusion: Dermanyssus gallinae was the most prevalent blood feeder mite in the breeder and caged layer flocks in Iran, while O. bursa was reported as a first record, which found only in a breeder flock in Mazanderan Province. It seems that its presence is limited into the area which affected by both warm and humid environmental conditions.

Effects of the mutation of selected genes of cotton leaf curl Kokhran virus on infectivity, symptoms and the maintenance of cotton leaf curl Multan betasatellite

NARCIS (Netherlands)

Iqbal, Z.; Sattar, M.N.; Kvarnheden, A.; Mansoor, S.; Briddon, R.W.

2012-01-01

Cotton leaf curl Kokhran virus (CLCuKoV) is a cotton-infecting monopartite begomovirus (family Geminiviridae). The effects of mutation of the coat protein (CP), V2, C2 and C4 genes of CLCuKoV on infectivity and symptoms in Nicotiana benthamiana were investigated. Each mutation introduced a premature

Varroa destructor mite in Africanized honeybee colonies Apis mellifera L. under royal jelly or honey production

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Pedro da Rosa Santos

2015-08-01

Full Text Available This study evaluated the level of invasion of Varroa mite into worker brood cells, the infestation rate on adult worker honeybees, total and effective reproduction rates of the mite in Africanized honeybee colonies under royal jelly or honey production. Invasion and infestation rates were not statistically different between honeybee colonies producing honey or royal jelly and the averages for these parameters were 5.79 and 8.54%, respectively. Colonies producing honey presented a higher (p < 0.05 total and effective reproduction of Varroa than colonies producing royal jelly. There was a negative correlation between levels of invasion and infestation with minimum external temperature, relative humidity and rainfall. The variables month and season influenced the development of the mite, but rates were low and within the range normally found in Brazil for Africanized honeybee colonies, which confirm the greater resistance of these honeybees to Varroa destructor than European honeybees.

Wind Stress, METOP ASCAT, 0.25 degrees, Global, Near Real Time, Curl

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes near real time wind stress data in zonal, meridional, modulus, and wind stress curl sets. This data begins with wind velocity...

A selective sweep in a Varroa destructor resistant honeybee (Apis mellifera) population.

Science.gov (United States)

Lattorff, H Michael G; Buchholz, Josephine; Fries, Ingemar; Moritz, Robin F A

2015-04-01

The mite Varroa destructor is one of the most dangerous parasites of the Western honeybee (Apis mellifera) causing enormous colony losses worldwide. Various chemical treatments for the control of the Varroa mite are currently in use, which, however, lead to residues in bee products and often to resistance in mites. This facilitated the exploration of alternative treatment methods and breeding for mite resistant honeybees has been in focus for breeders in many parts of the world with variable results. Another approach has been applied to a honeybee population on Gotland (Sweden) that was exposed to natural selection and survived Varroa-infestation for more than 10years without treatment. Eventually this population became resistant to the parasite by suppressing the reproduction of the mite. A previous QTL mapping study had identified a region on chromosome 7 with major loci contributing to the mite resistance. Here, a microsatellite scan of the significant candidate QTL regions was used to investigate potential footprints of selection in the original population by comparing the study population on Gotland before (2000) and after selection (2007). Genetic drift had caused an extreme loss of genetic diversity in the 2007 population for all genetic markers tested. In addition to this overall reduction of heterozygosity, two loci on chromosome 7 showed an even stronger and significant reduction in diversity than expected from genetic drift alone. Within the selective sweep eleven genes are annotated, one of them being a putative candidate to interfere with reduced mite reproduction. A glucose-methanol-choline oxidoreductase (GMCOX18) might be involved in changing volatiles emitted by bee larvae that might be essential to trigger oogenesis in Varroa. Copyright © 2015 Elsevier B.V. All rights reserved.

[Dynamics of infection of Fringilla coelebs chaffinch nestlings with feather mites (Acari: Analgoidea)].

Science.gov (United States)

Mironov, S V; Malyshev, L L

2002-01-01

on 11th day 60.3 +/- 5.7 mites per nestling. In the micropopulation of this species, the tritonymphs count 38.3%, and the quota of males and females is 25.3% each. The migration of this species goes most intensively, than in two other species. An analitic selection of logistic curves shows, that the increasing of mite number during the process of infection with three mite species may be most adequately described by the sigmoid curves with clearly recognizable levels of saturation, which can be theoretically reached. Indeed, the number of mite individuals being able to migrate onto the nestlings is limited by their number on a respective chaffinch female. In a contrast, the increasing of plumage indices, for instance the length of flight feathers, has almost linear character during the period of observation. The beginning of mite migration is determined by the development of respective microhabitats in the plumage of nestlings, or at least by the development of certain structure elements of plumage, where mites are able to attach for a while, before that moment, when the nestlings will develop the plumage completely and begin to fly. In three mite species examined, the process of infection was performed by older stages, namely by the imago and/or tritonymphs. This can be explained by two reasons. On the one hand, the older stages are most active in their movement, resistible and able to survive successfully on new host individuals. On the other hand, the older stage are ready for the reproduction or will be ready after one moulting. The older stages of mites can quickly create a large and self-supporting micropopulations on the birds, therefore this strategy ensures a successful subsequent existence of the parasite species. In cases, when mites (A. passerinus, M. microphylla) migrate into the respective microhabitats structurally corresponding to their normal microhabitats on adult birds, the micropopulations of these mite species include a significant or dominant

Acaricide resistance and resistance mechanisms in Tetranychus urticae populations from rose greenhouses in the Netherlands

NARCIS (Netherlands)

Khajehali, J.; Van Nieuwenhuyse, P.; Demaeght, P.; Tirry, L.; Van Leeuwen, T.

2011-01-01

BACKGROUND: Spider mites are important crop pests that rapidly develop resistance to acaricides. To investigate whether acaricide resistance is a threat to greenhouse rose culture in the Netherlands, the susceptibility of 15 strains of Tetranychus urticae was tested to several currently used

Haematophagus Mites in Poultry Farms of Iran

Directory of Open Access Journals (Sweden)

S Rahbari

2009-12-01

Full Text Available Background: Blood sucking mites are important avian ectoparasites which being found on bird species worldwide. Their presence are problematic for the producers either through potential direct effects on weight gain, egg produc­tion, sperm production in roosters or as nuisance pests on worker handle hens and eggs. The aim of this study was pointing out of the status of haematophagus mites."nMethods: Eight caged layer and four breeder flocks were visited, monitoring for the presence of chicken mites per­formed by removing and examining debris from poultry house, infested nesting material collected into zip lock plas­tic bags and at least 20 birds were also randomly selected to examine the presence of chicken mites. Mites obtained from each population were mounted in Hoyer,s medium on microscope slides and identified. All eight caged layer and four breeder flocks were inspected, which were infested with chicken blood feeding mites."nResults: Massive infestations of Dermanyssus gallinae were common with huge numbers of parasites on birds, cages and the conveyor belts for egg. Only one farm from Mazandaran Province was infested to Ornithonyssus bursa."nConclusion: Dermanyssus gallinae was the most prevalent blood feeder mite in the breeder and caged layer flocks in Iran, while O. bursa was reported as a first record, which found only in a breeder flock in Mazanderan Province. It seems that its presence is limited into the area which affected by both warm and humid environmental conditions.  Keywords: Dermanyssus gallinae, Ornithonyssus bursa, Poultry, Iran

Gene expression in response to Cotton Leaf Curl Virus infection in Gossypium hirsutum under variable environmental conditions

Directory of Open Access Journals (Sweden)

Rehman Iqra

2017-01-01

Full Text Available Cotton Leaf Curl Disease (CLCuD is one of the threatening constrains of cotton production in Pakistan for which no adequate remedy is available until now. Local variety of Gossypium hirsutum (FH-142 was grown in field and infected naturally by CLCuV under variable range of temperature and humidity. Plants showed thickening of veins in lower leaf surface at 34°C and 60% relative humidity at 15days post infection (dpi and curling of leaf margins at 33°C with 58% relative humidity at 30dpi. Remarkable leaf darkening was observed with reduced boll formation at 45dpi at 26°C and 41% relative humidity. Enation developed, severe thickening and curling of leaves intensified and plants showed dwarf growth at 60dpi at 24°C with 52% relative humidity. PCR amplification of Rep associated gene confirmed the presence of CLCuD-associated begomovirus in the infected samples. Quantitative RT-PCR confirmed the amplification and differential expression of a number of pathogen stress responsive genes at different levels of temperature and humidity. This observation predicts that Cotton Leaf Curl Virus (CLCuV interacts with several host genes that are upregulated to make plants susceptible or suppress other genes to overcome host defense responses.

Development of a cDNA microarray for the measurement of gene expression in the sheep scab mite Psoroptes ovis

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Burgess Stewart TG

2012-02-01

Full Text Available Abstract Background Sheep scab is caused by the ectoparasitic mite Psoroptes ovis which initiates a profound cutaneous inflammatory response, leading to the development of the skin lesions which are characteristic of the disease. Existing control strategies rely upon injectable endectocides and acaricidal dips but concerns over residues, eco-toxicity and the development of acaricide resistance limit the sustainability of this approach. In order to identify alternative means of disease control, a deeper understanding of both the parasite and its interaction with the host are required. Methods Herein we describe the development and utilisation of an annotated P. ovis cDNA microarray containing 3,456 elements for the measurement of gene expression in this economically important ectoparasite. The array consists of 981 P. ovis EST sequences printed in triplicate along with 513 control elements. Array performance was validated through the analysis of gene expression differences between fed and starved P. ovis mites. Results Sequences represented on the array include homologues of major house dust mite allergens and tick salivary proteins, along with factors potentially involved in mite reproduction and xenobiotic metabolism. In order to validate the performance of this unique resource under biological conditions we used the array to analyse gene expression differences between fed and starved P. ovis mites. These analyses identified a number of house dust mite allergen homologues up-regulated in fed mites and P. ovis transcripts involved in stress responses, autophagy and chemosensory perception up-regulated in starved mites. Conclusion The P. ovis cDNA microarray described here has been shown to be both robust and reproducible and will enable future studies to analyse gene expression in this important ectoparasite.

Molecular characterization of two isolates of sweet potato leaf curl ...

African Journals Online (AJOL)

Comparison analysis showed that DNA-A sequence of JS1 isolate was closely related to that of sweet potato leaf curl virus (SPLCV) from United States with nucleotide sequence identity of 97.0% and DNA-A of Y338 showed highest sequence identity at 97.8% with an isolate of SPLCV from China. Phylogenetic analysis ...

House dust mites in the city of Lima, Peru.

Science.gov (United States)

Croce, M; Costa-Manso, E; Baggio, D; Croce, J

2000-01-01

Since mites are the most common house dust allergens, knowledge about the species most prevalent in a region is important for diagnostic and specific immunotherapy purposes. In order to establish the prevalence of house dust mites in different city districts, 100 house dust samples were collected from different parts of Lima. Lima is a city of tropical climate located along the coast of the Pacific Ocean. The relative air humidity is 80-90% and the various districts studied are located at altitudes ranging from 37-355 meters. The mite Blomia tropicalis was the organism most frequently detected, being present in 59% of the house dust samples. Dermatophagoides pteronyssinus occupied second place (15.9%), followed by Chortoglyphus arcuatus and Tyrophagus putrescentiae. These four mites, taken together, represented more than 90% of the mites detected. No specimen of the species Dermatophagoides farinae was detected. We conclude that B. tropicalis and D. pteronyssinus are the most common house dust mites in Lima. Considering the high prevalence of B. tropicalis in Lima and the fact that its cross-reactivity with antigens of the mites of the family Pyroglyphidae is minimal, we conclude that sensitization to this mite should be investigated separately in allergic patients living in Lima.

Phenotypic- and Genotypic-Resistance Detection for Adaptive Resistance Management in Tetranychus urticae Koch.

Directory of Open Access Journals (Sweden)

Deok Ho Kwon

Full Text Available Rapid resistance detection is necessary for the adaptive management of acaricide-resistant populations of Tetranychus urticae. Detection of phenotypic and genotypic resistance was conducted by employing residual contact vial bioassay (RCV and quantitative sequencing (QS methods, respectively. RCV was useful for detecting the acaricide resistance levels of T. urticae, particularly for on-site resistance detection; however, it was only applicable for rapid-acting acaricides (12 out of 19 tested acaricides. QS was effective for determining the frequencies of resistance alleles on a population basis, which corresponded to 12 nonsynonymous point mutations associated with target-site resistance to five types of acaricides [organophosphates (monocrotophos, pirimiphos-methyl, dimethoate and chlorpyrifos, pyrethroids (fenpropathrin and bifenthrin, abamectin, bifenazate and etoxazole]. Most field-collected mites exhibited high levels of multiple resistance, as determined by RCV and QS data, suggesting the seriousness of their current acaricide resistance status in rose cultivation areas in Korea. The correlation analyses revealed moderate to high levels of positive relationships between the resistance allele frequencies and the actual resistance levels in only five of the acaricides evaluated, which limits the general application of allele frequency as a direct indicator for estimating actual resistance levels. Nevertheless, the resistance allele frequency data alone allowed for the evaluation of the genetic resistance potential and background of test mite populations. The combined use of RCV and QS provides basic information on resistance levels, which is essential for choosing appropriate acaricides for the management of resistant T. urticae.

Wind Stress, QuikSCAT SeaWinds, 0.25 degrees, Global, Science Quality, Curl

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NOAA CoastWatch distributes science quality wind stress data in zonal, meridional, modulus, and wind stress curl sets. This data begins with wind velocity...

Global associations between birds and vane-dwelling feather mites.

Science.gov (United States)

Doña, Jorge; Proctor, Heather; Mironov, Sergey; Serrano, David; Jovani, Roger

2016-11-01

Understanding host-symbiont networks is a major question in evolutionary ecology. Birds host a great diversity of endo- and ectosymbiotic organisms, with feather mites (Arachnida: Acariformes: Analgoidea, Pterolichoidea) being among the most diverse of avian symbionts. A global approach to the ecology and evolution of bird-feather-mite associations has been hampered because of the absence of a centralized data repository. Here we present the most extensive data set of associations between feather mites and birds. Data include 12 036 records of 1887 feather mite species located on the flight feathers of 2234 bird species from 147 countries. Feather mites typically located inside quills, on the skin, or on downy body feathers are not included. Data were extracted from 493 published sources dating from 1882 to 2015. Data exploration shows that although most continents and bird families are represented, most bird species remain unexplored for feather mites. Nevertheless, this is the most comprehensive data set available for enabling global macroecological analyses of feather mites and their hosts, such as ecological network analyses. This metadata file outlines the structure of these data and provides primary references for all records used. © 2016 by the Ecological Society of America.

Evolutionary genomics of miniature inverted-repeat transposable elements (MITEs) in Brassica.

Science.gov (United States)

Nouroz, Faisal; Noreen, Shumaila; Heslop-Harrison, J S

2015-12-01

Miniature inverted-repeat transposable elements (MITEs) are truncated derivatives of autonomous DNA transposons, and are dispersed abundantly in most eukaryotic genomes. We aimed to characterize various MITEs families in Brassica in terms of their presence, sequence characteristics and evolutionary activity. Dot plot analyses involving comparison of homoeologous bacterial artificial chromosome (BAC) sequences allowed identification of 15 novel families of mobile MITEs. Of which, 5 were Stowaway-like with TA Target Site Duplications (TSDs), 4 Tourist-like with TAA/TTA TSDs, 5 Mutator-like with 9-10 bp TSDs and 1 novel MITE (BoXMITE1) flanked by 3 bp TSDs. Our data suggested that there are about 30,000 MITE-related sequences in Brassica rapa and B. oleracea genomes. In situ hybridization showed one abundant family was dispersed in the A-genome, while another was located near 45S rDNA sites. PCR analysis using primers flanking sequences of MITE elements detected MITE insertion polymorphisms between and within the three Brassica (AA, BB, CC) genomes, with many insertions being specific to single genomes and others showing evidence of more recent evolutionary insertions. Our BAC sequence comparison strategy enables identification of evolutionarily active MITEs with no prior knowledge of MITE sequences. The details of MITE families reported in Brassica enable their identification, characterization and annotation. Insertion polymorphisms of MITEs and their transposition activity indicated important mechanism of genome evolution and diversification. MITE families derived from known Mariner, Harbinger and Mutator DNA transposons were discovered, as well as some novel structures. The identification of Brassica MITEs will have broad applications in Brassica genomics, breeding, hybridization and phylogeny through their use as DNA markers.

Air-conditioner filters enriching dust mites allergen.

Science.gov (United States)

Zhan, Xiaodong; Li, Chaopin; Xu, Haifeng; Xu, Pengfei; Zhu, Haibin; Diao, Jidong; Li, Na; Zhao, Beibei

2015-01-01

We detected the concentration of dust mites allergen (Der f1 & Der p1) in the air of different places before and after the starting of air-conditioners in Wuhu City, Anhui, China, and to discuss the relation between the dust mites allergen in air-conditioner filters and the asthma attack. The dust samples were collected from the air-conditioner filters in dining rooms, shopping malls, hotels and households respectively. Concentrations of dust mites major group allergen 1 (Der f 1, Der p1) were detected with enzyme linked immunosorbent assay (ELISA), and the dust mite immune activities were determined by dot-ELISA. The concentration of Der f1 in dining rooms, shopping malls, hotels and households was 1.52 μg/g, 1.24 μg/g, 1.31 μg/g and 1.46 μg/g respectively, and the concentration of Der p1 in above-mentioned places was 1.23 μg/g, 1.12 μg/g, 1.16 μg/g and 1.18 μg/g respectively. The concentration of Der f1 & Der p1 in air was higher after the air-conditioners starting one hours later, and the difference was significant (Pair-conditioner filters can enrich dust mites major group allergen, and the allergens can induce asthma. The air-conditioner filters shall be cleaned or replaced regularly to prevent or reduce accumulation of the dust mites and its allergens.

Suppression of cotton leaf curl disease symptoms in Gossypium hirsutum through over expression of host-encoded miRNAs.

Science.gov (United States)

Akmal, Mohd; Baig, Mirza S; Khan, Jawaid A

2017-12-10

Cotton leaf curl disease (CLCuD), a major factor resulting in the enormous yield losses in cotton crop, is caused by a distinct monopartite begomovirus in association with Cotton leaf curl Multan betasatellite (CLCuMB). Micro(mi)RNAs are known to regulate gene expression in eukaryotes, including antiviral defense in plants. In a previous study, we had computationally identified a set of cotton miRNAs, which were shown to have potential targets in the genomes of Cotton leaf curl Multan virus (CLCuMuV) and CLCuMB at multiple loci. In the current study, effect of Gossypium arboreum-encoded miRNAs on the genome of CLCuMuV and CLCuMB was investigated in planta. Two computationally predicted cotton-encoded miRNAs (miR398 and miR2950) that showed potential to bind multiple Open Reading Frames (ORFs; C1, C4, V1, and non- coding intergenic region) of CLCuMuV, and (βC1) of CLCuMB were selected. Functional validation of miR398 and miR2950 was done by overexpression approach in G. hirsutum var. HS6. A total of ten in vitro cotton plants were generated from independent events and subjected to biological and molecular analyses. Presence of the respective Precursor (pre)-miRNA was confirmed through PCR and Southern blotting, and their expression level was assessed by semi quantitative RT-PCR, Real Time quantitative PCR and northern hybridization in the PCR-positive lines. Southern hybridization revealed 2-4 copy integration of T-DNA in the genome of the transformed lines. Remarkably, expression of pre-miRNAs was shown up to 5.8-fold higher in the transgenic (T 0 ) lines as revealed by Real Time PCR. The virus resistance was monitored following inoculation of the transgenic cotton lines with viruliferous whitefly (Bemisia tabaci) insect vector. After inoculation, four of the transgenic lines remained apparently symptom free. While a very low titre of viral DNA could be detected by Rolling circle amplification, betasatellite responsible for symptom induction could not be detected

Cleaner mites: sanitary mutualism in the miniature ecosystem of neotropical bee nests.

Science.gov (United States)

Biani, Natalia B; Mueller, Ulrich G; Wcislo, William T

2009-06-01

Cleaning symbioses represent classic models of mutualism, and some bee mites are thought to perform cleaning services for their hosts in exchange for suitable environments for reproduction and dispersal. These mutual benefits, however, have not been rigorously demonstrated. We tested the sanitary role of bee mites by correlating mite loads with fungal contamination in natural nests of Megalopta genalis and Megalopta ecuadoria and by experimentally manipulating mite loads in artificial cells with developing brood. Field observations revealed significant correlations between the presence of mites and the absence of fungi inside the brood cells, as well as between the absence of mites and increased bee mortality. Likewise, experimental brood cells with mites have fewer fungal colonies than do cells without mites. Field observations and experimental manipulations, therefore, provide clear evidence of the sanitary effect of mites in nests of Megalopta bees. This bee-mite association constitutes one of the few examples of terrestrial cleaning mutualisms.

Three Species of Ectoparasite Mites (Acari: Pterygosomatidae Infested Geckos in Indonesia

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TARUNI SRI PRAWASTI

2013-06-01

Full Text Available Limited data is hitherto available on the diversity and dispersal of parasitic mites of geckos in Indonesia. Here, we collected three species of geckos, namely Cosymbotus platyurus, Hemidactylus frenatus, and H. garnotii throughout Indonesia to study the distribution and diversity of its parasitic mites. We conducted detail morphological analysis of the mites using whole mount polyvinyl lactophenol and scanning electron microscope preparation. Three species of ectoparasite mites from genus Geckobia were identified in a total of 221 individuals out of 448 geckos collected from 25 sites in Indonesia. Two species were G. glebosum and G. bataviensis, and the other one was designated as Geckobia sp 1. Based on our result, the three mites species were spread randomly and live sympatrically. The G. bataviensis mite showed the widest distribution, because it was found in almost all gecko collection sites, hence the most cosmopolitan mites. We also found that C. platyurus gecko had the lowest mite prevalence which might due to the fact that it has the least number of skin folds, an important site for mite protection. This result implies that further research on the relationship of anatomy of gecko skin with chelicera and claw structure of mites is necessary in the future.

Curling Edges: A Problem that Has Plagued Scrolls for Millennia

Science.gov (United States)

Chou, Ming-Han; Shen, Wei-Chao; Wang, Yi-Ping; Hung, Sun-Hsin; Hong, Tzay-Ming

2014-01-01

Qi-Wa refers to the up curl on the lengths of hand scrolls and hanging scrolls, which has troubled Chinese artisans and emperors for as long as the art of painting and calligraphy has existed. This warp is unwelcome not only for aesthetic reasons, but its potential damage to the fiber and ink. Although it is generally treated as a part of the cockling and curling due to moisture, consistency of paste, and defects from the mounting procedures, we demonstrate that the spontaneous extrinsic curvature incurred from the storage is in fact more essential to understanding and curing Qi-Wa. In contrast to the former factors whose effects are less predictable, the plastic deformation and strain distribution on a membrane are a well-defined mechanical problem. We study this phenomenon by experiments, theoretical models, and molecular dynamics simulation, and obtain consistent scaling relations for the Qi-Wa height. This knowledge enables us to propose modifications on the traditional mounting techniques that are tested on real mounted paper to be effective at mitigating Qi-Wa. By experimenting on polymer-based films, we demonstrate the possible relevance of our study to the modern development of flexible electronic paper.

EFFICACY OF 15% FORMIC ACID ON VARROA MITES IN DIFFERENT FORMS OF APPLICATION

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M MUŽA

2002-05-01

Full Text Available Varroa destructor is a parasitic mite of the honeybee, Apis mellifera, responsible for reduced honey and brood production, higher bee mortality in winter. Because the resistance to the acaricides and they residues to bee products, alternative products and methods have been used against Varroa. One of this methods is treatment with formic acid. Formic acid induce to Varroa mite in brood and do not leave any residues in products. Concentric formic acid (60-85% is very effective, but at higher air temperature, it has influence on bee. In the last few years, except concentric formic acid, 15 % formic acid was recommended as control of varroosis. Diluted formic acid (15% reduced the bee response to treatment. In treatment with 15% formic acid, higher air temperature and different forms of application have positive influence to they function (65 – 95%.

Ecological Factors Determining Abundance of Parasitic Mites on Aedes spp. Larvae

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Nurhadi Eko Firmansyah

2017-12-01

Full Text Available Ability to infestation and abundance of parasitic mites in Aedes spp. larvae cannot be separated from the influence of various factors. Ecological factors have been suggested to play a role determine the presence of parasitic mites that under certain conditions become a key factor in determining the abundance of parasitic mites on Aedes spp. larvae. The aim of this study to determine the ecological factors affect the abundance of parasitic mites on Aedes spp. larvae in Bogor Regency. Capturing of Aedes spp. larvae was performed directly on the habitats found in indoor and outdoor. Capturing mites in the body of Aedes spp. larvae was performed using insect forceps. Ecological factors measured were dissolved oxygen (DO, pH, temperature, and total dissolved solid (TDS. The influence of ecological factors was analyzed using regression and correlation analysis. The result of mite identification has been obtained three species of mites that are Halacarus sp., Histiostoma sp., and Hydrozetes sp. The result indicated that total dissolved solid (TDS and temperature was the factors that determined the abundance of mites. The factors of pH, and dissolved oxygen (DO did not determine the abundance of parasitic mites of Aedes spp. larvae. The research result can be further developed as a new alternative to Dengue Hemorraghic Fever control and provide information on parasitic mites that infest Aedes spp. larvae. In addition, this results become an early step in controlling of Aedes spp. strategy platform by the parasitic mites.

The acaricidal speed of kill of orally administered fluralaner against poultry red mites (Dermanyssus gallinae) on laying hens and its impact on mite reproduction.

Science.gov (United States)

Brauneis, Maria D; Zoller, Hartmut; Williams, Heike; Zschiesche, Eva; Heckeroth, Anja R

2017-12-02

Dermanyssus gallinae, the poultry red mite, is a growing threat to chickens in poultry farms. This nocturnal hematophagous ectoparasite has a rapid rate of proliferation with a negative impact on the birds' health, welfare and productivity resulting in severe economic consequences for poultry farmers. A study was performed with fluralaner, a novel systemic ectoparasiticide, to evaluate its effect on mite vitality and reproduction after oral administration to laying hens. Sixteen healthy hens were randomly allocated to two study groups (n = 8). One group was orally treated with fluralaner by gavage at a dose of 0.5 mg/kg bodyweight twice 7 days apart. The negative control group received no treatment. Hens in each group were repeatedly infested with approximately 200 unfed adult D. gallinae at 1, 5, 8, 12, 15, 19, 22 and 26 days after the initial administration. After infestation and feeding for 2.5 h, 25 engorged mites per hen were collected and incubated in tubes. Mites were assessed for vitality (dead/live) at 4, 8, 12, and 24 h after each infestation. Tubes containing eggs and/or living mites were incubated another 8 days for assessment of mite reproductive capacity. Fluralaner demonstrated a fast speed of kill in mites within 4 h post-infestation for 12 days after treatment initiation. An efficacy (mite mortality) of 98.7-100% was achieved. At 15 days after treatment initiation, 100% efficacy was achieved within 24 h post-infestation, and no mite oviposition occurred during this period. Nineteen days after treatment initiation, the mites' ability to generate nymphs was reduced by 90.8%, which decreased to < 24.1% at later infestations. Fluralaner administered orally to hens twice, 7 days apart, provides efficacy against experimental poultry red mite infestation for at least 2 weeks. The demonstrated rapid speed of kill results in substantial depletion of the mites' oviposition and suggests that fluralaner can be an effective tool in the control

Observability of the effects of curl-free magnetic vector potential on ...

Indian Academy of Sciences (India)

We discuss here the prediction, based on a formalism by the author, on the observable effects of a curl-free magnetic vector potential on the macroscale as against the microscale of the Aharonov–Bohm effect. A new quantum concept – the 'transition amplitude wave' – postulated in the formalism has already been shown to ...

Does the removal of mite-infested brood facilitate grooming?

Science.gov (United States)

The relationship between the removal of mite-infested brood and mite drop was compared using Russian (RHB, n = 9) and Italian (IHB, n = 9) honey bee colonies. A cloake board was used to isolate test brood frame on the top hive body and the metal sheet served as a varroa trap. Inoculum mites were col...

Pheromonal Communication in the European House Dust Mite, Dermatophagoides pteronyssinus

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Johannes L.M. Steidle

2014-08-01

Full Text Available Despite the sanitary importance of the European house dust mite Dermatophagoides pteronyssinus (Trouessart, 1897, the pheromonal communication in this species has not been sufficiently studied. Headspace analysis using solid phase micro extraction (SPME revealed that nerol, neryl formate, pentadecane, (6Z,9Z-6,9-heptadecadiene, and (Z-8-heptadecene are released by both sexes whereas neryl propionate was released by males only. Tritonymphs did not produce any detectable volatiles. In olfactometer experiments, pentadecane and neryl propionate were attractive to both sexes as well as to tritonymphs. (Z-8-heptadecene was only attractive to male mites. Therefore it is discussed that pentadecane and neryl propionate are aggregation pheromones and (Z-8-heptadecene is a sexual pheromone of the European house dust mite D. pteronyssinus. To study the potential use of pheromones in dust mite control, long-range olfactometer experiments were conducted showing that mites can be attracted to neryl propionate over distances of at least 50 cm. This indicates that mite pheromones might be useable to monitor the presence or absence of mites in the context of control strategies.

Domatia reduce larval cannibalism in predatory mites

NARCIS (Netherlands)

Ferreira, J.A.M.; Eshuis, B.; Janssen, A.; Sabelis, M.W.

2008-01-01

1. Acarodomatia are small structures on the underside of leaves of many plant species, which are mainly inhabited by carnivorous and fungivorous mites. 2. Domatia are thought to protect these mites against adverse environmental conditions and against predation. They are considered as an indirect

Respiratory allergy caused by house dust mites

DEFF Research Database (Denmark)

Calderón, Moisés A; Linneberg, Allan; Kleine-Tebbe, Jörg

2015-01-01

consequences in patients with respiratory allergic diseases. We investigate the epidemiology of HDM allergy to explore the interaction between mites and human subjects at the population, individual, and molecular levels. Core and recent publications were identified by using "house dust mite" as a key search...

Interactions between natural enemies: Effect of a predatory mite on transmission of the fungus Neozygites floridana in two-spotted spider mite populations.

Science.gov (United States)

Trandem, Nina; Berdinesen, Ronny; Pell, Judith K; Klingen, Ingeborg

2016-02-01

Introducing the predatory mite Phytoseiulus persimilis into two-spotted spider mite, Tetranychus urticae, populations significantly increased the proportion of T. urticae infected with the spider mite pathogen Neozygites floridana in one of two experiments. By the final sampling occasion, the number of T. urticae in the treatment with both the predator and the pathogen had declined to zero in both experiments, while in the fungus-only treatment T. urticae populations still persisted (20-40 T. urticae/subsample). Releasing P. persimilis into crops in which N. floridana is naturally present has the potential to improve spider mite control more than through predation alone. Copyright © 2016 Elsevier Inc. All rights reserved.

Under the lash: Demodex mites in human diseases

OpenAIRE

Lacey, Noreen; Kavanagh, Kevin; Tseng, Scheffer C.G.

2009-01-01

Demodex mites, class Arachnida and subclass Acarina, are elongated mites with clear cephalothorax and abdomens, the former with four pairs of legs. There are more than 100 species of Demodex mite, many of which are obligatory commensals of the pilosebaceous unit of mammals including cats, dogs, sheep, cattle, pigs, goats, deer, bats, hamsters, rats and mice. Among them, Demodex canis, which is found ubiquitously in dogs, is the most documented and investigated. In excessive numbers D. canis c...

The management of house dust mite allergies

NARCIS (Netherlands)

Bronswijk, van J.E.M.H.; Schober, G.; Kniest, F.M.

1990-01-01

A safe and practical home sanitation procedure for the removal of house dust mites (Dermatophagoides pteronyssinus) and their allergens is described. The severity of mite infestation was assessed with the use of the Acarex test, which measures the concentration of guanine in house dust, and all

Varroa Sensitive Hygiene contributes to naturally selected varroa resistance in honey bees

OpenAIRE

Panziera, Delphine; Langevelde, van, Frank; Blacquière, Tjeerd

2017-01-01

The parasitic mite Varroa destructor is a serious threat for western honey bee colonies and beekeepers are compelled to control it to keep their colonies healthy. Yet, by controlling varroa no resistance to the parasite can evolve. As a trial, honey bee colonies have been left untreated in isolated locations to allow development of resistance or tolerance to the mite. These colonies developed an ability to live without control measures against varroa, although the traits responsible for this ...

Poultry red mite (Dermanyssus gallinae) infestation: a broad impact parasitological disease that still remains a significant challenge for the egg-laying industry in Europe.

Science.gov (United States)

Sigognault Flochlay, Annie; Thomas, Emmanuel; Sparagano, Olivier

2017-08-01

The poultry red mite, Dermanyssus gallinae, has been described for decades as a threat to the egg production industry, posing serious animal health and welfare concerns, adversely affecting productivity, and impacting public health. Research activities dedicated to controlling this parasite have increased significantly. Their veterinary and human medical impact, more particularly their role as a disease vector, is better understood. Nevertheless, red mite infestation remains a serious concern, particularly in Europe, where the prevalence of red mites is expected to increase, as a result of recent hen husbandry legislation changes, increased acaricide resistance, climate warming, and the lack of a sustainable approach to control infestations. The main objective of the current work was to review the factors contributing to this growing threat and to discuss their recent development in Europe. We conclude that effective and sustainable treatment approach to control poultry red mite infestation is urgently required, included integrated pest management.

Phoretic mites identified on andean hummingbirds (Trochilidae of Caldas, Colombia

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Natalia López-Orozco

Full Text Available Within the bird-plant-mite system, the relationship between hummingbirds, flowers, and mites remains poorly understood. In this study, we evaluated the degree of association between nasal mites and eight species of Andean hummingbirds in Colombia (Amazilia saucerrottei,A. tzacatl, Chalybura buffonii,Chlorostilbon mellisugus, Florisuga mellivora, Glaucis hirsutus, Phaethornis guy and P. striigularis. Over a five-month period (trapping effort 360 hours/month, a total of 178 birds were captured, from which 81 mite specimens were collected and identified as belonging to three genera (Proctolaelaps, Rhinoseius andTropicoseius spanning eleven species. This is the first report of its kind from Colombia on the identification of the mite speciesP. rabulatus, R. luteyni, R. rafinskii, T. berryi, T. colwelli, T. erro and T. uniformisand the first record of P. guy as phoretic host forProctolaelaps rabulatus. Morphological characteristics (length of the dorsal plate, width of the dorsal plate and setae z5 length alone failed to distinguish between mite species. The ecologic impact of this relationship on flowers with respect to nectar and pollen availability and the effect of mites on pollination by hummingbirds needs to be determined.

Phoretic mites identified on Andean hummingbirds (Trochilidae) of Caldas, Colombia.

Science.gov (United States)

López-Orozco, Natalia; Cañón-Franco, William Alberto

2013-01-01

Within the bird-plant-mite system, the relationship between hummingbirds, flowers, and mites remains poorly understood. In this study, we evaluated the degree of association between nasal mites and eight species of Andean hummingbirds in Colombia (Amazilia saucerrottei, A. tzacatl, Chalybura buffonii, Chlorostilbon mellisugus, Florisuga mellivora, Glaucis hirsutus, Phaethornis guy and P. striigularis). Over a five-month period (trapping effort 360 hours/month), a total of 178 birds were captured, from which 81 mite specimens were collected and identified as belonging to three genera (Proctolaelaps, Rhinoseius and Tropicoseius) spanning eleven species. This is the first report of its kind from Colombia on the identification of the mite species P. rabulatus, R. luteyni, R. rafinskii, T. berryi, T. colwelli, T. erro and T. uniformis and the first record of P. guy as phoretic host for Proctolaelaps rabulatus. Morphological characteristics (length of the dorsal plate, width of the dorsal plate and setae z5 length) alone failed to distinguish between mite species. The ecologic impact of this relationship on flowers with respect to nectar and pollen availability and the effect of mites on pollination by hummingbirds needs to be determined.

Comparative Study of Different Nano-Formulations of Curcumin for Reversal of Doxorubicin Resistance in K562R Cells.

Science.gov (United States)

Dash, Tapan K; Konkimalla, V Badireenath

2017-02-01

Curcumin is very well established as a chemo-therapeutic, chemo-preventive and chemo-sensitizing agent in diverse disease conditions. As the isolated pure form has poor solubility and pharmacokinetic problems, therefore it is encapsulated in to several nano-formulations to improve its bioavailability. Here in the current study, we aim to compare different nano-formulations of curcumin for their chemo-sensitizing activity in doxorubicin (DOX) resistant K562 cells. Four different curcumin formulations were prepared namely DMSO assisted curcumin nano-dispersion (CurD, 260 nm), liposomal curcumin (CurL, 165 nm), MPEG-PCL micellar curcumin (CurM, 18 nm) and cyclodextrin encapsulated curcumin (CurN, 37 nm). The formulations were subjected to particle characterizations (size, zeta potential, release studies), followed by biological assays such as cellular uptake, P-gp inhibitory activity and reversal of DOX resistance by co-treatment with DOX. Curcumin uptake in K562N and K562R cells was mildly reduced when treated with CurL and CurM, while for CurD and CurN the uptake remained equivalent. However, CurL retained P-gp inhibitory activity of curcumin and with a considerable chemo-sensitizing effect but CurM showed no P-gp inhibitory activity. CurN retained above biological activities, but requires a secondary carrier under in vivo conditions. From the results, CurM was found to be most suitable for solubilization of curcumin where as CurL can be considered as most suitable nano-formulation for reversal of DOX resistance.

Large-Deformation Curling Actuators Based on Carbon Nanotube Composite: Advanced-Structure Design and Biomimetic Application.

Science.gov (United States)

Chen, Luzhuo; Weng, Mingcen; Zhou, Zhiwei; Zhou, Yi; Zhang, Lingling; Li, Jiaxin; Huang, Zhigao; Zhang, Wei; Liu, Changhong; Fan, Shoushan

2015-12-22

In recent years, electroactive polymers have been developed as actuator materials. As an important branch of electroactive polymers, electrothermal actuators (ETAs) demonstrate potential applications in the fields of artificial muscles, biomimetic devices, robotics, and so on. Large-shape deformation, low-voltage-driven actuation, and ultrafast fabrication are critical to the development of ETA. However, a simultaneous optimization of all of these advantages has not been realized yet. Practical biomimetic applications are also rare. In this work, we introduce an ultrafast approach to fabricate a curling actuator based on a newly designed carbon nanotube and polymer composite, which completely realizes all of the above required advantages. The actuator shows an ultralarge curling actuation with a curvature greater than 1.0 cm(-1) and bending angle larger than 360°, even curling into a tubular structure. The driving voltage is down to a low voltage of 5 V. The remarkable actuation is attributed not only to the mismatch in the coefficients of thermal expansion but also to the mechanical property changes of materials during temperature change. We also construct an S-shape actuator to show the possibility of building advanced-structure actuators. A weightlifting walking robot is further designed that exhibits a fast-moving motion while lifting a sample heavier than itself, demonstrating promising biomimetic applications.

Molecular and Biochemical Characterization of Cotton Epicuticular Wax in Defense Against Cotton Leaf Curl Disease.

Science.gov (United States)

Khan, Muhammad Azmat Ullah; Shahid, Ahmad Ali; Rao, Abdul Qayyum; Bajwa, Kamran Shehzad; Samiullah, Tahir Rehman; Muzaffar, Adnan; Nasir, Idrees Ahmad; Husnain, Tayyab

2015-12-01

Gossypium arboreumis resistant to Cotton leaf curl Burewala virus and its cognate Cotton leaf curl Multan beta satellite ( CLCuBuV and CLCuMB ). However, the G. arboreum wax deficient mutant (GaWM3) is susceptible to CLCuV . Therefore, epicuticular wax was characterized both quantitatively and qualitatively for its role as physical barrier against whitefly mediated viral transmission and co-related with the titer of each viral component (DNA-A, alphasatellite and betasatellite) in plants. The hypothesis was the CLCuV titer in cotton is dependent on the amount of wax laid down on plant surface and the wax composition. Analysis of the presence of viral genes, namely alphasatellite, betasatellite and DNA-A, via real-time PCR in cotton species indicated that these genes are detectable in G. hirsutum , G. harknessii and GaWM3, whereas no particle was detected in G. arboreum . Quantitative wax analysis revealed that G. arboreum contained 183 μg.cm -2 as compared to GaWM3 with only 95 μg.cm -2 . G. hirsutum and G. harknessii had 130 μg.cm -2 and 146 μg.cm -2 , respectively. The GCMS results depicted that Lanceol, cis was 45% in G. harknessii . Heptadecanoic acid was dominant in G. arboreum with 25.6%. GaWM3 had 18% 1,2,-Benenedicarboxylic acid. G. hirsutum contained 25% diisooctyl ester. The whitefly feeding assay with Nile Blue dye showed no color in whiteflies gut fed on G. arboreum . In contrast, color was observed in the rest of whiteflies. From results, it was concluded that reduced quantity as well as absence of (1) 3-trifluoroacetoxytetradecane, (2) 2-piperidinone,n-|4-bromo-n-butyl|, (3) 4-heptafluorobutyroxypentadecane, (4) Silane, trichlorodocosyl-, (5) 6- Octadecenoic acid, methyl ester, and (6) Heptadecanoicacid,16-methyl-,methyl ester in wax could make plants susceptible to CLCuV , infested by whiteflies.

Effect of reagins and allergen extracts on radioallergosorbent assays for mite allergen

International Nuclear Information System (INIS)

Tovey, E.R.; Vandenberg, R.A.

1978-01-01

The reproducibility of the radioallergosorbent (RAST) inhibition and direct binding assays with mite allergen were investigated in the presence of heterogeneous extracts and non-mite sensitive atopic sera. Both contain components similar to potential contaminants which would occur in the assay of mite allergen and dust allergen extracts. The standardized inhibition and direct binding assays employed had a day to day (n = 4) coefficient of variation [(s.d. x 100)/mean] of 15% and 24% respectively. The inhibition assay for mite allergen was reproducible in the presence of protein concentrations of added plant, fungal, arthropod and animal extracts in excess of the protein concentrations that occur under the operational mite assay conditions. The mite inhibition assay was also reproducible in the presence of non-mite allergen extracts, with and without additional sera containing IgE specific for the non0mite allergens. The binding of a constant quantity of mite allergen to the activated solid phase in the direct binding assay was reproducible in the presence of added bovine serum albumin, and of a fungal or arthropod extract, representing the heterogeneous components of an allergen extract at the concentrations of total protein known to occur in the direct binding assay of mite extracts. (author)

Mites and fungi in heavily infested stores in the Czech Republic.

Science.gov (United States)

Hubert, J; Stejskal, V; Munzbergová, Z; Kubátová, A; Vánová, M; Zd'árková, E

2004-12-01

Toxigenic and allergen-producing fungi represent a serious hazard to human food and animal feed safety. Ninety-four fungal species were isolated from mite-infested samples of seeds taken from Czech seed stores. Fungi were isolated from the surface of four kinds of seeds (wheat, poppy, lettuce, and mustard) and from the gut and external surface of five species of mites (i.e., Acarus siro L., 1758, Caloglyphus rhizoglyphoides (Zachvatkin, 1973), Lepidoglyphus destructor (Schrank, 1781), Tyrophagus putrescentnae (Schrank, 1781) and Cheyletus malaccensis Oudemans 1903) separately. Multivariate analysis of fungi complex composition showed that the frequency of fungal was species significantly influenced by the kind of seed. Fungal frequencies differed between mites gut and exoskeleton surface and between the surfaces of mites and seeds. Three groups of fungal species were recognized: 1) mite surface-associated fungi: Penicillium brevicompactum, Alternaria alternata, and Aspergillus versicolor; 2) mite surface- and seed-associated fungi: Aspergillus niger, Penicillium crustosum, Penicillium aurantiogriseum, Penicillium chrysogenum, and Aspergillus flavus; and 3) seed-associated fungi: Cladosporium herbarum, Mucor dimorphosporus f. dimorphosporus, Botrytis cinerea, Penicillium griseofulvum, and Eurotium repens. Mite-carried species of microfungi are known to produce serious mycotoxins (e.g., aflatoxin B1, cyclopiazonic acid, sterigmatocystin, ochratoxin A, and nephrotoxic glycopeptides) as well as allergen producers (e.g., A. alternata and P. brevicompactum). Storage mites may play an important role in the spread of some medically hazardous micromycetes. In addition, these mite-fungi associations may heighten the risk of occurrence of mycotoxins in food and feed stuffs and cause mixed contamination by fungal and mite allergens.

Brain metabolomic profiling of eastern honey bee (Apis cerana infested with the mite Varroa destructor.

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Jiang-Li Wu

Full Text Available The mite Varroa destructor is currently the greatest threat to apiculture as it is causing a global decrease in honey bee colonies. However, it rarely causes serious damage to its native hosts, the eastern honey bees Apis cerana. To better understand the mechanism of resistance of A. cerana against the V. destructor mite, we profiled the metabolic changes that occur in the honey bee brain during V. destructor infestation. Brain samples were collected from infested and control honey bees and then measured using an untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS-based global metabolomics method, in which 7918 and 7462 ions in ESI+ and ESI- mode, respectively, were successfully identified. Multivariate statistical analyses were applied, and 64 dysregulated metabolites, including fatty acids, amino acids, carboxylic acid, and phospholipids, amongst others, were identified. Pathway analysis further revealed that linoleic acid metabolism; propanoate metabolism; and glycine, serine, and threonine metabolism were acutely perturbed. The data obtained in this study offer insight into the defense mechanisms of A. cerana against V. destructor mites and provide a better method for understanding the synergistic effects of parasitism on honey bee colonies.

Differential Gene Expression Associated with Honey Bee Grooming Behavior in Response to Varroa Mites.

Science.gov (United States)

Hamiduzzaman, Mollah Md; Emsen, Berna; Hunt, Greg J; Subramanyam, Subhashree; Williams, Christie E; Tsuruda, Jennifer M; Guzman-Novoa, Ernesto

2017-05-01

Honey bee (Apis mellifera) grooming behavior is an important mechanism of resistance against the parasitic mite Varroa destructor. This research was conducted to study associations between grooming behavior and the expression of selected immune, neural, detoxification, developmental and health-related genes. Individual bees tested in a laboratory assay for various levels of grooming behavior in response to V. destructor were also analyzed for gene expression. Intense groomers (IG) were most efficient in that they needed significantly less time to start grooming and fewer grooming attempts to successfully remove mites from their bodies than did light groomers (LG). In addition, the relative abundance of the neurexin-1 mRNA, was significantly higher in IG than in LG, no groomers (NG) or control (bees without mite). The abundance of poly U binding factor kd 68 and cytochrome p450 mRNAs were significantly higher in IG than in control bees. The abundance of hymenoptaecin mRNA was significantly higher in IG than in NG, but it was not different from that of control bees. The abundance of vitellogenin mRNA was not changed by grooming activity. However, the abundance of blue cheese mRNA was significantly reduced in IG compared to LG or NG, but not to control bees. Efficient removal of mites by IG correlated with different gene expression patterns in bees. These results suggest that the level of grooming behavior may be related to the expression pattern of vital honey bee genes. Neurexin-1, in particular, might be useful as a bio-marker for behavioral traits in bees.

Below-ground plant parts emit herbivore-induced volatiles: olfactory responses of a predatory mite to tulip bulbs infested by rust mites.

Science.gov (United States)

Aratchige, N S; Lesna, I; Sabelis, M W

2004-01-01

Although odour-mediated interactions among plants, spider mites and predatory mites have been extensively studied above-ground, belowground studies are in their infancy. In this paper, we investigate whether feeding by rust mites (Aceria tulipae) cause tulip bulbs to produce odours that attract predatory mites (Neoseiulus cucumeris). Since our aim was to demonstrate such odours and not their relevance under soil conditions, the experiments were carried out using a classic Y-tube olfactometer in which the predators moved on a Y-shaped wire in open air. We found that food-deprived female predators can discriminate between odours from infested bulbs and odours from uninfested bulbs or artificially wounded bulbs. No significant difference in attractiveness to predators was found between clean bulbs and bulbs either wounded 30 min or 3 h before the experiment. These results indicate that it may not be simply the wounding of the bulbs, but rather the feeding by rust mites, which causes the bulb to release odours that attract N. cucumeris. Since bulbs are belowground plant structures, the olfactometer results demonstrate the potential for odour-mediated interactions in the soil. However, their importance in the actual soil medium remains to be demonstrated.

Investigations on the Effects of Five Different Plant Extracts on the Two-Spotted Mite Tetranychus urticae Koch (Arachnida: Tetranychidae

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Pervin Erdogan

2012-01-01

Full Text Available Two-spotted mite, Tetranychus urticae Koch (Arac.: Tetranychidae, is an economic pest worldwide including Turkey, causing serious damage to vegetables, flowers, and fruit crops. In recent years, broad-spectrum insecticides/miticides have been used to control this pest in Turkey. Control is difficult mainly due to resistance to conventional pesticides. This study was conducted to determine efficacy of pesticides extracted from five different plants [i.e., Allium sativum L. (Amaryllidaceae, Rhododendron luteum S. (Ericaceae, Helichrysum arenarium L. (Asteraceae, Veratrum album L. (Liliaceae, and Tanacetum parthenium L. (Asteraceae] against this mite. Bioassays were tested by two different methods to determine the effects of varying concentrations. Experiments were performed using 3 cm diameter leaf disk from unsprayed bean plants (Phaseolus vulgaris L.. In addition, the effects of the extracts on reproduction and oviposition were investigated. The extract yielded high mortality. In the lowest-concentration bioassays, the adult mites laid lower numbers of eggs compared to the untreated control. No ovicidal effect was observed.

Sensitization to 10 mites in a tropic area. Der p and Der f are important risk factor for sensitization to other mites from Pyroglyphidae, Acaridae, Chortoglyphidae, and Glyciphagidae families

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Jorge Sánchez

2017-06-01

Full Text Available Background: Much is known about the frequency of sensitization to Blomia tropicalis, Dermatophagoides pteronyssinus and Dermatophagoides farinae, although less is known about sensitization to other species and their possible interactions. Objective: In patients with allergic manifestations, to evaluate the frequency of sensitization to 10 species of mites in a tropical area and their possible interactions. Methods: Cross-sectional study. Sensitization was evaluated by skin tests. A generalized linear Poisson regression model with robust variance was used. Based on the sensitization probability reasons and social networking analysis, explorations of relationship for 10 mites were performed. Results: 147 patients were included. The highest sensitization was found to mites' family Pyroglyphidae (> 70 % and less frequently was the Glycyphagidae family (< 50 %. Sensitization to any mites significantly increased the likelihood of sensitization to others. Sensitization to Der f or Der p increased, more than 20 times the likelihood of sensitization to other mites of the Pyroglyphidae family and more than 10 times to mites from other families. Sensitization to mites from Glycyphagidae, Chortoglyphidae or Acaridae family also increased the risk of sensitization to other mites but less than 5 times. Conclusion: Sensitization to mites is frequent in tropical area. Pyroglyphidae sensitization is the main risk factor for polysensitization with other mites from Glycyphagidae, Chortoglyphidae or Acaridae. These results must be considered at diagnosis and treatment of allergy diseases.

House-dust mites in our homes are a contamination from outdoor sources.

Science.gov (United States)

Hallas, Thorkil E

2010-05-01

Avoidance advices for house-dust mite sensitized persons are currently based upon the idea, that the mites (Dermatophagoides spp.) are part of the indoor fauna. A closer look at development stages in the house-dust samples shows, however, that only the mites' active stages are present there and that the stages between them, the inactive moulting stages, are absent. Therefore the mites probably do not carry out their life cycles in our dwellings, but are more likely contaminations from the open. Findings of low level concentrations can be explained by mites coming from outdoors and sedimented in accordance with known physical laws. The occasional finding of higher concentrations is the result of synchronized populations of the mites developing outdoors and being passively transported into our homes by wind and dust. The hypothesis explains why we find mites in our homes but nonetheless have no effect of avoidance measures. The verification of the entire hypothesis or part of it may have great impact on the management of the disease house-dust mite allergy.

Under the lash: Demodex mites in human diseases.

Science.gov (United States)

Lacey, Noreen; Kavanagh, Kevin; Tseng, Scheffer C G

2009-08-01

Demodex mites, class Arachnida and subclass Acarina, are elongated mites with clear cephalothorax and abdomens, the former with four pairs of legs. There are more than 100 species of Demodex mite, many of which are obligatory commensals of the pilosebaceous unit of mammals including cats, dogs, sheep, cattle, pigs, goats, deer, bats, hamsters, rats and mice. Among them, Demodex canis, which is found ubiquitously in dogs, is the most documented and investigated. In excessive numbers D. canis causes the inflammatory disease termed demodicosis (demodectic mange, follicular mange or red mange), which is more common in purebred dogs and has a hereditary predisposition in breeding kennels1. Two distinct Demodex species have been confirmed as the most common ectoparasite in man. The larger Demodex folliculorum, about 0.3-0.4 mm long, is primarily found as a cluster in the hair follicle (Figure 1a), while the smaller Demodex brevis, about 0.2-0.3 mm long with a spindle shape and stubby legs, resides solitarily in the sebaceous gland (Figure 1b). These two species are also ubiquitously found in all human races without gender preference. The pathogenic role of Demodex mites in veterinary medicine is not as greatly disputed as in human diseases. In this article, we review the key literature and our joint research experience regarding the pathogenic potential of these two mites in causing inflammatory diseases of human skin and eye. We hope that the evidence summarized herein will invite readers to take a different look at the life of Demodex mites in several common human diseases.

Geostatistics as a tool to study mite dispersion in physic nut plantations.

Science.gov (United States)

Rosado, J F; Picanço, M C; Sarmento, R A; Pereira, R M; Pedro-Neto, M; Galdino, T V S; de Sousa Saraiva, A; Erasmo, E A L

2015-08-01

Spatial distribution studies in pest management identify the locations where pest attacks on crops are most severe, enabling us to understand and predict the movement of such pests. Studies on the spatial distribution of two mite species, however, are rather scarce. The mites Polyphagotarsonemus latus and Tetranychus bastosi are the major pests affecting physic nut plantations (Jatropha curcas). Therefore, the objective of this study was to measure the spatial distributions of P. latus and T. bastosi in the physic nut plantations. Mite densities were monitored over 2 years in two different plantations. Sample locations were georeferenced. The experimental data were analyzed using geostatistical analyses. The total mite density was found to be higher when only one species was present (T. bastosi). When both the mite species were found in the same plantation, their peak densities occurred at different times. These mites, however, exhibited uniform spatial distribution when found at extreme densities (low or high). However, the mites showed an aggregated distribution in intermediate densities. Mite spatial distribution models were isotropic. Mite colonization commenced at the periphery of the areas under study, whereas the high-density patches extended until they reached 30 m in diameter. This has not been reported for J. curcas plants before.

Novel Mutations in the Voltage-Gated Sodium Channel of Pyrethroid-Resistant Varroa destructor Populations from the Southeastern USA

Science.gov (United States)

González-Cabrera, Joel; Rodríguez-Vargas, Sonia; Davies, T. G. Emyr; Field, Linda M.; Schmehl, Daniel; Ellis, James D.; Krieger, Klemens; Williamson, Martin S.

2016-01-01

The parasitic mite Varroa destructor has a significant worldwide impact on bee colony health. In the absence of control measures, parasitized colonies invariably collapse within 3 years. The synthetic pyrethroids tau-fluvalinate and flumethrin have proven very effective at managing this mite within apiaries, but intensive control programs based mainly on one active ingredient have led to many reports of pyrethroid resistance. In Europe, a modification of leucine to valine at position 925 (L925V) of the V. destructor voltage-gated sodium channel was correlated with resistance, the mutation being found at high frequency exclusively in hives with a recent history of pyrethroid treatment. Here, we identify two novel mutations, L925M and L925I, in tau-fluvalinate resistant V. destructor collected at seven sites across Florida and Georgia in the Southeastern region of the USA. Using a multiplexed TaqMan® allelic discrimination assay, these mutations were found to be present in 98% of the mites surviving tau-fluvalinate treatment. The mutations were also found in 45% of the non-treated mites, suggesting a high potential for resistance evolution if selection pressure is applied. The results from a more extensive monitoring programme, using the Taqman® assay described here, would clearly help beekeepers with their decision making as to when to include or exclude pyrethroid control products and thereby facilitate more effective mite management programmes. PMID:27191597

Novel Mutations in the Voltage-Gated Sodium Channel of Pyrethroid-Resistant Varroa destructor Populations from the Southeastern USA.

Science.gov (United States)

González-Cabrera, Joel; Rodríguez-Vargas, Sonia; Davies, T G Emyr; Field, Linda M; Schmehl, Daniel; Ellis, James D; Krieger, Klemens; Williamson, Martin S

2016-01-01

The parasitic mite Varroa destructor has a significant worldwide impact on bee colony health. In the absence of control measures, parasitized colonies invariably collapse within 3 years. The synthetic pyrethroids tau-fluvalinate and flumethrin have proven very effective at managing this mite within apiaries, but intensive control programs based mainly on one active ingredient have led to many reports of pyrethroid resistance. In Europe, a modification of leucine to valine at position 925 (L925V) of the V. destructor voltage-gated sodium channel was correlated with resistance, the mutation being found at high frequency exclusively in hives with a recent history of pyrethroid treatment. Here, we identify two novel mutations, L925M and L925I, in tau-fluvalinate resistant V. destructor collected at seven sites across Florida and Georgia in the Southeastern region of the USA. Using a multiplexed TaqMan® allelic discrimination assay, these mutations were found to be present in 98% of the mites surviving tau-fluvalinate treatment. The mutations were also found in 45% of the non-treated mites, suggesting a high potential for resistance evolution if selection pressure is applied. The results from a more extensive monitoring programme, using the Taqman® assay described here, would clearly help beekeepers with their decision making as to when to include or exclude pyrethroid control products and thereby facilitate more effective mite management programmes.

Morphology of the olfactory system in the predatory mite Phytoseiulus persimilis

NARCIS (Netherlands)

van Wijk, M.; Wadman, W.J.; Sabelis, M.W.

2006-01-01

The predatory mite Phytoseiulus persimilis locates its prey, the two-spotted spider mite, by means of herbivore-induced plant volatiles. The olfactory response to this quantitatively and qualitatively variable source of information is particularly well documented. The mites perform this task with a

Ecology, life history and management of tropilaelaps mites

Science.gov (United States)

Parasitic mites are the major threat of the Western honey bee, Apis mellifera. For much of the world, Varroa destructor single-handedly inflicts unsurmountable problems to A. mellifera beekeeping. However, A. mellifera in Asia is also faced with another genus of destructive parasitic mite, Tropilae...

Natural biological control of pest mites in Brazilian sun coffee agroecosystems.

Science.gov (United States)

Teodoro, Adenir V; Sarmento, Renato A; Rêgo, Adriano S; da Graça S Maciel, Anilde

2010-06-01

Coffee is one of the leading commodities in tropical America. Although plantations are usually established under a canopy of trees in most producing countries in the region, Brazilian coffee is mostly produced under full sun conditions. Such simple, single-crop agroecosystems with intensive agrochemical inputs often suffer with pests like mites. Predatory mites of the family Phytoseiidae are the main natural enemies associated with pest mites in the field. However, these beneficial arthropods struggle to survive in intensive agroecosystems such as coffee monocultures due to unfavorable microclimatic conditions, widespread pesticide use, and lack of alternative food (pollen, nectar). Conservation biological control uses a range of management strategies to sustain and enhance populations of indigenous natural enemies such as predatory mites. We discuss here conservation biological control as a strategy to improve biological control of pest mites by native predatory mites in Brazilian coffee monocultures as well as some related patents.

The effect of antibiotics on associated bacterial community of stored product mites.

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Jan Kopecky

Full Text Available Bacteria are associated with the gut, fat bodies and reproductive organs of stored product mites (Acari: Astigmata. The mites are pests due to the production of allergens. Addition of antibiotics to diets can help to characterize the association between mites and bacteria.Ampicillin, neomycin and streptomycin were added to the diets of mites and the effects on mite population growth (Acarus siro, Lepidoglyphus destructor and Tyrophagus putrescentiae and associated bacterial community structure were assessed. Mites were treated by antibiotic supplementation (1 mg g(-1 of diet for 21 days and numbers of mites and bacterial communities were analyzed and compared to the untreated control. Bacterial quantities, determined by real-time PCR, significantly decreased in antibiotic treated specimens from 5 to 30 times in A. siro and T. putrescentiae, while no decline was observed in L. destructor. Streptomycin treatment eliminated Bartonella-like bacteria in the both A. siro and T. putrescentiae and Cardinium in T. putrescentiae. Solitalea-like bacteria proportion increased in the communities of neomycin and streptomycin treated A. siro specimens. Kocuria proportion increased in the bacterial communities of ampicillin and streptomycin treated A. siro and neomycin and streptomycin treated L. destructor.The work demonstrated the changes of mite associated bacterial community under antibiotic pressure in pests of medical importance. Pre-treatment of mites by 1 mg g(-1 antibiotic diets improved mite fitness as indicated accelerated population growth of A. siro pretreated streptomycin and neomycin and L. destructor pretreated by neomycin. All tested antibiotics supplemented to diets caused the decrease of mite growth rate in comparison to the control diet.

Storage mite contamination of commercial dry dog food in south-eastern Australia.

Science.gov (United States)

Hibberson, C E; Vogelnest, L J

2014-06-01

To evaluate contamination of unopened and opened stored sources of commercial dry dog food by viable storage mites. Prospective laboratory and field study. Samples were collected from nine brands of previously unopened bags (new bags) of dry food and 20 field sources of stored dry food in homes in Sydney and Canberra, Australia. All samples were initially examined for the presence of mites using a stereo-binocular microscope and then placed in separate filter-paper-sealed containers. Field samples were incubated at an average temperature of 29°C and 78% relative humidity (RH) for 5 weeks and then at average 26°C/83% RH for 8 weeks. Paired new-bag samples were stored under room conditions (average 23°C/47% RH) and controlled incubator conditions (average 26°C/80% RH) for 6 weeks. All samples were thoroughly examined for mites, mite eggs and visible mould once weekly using a stereo-binocular microscope. Storage mites were not visualised in any of the field samples or in new-bag samples stored at room temperature. Storage mites, identified as Tyrophagus putrescentiae, were visualised in increasing numbers in seven of nine new-bag samples after incubation, with first mites and then eggs evident after 3 weeks of incubation. We confirmed the presence of viable storage mites in a range of previously unopened commercial dry dog foods in Australia and confirmed the possibility of heavy storage mite contamination for dry food stored under conditions of moderate temperature and high humidity. These findings have relevance to storage mite and/or dust mite sensitivity in canine atopic dermatitis. © 2014 Australian Veterinary Association.

Is the begomovirus, sweet potato leaf curl virus, really seed transmitted in sweetpotato?

Science.gov (United States)

Sweetpotato is one of the major root crops in the world and is also widely grown in the southern United States. Sweet potato leaf curl virus (SPLCV) is a begomovirus posing a serious threat to sweetpotato production worldwide and is primarily transmitted by whitefly (Bemisia tabaci) or through veget...

House-dust mites in our homes are a contamination from outdoor sources

DEFF Research Database (Denmark)

Hallas, Thorkil E.

2010-01-01

there and that the stages between them, the inactive moulting stages, are absent. Therefore the mites probably do not carry out their life cycles in our dwellings, but are more likely contaminations from the open. Findings of low level concentrations can be explained by mites coming from outdoors and sedimented......Avoidance advices for house-dust mite sensitized persons are currently based upon the idea, that the mites (Dermatophagoides spp.) are part of the indoor fauna. A closer look at development stages in the house-dust samples shows, however, that only the mites' active stages are present...... no effect of avoidance measures. The verification of the entire hypothesis or part of it may have great impact on the management of the disease house-dust mite allergy....

Ubiquity and diversity of human-associated Demodex mites.

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Megan S Thoemmes

Full Text Available Demodex mites are a group of hair follicle and sebaceous gland-dwelling species. The species of these mites found on humans are arguably the animals with which we have the most intimate interactions. Yet, their prevalence and diversity have been poorly explored. Here we use a new molecular method to assess the occurrence of Demodex mites on humans. In addition, we use the 18S rRNA gene (18S rDNA to assess the genetic diversity and evolutionary history of Demodex lineages. Within our samples, 100% of people over 18 years of age appear to host at least one Demodex species, suggesting that Demodex mites may be universal associates of adult humans. A phylogenetic analysis of 18S rDNA reveals intraspecific structure within one of the two named human-associated Demodex species, D. brevis. The D. brevis clade is geographically structured, suggesting that new lineages are likely to be discovered as humans from additional geographic regions are sampled.

Can Plant Defence Mechanisms Provide New Approaches for the Sustainable Control of the Two-Spotted Spider Mite Tetranychus urticae?

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Blas Agut

2018-02-01

Full Text Available Tetranychus urticae (T. urticae Koch is a cosmopolitan, polyphagous mite which causes economic losses in both agricultural and ornamental plants. Some traits of T. urticae hamper its management, including a short life cycle, arrhenotokous parthenogenesis, its haplodiploid sex determination system, and its extraordinary ability to adapt to different hosts and environmental conditions. Currently, the use of chemical and biological control are the major control methods used against this mite. In recent years, some studies have focused on plant defence mechanisms against herbivores. Various families of plant compounds (such as flavonoids, glucosinolates, or acyl sugars have been shown to behave as acaricides. Plants can be induced upon appropriate stimuli to increase their resistance against spider mites. This knowledge, together with the understanding of mechanisms by which T. urticae detoxifies and adapts to pesticides, may complement the control of this pest. Herein, we describe plant volatile compounds (VOCs with repellent activity, and new findings about defence priming against spider mites, which interfere with the T. urticae performance. The use of VOCs and defence priming can be integrated into current management practices and reduce the damage caused by T. urticae in the field by implementing new, more sustainable crop management tools.

Mites (acari) infesting commensal rats in Suez Canal zone, Egypt.

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el Kady, G A; Shoukry, A; Ragheb, D A; el Said, A M; Habib, K S; Morsy, T A

1995-08-01

Mites are arthropods distinguished from ticks by usually being microscopical in size and have a hypostome unarmed with tooth-like anchoring processes. They are group in a number of suborders, each with super-families and families including many genera of medical and economic importance. In this paper, commensal rodents (Rattus norvegicus, R. r. alexandrinus and R. r. frugivorous) were surveyed in the Suez Canal Zone for their acari ectoparasites. Four species of mites were recovered. In a descending order of mite indices, they were Eulaelaps stabularis (4.83 on 6 rats), Laelaps nuttalli (3.11 on 27 rats), Ornithonyssus bacoti (1.66 on 9 rats) and Dermanyssus gallinae (0.66 on 24 rats). The overall mite indices in the three governorates were 3.66 in Suez, 2.82 in Ismailia and zero in Port Said. The medical and economic importance of the mites were discussed.

Arrhenotoky and oedipal mating in the northern fowl mite (Ornithonyssus sylviarum (Acari: Gamasida: Macronyssidae

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McCulloch John B

2012-12-01

Full Text Available Abstract Background The northern fowl mite (NFM; Ornithonyssus sylviarum is a blood-feeding ectoparasite of birds and a major pest of poultry in the United States. Mite populations spread rapidly in commercial flocks, reach peak burdens of >70,000 mites per bird and have developed resistance to many pesticides. Despite decades as a pest in the United States, the reproductive biology of NFM remains unclear. Based on karyotypes, the NFM has haplodiploid sex determination, which suggests unmated females could produce male offspring (arrhenotoky. Thus, unmated females could disseminate to a new host and initiate an infestation by producing and mating with sons (oedipal mating. Methods We used small capsules to isolate and recover NFM on host chickens. Mites in capsules could blood feed, develop and reproduce, but could not contact other mites. Individual larvae were matured in isolation to produce known, unmated females. We evaluated reproduction of (I previously mated females (i in isolation, or (ii paired with a male, and (II unmated (virgin females in isolation. In each treatment we recorded the number and sexes of offspring produced over time. Results Mated NFM produced female and male offspring in isolation, or when paired with a male. When paired with a male, females produced a female-biased sex ratio of the offspring (F:M ratio ~5:1. Unmated, female NFM produced exclusively male offspring when in isolation. When paired with their sons that had developed to maturity, the "virgin" females were able to mate and subsequently produce female offspring. Conclusions This study found that females with immediate access to sperm produced mostly female offspring. Virgin female NFM initially produced only male offspring and subsequently used oedipal mating to produce female offspring. Using this reproductive system NFM could successfully colonize new hosts as immature, or unmated females. The strong female-biased sex ratio of NFM populations suggests a

Resistance in Cucumis sativus L. to Tetranychus urticae Koch

NARCIS (Netherlands)

Ponti, de O.M.B.

1980-01-01

Chapter 1
The role of plant breeding and particularly of host plant resistance in integrated control is discussed. Host plant resistance to insects and mites, especially to Tetranychus urticae is reviewed. A standard terminology for disease and pest

Weed management practices affect the diversity and relative abundance of physic nut mites.

Science.gov (United States)

Saraiva, Althiéris de Sousa; Sarmento, Renato A; Erasmo, Eduardo A L; Pedro-Neto, Marçal; de Souza, Danival José; Teodoro, Adenir V; Silva, Daniella G

2015-03-01

Crop management practices determine weed community, which in turn may influence patterns of diversity and abundance of associated arthropods. This study aimed to evaluate whether local weed management practices influence the diversity and relative abundance of phytophagous and predatory mites, as well as mites with undefined feeding habits--of the families Oribatidae and Acaridae--in a physic nut (Jatropha curcas L.) plantation subjected to (1) within-row herbicide spraying and between-row mowing; (2) within-row herbicide spraying and no between-row mowing; (3) within-row weeding and between-row mowing; (4) within-row weeding and no between-row mowing; and (5) unmanaged (control). The herbicide used was glyphosate. Herbicide treatments resulted in higher diversity and relative abundance of predatory mites and mites with undefined feeding habit on physic nut shrubs. This was probably due to the toxic effects of the herbicide on mites or to removal of weeds. Within-row herbicide spraying combined with between-row mowing was the treatment that most contributed to this effect. Our results show that within-row weeds harbor important species of predatory mites and mites with undefined feeding habit. However, the dynamics of such mites in the system can be changed according to the weed management practice applied. Among the predatory mites of the family Phytoseiidae Amblydromalus sp. was the most abundant, whereas Brevipalpus phoenicis was the most frequent phytophagous mite and an unidentified oribatid species was the most frequent mite with undefined feeding habit.

Role of secondary metabolites biosynthesis in resistance to cotton ...

African Journals Online (AJOL)

use

2011-12-12

Dec 12, 2011 ... Disease percentage on six cotton varieties with respect to time for cotton leaf curl virus (CLCuV) was evaluated. In August 2007, the maximum disease was observed in CIM-506, CYTO-89 and BH-118. (susceptible), whereas CIM-443 was resistant with lower disease percentage. It was found that the leaf.

Discovering Host Genes Involved in the Infection by the Tomato Yellow Leaf Curl Virus Complex and in the Establishment of Resistance to the Virus Using Tobacco Rattle Virus-based Post Transcriptional Gene Silencing

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Rosa Lozano-Durán

2013-03-01

Full Text Available The development of high-throughput technologies allows for evaluating gene expression at the whole-genome level. Together with proteomic and metabolomic studies, these analyses have resulted in the identification of plant genes whose function or expression is altered as a consequence of pathogen attacks. Members of the Tomato yellow leaf curl virus (TYLCV complex are among the most important pathogens impairing production of agricultural crops worldwide. To understand how these geminiviruses subjugate plant defenses, and to devise counter-measures, it is essential to identify the host genes affected by infection and to determine their role in susceptible and resistant plants. We have used a reverse genetics approach based on Tobacco rattle virus-induced gene silencing (TRV-VIGS to uncover genes involved in viral infection of susceptible plants, and to identify genes underlying virus resistance. To identify host genes with a role in geminivirus infection, we have engineered a Nicotiana benthamiana line, coined 2IRGFP, which over-expresses GFP upon virus infection. With this system, we have achieved an accurate description of the dynamics of virus replication in space and time. Upon silencing selected N. benthamiana genes previously shown to be related to host response to geminivirus infection, we have identified eighteen genes involved in a wide array of cellular processes. Plant genes involved in geminivirus resistance were studied by comparing two tomato lines: one resistant (R, the other susceptible (S to the virus. Sixty-nine genes preferentially expressed in R tomatoes were identified by screening cDNA libraries from infected and uninfected R and S genotypes. Out of the 25 genes studied so far, the silencing of five led to the total collapse of resistance, suggesting their involvement in the resistance gene network. This review of our results indicates that TRV-VIGS is an exquisite reverse genetics tool that may provide new insights into the

A study on the strength of leg extention and leg curl exercise measured with the "Tremax System" and the "ADR" (Aero Dynamic Resistance System)

OpenAIRE

安藤, 勝英

1995-01-01

This is a study on the nature of the extensor and flexor muscles by the leg extention and leg curl exercise. The strength of the static muscles were measured with the "Tremax system" and for the strength of the dynamic muscles the "ADR" was used. Measuring the strength of the extensor muscles at bar no.1 to 4 of the Tremax System，it comes to a maximum at bar no.2 (extention 60°) but it declines radically when approaching extention 0°. Compared to the extensor muscles, the flexor muscules show...

Identification of a disease complex involving a novel monopartite begomovirus with beta- and alphasatellites associated with okra leaf curl disease in Oman.

Science.gov (United States)

Akhtar, Sohail; Khan, Akhtar J; Singh, Achuit S; Briddon, Rob W

2014-05-01

Okra leaf curl disease (OLCD) is an important viral disease of okra in tropical and subtropical areas. The disease is caused by begomovirus-satellite complexes. A begomovirus and associated betasatellite and alphasatellite were identified in symptomatic okra plants from Barka, in the Al-Batinah region of Oman. Analysis of the begomovirus sequences showed them to represent a new begomovirus most closely related to cotton leaf curl Gezira virus (CLCuGeV), a begomovirus of African origin. The sequences showed less than 85 % nucleotide sequence identity to CLCuGeV isolates. The name okra leaf curl Oman virus (OLCOMV) is proposed for the new virus. Further analysis revealed that the OLCOMV is a recombinant begomovirus that evolved by the recombination of CLCuGeV isolates with tomato yellow leaf curl virus-Oman (TYLCV-OM). An alpha- and a betasatellite were also identified from the same plant sample, which were also unique when compared to sequences available in the databases. However, although the betasatellite appeared to be of African origin, the alphasatellite was most closely related to alphasatellites originating from South Asia. This is the first report of a begomovirus-satellite complex infecting okra in Oman.

Sarcoptes scabiei mites modulate gene expression in human skin equivalents.

Directory of Open Access Journals (Sweden)

Marjorie S Morgan

Full Text Available The ectoparasitic mite, Sarcoptes scabiei that burrows in the epidermis of mammalian skin has a long co-evolution with its hosts. Phenotypic studies show that the mites have the ability to modulate cytokine secretion and expression of cell adhesion molecules in cells of the skin and other cells of the innate and adaptive immune systems that may assist the mites to survive in the skin. The purpose of this study was to identify genes in keratinocytes and fibroblasts in human skin equivalents (HSEs that changed expression in response to the burrowing of live scabies mites. Overall, of the more than 25,800 genes measured, 189 genes were up-regulated >2-fold in response to scabies mite burrowing while 152 genes were down-regulated to the same degree. HSEs differentially expressed large numbers of genes that were related to host protective responses including those involved in immune response, defense response, cytokine activity, taxis, response to other organisms, and cell adhesion. Genes for the expression of interleukin-1α (IL-1α precursor, IL-1β, granulocyte/macrophage-colony stimulating factor (GM-CSF precursor, and G-CSF precursor were up-regulated 2.8- to 7.4-fold, paralleling cytokine secretion profiles. A large number of genes involved in epithelium development and keratinization were also differentially expressed in response to live scabies mites. Thus, these skin cells are directly responding as expected in an inflammatory response to products of the mites and the disruption of the skin's protective barrier caused by burrowing. This suggests that in vivo the interplay among these skin cells and other cell types, including Langerhans cells, dendritic cells, lymphocytes and endothelial cells, is responsible for depressing the host's protective response allowing these mites to survive in the skin.

Sarcoptes scabiei Mites Modulate Gene Expression in Human Skin Equivalents

Science.gov (United States)

Morgan, Marjorie S.; Arlian, Larry G.; Markey, Michael P.

2013-01-01

The ectoparasitic mite, Sarcoptes scabiei that burrows in the epidermis of mammalian skin has a long co-evolution with its hosts. Phenotypic studies show that the mites have the ability to modulate cytokine secretion and expression of cell adhesion molecules in cells of the skin and other cells of the innate and adaptive immune systems that may assist the mites to survive in the skin. The purpose of this study was to identify genes in keratinocytes and fibroblasts in human skin equivalents (HSEs) that changed expression in response to the burrowing of live scabies mites. Overall, of the more than 25,800 genes measured, 189 genes were up-regulated >2-fold in response to scabies mite burrowing while 152 genes were down-regulated to the same degree. HSEs differentially expressed large numbers of genes that were related to host protective responses including those involved in immune response, defense response, cytokine activity, taxis, response to other organisms, and cell adhesion. Genes for the expression of interleukin-1α (IL-1α) precursor, IL-1β, granulocyte/macrophage-colony stimulating factor (GM-CSF) precursor, and G-CSF precursor were up-regulated 2.8- to 7.4-fold, paralleling cytokine secretion profiles. A large number of genes involved in epithelium development and keratinization were also differentially expressed in response to live scabies mites. Thus, these skin cells are directly responding as expected in an inflammatory response to products of the mites and the disruption of the skin’s protective barrier caused by burrowing. This suggests that in vivo the interplay among these skin cells and other cell types, including Langerhans cells, dendritic cells, lymphocytes and endothelial cells, is responsible for depressing the host’s protective response allowing these mites to survive in the skin. PMID:23940705

A feeding protocol for delivery of agents to assess development in Varroa mites.

Directory of Open Access Journals (Sweden)

Ana R Cabrera

Full Text Available A novel feeding protocol for delivery of bio-active agents to Varroa mites was developed by providing mites with honey bee larva hemolymph supplemented with cultured insect cells and selected materials delivered on a fibrous cotton substrate. Mites were starved, fed on treated hemolymph to deliver selected agents and then returned to bee larvae. Transcript levels of two reference genes, actin and glyceraldehyde 3-phosphate dehydrogenase (GAPDH, as well as for nine selected genes involved in reproductive processes showed that the starvation and feeding protocol periods did not pose a high level of stress to the mites as transcript levels remained comparable between phoretic mites and those completing the protocol. The feeding protocol was used to deliver molecules such as hormone analogs or plasmids. Mites fed with Tebufenozide, an ecdysone analog, had higher transcript levels of shade than untreated or solvent treated mites. In order to extend this feeding protocol, cultured insect cells were incorporated to a final ratio of 1 part cells and 2 parts hemolymph. Although supplementation with Bombyx mori Bm5 cells increased the amount of hemolymph consumed per mite, there was a significant decrease in the percentage of mites that fed and survived. On the other hand, Drosophila melanogaster S2 cells reduced significantly the percentage of mites that fed and survived as well as the amount of hemolymph consumed. The feeding protocol provides a dynamic platform with which to challenge the Varroa mite to establish efficacy of control agents for this devastating honey bee pest.

Novel Mutations in the Voltage-Gated Sodium Channel of Pyrethroid-Resistant Varroa destructor Populations from the Southeastern USA.

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Joel González-Cabrera

Full Text Available The parasitic mite Varroa destructor has a significant worldwide impact on bee colony health. In the absence of control measures, parasitized colonies invariably collapse within 3 years. The synthetic pyrethroids tau-fluvalinate and flumethrin have proven very effective at managing this mite within apiaries, but intensive control programs based mainly on one active ingredient have led to many reports of pyrethroid resistance. In Europe, a modification of leucine to valine at position 925 (L925V of the V. destructor voltage-gated sodium channel was correlated with resistance, the mutation being found at high frequency exclusively in hives with a recent history of pyrethroid treatment. Here, we identify two novel mutations, L925M and L925I, in tau-fluvalinate resistant V. destructor collected at seven sites across Florida and Georgia in the Southeastern region of the USA. Using a multiplexed TaqMan® allelic discrimination assay, these mutations were found to be present in 98% of the mites surviving tau-fluvalinate treatment. The mutations were also found in 45% of the non-treated mites, suggesting a high potential for resistance evolution if selection pressure is applied. The results from a more extensive monitoring programme, using the Taqman® assay described here, would clearly help beekeepers with their decision making as to when to include or exclude pyrethroid control products and thereby facilitate more effective mite management programmes.

Naturally selected honey bee (Apis mellifera) colonies resistant to Varroa destructor do not groom more intensively

NARCIS (Netherlands)

Kruitwagen, Astrid; Langevelde, van Frank; Dooremalen, van Coby; Blacquière, Tjeerd

2017-01-01

The ectoparasitic mite Varroa destructor is an important cause of high colony losses of the honey bee Apis mellifera. In The Netherlands, two resistant A. mellifera populations developed naturally after ceasing varroa control. As a result, mite infestation levels of the colonies of these populations

Health effects of predatory beneficial mites and wasps in greenhouses

DEFF Research Database (Denmark)

Bælum, Jesper; Enkegaard, Annie; Doekes, Gert

A three-year study of 579 greenhouse workers in 31 firms investigated the effect of four different beneficial arthropods. It was shown that the thrips mite Amblyseeius cucumeris and the spider mite predator Phytoseiulus persimilis may cause allergy measured by blood tests as well as eye and nose...... symptoms. No effect was seen by the predator wasp Aphidius colemani nor the predator mite Hypoaspis miles and no effect on lung diseases were seen....

MITEE: A Compact Ultralight Nuclear Thermal Propulsion Engine for Planetary Science Missions

Science.gov (United States)

Powell, J.; Maise, G.; Paniagua, J.

2001-01-01

A new approach for a near-term compact, ultralight nuclear thermal propulsion engine, termed MITEE (Miniature Reactor Engine) is described. MITEE enables a wide range of new and unique planetary science missions that are not possible with chemical rockets. With U-235 nuclear fuel and hydrogen propellant the baseline MITEE engine achieves a specific impulse of approximately 1000 seconds, a thrust of 28,000 newtons, and a total mass of only 140 kilograms, including reactor, controls, and turbo-pump. Using higher performance nuclear fuels like U-233, engine mass can be reduced to as little as 80 kg. Using MITEE, V additions of 20 km/s for missions to outer planets are possible compared to only 10 km/s for H2/O2 engines. The much greater V with MITEE enables much faster trips to the outer planets, e.g., two years to Jupiter, three years to Saturn, and five years to Pluto, without needing multiple planetary gravity assists. Moreover, MITEE can utilize in-situ resources to further extend mission V. One example of a very attractive, unique mission enabled by MITEE is the exploration of a possible subsurface ocean on Europa and the return of samples to Earth. Using MITEE, a spacecraft would land on Europa after a two-year trip from Earth orbit and deploy a small nuclear heated probe that would melt down through its ice sheet. The probe would then convert to a submersible and travel through the ocean collecting samples. After a few months, the probe would melt its way back up to the MITEE lander, which would have replenished its hydrogen propellant by melting and electrolyzing Europa surface ice. The spacecraft would then return to Earth. Total mission time is only five years, starting from departure from Earth orbit. Other unique missions include Neptune and Pluto orbiter, and even a Pluto sample return. MITEE uses the cermet Tungsten-UO2 fuel developed in the 1960's for the 710 reactor program. The W-UO2 fuel has demonstrated capability to operate in 3000 K hydrogen for

The residual and direct effects of reduced-risk and conventional miticides on twospotted spider mites, Tetranychus urticae (Acari: Tetranychidae) and predatory mites (Acari: Phytoseiidae)

International Nuclear Information System (INIS)

Liburd, O.E.; White, J.C.; Rhodes, E.M.; Browdy, A.A.

2007-01-01

The residual effects of several reduced-risk and conventional miticides were evaluated in strawberries (Fragaria × ananassa Duchesne) on the twospotted spider mite (TSSM), Tetranychus urticae Koch (Acari: Tetranychidae) and on 2 predatory mites, Neoseiulus californicus McGregor and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae). Experiments were conducted in the laboratory and greenhouse. The greenhouse experiments also tested the direct effects of the miticides on TSSM. The efficacy of conventional and reduced-risk miticides was evaluated on strawberry leaf discs and on whole plants for control of TSSM. Furthermore, the residual effects of these miticides were evaluated on whole strawberry plants against selective predatory mites. For TSSM, 5 treatments were evaluated: a conventional miticide; fenbutatin-oxide (Vendex[reg]) and 3 reduced-risk miticides; binfenazate (Acramite 50WP[reg]), activated garlic extract (Repel[reg]), sesame seed and castor oil (Wipeout[reg]), and a water-treated control. For predatory mites, the residual effects of only Acramite[reg] and Vendex[reg] were evaluated. Acramite[reg] was the most effective acaricide in reducing TSSM populations in both the laboratory and greenhouse experiments. Vendex[reg] and Wipeout[reg] were also effective in the laboratory, but did not cause significant reduction of TSSM in the greenhouse. Repel[reg] was the least effective of the 4 pesticides evaluated. Neither Acramite[reg] nor Vendex[reg] had a significant effect on either predatory mite species. However, there appeared to be more predatory mites on the Vendex[reg]-treated plants than on the Acramite[reg]-treated plants. There were significantly more predatory mites of both species on the cue plants, which were inoculated with TSSM versus the non-cue plants, which were not inoculated. (author) [es

Direct measurement of conformational strain energy in protofilaments curling outward from disassembling microtubule tips.

Science.gov (United States)

Driver, Jonathan W; Geyer, Elisabeth A; Bailey, Megan E; Rice, Luke M; Asbury, Charles L

2017-06-19

Disassembling microtubules can generate movement independently of motor enzymes, especially at kinetochores where they drive chromosome motility. A popular explanation is the 'conformational wave' model, in which protofilaments pull on the kinetochore as they curl outward from a disassembling tip. But whether protofilaments can work efficiently via this spring-like mechanism has been unclear. By modifying a previous assay to use recombinant tubulin and feedback-controlled laser trapping, we directly demonstrate the spring-like elasticity of curling protofilaments. Measuring their mechanical work output suggests they carry ~25% of the energy of GTP hydrolysis as bending strain, enabling them to drive movement with efficiency similar to conventional motors. Surprisingly, a β-tubulin mutant that dramatically slows disassembly has no effect on work output, indicating an uncoupling of disassembly speed from protofilament strain. These results show the wave mechanism can make a major contribution to kinetochore motility and establish a direct approach for measuring tubulin mechano-chemistry.

Host preference of the sheep scab mite, Psoroptes ovis : short communication

Directory of Open Access Journals (Sweden)

T. Meintjies

2002-07-01

Full Text Available Sheep scab mites, Psoroptes ovis, collected from a Merino donor sheep, were used to infest Merino and Dorper sheep, and Angora and Boer goats. Mites were placed on the sheep on 1 or 2 occasions and on 5 occasions on the goats. All the animals were examined at regular intervals for the presence of scab lesions and living mites. Both sheep breeds developed lesions, but those on the Merino sheep were always larger than those on the Dorper sheep at the same intervals after infestation. None of the goats developed lesions or showed signs of irritation, or harboured any mites.

Invasion of Varroa mites into honey bee brood cells

NARCIS (Netherlands)

Boot, W.J.

1995-01-01

The parasitic mite Varroa-jacobsoni is one of the most serious pests of Western honey bees, Apis mellifera. The mites parasitize adult bees, but reproduction only occurs while parasitizing on honey bee brood. Invasion into a

The role of onion-associated fungi in bulb mite infestation and damage to onion seedlings.

Science.gov (United States)

Ofek, Tal; Gal, Shira; Inbar, Moshe; Lebiush-Mordechai, Sara; Tsror, Leah; Palevsky, Eric

2014-04-01

In Israel Rhizoglyphus robini is considered to be a pest in its own right, even though the mite is usually found in association with fungal pathogens. Plant protection recommendations are therefore to treat germinating onions seedlings, clearly a crucial phase in crop production, when mites are discovered. The aim of this study was to determine the role of fungi in bulb mite infestation and damage to germinating onion seedlings. Accordingly we (1) evaluated the effect of the mite on onion seedling germination and survival without fungi, (2) compared the attraction of the mite to species and isolates of various fungi, (3) assessed the effect of a relatively non-pathogenic isolate of Fusarium oxysporum on mite fecundity, and (4) determined the effects of the mite and of F. oxysporum separately and together, on onion seedling germination and sprout development. A significant reduction of seedling survival was recorded only in the 1,000 mites/pot treatment, after 4 weeks. Mites were attracted to 6 out of 7 collected fungi isolates. Mite fecundity on onion sprouts infested with F. oxysporum was higher than on non-infested sprouts. Survival of seedlings was affected by mites, fungi, and their combination. Sprouts on Petri dishes after 5 days were significantly longer in the control and mite treatments than both fungi treatments. During the 5-day experiment more mites were always found on the fungi-infected sprouts than on the non-infected sprouts. Future research using suppressive soils to suppress soil pathogens and subsequent mite damage is proposed.

New approach for the study of mite reproduction: The first transcriptome analysis of a mite, Phytoseiulus persimilis (Acari: Phytoseiidae).

Science.gov (United States)

Cabrera, Ana R; Donohue, Kevin V; Khalil, Sayed M S; Scholl, Elizabeth; Opperman, Charles; Sonenshine, Daniel E; Roe, R Michael

2011-01-01

Many species of mites and ticks are of agricultural and medical importance. Much can be learned from the study of transcriptomes of acarines which can generate DNA-sequence information of potential target genes for the control of acarine pests. High throughput transcriptome sequencing can also yield sequences of genes critical during physiological processes poorly understood in acarines, i.e., the regulation of female reproduction in mites. The predatory mite, Phytoseiulus persimilis, was selected to conduct a transcriptome analysis using 454 pyrosequencing. The objective of this project was to obtain DNA-sequence information of expressed genes from P. persimilis with special interest in sequences corresponding to vitellogenin (Vg) and the vitellogenin receptor (VgR). These genes are critical to the understanding of vitellogenesis, and they will facilitate the study of the regulation of mite female reproduction. A total of 12,556 contiguous sequences (contigs) were assembled with an average size of 935bp. From these sequences, the putative translated peptides of 11 contigs were similar in amino acid sequences to other arthropod Vgs, while 6 were similar to VgRs. We selected some of these sequences to conduct stage-specific expression studies to further determine their function. 2010 Elsevier Ltd. All rights reserved.

Irradiation as a phytosanitary treatment for mites of the specie Tyrophagus putrescentiae (Acari: Acaridae)

Energy Technology Data Exchange (ETDEWEB)

Arthur, Valter, E-mail: varthur@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Radiobiologia e Ambiente; Mineiro, Jeferson L.C. [Instituto Biologico de Sao Paulo/APTA, Sao Paulo, SP (Brazil). Lab. de Entomologia Economico

2009-07-01

In great populations mites of the specie Tyrophagus putrescentiae can cause damages in stored products. The work had as objective to evaluate the effects of the gamma radiation of the Cobalt-60 to control the mites of the specie T. putrescentiae. The mites were irradiated with doses of 0 (control), 300, 400, 500, 600, 700, 800 Gy, in a source of Cobalt-60 type Gammacell-220, with a dose rate of 0.718 kGy/hour. Each treatment consisted of four repetitions containing 10 mites each, in a total of approximately 40 mites for treatment. The evaluations were daily, being counted the number of mites died, put eggs and emerged larvae. Based on the obtained results it was concluded that the dose sterilizing for the mites of this specie was of 300 Gy. Already the dose of 600 Gy induced the total mortality of the mites after 11 days of the irradiation process. (author)

Candidate predators for biological control of the poultry red mite Dermanyssus gallinae

NARCIS (Netherlands)

Lesna, I.; Wolfs, P.; Faraji, F.; Roy, L.; Komdeur, J.; Sabelis, M.W.

2009-01-01

The poultry red mite, Dermanyssus gallinae, is currently a significant pest in the poultry industry in Europe. Biological control by the introduction of predatory mites is one of the various options for controlling poultry red mites. Here, we present the first results of an attempt to identify

Candidate predators for biological control of the poultry red mite Dermanyssus gallinae

NARCIS (Netherlands)

Lesna, Izabela; Wolfs, Peter; Faraji, Farid; Roy, Lise; Komdeur, Jan; Sabelis, Maurice W.

The poultry red mite, Dermanyssus gallinae, is currently a significant pest in the poultry industry in Europe. Biological control by the introduction of predatory mites is one of the various options for controlling poultry red mites. Here, we present the first results of an attempt to identify

A review on the factors affecting mite growth in stored grain commodities.

Science.gov (United States)

Collins, D A

2012-03-01

A thorough review of the literature has identified the key factors and interactions that affect the growth of mite pests on stored grain commodities. Although many factors influence mite growth, the change and combinations of the physical conditions (temperature, relative humidity and/or moisture content) during the storage period are likely to have the greatest impact, with biological factors (e.g. predators and commodity) playing an important role. There is limited information on the effects of climate change, light, species interactions, local density dependant factors, spread of mycotoxins and action thresholds for mites. A greater understanding of these factors may identify alternative control techniques. The ability to predict mite population dynamics over a range of environmental conditions, both physical and biological, is essential in providing an early warning of mite infestations, advising when appropriate control measures are required and for evaluating control measures. This information may provide a useful aid in predicting and preventing mite population development as part of a risk based decision support system.

Genetic diversity in upland cotton for cotton leaf curl virus disease, earliness and fiber quality

International Nuclear Information System (INIS)

Saeed, F.; Farooq, J.; Mahmood, A.; Hussain, T.

2014-01-01

In Pakistan during last two decades the major factor limiting cotton production is cotton leaf curl virus disease (CLCuD). For estimation of genetic diversity regarding CLCuD tolerance, fiber quality and some yield contributing traits, 101 cotton genotypes imported from USA were evaluated. Different statistical procedures like cluster, principle components (PC) and correlation analysis were employed to identify the suitable genotypes that can be further exploited in breeding programme. Significant associations were found between yield contributing trait, boll weight and fiber related trait, staple length. Earliness related traits, like days taken to 1 square and days taken to 1 flower had positive correlation with each other and both these traits also showed their positive association with ginning out turn. The negative significant correlation of CLCuD was obtained with monopodial branches, sympodial branches and plant height. Principal component (PC) analysis showed first five PCs having eigen value >1 explaining 67.8% of the total variation with days to st 1 square and flowering along with plant height and sympodia plant which were being the most important characters in PC1. Cluster analysis classified 101 accessions into five divergent groups. The genotypes in st cluster 1 only showed reasonable values for days to 1 square and flower, sympodia per plant, ginning out turn, staple length and fiber fineness and the genotypes in cluster 5 showed promising values for the traits like cotton leaf curl virus, ginning out turn and fiber fineness. The genotypes in cluster 1 and 5 may be combined to obtain desirable traits related to earliness and better disease tolerance. Scatter plot and tree diagrams demonstrated sufficient diversity among the cotton accessions for various traits and some extent of association between various clusters. It is concluded that diversity among the genotypes could be utilized for the development of CLCuD resistant lines with increased seed

Norwegian honey bees surviving Varroa destructor mite infestations by means of natural selection.

Science.gov (United States)

Oddie, Melissa A Y; Dahle, Bjørn; Neumann, Peter

2017-01-01

Managed, feral and wild populations of European honey bee subspecies, Apis mellifera , are currently facing severe colony losses globally. There is consensus that the ectoparasitic mite Varroa destructor , that switched hosts from the Eastern honey bee Apis cerana to the Western honey bee A. mellifera , is a key factor driving these losses. For >20 years, breeding efforts have not produced European honey bee colonies that can survive infestations without the need for mite control. However, at least three populations of European honey bees have developed this ability by means of natural selection and have been surviving for >10 years without mite treatments. Reduced mite reproductive success has been suggested as a key factor explaining this natural survival. Here, we report a managed A. mellifera population in Norway, that has been naturally surviving consistent V. destructor infestations for >17 years. Surviving colonies and local susceptible controls were evaluated for mite infestation levels, mite reproductive success and two potential mechanisms explaining colony survival: grooming of adult worker bees and Varroa Sensitive Hygiene (VSH): adult workers specifically detecting and removing mite-infested brood. Mite infestation levels were significantly lower in surviving colonies and mite reproductive success was reduced by 30% when compared to the controls. No significant differences were found between surviving and control colonies for either grooming or VSH. Our data confirm that reduced mite reproductive success seems to be a key factor for natural survival of infested A. mellifera colonies. However, neither grooming nor VSH seem to explain colony survival. Instead, other behaviors of the adult bees seem to be sufficient to hinder mite reproductive success, because brood for this experiment was taken from susceptible donor colonies only. To mitigate the global impact of V. destructor , we suggest learning more from nature, i.e., identifying the obviously

Norwegian honey bees surviving Varroa destructor mite infestations by means of natural selection

Directory of Open Access Journals (Sweden)

Melissa A.Y. Oddie

2017-10-01

Full Text Available Background Managed, feral and wild populations of European honey bee subspecies, Apis mellifera, are currently facing severe colony losses globally. There is consensus that the ectoparasitic mite Varroa destructor, that switched hosts from the Eastern honey bee Apis cerana to the Western honey bee A. mellifera, is a key factor driving these losses. For >20 years, breeding efforts have not produced European honey bee colonies that can survive infestations without the need for mite control. However, at least three populations of European honey bees have developed this ability by means of natural selection and have been surviving for >10 years without mite treatments. Reduced mite reproductive success has been suggested as a key factor explaining this natural survival. Here, we report a managed A. mellifera population in Norway, that has been naturally surviving consistent V. destructor infestations for >17 years. Methods Surviving colonies and local susceptible controls were evaluated for mite infestation levels, mite reproductive success and two potential mechanisms explaining colony survival: grooming of adult worker bees and Varroa Sensitive Hygiene (VSH: adult workers specifically detecting and removing mite-infested brood. Results Mite infestation levels were significantly lower in surviving colonies and mite reproductive success was reduced by 30% when compared to the controls. No significant differences were found between surviving and control colonies for either grooming or VSH. Discussion Our data confirm that reduced mite reproductive success seems to be a key factor for natural survival of infested A. mellifera colonies. However, neither grooming nor VSH seem to explain colony survival. Instead, other behaviors of the adult bees seem to be sufficient to hinder mite reproductive success, because brood for this experiment was taken from susceptible donor colonies only. To mitigate the global impact of V. destructor, we suggest learning

Behaviour of coconut mites preceding take-off to passive aerial dispersal.

Science.gov (United States)

Melo, J W S; Lima, D B; Sabelis, M W; Pallini, A; Gondim, M G C

2014-12-01

For more than three decades the coconut mite Aceria guerreronis Keifer is one of the most important pests of coconut palms and has recently spread to many coconut production areas worldwide. Colonization of coconut palms is thought to arise from mites dispersing aerially after take-off from other plants within the same plantation or other plantations. The underlying dispersal behaviour of the mite at take-off, in the airborne state and after landing is largely unknown and this is essential to understand how they spread from tree to tree. In this article we studied whether take-off to aerial dispersal of coconut mites is preceded by characteristic behaviour, whether there is a correlation between the body position preceding aerial dispersal and the direction of the wind, and whether the substrate (outer surface of coconut bracts or epidermis) and the wind speed matter to the decision to take-off. We found that take-off can sometimes be preceded by a raised body stance, but more frequently take-off occurs while the mite is walking or resting on its substrate. Coconut mites that become airborne assumed a body stance that had no relation to the wind direction. Take-off was suppressed on a substrate providing food to coconut mites, but occurred significantly more frequently on the outer surface of coconut bracts than on the surface of the fruit. For both substrates, take-off frequency increased with wind speed. We conclude that coconut mites have at least some degree of control over take-off for aerial dispersal and that there is as yet no reason to infer that a raised body stance is necessary to become airborne.

Macrodinychus mites as parasitoids of invasive ants: an overlooked parasitic association.

Science.gov (United States)

Lachaud, Jean-Paul; Klompen, Hans; Pérez-Lachaud, Gabriela

2016-07-21

Mites are frequent ant symbionts, yet the exact nature of their interactions with their hosts is poorly known. Generally, myrmecophilous mites show adaptations for dispersal through phoresis, but species that lack such an adaptation may have evolved unusual specialized relationships with their hosts. The immature stages of Macrodinychus multispinosus develop as ectoparasitoids of pupae of the invasive ant Paratrechina longicornis. Feeding stages show regressed locomotor appendages. These mites complete their development on a single host, sucking all of its body content and therefore killing it. Locally high proportions of parasitized host pupae suggest that M. multispinosus could serve as a biological control agent. This is the ninth species of Macrodinychus reported as ant parasite, and the third known as parasitoid of invasive ants, confirming a unique habit in the evolution of mite feeding strategies and suggesting that the entire genus might be parasitic on ants. Several mites' characteristics, such as their protective morphology, possible viviparity, lack of a specialized stage for phoretic dispersal, and low host specificity, combined with both the general low aggressiveness of invasive P. longicornis towards other ants and its possible susceptibility to generalist ectoparasites would account for the host shift in native macrodinychid mites.

A burst of ABC genes in the genome of the polyphagous spider mite Tetranychus urticae.

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Dermauw, Wannes; Osborne, Edward John; Clark, Richard M; Grbić, Miodrag; Tirry, Luc; Van Leeuwen, Thomas

2013-05-10

The ABC (ATP-binding cassette) gene superfamily is widespread across all living species. The majority of ABC genes encode ABC transporters, which are membrane-spanning proteins capable of transferring substrates across biological membranes by hydrolyzing ATP. Although ABC transporters have often been associated with resistance to drugs and toxic compounds, within the Arthropoda ABC gene families have only been characterized in detail in several insects and a crustacean. In this study, we report a genome-wide survey and expression analysis of the ABC gene superfamily in the spider mite, Tetranychus urticae, a chelicerate ~ 450 million years diverged from other Arthropod lineages. T. urticae is a major agricultural pest, and is among of the most polyphagous arthropod herbivores known. The species resists a staggering array of toxic plant secondary metabolites, and has developed resistance to all major classes of pesticides in use for its control. We identified 103 ABC genes in the T. urticae genome, the highest number discovered in a metazoan species to date. Within the T. urticae ABC gene set, all members of the eight currently described subfamilies (A to H) were detected. A phylogenetic analysis revealed that the high number of ABC genes in T. urticae is due primarily to lineage-specific expansions of ABC genes within the ABCC, ABCG and ABCH subfamilies. In particular, the ABCC subfamily harbors the highest number of T. urticae ABC genes (39). In a comparative genomic analysis, we found clear orthologous relationships between a subset of T. urticae ABC proteins and ABC proteins in both vertebrates and invertebrates known to be involved in fundamental cellular processes. These included members of the ABCB-half transporters, and the ABCD, ABCE and ABCF families. Furthermore, one-to-one orthologues could be distinguished between T. urticae proteins and human ABCC10, ABCG5 and ABCG8, the Drosophila melanogaster sulfonylurea receptor and ecdysone-regulated transporter E

Whole genome amplification of Chelex-extracted DNA from a single mite: a method for studying genetics of the predatory mite Phytoseiulus persimilis.

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Konakandla, Bhanu; Park, Yoonseong; Margolies, David

2006-01-01

We developed and optimized a method using Chelex DNA extraction followed by whole genome amplification (WGA) to overcome problems conducting molecular genetic studies due to the limited amount of DNA obtainable from individual small organisms such as predatory mites. The DNA from a single mite, Phytoseiulus persimilis Athias-Henrot (Acari: Phytoseiidae), isolated in Chelex suspension was subjected to WGA. More than 1000-fold amplification of the DNA was achieved using as little as 0.03 ng genomic DNA template. The DNA obtained by the WGA was used for polymerase chain reaction followed by direct sequencing. From WGA DNA, nuclear DNA intergenic spacers ITS1 and ITS2 and a mitochondrial DNA 12S marker were tested in three different geographical populations of the predatory mite: California, the Netherlands, and Sicily. We found a total of four different alleles of the 12S in the Sicilian population, but no polymorphism was identified in the ITS marker. The combination of Chelex DNA extraction and WGA is thus shown to be a simple and robust technique for examining molecular markers for multiple loci by using individual mites. We conclude that the methods, Chelex extraction of DNA followed by WGA, provide a large quantity of DNA template that can be used for multiple PCR reactions useful for genetic studies requiring the genotypes of individual mites.

The Tropilaelaps mites threat: Observations of their reproductive success

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Tropilaelaps spp. are more successful parasitic mites of Apis mellifera than Varroa destructor in Asia (Burgett et al., Bee World 64:25-28). We sought explanations to this success by assessing their fecundity on European bees in three short experiments using the mite transfer technique: 1) fecundity...

IPM potentials of microbial pathogens and diseases of mites

NARCIS (Netherlands)

van der Geest, L.P.S.; Ciancio, A.; Mukerji, K.G.

2010-01-01

An overview is given of diseases in mites, caused by infectious microorganisms. Many pathogens play an important role in the regulation of natural populations of mite populations and are for this reason subject of research on the feasibility to develop such pathogens to biological control agents.

Association between HLA genes and dust mite sensitivity in a Brazilian population.

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da Costa Lima Caniatti, Marcela Caleffi; Borelli, Sueli Donizete; Guilherme, Ana Lúcia Falavigna; Tsuneto, Luiza Tamie

2017-02-01

Type I hypersensitivity, also known as IgE-mediated allergy, is a complex, multifactorial condition whose onset and severity are influenced by both genetic and environmental factors. Mite allergens stimulate the production of humoral response (IgE), especially in children, which is closely involved in atopic asthma and rhinitis. This study aimed to investigate the association between HLA class I (-A, -B, and -C), and HLA class II (-DRB1) genes in individuals sensitive to dust mites (Dermatophagoides farinae, Dermatophagoides pteronyssinus, or Blomia tropicalis) and mite-insensitive controls. 396 participants were grouped as mite-sensitive and mite-insensitive according to immediate hypersensitivity as determined by skin-prick tests, and to HLA genotyping by polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO). After chi-square heterogeneity testing no significant differences were observed in HLA-A, B, and C genes, except for the HLA-DRB1 locus, which, showed a negative association for DRB1∗04, between mite-sensitive and mite-insensitive individuals. In high resolution, DRB1∗04:11 allele was significantly different from all other results (P=0.0042, OR=0.26, and 95%CI=0.09-0.70). The analysis stratified by etiologic agent confirmed these associations. Our results suggest a possible association between HLA-DRB1 genes and hypersensitivity to dust mites. Copyright © 2016 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

A weak Galerkin least-squares finite element method for div-curl systems

Science.gov (United States)

Li, Jichun; Ye, Xiu; Zhang, Shangyou

2018-06-01

In this paper, we introduce a weak Galerkin least-squares method for solving div-curl problem. This finite element method leads to a symmetric positive definite system and has the flexibility to work with general meshes such as hybrid mesh, polytopal mesh and mesh with hanging nodes. Error estimates of the finite element solution are derived. The numerical examples demonstrate the robustness and flexibility of the proposed method.

House dust mites on skin, clothes, and bedding of atopic dermatitis patients.

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Teplitsky, Valery; Mumcuoglu, Kosta Y; Babai, Ilan; Dalal, Ilan; Cohen, Rifka; Tanay, Amir

2008-08-01

Atopic dermatitis is a common allergic condition in children, often associated with a positive skin reaction to house dust mite allergens. To determine the presence of house dust mites on the skin, clothes, and bedding of patients with atopic dermatitis. Nineteen patients with atopic dermatitis were examined during a 2-year period. Samples from affected and healthy skin surfaces were obtained with adhesive tape, and dust samples from bedding and clothes were collected with a vacuum cleaner at the start of the study and 3-6 weeks later, and examined for the presence of house dust mites. The findings were compared with those of 21 healthy controls. The most common mite species on skin were Dermatophagoides pteronyssinus and Dermatophagoides farinae, which were found in nine patients and three controls. The patient group showed a significantly larger percentage of samples with mites than did the control group (34.9% and 7.9%, respectively) (P bedding of patients, or between patients and controls with regard to the number of mites on the clothes and bedding. Patients with atopic dermatitis showed a higher prevalence of mites on their skin than did healthy individuals, which could be involved in allergic sensitization and disease exacerbation.

The predatory mite Neoseiulus womersleyi (Acari: Phytoseiidae) follows extracts of trails left by the two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae).

Science.gov (United States)

Shinmen, Tsubasa; Yano, Shuichi; Osakabe, Mh

2010-10-01

As it walks, the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) spins a trail of silk threads, that is followed by the predatory mite, Neoseiulus womersleyi Schicha (Acari: Phytoseiidae). Starved adult female N. womersleyi followed T. urticae trails laid down by five T. urticae females but did not follow a trail of one T. urticae female, suggesting that the amount of spun threads and their chemical components should correlate positively with the number of T. urticae individuals. To examine whether chemical components of T. urticae trails are responsible for the predatory mite's trail following, we collected separate T. urticae threads from the exuviae and eggs, and then washed the threads with methanol to separate chemical components from physical attributes of the threads. Female N. womersleyi did not follow T. urticae trails that had been washed with methanol but contained physical residues, but they did follow the direction to which the methanol extracts of the T. urticae trails was applied. These results suggest that the predatory mite follows chemical, not physical, attributes of T. urticae trails.

Disentangling mite predator-prey relationships by multiplex PCR.

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Pérez-Sayas, Consuelo; Pina, Tatiana; Gómez-Martínez, María A; Camañes, Gemma; Ibáñez-Gual, María V; Jaques, Josep A; Hurtado, Mónica A

2015-11-01

Gut content analysis using molecular techniques can help elucidate predator-prey relationships in situations in which other methodologies are not feasible, such as in the case of trophic interactions between minute species such as mites. We designed species-specific primers for a mite community occurring in Spanish citrus orchards comprising two herbivores, the Tetranychidae Tetranychus urticae and Panonychus citri, and six predatory mites belonging to the Phytoseiidae family; these predatory mites are considered to be these herbivores' main biological control agents. These primers were successfully multiplexed in a single PCR to test the range of predators feeding on each of the two prey species. We estimated prey DNA detectability success over time (DS50), which depended on the predator-prey combination and ranged from 0.2 to 18 h. These values were further used to weight prey detection in field samples to disentangle the predatory role played by the most abundant predators (i.e. Euseius stipulatus and Phytoseiulus persimilis). The corrected predation value for E. stipulatus was significantly higher than for P. persimilis. However, because this 1.5-fold difference was less than that observed regarding their sevenfold difference in abundance, we conclude that P. persimilis is the most effective predator in the system; it preyed on tetranychids almost five times more frequently than E. stipulatus did. The present results demonstrate that molecular tools are appropriate to unravel predator-prey interactions in tiny species such as mites, which include important agricultural pests and their predators. © 2015 John Wiley & Sons Ltd.

Wind stress, curl and vertical velocity in the Bay of Bengal during southwest monsoon, 1984

Digital Repository Service at National Institute of Oceanography (India)

Babu, M.T.; Heblekar, A.K.; Murty, C.S.

Wind distribution observed during southwest monsoon of 1984 has used to derive the mean wind stress for the season at every 1 degree square grid and curl over the Bay of Bengal. Two regions of maximum wind stress are present over the Bay of Bengal...

STUDY OF ACAROID MITES POLLUTION IN STORED FRUIT-DERIVED CHINESE MEDICINAL MATERIALS.

Science.gov (United States)

Xu, Li-fa; Li, He-xia; Xu, Peng-fei; Xu, Hai-feng; Li, Chao-pin

2015-08-01

to investigate the species and breeding density of acaroid mites in stored fruit-derived Chinese medicinal materials in Anhui province. samples of stored fruit-derived Chinese medicinal materials were collected from 30 herb stores and storehouses in 17 Anhui cities, where the breeding acaroids mites were detected. 20 species of acaroids mites were found in 33 samples, belonging to 15 genus, 5 families of the acaridae respectively, among which T. putrescentiae, A. farinae, C. lactis, and C. berlesei are predominant species. stored fruit-derived Chinese medicinal materials in Anhui areas suffer from serious acaroid mites pollution. Therefore, proactive measures should be taken to control acaroid mites from breeding in an effort to reduce the harm on medicinal materials. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Species diversity of phytoseiid mites on different ecosystems in Sari district

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Javad Omidi

2016-03-01

Full Text Available Introduction Mites of the Phytoseiidae family have been extensively studied as biological control agents of different mites and insect pests. Some species also feed on nematodes, fungal spores, pollen and exudates from plants and insects. About 2,300 phytoseiid species belonging to 90 genera have been described in this family (Chant and McMurtry 2007. Considerable efforts have been made in recent years to the collection and identification of the predaceous phytoseiid mites in Iran (Rahmani et al. 2010. Despite some studies on phytoseiid mites in Iran, our knowledge remains limited about their fauna and diversity in Mazandaran province. The data of these studies showed that until recently, only 75 species were reported from Iran. The objective of this study was to evaluate the species diversity of Phytoseiidae and access to effective predatory mites for biological control of injurious mite pests in Sari, the center of Mazandaran province (Southern coast of the Caspian Sea, 35 ° 47'-36 ° 35' N, 50 ° 34'-54 ° 10' E Materials and methods Samples were taken from 80 plant species belonging to 46 plant families including forest trees, orchards and farm crops representing three types of ecosystems from September 2011 to October 2012. Harvested samples of each plant were separately collected in plastic bags and labeled with region and date of collection. The bags were transported to the laboratory on the same day and stored in a refrigerator at about 4°C for up to a week, until the materials washed for mite extraction. Samples were composed of leaves, stems and shoots of different ages and the number of leaves per sample varied between plant species. In order to assimilate the samples, a volume nearly equal mass of each sample were put in a two-liter water container. The mites were floated on water by adding 1.5 liters of tap water and a few droplets of detergent. The plant leaves and shoots were shaken for several times until the mites fall from

Relationships between early spring wheat streak mosaic severity levels and grain yield: Implications for management decisions

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Wheat streak mosaic (WSM) caused by Wheat streak mosaic virus, which is transmitted by the wheat curl mite (Aceria tosichella), is a major yield-limiting disease in the Texas High Plains. In addition to its impact on grain production, the disease reduces water-use efficiency by affecting root develo...

Ectoparasitic chigger mites on large oriental vole (Eothenomys miletus) across southwest, China.

Science.gov (United States)

Peng, Pei-Ying; Guo, Xian-Guo; Song, Wen-Yu; Hou, Peng; Zou, Yun-Ji; Fan, Rong

2016-02-01

An investigation of chigger mites on the large oriental vole, Eothenomys miletus (Rodentia: Cricetidae), was conducted between 2001 and 2013 at 39 localities across southwest China, and 2463 individuals of the vole hosts were captured and examined, which is a big host sample size. From the body surface of E. miletus, 49,850 individuals of chigger mites were collected, and they were identified as comprising 175 species, 13 genera, and 3 subfamilies in 2 families (Trombiculidae and Leeuwenhoekiidae). The 175 species of chigger mites from such a single rodent species (E. miletus) within a certain region (southwest China) extremely exceeded all the species of chigger mites previously recorded from multiple species of hosts in a wide region or a whole country in some other countries, and this suggests that E. miletus has a great potential to harbor abundant species of chigger mites on its body surface. Of 175 mite species, Leptotrombidium scutellare was the most dominant species, which has been proved as one of the main vectors of scrub typhus and the potential vector of haemorrhagic fever with renal syndrome (HFRS) in China. The patchiness index (m*/m) was used to measure the spatial patterns of the dominant chigger mite species, and all the three dominant mite species (L. scutellare, Leptotrombidium sinicum, and Helenicula simena) showed aggregated distributions among the different host individuals. The coefficient of association (V) was adopted to measure the interspecies interaction between the dominant mite species and a slightly positive association existed between L. scutellare and L. sinicum (V = 0.28, P size over a wide realm of geographical regions is needed in the field investigation in order to obtain a true picture of species diversity and species composition.

Sensitization of children in the Stockholm area to house dust mites.

Science.gov (United States)

Nordvall, S L; Eriksson, M; Rylander, E; Schwartz, B

1988-09-01

Atopic sensitization of children in the Stockholm area to house dust mites (HDM) was investigated in a case-control study. Sixty children with and 60 without positive skin prick tests for HDM were matched for age and sex. HDM-sensitized children had previously more often lived in other areas known to be mite infested than the control children. Sensitization to mites was related to dampness in the homes, but no significant relationship was found to the type of residence, frequent visits to a summer house in the archipelago or parental smoking. Dust samples from mattresses of the children with the strongest positive reactions to mites in skin prick tests and the respective controls were subjected to an enzyme immunoassay, to measure the content of the major allergens of the Dermatophagoides (D.) species D. pterinyssinus, D. farinae and D. microceras. Mattress dust samples from the beds of HDM-sensitized children contained significantly higher HDM antigen concentrations than those from the beds of controls. Private houses contained significantly more HDM antigens than flats and 10 of 11 homes in which a dampness problem was recognized contained mite antigens. It is postulated that mite infestation is increasing in the area, energy-saving measures creating improved conditions for HDM survival.

Predicting the presence of whiteflies and tomato yellow leaf curl virus in Florida tomato fields

Science.gov (United States)

Florida is one of the leading states for production of fresh market tomatoes. Production is severely affected by Tomato yellow leaf curl virus (TYLCV). The objective of this study was to identify landscape and climatic factors that drive whitefly populations and TYLCV incidence in commercial tomato ...

Child car seats – a habitat for house dust mites and reservoir for harmful allergens

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David Clarke

2015-02-01

Full Text Available [b]Introduction and objective[/b]. House dust mites produce allergens which can cause or aggravate diseases such as asthma, eczema and rhinitis. The objectives of this study are to quantify typical house dust mite and Der p 1 allergen levels in child car seats, and to determine external variables that may influence mite populations in cars. [b]Materials and Methods[/b]. Dust samples were collected from the child car seats and driver seats of 106 cars using a portable vacuum sampling pump over a two minute sampling period. Mites were counted and identified and results were expressed as mites per gram (mites/g of dust, while Der p 1 content of samples were measured by enzyme-linked immunosorbent assay (ELISA. Questionnaires were completed by participants to identify environmental and behavioural effects on mite populations. Results were analysed using General Linear Model (GLM procedures. [b]Results[/b]. Twelve species of mites, of which nine are known to produce harmful allergens, were recorded from 212 dust samples. Over 80% of drivers’ seats and over 77% of child car seats harboured dust mites with a significant correlation (p = 0.001 between the mites/g of dust and Der p 1 content recovered from each seat. A mean of 53 mites/g of dust per seat was recovered, with a mean Der p 1 level of 1.1µg/g. Over 12% of driver seats and 15% of child car seats contained house dust mite levels sufficient to be risk factors for sensitisation and allergic reactions. [b]Conclusions[/b]. Child car seats and driver seats are habitats to a range of mite species which can be present in sufficient concentrations to cause or aggravate allergen related illnesses in individuals who are genetically predisposed.

Mite diversity on plants of different families found in the Brazilian Atlantic Forest

International Nuclear Information System (INIS)

Castro, Tatiane M.M.G. de; Moraes, Gilberto J. de

2007-01-01

This work reports the occurrence of mites predominantly predatory, phytophagous and with varied feeding habits on plants of the Atlantic Forest vegetation type of the State of Sao Paulo. The objective was to estimate the possible role of the Atlantic Forest vegetation as reservoir of these groups of mites which are also found on plants of agricultural importance. Samples were taken from 187 plant species belonging to 73 families in three vegetation types of the Atlantic Forest from February of 2001 to October of 2002. A total of 2,887 mites belonging to 163 morpho-species of 16 families were collected. Mite diversity was high, especially of predatory mites; these corresponded to 1,562 specimens of 92 morpho-species. Within this group, Phytoseiidae comprised 71% of the specimens and 62% of the morpho-species. Phytophagous mites comprised 836 specimens of 36 morpho-species. Within this group, Tenuipalpidae comprised the larger proportion of specimens (61%) whereas Tetranychidae corresponded to the larger proportion of morpho-species (64%). Mites with varied feeding habits corresponded to 491 specimens of 36 morpho-species. In this group, the larger proportion of specimens (52%) consisted of Ascidae and the larger proportion of morpho-species (42%) consisted of Tydeinae (family Tydeidae). High abundance and high morpho-species richness of mites of predominantly predatory, phytophagous and variable feeding habits were observed on 17, five and nine plant species, respectively. The results obtained suggest the importance of plants of the studied vegetation as reservoirs of predatory mites. (author)

Mite diversity on plants of different families found in the Brazilian Atlantic Forest

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Castro, Tatiane M.M.G. de [UNESP, Jaboticabal, SP (Brazil). Faculdade de Ciencias Agrarias e Veterinarias. Dept. de Fitossanidade]. E-mail: tatianemarie@yahoo.com.br; Moraes, Gilberto J. de [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. Entomologia, Fitopatologia e Zoologia Agricola]. E-mail: gjmoraes@esalq.usp.br

2007-09-15

This work reports the occurrence of mites predominantly predatory, phytophagous and with varied feeding habits on plants of the Atlantic Forest vegetation type of the State of Sao Paulo. The objective was to estimate the possible role of the Atlantic Forest vegetation as reservoir of these groups of mites which are also found on plants of agricultural importance. Samples were taken from 187 plant species belonging to 73 families in three vegetation types of the Atlantic Forest from February of 2001 to October of 2002. A total of 2,887 mites belonging to 163 morpho-species of 16 families were collected. Mite diversity was high, especially of predatory mites; these corresponded to 1,562 specimens of 92 morpho-species. Within this group, Phytoseiidae comprised 71% of the specimens and 62% of the morpho-species. Phytophagous mites comprised 836 specimens of 36 morpho-species. Within this group, Tenuipalpidae comprised the larger proportion of specimens (61%) whereas Tetranychidae corresponded to the larger proportion of morpho-species (64%). Mites with varied feeding habits corresponded to 491 specimens of 36 morpho-species. In this group, the larger proportion of specimens (52%) consisted of Ascidae and the larger proportion of morpho-species (42%) consisted of Tydeinae (family Tydeidae). High abundance and high morpho-species richness of mites of predominantly predatory, phytophagous and variable feeding habits were observed on 17, five and nine plant species, respectively. The results obtained suggest the importance of plants of the studied vegetation as reservoirs of predatory mites. (author)

Design and development of the MITEE-B bi-modal nuclear propulsion engine

International Nuclear Information System (INIS)

Paniagua, John C.; Powell, James R.; Maise, George

2003-01-01

Previous studies of compact, ultra-lightweight high performance nuclear thermal propulsion engines have concentrated on systems that only deliver high thrust. However, many potential missions also require substantial amounts of electric power. Studies of a new, very compact and lightweight bi-modal nuclear engine that provides both high propulsive thrust and high electric power for planetary science missions are described. The design is a modification of the MITEE nuclear thermal engine concept that provided only high propulsive thrust. In the new design, MITEE-B, separate closed cooling circuits are incorporated into the reactor, which transfers useful amounts of thermal energy to a small power conversion system that generates continuous electric power over the full life of the mission, even when the engine is not delivering propulsive thrust. Two versions of the MITEE-B design are described and analyzed. Version 1 generates 1 kW(e) of continuous power for control of the spacecraft, sensors, data transmission, etc. This power level eliminates the need for RTG's on missions to the outer planets, and allowing considerably greater operational capability for the spacecraft. This, plus its high thrust and high specific impulse propulsive capabilities, makes MITEE-B very attractive for such missions. In Version 2, of MITEE-B, a total of 20 kW(e) is generated, enabling the use of electric propulsion. The combination of high open cycle propulsion thrust (20,000 Newtons) with a specific impulse of ∼1000 seconds for short impulse burns, and long term (months to years), electric propulsion greatly increases MITEE's ΔV capability. Version 2 of MITEE-B also enables the production and replenishment of H2 propellant using in-situ resources, such as electrolysis of water from the ice sheet on Europa and other Jovian moons. This capability would greatly increase the ΔV available for certain planetary science missions. The modifications to the MITEE multiple pressure tube

Nasal mites (Mesostigmata, Rhinonyssidae in Sternidae (Aves: Charadriiformes on the southern Coast of Brazil

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Diego Silva da Silva

2018-02-01

Full Text Available Abstract Six species of birds of the family Sternidae are often found on the southern coast of South America. Sterna trudeaui, S. hirundinacea, Thalasseus maximus, T. acuflavidus and Sternula superciliaris are South American residents and Sterna hirundo, a Nearctic migrant. At least 500 species of nasal mites have been described around the world, and Rhinonyssidae is the most diverse family. These mites are bloodsucking endoparasites that inhabit the respiratory system of birds. This study aimed to report on occurrences of nasal mites in Sternidae on the southern coast of Brazil. Of the 106 birds analyzed, 8.5% (9 birds were parasitized by nasal mites. This report provides the first record in the Neotropical region for two mite species, Sternostoma boydi and Larinyssus orbicularis parasitizing Thalasseus acuflavidus and Sternula superciliaris. No nasal mites were found in Sterna trudeaui or Thalasseus maximus. One host individual (T. acuflavidus was parasitized by two species of nasal mites, S. boydi and L. orbicularis.

Short form of Demodex species mite in the dog: occurrence and measurements.

Science.gov (United States)

Chesney, C J

1999-02-01

A form of Demodex species mite shorter in length than Demodex canis was found in six consecutive cases of canine demodicosis. The mean length of the parasite was 122.6 microns (SD 12.0 microns, 39 mites counted), significantly shorter than either male or female forms of D canis (P < 0.0001). The proportion of short to long mites in each case varied from 0.5 to 22 per 100. In young dogs, skin signs associated with the presence of mites were first noted after about seven months, while in the oldest subject the disease became apparent at 10 years of age. This form of mite has now been found in four countries over three continents, the findings suggesting that it is not uncommon and is acquired in puppyhood, although it may be carried unnoticed for many years.

Pyroglyphid mites, xerophilic fungi and allergenic activity in dust from hospital mattresses.

Science.gov (United States)

v d Lustgraaf, B; Jorde, W

1977-12-01

Dust from mattresses of different composition and age was analysed for mites, xerophilic fungi and allergenic activity. The mites of the genus Demodex were the most abundant (58.2 per cent). Also pyroglyphid mites occurred commonly (36.6 per cent). Pyroglyphid mites were present in small numbers (mean: 1 specimen/0.2 g of dust) in 12 out of the 17 older polyester-foam mattresses. The 11 cotton-horsechair mattresses and the newly used polyester-foam mattresses (three tested) were without them. The dust from the cotton-horsehair mattresses had a significantly higher allergenic activity than from those of polyester-foam. Xerophilic fungi were isolated in three out of 31 mattresses. The species isolated belonged to the genus Aspergillus and Eurotium. E. repens occurred most frequently. Disinfection of mattresses was suggested to have a negative influence on the occurrence of mites and fungi.

Two simple techniques for the safe Sarcoptes collection and individual mite DNA extraction.

Science.gov (United States)

Soglia, Dominga; Rambozzi, Luisa; Maione, Sandra; Spalenza, Veronica; Sartore, Stefano; Alasaad, Samer; Sacchi, Paola; Rossi, Luca

2009-10-01

Availability of mites is a recognized limiting factor of biological and genetic investigations of the genus Sarcoptes. Current methods of deoxyribonucleic acid (DNA) extraction from individual mites also need substantial improvement in efficiency and operator friendliness. We have first developed a technique for efficient and safe extraction of living mites from scabietic skin samples (crusts or deep skin scrapings). Its core device is a large plastic syringe connected with a 1.5-ml Eppendorf tube. The source material is introduced in the syringe and the device in a shoe box with the tip half of the tube emerging. Mites migrate towards a heat source during a minimum of 36 h. Then, the tube is detached and the mites utilized without risks for the operators. A second technique allows operator-friendly manipulation of individual mites for DNA extraction. Fixed mites are isolated by adhesion to a small strip of polyvinyl chloride (PVC) adhesive tape operated with tweezers. Then, mite and strip are plunged in the lyses buffer and the sample twice submitted to thermal shock for disruption of the chitinous exoskeleton. Data show that the tape does not interfere with successive DNA extraction with a commercial kit. The corresponding protocol, that we briefly name "PVC adhesive tape + thermal shock + kit DNA extraction," compares favorably with the available ones.

A survey of mites on farm animals in Libya.

Science.gov (United States)

Gabaj, M M; Beesley, W N; Awan, M A

1992-10-01

In 1985-1988, 2287 farm animals (cattle, camels, sheep, goats, horses, donkeys, dogs and rabbits) suspected of carrying parasitic mites were examined at 58 farms throughout Libya. Mites were identified on 1303 of these animals. The commonest parasites on cattle were Psoroptes and Chorioptes, on camels and sheep were Sarcoptes and Psoroptes, and on goats were Sarcoptes and Demodex. Infested horses carrier Psoroptes or Chorioptes, and one donkey carried Sarcoptes. Otodectes was common on dogs, but Sarcoptes was rare and no Demodex were seen. Rabbits often had psoroptic ear mange or sarcoptic body mange. Dermanyssus gallinae and Ornithonyssus bursa were seen on chickens, but no mites were found on pigeons, ducks or turkeys.

Dehydration Stress Contributes to the Enhancement of Plant Defense Response and Mite Performance on Barley

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M. E. Santamaria

2018-04-01

Full Text Available Under natural conditions, plants suffer different stresses simultaneously or in a sequential way. At present, the combined effect of biotic and abiotic stressors is one of the most important threats to crop production. Understanding how plants deal with the panoply of potential stresses affecting them is crucial to develop biotechnological tools to protect plants. As well as for drought stress, the economic importance of the spider mite on agriculture is expected to increase due to climate change. Barley is a host of the polyphagous spider mite Tetranychus urticae and drought produces important yield losses. To obtain insights on the combined effect of drought and mite stresses on the defensive response of this cereal, we have analyzed the transcriptomic responses of barley plants subjected to dehydration (water-deficit treatment, spider mite attack, or to the combined dehydration-spider mite stress. The expression patterns of mite-induced responsive genes included many jasmonic acid responsive genes and were quickly induced. In contrast, genes related to dehydration tolerance were later up-regulated. Besides, a higher up-regulation of mite-induced defenses was showed by the combined dehydration and mite treatment than by the individual mite stress. On the other hand, the performance of the mite in dehydration stressed and well-watered plants was tested. Despite the stronger defensive response in plants that suffer dehydration and mite stresses, the spider mite demonstrates a better performance under dehydration condition than in well-watered plants. These results highlight the complexity of the regulatory events leading to the response to a combination of stresses and emphasize the difficulties to predict their consequences on crop production.

Dehydration Stress Contributes to the Enhancement of Plant Defense Response and Mite Performance on Barley

Science.gov (United States)

Santamaria, M. E.; Diaz, Isabel; Martinez, Manuel

2018-01-01

Under natural conditions, plants suffer different stresses simultaneously or in a sequential way. At present, the combined effect of biotic and abiotic stressors is one of the most important threats to crop production. Understanding how plants deal with the panoply of potential stresses affecting them is crucial to develop biotechnological tools to protect plants. As well as for drought stress, the economic importance of the spider mite on agriculture is expected to increase due to climate change. Barley is a host of the polyphagous spider mite Tetranychus urticae and drought produces important yield losses. To obtain insights on the combined effect of drought and mite stresses on the defensive response of this cereal, we have analyzed the transcriptomic responses of barley plants subjected to dehydration (water-deficit) treatment, spider mite attack, or to the combined dehydration-spider mite stress. The expression patterns of mite-induced responsive genes included many jasmonic acid responsive genes and were quickly induced. In contrast, genes related to dehydration tolerance were later up-regulated. Besides, a higher up-regulation of mite-induced defenses was showed by the combined dehydration and mite treatment than by the individual mite stress. On the other hand, the performance of the mite in dehydration stressed and well-watered plants was tested. Despite the stronger defensive response in plants that suffer dehydration and mite stresses, the spider mite demonstrates a better performance under dehydration condition than in well-watered plants. These results highlight the complexity of the regulatory events leading to the response to a combination of stresses and emphasize the difficulties to predict their consequences on crop production. PMID:29681917

Prey preference of the phytoseiid mite Typhlodromus pyri. 1. Response to volatile kairomones.

NARCIS (Netherlands)

Dicke, M.

1988-01-01

Using a Y-tube olfactometer, a study has been made of the response of females of the predatory miteTyphlodromus pyri Scheuten (Acarina: Phytoseiidae) to volatile kairomones of three prey species: the European red spider mite (Panonychus ulmi (Koch)), the two-spotted spider mite (Tetranychus urticae

HOUSE DUST MITE CONTAMINATION IN HOTELS AND INNS IN BANDAR ABBAS, SOUTH OF IRAN

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M. Soleimani, J. Rafinejad

2008-07-01

Full Text Available House dust mites have been shown to be strongly associated with allergic respiratory diseases such as, bronchial asthma, rhinitis and atopic dermatitis in the world. The climatic conditions of Bandar-Abbas, which is located in a coastal area and has a humid subtropical climate, provide a suitable place to proliferate mites. The aim of this study was to determine the contamination rate and analyze the house dust mite fauna in hotels and inns in Bandar-Abbas that had not been investigated previously. In this study 6 hotels and 6 inns were selected randomly in six areas of Bandar-Abbas. Two dust samples were collected from each place with a vacuum cleaner. One square meter of carpets and mattresses were vacuumed for a period of 1 min. Then the samples were cleared in lactic acid and then mites were mounted in Hoyer's medium for study and identification. A total of 2644 mites were collected and identified. The major mite family was Pyroglyphidae (98%. Dermatophagoides pteronyssinus was the most frequent and most numerous species recorded, occurring in 91% of samples examined and forming 88% of the Pyroglyphidae and 86% of the total mite populations. The family Cheyletidae was less commonly found with Cheyletus malaccensis (2%. Most of the mites were isolated from the carpets (57.5%, and a smaller number from mattresses (42.5%. Mites were present in 96% of the dust samples. Results revealed that all inns and 83% of hotels were contaminated by more than one species of mite and 34% of them had a population of more than 100 mites /g dust. This rate of contamination can be a major risk factor in asthma and other respiratory allergic diseases

Sampling plans for pest mites on physic nut.

Science.gov (United States)

Rosado, Jander F; Sarmento, Renato A; Pedro-Neto, Marçal; Galdino, Tarcísio V S; Marques, Renata V; Erasmo, Eduardo A L; Picanço, Marcelo C

2014-08-01

The starting point for generating a pest control decision-making system is a conventional sampling plan. Because the mites Polyphagotarsonemus latus and Tetranychus bastosi are among the most important pests of the physic nut (Jatropha curcas), in the present study, we aimed to establish sampling plans for these mite species on physic nut. Mite densities were monitored in 12 physic nut crops. Based on the obtained results, sampling of P. latus and T. bastosi should be performed by assessing the number of mites per cm(2) in 160 samples using a handheld 20× magnifying glass. The optimal sampling region for T. bastosi is the abaxial surface of the 4th most apical leaf on the branch of the middle third of the canopy. On the abaxial surface, T. bastosi should then be observed on the side parts of the middle portion of the leaf, near its edge. As for P. latus, the optimal sampling region is the abaxial surface of the 4th most apical leaf on the branch of the apical third of the canopy on the abaxial surface. Polyphagotarsonemus latus should then be assessed on the side parts of the leaf's petiole insertion. Each sampling procedure requires 4 h and costs US$ 7.31.

Mite Biodiversity Under the Low Temperature Scanning Electron Microscope

Science.gov (United States)

To date, more than 55,000 mite species have been described and only a few of them have been studied. Some mites are adapted to live deep in soil, others in fresh or sea water, some are on plants, algae, fungi or animals, and others are able to survive in both extreme cold and hot temperatures. The...

Límites y control constitucional en México

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Arminda Balbuena Cisneros

2007-01-01

Full Text Available Los límites a la reforma constitucional es un tema siempre vigente en el derecho constitucional, ello es así por las posibles arbitrariedades que pueden cometer los órganos detentadores del poder mediante las modificaciones a la constitución. En México, hoy en día este tema cobra particular relevancia por el profundo proceso de reforma que se vive, y por la controvertida posición que la corte mexicana ha adoptado en relación con los límites a la reforma. El presente artículo trata de dar una visión general de los límites al poder de reforma y, en particular, de la posición que la suprema corte de justicia de la nación ha adoptado respecto a los mismos.

Geographic variation in ectoparasitic mites diversity in Tadarida Brasiliensis (Chiroptera, Molossidae

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Tatiana C. Pesenti

2014-12-01

Full Text Available Tadarida brasiliensis (Geoffroy, 1824, the Brazilian free-tailed bat, is an insectivorous bat that occurs from southern United States of America to southern South America. In this study we present the first data on diversity of ectoparasitic mites of T. brasiliensis in Brazil. A compilation and analysis of the studies of mite diversity conducted in different points the geographic distribution this bat species are provided. The mites were collected from March 2010 to November 2011 on 160 T. brasiliensis adult bats captured in southern Brazil. Four species of mites have been found: Chiroptonyssus robustipes (Ewing, 1925, Ewingana longa (Ewing, 1938, Ewingana inaequalis (Radford, 1948, and specimens of Cheyletidae. Chiroptonyssus robustipes was the most prevalent species (100%, followed by E. longa (20%, E. inaequalis (10%, and specimens of Cheyletidae (1.25%. The data currently available show that C. robustipes parasitizes T. brasiliensis throughout its region of occurrence, and this mite is highly prevalent and abundant. The two species of Ewingana accompany the geographical distribution of T. brasiliensis, but with much lower prevalence and abundance.

Flat acoustic lens by acoustic grating with curled slits

KAUST Repository

Peng, Pai

2014-10-01

We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

Prevailing indoor climate classification to predict house-dust mite abundance in Dutch homes

NARCIS (Netherlands)

Schober, G.; Verstappen, I.; Snijders, M.C.L.; Bronswijk, van J.E.M.H.

1995-01-01

In Europe 10-15 % of the human population is sensitized to allergens of house dust mites (Pyroglyphidae). Population development of house dust mites is primarily influenced by water activity (aw) of the mite habitat. The availability of H20 (water-activity and relative humidity) in the niches of

SIMULTANEOUS PRODUCTIVE GROWTH GROUPS (SPGG: INNOVATION ON PAPAYA MITE MANAGEMENT

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Marycruz Abato-Zárate

2011-11-01

Full Text Available Grower’s previous experience and their ability to communicate technical information to other growers, allows greater adoption of technologies. Thus, appropriation of technologies of mite management and sampling was evaluated, based on the “Simultaneous Productive Growth Groups (SPGG” technology transfer model. A preliminary diagnosis was made, evaluating the technology transfer achieved by six leading growers showing up continuously to seven meetings carried out from March to July 2010, and also by 19 growers showing up on a more irregular basis. All growers were from the municipality of Cotaxtla and belonged to the Papaya-Product-System of Veracruz, Mexico. Participation, attitude and efficacy of training were evaluated with a survey. Forty-two percent of growers considered the papaya ring spot virus as the main problem and 48 % revealed spider mites as the second one; 96 % used pesticides on spider mites. Participation of the SPGG basic group was 71 %, who agreed on sampling, recording data in sampling forms and using selective acaricides. Seventy percent were able to recognize spider mites from predatory mites and 83 % recognized selective acaricides. Growers considered that sampling can help reduce control costs. The SPGG model allowed building collective knowledge and better decision making by the working group.

[Mites associated with two species of the genus Odontotaenius (Coleoptera: Passalidae) in Mexico].

Science.gov (United States)

Barrios-Torres, Pilar Liliana; Villegas-Guzmán, Gabriel A

2015-09-01

Mites can establish association with different arthropods as coleopterans tamites scaraoaeicae ana Passalidae. Passalids are distributed in tropical and templates zones, and until now, more than 200 species of mites have been associated to them. One of the relationships between passalids and mites is the phoresy where one small animal (the phoretic) seeks out and attaches to another animal (the host) for transportation. Herein, we studied the mites associated to O. zodiacus and O. striatopunctatus; for this, 80 Odontotaenius with mites were reviewed; passalids were collected in and under decaying logs from six states of Mexico, and were individually kept in vials with 80% ethanol. The specimens were carried to the laboratory and mites removed with fine-pointed forceps under stereo microscope. The mites were stored with 80 % alcohol until some were cleared with lacto-phenol and mounted in Hoyer's solution. We found 1,945 mites belonging to 13 families (Acaridae, Ascidae, Diarthrophallidae, Digamasellidae, Diplogyniidae, Euzerconidae, Heterocheylidae, Histiostomatidae, Klinckowstroemiidae, Laelapidae, Megisthanidae, Trematuridae, and Uropodidae) and 42 species, being the most abundant species Anoelus sp. For O. striatopunctatus (16 specimens) we found 562 mites (95 female female, 34 male male, 197 hypopus, 234 deutonymph, 2 tritonymph) of 11 families and 22 species; the most abundant were Uropodidae (42 %) and Histiostomatidae (26 %). While for 0. zodiacus (64 specimens) were found 1,383 mites (300 female female, 204 male male, 608 hypopus, 139 deutonymphs, 133 tritonymphs) of 10 families and 30 species; the most abundant were: Diartrophallidae, Acaridae, and Histiostomatidae (23 % for the two first and 21 % for third). The high abundance and richness was in O. zodiacus, likewise Margalef (S') and Shanon-Winner (H') indexes were higher in this species (O. zodiacus S' = 4.05, H' = 2.2; O. striatopunctatus S' = 3.34, H' = 1.94), while Equity (EH) was similar to both

Characterization of a group of MITEs with unusual features from two coral genomes.

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Shi Wang

Full Text Available BACKGROUND: Miniature inverted-repeat transposable elements (MITEs, which are common in eukaryotic genomes, are small non-coding elements that transpose by utilizing transposases encoded by autonomous transposons. Recent genome-wide analyses and cross-mobilization assays have greatly improved our knowledge on MITE proliferation, however, specific mechanisms for the origin and evolution of MITEs are still unclear. PRINCIPAL FINDINGS: A group of coral MITEs called CMITE were identified from two corals, Acropora millepora and Acropora palmata. CMITEs conform to many common characteristics of MITEs, but also present several unusual features. The most unusual feature of CMITEs is conservation of the internal region, which is more conserved between MITE families than the TIRs. The origin of this internal region remains unknown, although we found one CMITE family that seems to be derived from a piggyBac-like transposon in A. millepora. CMITEs can form tandem arrays, suggesting an unconventional way for MITEs to increase copy numbers. We also describe a case in which a novel transposable element was created by a CMITE insertion event. CONCLUSIONS: To our knowledge, this is the first report of identification of MITEs from coral genomes. Proliferation of CMITEs seems to be related to the transposition machinery of piggyBac-like autonomous transposons. The highly conserved internal region of CMITEs suggests a potential role for this region in their successful transposition. However, the origin of these unusual features in CMITEs remains unclear, and thus represents an intriguing topic for future investigations.

Characterization of a group of MITEs with unusual features from two coral genomes.

Science.gov (United States)

Wang, Shi; Zhang, Lingling; Meyer, Eli; Matz, Mikhail V

2010-05-18

Miniature inverted-repeat transposable elements (MITEs), which are common in eukaryotic genomes, are small non-coding elements that transpose by utilizing transposases encoded by autonomous transposons. Recent genome-wide analyses and cross-mobilization assays have greatly improved our knowledge on MITE proliferation, however, specific mechanisms for the origin and evolution of MITEs are still unclear. A group of coral MITEs called CMITE were identified from two corals, Acropora millepora and Acropora palmata. CMITEs conform to many common characteristics of MITEs, but also present several unusual features. The most unusual feature of CMITEs is conservation of the internal region, which is more conserved between MITE families than the TIRs. The origin of this internal region remains unknown, although we found one CMITE family that seems to be derived from a piggyBac-like transposon in A. millepora. CMITEs can form tandem arrays, suggesting an unconventional way for MITEs to increase copy numbers. We also describe a case in which a novel transposable element was created by a CMITE insertion event. To our knowledge, this is the first report of identification of MITEs from coral genomes. Proliferation of CMITEs seems to be related to the transposition machinery of piggyBac-like autonomous transposons. The highly conserved internal region of CMITEs suggests a potential role for this region in their successful transposition. However, the origin of these unusual features in CMITEs remains unclear, and thus represents an intriguing topic for future investigations.

Higher-level molecular phylogeny of the water mites (Acariformes: Prostigmata: Parasitengonina: Hydrachnidiae).

Science.gov (United States)

Dabert, Miroslawa; Proctor, Heather; Dabert, Jacek

2016-08-01

With nearly 6000 named species, water mites (Hydrachnidiae) represent the largest group of arachnids to have invaded and extensively diversified in freshwater habitats. Water mites together with three other lineages (the terrestrial Erythraiae and Trombidiae, and aquatic Stygothrombiae), make up the hyporder Parasitengonina, which is characterized by having parasitic larvae and predatory nymphs and adults. Relationships between the Hydrachnidiae and other members of the Parasitengonina are unclear, as are relationships among the major lineages of water mites. Monophyly of water mites has been asserted, with the possible exception of the morphologically distinctive Hydrovolzioidea. Here we infer the phylogeny of water mites using multiple molecular markers and including representatives of all superfamilies of Hydrachnidiae and of almost all other Parasitengonina. Our results support a monophyletic Parasitengonina including Trombidiae, Stygothrombiae, and Hydrachnidiae. A monophyletic Hydrachnidiae, including Hydrovolzioidea, is strongly supported. Terrestrial Parasitengonina do not form a monophyletic sister group to water mites. Stygothrombiae is close to water mites but is not nested within this clade. Water mites appear to be derived from ancestors close to Stygothrombiae or the erythraoid group Calyptostomatoidea; however, this relationship is not clear because of extremely short branches in this part of the parasitengonine tree. We recovered with strong support all commonly accepted water mite superfamilies except for Hydryphantoidea, which is clearly paraphyletic. Our data support the previously proposed clades Protohydrachnidia (Hydrovolzioidea and Eylaoidea), Euhydrachnidia (all remaining superfamilies), and the euhydrachnid subclade Neohydrachnidia (Lebertioidea, Hydrachnoidea, Hygrobatoidea, and Arrenuroidea). We found that larval leg structure and locomotory behavior are strongly congruent with the molecular phylogeny. Other morphological and behavioral

Association of an Alphasatellite with Tomato Yellow Leaf Curl Virus and Ageratum Yellow Vein Virus in Japan is Suggestive of a Recent Introduction

OpenAIRE

Shahid, Muhammad Shafiq; Ikegami, Masato; Waheed, Abdul; Briddon, Rob W.; Natsuaki, Keiko T.

2014-01-01

Samples were collected in 2011 from tomato plants exhibiting typical tomato leaf curl disease symptoms in the vicinity of Komae, Japan. PCR mediated amplification, cloning and sequencing of all begomovirus components from two plants from different fields showed the plants to be infected by Tomato yellow leaf curl virus (TYLCV) and Ageratum yellow vein virus (AYVV). Both viruses have previously been shown to be present in Japan, although this is the first identification of AYVV on mainland Jap...

Feather mites (Acari, Astigmata from Azorean passerines (Aves, Passeriformes: lower species richness compared to European mainland

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Rodrigues Pedro

2015-01-01

Full Text Available Ten passerine species were examined on three islands of the Azores (North Atlantic during 2013 and 2014 in order to identify their feather mite assemblages. We recorded 19 feather mite species belonging to four families of the superfamily Analgoidea (Analgidae, Proctophyllodidae, Psoroptoididae and Trouessartiidae. A high prevalence of feather mite species was recorded on the majority of the examined host species. Only three passerine species (Sylvia atricapilla, Regulus regulus and Serinus canaria presented the same full complex of mite species as commonly occurs in the plumage of their closest relatives in continental Europe. Passer domesticus presented the same limited fauna of feather mites living in the plumage as do its co-specifics in continental Europe. Carduelis carduelis bears the same feather mite species as do most of its continental populations in Europe, but it lacks one mite species occurring on this host in Egypt. Turdus merula, Pyrrhula murina and Fringilla coelebs are missing several mite species common to their continental relatives. This diminution could be explained by the founder effect, whereby a limited number of colonizing individuals did not transport the full set of feather mite species, or by the extinction of some mite species after initially having reached the Azores. The only individual of Motacilla cinerea sampled in this study presented a new host record for the mite species Trouessartia jedliczkai.

Whiteflies interfere with indirect plant defense against spider mites in Lima bean

Science.gov (United States)

Zhang, Peng-Jun; Zheng, Si-Jun; van Loon, Joop J. A.; Boland, Wilhelm; David, Anja; Mumm, Roland; Dicke, Marcel

2009-01-01

Plants under herbivore attack are able to initiate indirect defense by synthesizing and releasing complex blends of volatiles that attract natural enemies of the herbivore. However, little is known about how plants respond to infestation by multiple herbivores, particularly if these belong to different feeding guilds. Here, we report the interference by a phloem-feeding insect, the whitefly Bemisia tabaci, with indirect plant defenses induced by spider mites (Tetranychus urticae) in Lima bean (Phaseolus lunatus) plants. Additional whitefly infestation of spider-mite infested plants resulted in a reduced attraction of predatory mites (Phytoseiulus persimilis) compared to attraction to plants infested by spider mites only. This interference is shown to result from the reduction in (E)-β-ocimene emission from plants infested by both spider mites and whiteflies. When using exogenous salicylic acid (SA) application to mimic B. tabaci infestation, we observed similar results in behavioral and chemical analyses. Phytohormone and gene-expression analyses revealed that B. tabaci infestation, as well as SA application, inhibited spider mite-induced jasmonic acid (JA) production and reduced the expression of two JA-regulated genes, one of which encodes for the P. lunatus enzyme β-ocimene synthase that catalyzes the synthesis of (E)-β-ocimene. Remarkably, B. tabaci infestation concurrently inhibited SA production induced by spider mites. We therefore conclude that in dual-infested Lima bean plants the suppression of the JA signaling pathway by whitefly feeding is not due to enhanced SA levels. PMID:19965373

Stability evaluation of house dust mite vaccines for sublingual immunotherapy

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MARIJA GAVROVIĆ-JANKULOVIĆ

2010-01-01

Full Text Available Allergen-specific immunotherapy with house dust mite (HDM allergen extracts can effectively alleviate the symptoms of allergic rhinitis and asthma. The efficacy of the immunotherapeutic treatment is highly dependent on the quality of house dust mite vaccines. This study was performed to assess the stability of house dust mite allergen vaccines prepared for sublingual immunotherapy. Lyophilized Dermatophagoides pteronyssinus (Dpt mite bodies were the starting material for the production of sublingual vaccines in four therapeutic concentrations. The stability of the extract for vaccine production, which was stored below 4 °C for one month, showed consistence in the protein profile in SDS PAGE. ELISA-inhibition showed that the potencies of Dpt vaccines during a 12 month period were to 65–80 % preserved at all analyzed therapeutic concentrations. This study showed that glycerinated Dpt vaccines stored at 4 °C preserved their IgE-binding potential during a 12 month period, implying their suitability for sublingual immunotherapeutic treatment of HDM allergy.

Feather and nest mites of two common resident birds in two ecologically different Egyptian governorates.

Science.gov (United States)

Morsy, T A; Mazyad, S A; Younis, M S

1999-08-01

The study of the role played by birds in the distribution of various bacterial, viral and parasitic infections is increasingly from year to year, taking into consideration the flying ability of birds and their migration for food and vital processes. Two of the common Egyptian resident birds, house sparrow (Passer d. niloticus) and laughing dove (Streptopelia s. aegyptiaca) were chosen to study their mite fauna. The overall mite index was 4.74 on the house sparrow and 7.22 on the laughing dove. As to mites, a total of 31 species belonging to 23 genera, 17 families and 3 suborders were collected. The common mites on both types of birds were 22 species. Three species only on house sparrow, and six species only on laughing dove. The house sparrow served host for 25 mite species and the laughing dove served host for 28 mite species. The infestation rates of mites on house sparrow ranged between 1.11% to 23.33% and 0.21% to 34.54% in Sharkia and Qalyobia governorates respectively. For laughing dove, the mite infestation rates ranged between 0.82% to 50% and 3.45% to 55.17% for both governorates respectively. Some of the collected mites have medical and/or veterinary importance. The whole results were discussed.

Varroa destructor Mites Can Nimbly Climb from Flowers onto Foraging Honey Bees.

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David T Peck

Full Text Available Varroa destructor, the introduced parasite of European honey bees associated with massive colony deaths, spreads readily through populations of honey bee colonies, both managed colonies living crowded together in apiaries and wild colonies living widely dispersed in natural settings. Mites are hypothesized to spread between most managed colonies via phoretically riding forager bees when they engage in robbing colonies or they drift between hives. However, widely spaced wild colonies show Varroa infestation despite limited opportunities for robbing and little or no drifting of bees between colonies. Both wild and managed colonies may also exchange mites via another mechanism that has received remarkably little attention or study: floral transmission. The present study tested the ability of mites to infest foragers at feeders or flowers. We show that Varroa destructor mites are highly capable of phoretically infesting foraging honey bees, detail the mechanisms and maneuvers by which they do so, and describe mite behaviors post-infestation.

Varroa destructor Mites Can Nimbly Climb from Flowers onto Foraging Honey Bees

Science.gov (United States)

Smith, Michael L.; Seeley, Thomas D.

2016-01-01

Varroa destructor, the introduced parasite of European honey bees associated with massive colony deaths, spreads readily through populations of honey bee colonies, both managed colonies living crowded together in apiaries and wild colonies living widely dispersed in natural settings. Mites are hypothesized to spread between most managed colonies via phoretically riding forager bees when they engage in robbing colonies or they drift between hives. However, widely spaced wild colonies show Varroa infestation despite limited opportunities for robbing and little or no drifting of bees between colonies. Both wild and managed colonies may also exchange mites via another mechanism that has received remarkably little attention or study: floral transmission. The present study tested the ability of mites to infest foragers at feeders or flowers. We show that Varroa destructor mites are highly capable of phoretically infesting foraging honey bees, detail the mechanisms and maneuvers by which they do so, and describe mite behaviors post-infestation. PMID:27942015

Varroa destructor Mites Can Nimbly Climb from Flowers onto Foraging Honey Bees.

Science.gov (United States)

Peck, David T; Smith, Michael L; Seeley, Thomas D

2016-01-01

Varroa destructor, the introduced parasite of European honey bees associated with massive colony deaths, spreads readily through populations of honey bee colonies, both managed colonies living crowded together in apiaries and wild colonies living widely dispersed in natural settings. Mites are hypothesized to spread between most managed colonies via phoretically riding forager bees when they engage in robbing colonies or they drift between hives. However, widely spaced wild colonies show Varroa infestation despite limited opportunities for robbing and little or no drifting of bees between colonies. Both wild and managed colonies may also exchange mites via another mechanism that has received remarkably little attention or study: floral transmission. The present study tested the ability of mites to infest foragers at feeders or flowers. We show that Varroa destructor mites are highly capable of phoretically infesting foraging honey bees, detail the mechanisms and maneuvers by which they do so, and describe mite behaviors post-infestation.

House Dust Mite Respiratory Allergy

DEFF Research Database (Denmark)

Calderón, Moisés A; Kleine-Tebbe, Jörg; Linneberg, Allan

2015-01-01

Although house dust mite (HDM) allergy is a major cause of respiratory allergic disease, specific diagnosis and effective treatment both present unresolved challenges. Guidelines for the treatment of allergic rhinitis and asthma are well supported in the literature, but specific evidence on the e......Although house dust mite (HDM) allergy is a major cause of respiratory allergic disease, specific diagnosis and effective treatment both present unresolved challenges. Guidelines for the treatment of allergic rhinitis and asthma are well supported in the literature, but specific evidence...... not extend beyond the end of treatment. Finally, allergen immunotherapy has a poor but improving evidence base (notably on sublingual tablets) and its benefits last after treatment ends. This review identifies needs for deeper physician knowledge on the extent and impact of HDM allergy in respiratory disease...... and therapy of HDM respiratory allergy in practice....

Mites (Acari Associated with the Desert Seed Harvester Ant, Messor pergandei (Mayr

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Kaitlin A. Uppstrom

2011-01-01

Full Text Available Mites (Acari associated with the seed harvester ant Messor pergandei were investigated in the Sonoran desert of Arizona. At least seven representatives of the mite genera Armacarus, Lemanniella, Petalomium, Forcellinia, Histiostoma, Unguidispus, and Cosmoglyphus are phoretically associated with M. pergandei. Most of these morphospecies show preference for specific phoretic attachment sites and primarily use female alates rather than male alates for dispersal. Five mite morphospecies were found in low numbers inhabiting the chaff piles: Tydeidae sp., Procaeculus sp., Anystidae sp., Bakerdania sp., and Tetranychidae sp. The phoretic Petalomium sp. was observed consuming fungus growing on a dead queen, but the roles of the other mite species remain mostly unresolved.

Role of Predatory Mites in Persistent Nonoccupational Allergic Rhinitis

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Paloma Poza Guedes

2016-01-01

Full Text Available Mites can sensitize and induce atopic disease in predisposed individuals and are an important deteriorating factor in patients with allergic rhinitis, asthma, and atopic dermatitis. Although Pyroglyphidae mites have been extensively studied, very scarce reports are available on Cheyletidae spp. especially regarding human respiratory pathology. The main objective of the present study is to investigate the clinical role of this predator mite (Cheyletus eruditus as a respiratory antigen in a selected sensitized human population. Fifty-two adult patients were recruited from the outpatient allergy clinic to assess their eligibility for the study. The thirty-seven subjects with persistent allergic rhinitis (PAR who fulfilled the ARIA criteria had a positive IgE response confirmed by skin prick test (SPT to C. eruditus. Only those individuals (37/47 with a positive SPT to C. eruditus showed a positive nasal provocation test (NPT, while 10 patients with nonallergic mild-to-moderate persistent rhinitis, control group, had a negative NPT with C. eruditus. The present paper describes a new role for the predator mite Cheyletus eruditus as a respiratory allergen in a selected subset of patients in a subtropical environment afflicted with persistent nonoccupational allergic rhinitis.

Functional characterization of glutathione S-transferases associated with insecticide resistance in Tetranychus urticae

NARCIS (Netherlands)

Pavlidi, N.; Tseliou, V.; Riga, M.; Nauen, R.; Van Leeuwen, T.; Labrou, N.E.; Vontas, J.

2015-01-01

The two-spotted spider mite Tetranychus urticae is one of the most important agricultural pests world-wide. It is extremely polyphagous and develops resistance to acaricides. The overexpression of several glutathione S-transferases (GSTs) has been associated with insecticide resistance. Here, we

Effect of gamma radiation on the toxicity of milbemectin and chlorfenapyr in acaricide resistant and susceptible strains of Tetranychus urticae Koch (Acari: Tetranychidae)

Energy Technology Data Exchange (ETDEWEB)

Nicastro, Roberto L.; Arthur, Valter; Machi, Andre R., E-mail: rnicastro@cena.usp.br, E-mail: arthur@cena.usp.br [Laboratorio de Radiobiologia e Ambiente (CENA/USP), Piracicaba, SP (Brazil); Sato, Mario E., E-mail: mesato@biologico.sp.gov.br [Laboratorio de Acarologia, Instituto Biologico, Campinas, SP (Brazil)

2011-07-01

The spider mite Tetranychus urticae Koch is considered one of the most important phytophagous mites, causing considerable damage in several agricultural crops. The aim of this study was to evaluate the effect of gamma radiation on the toxicity of the acaricides milbemectin and chlorfenapyr in resistant and susceptible strains of T. urticae. The R and S strains for milbemectin and chlorfenapyr were irradiated with gamma radiation at Gamma cell-220 source at doses of 5, 10, 20, 40 e 80 Gy. Five concentrations of milbemectin and chlorfenapyr were evaluated, making applications 24 hours after irradiation. Mites of the controls were sprayed with the same acaricide concentrations used for the R and S strains but they were not exposed to gamma radiation. Experiments on the effects of gamma radiation on the growth rates of mites for acaricide resistant and susceptible strains of T. urticae were also carried out. Tests with the Milbemectin S strain showed an increased susceptibility to the acaricide milbemectin, when the mites were irradiated (20 Gy), in comparison with the control (non irradiated mites). For the Milbemectin R strain, there was no significant influence of gamma irradiation on the toxicity of milbemectin to the mites of this strain. For the Chlorfenapyr S strain, the effect of gamma radiation was similar to that observed for Milbemectin S strain, with increased toxicity of chlorfenapyr to the mites of this susceptible strain. In the case of the Chlorfenapyr R strain, the mites exposed to gamma radiation showed to be more tolerant to chlorfenapyr, considering the LC{sub 10} values. The same trend was observed for the LC{sub 50} values, however, there was no significant difference with the control. The experiments showed that doses of 200 and 300 Gy eliminated the mite populations of acaricide resistant and susceptible strains of T. urticae, in a period of ten days. The dose of 100 Gy did not lead to total elimination of the mite populations, but reduced

Effect of gamma radiation on the toxicity of milbemectin and chlorfenapyr in acaricide resistant and susceptible strains of Tetranychus urticae Koch (Acari: Tetranychidae)

International Nuclear Information System (INIS)

Nicastro, Roberto L.; Arthur, Valter; Machi, Andre R.; Sato, Mario E.

2011-01-01

The spider mite Tetranychus urticae Koch is considered one of the most important phytophagous mites, causing considerable damage in several agricultural crops. The aim of this study was to evaluate the effect of gamma radiation on the toxicity of the acaricides milbemectin and chlorfenapyr in resistant and susceptible strains of T. urticae. The R and S strains for milbemectin and chlorfenapyr were irradiated with gamma radiation at Gamma cell-220 source at doses of 5, 10, 20, 40 e 80 Gy. Five concentrations of milbemectin and chlorfenapyr were evaluated, making applications 24 hours after irradiation. Mites of the controls were sprayed with the same acaricide concentrations used for the R and S strains but they were not exposed to gamma radiation. Experiments on the effects of gamma radiation on the growth rates of mites for acaricide resistant and susceptible strains of T. urticae were also carried out. Tests with the Milbemectin S strain showed an increased susceptibility to the acaricide milbemectin, when the mites were irradiated (20 Gy), in comparison with the control (non irradiated mites). For the Milbemectin R strain, there was no significant influence of gamma irradiation on the toxicity of milbemectin to the mites of this strain. For the Chlorfenapyr S strain, the effect of gamma radiation was similar to that observed for Milbemectin S strain, with increased toxicity of chlorfenapyr to the mites of this susceptible strain. In the case of the Chlorfenapyr R strain, the mites exposed to gamma radiation showed to be more tolerant to chlorfenapyr, considering the LC 10 values. The same trend was observed for the LC 50 values, however, there was no significant difference with the control. The experiments showed that doses of 200 and 300 Gy eliminated the mite populations of acaricide resistant and susceptible strains of T. urticae, in a period of ten days. The dose of 100 Gy did not lead to total elimination of the mite populations, but reduced significantly

Growth analysis of cotton crops infested with spider mites. I. Light interception and radiation-use efficiency

International Nuclear Information System (INIS)

Sadras, V.O.; Wilson, L.J.

1997-01-01

Two-spotted spider mites (Tetranychus urticae Koch) are important pests of cotton (Gossypium hirsutum L.). The effects of mites on cotton photosynthesis have been investigated at the leaf and cytological level but not at the canopy level. Our objective was to quantify the effects of timing and intensity of infestation by mites on cotton radiation-use efficiency (RUE). Leaf area, light interception, RUE, canopy temperature, and leaf nitrogen concentration (LNC) were assessed during two growing seasons in crops artificially infested with mites between 59 and 127 d after sowing. Normal and okra-leaf cultivars were compared. A mite index (MI = natural log of the area under the curve of mite number vs thermal time) was used to quantify the cumulative effects of mites on RUE, LNC, and canopy temperature. Crop growth reduction due to mites was greater in early- than in late-infested crops Growth reduction was primarily due to reductions in RUE, but in the more severe treatments accelerated leaf senescence and, hence. reduced light interception also contributed to reductions in crop growth. At a given date, infested okra-leaf crops usually had greater RUE than their normal-leaf counterparts. Both plant types, however. responded similarly to a given level of mite infestation. The ability of the okra-leaf cultivar to maintain greater RUE levels can be attributed. therefore, to its relative inhospitality for the development of mite colonies rather than to an intrinsically greater capacity to maintain photosynthesis under mite damage. Canopy temperature, LNC, and RUE showed a similar, biphasic pattern of response to Ml. In the first phase, response variables were almost unaffected by mites. In the second phase, there was a marked decline in RUE and LNC and a marked increase in canopy temperature with increasing MI. These results suggest (i) some degree of compensatory photosynthesis at low to moderate levels of mite infestation, and (ii) reductions in RUE of mite

Irradiation as a quarantine treatment of cut flowers, ginger and turmeric against mites, thrips and nematodes

International Nuclear Information System (INIS)

Bhuiya, A.D.; Majumder, M.Z.R.; Hahar, G.; Shahjahan, R.M.; Khan, M.

1999-01-01

Effect of radiation on different developmental stages of mites, thrips, and nematodes were observed to determine their sterility doses and to develop a method for detection of irradiated and unirradiated specimens. A brief survey on cut-flower and tuber associated pests, and their biological study along with the tolerance level of host products were conducted. Mites Oligonychus biharensis (Hirst) and Tetranychus sp., as well as four species of thrips viz. Retithrips syriacus (Mayet), Haplothrips gowdeyi Franklin, Frankliniella intonsa Tribom, and Microcephalothrips abdominalis Crowford were recognized as common pests damaging plants and cut-flowers. Common species of nematodes infesting ginger and turmeric were Meloidogyne spp. and Ditylenchus spp. Results indicated that a dose 0.2 kGy and above caused complete sterility of male and female mites and insects. Various pre-adult developmental stages required less irradiation dose (0.05-0.1 kGy) for sterilization. Variation of melanization in treated and untreated life stages of mites and thrips could not be observed even at 0.2 kGy with the 2-methyl DOPA spot test. Inhibition of melanization in irradiated pupal stages of thrips were observed at doses above 0.4 kGy. Both irradiated and unirradiated thrips were identical in their protein banding pattern. Virtually no protein bands were observed in irradiated and unirradiated nematodes when samples were run on 5% PAGE in TBE. Tube rose and marigold treated with higher dose (0.3 to 0.5 kGy) caused no remarkable morphological degradation for 7-8 days after irradiation. Nematodes were resistant to radiation. Complete elimination and abnormalities of J 2 stages of Meloidogyne spp. and Ditylenchus spp. were not observed even at 4.0 kGy although significant weight loss and spoilage of tubers were recorded after 14 days of radiation exposure. (author)

Factors Influencing Mesostigmata Mites (Acari, Parasitiformes In The Alkaline Fen Habitats

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Salmane Ineta

2015-04-01

Full Text Available Mesostigmata mite fauna was investigated in soil of one alkaline fen at Apšuciems in the Maritime Lowland in Latvia in 2009. Thirty sample plots were selected in the following way: half of them were located in Brown Bog Rush, Schoenus ferrugineus and half — in Saw-Sedge, Cladium mariscus prevailing habitat. Soil samples were collected using a soil borer. Vegetation cover was described in accordance with Braun-Blanquet classes. Mites were extracted using modified Berlese funnels. In total, more than 28 species were recorded, of them Prozercon kochi and Pergamasus vagabundus were dominant species. Mean density of Mesostigmata mites ranged from 520 to 2140 ind./m2. Mite abundance and distribution between habitats depended on vegetation cover of the vascular plants, while moss cover and soil pH had no significant influence.

Feather mites (Acari, Astigmata associated with birds in an Atlantic Forest fragment in Northeastern Brazil

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HM Silva

Full Text Available AbstractThe present study reports associations between feather mites (Astigmata and birds in an Atlantic Forest fragment in Rio Grande do Norte state, in Brazil. In the laboratory, mites were collected through visual examination of freshly killed birds. Overall, 172 individuals from 38 bird species were examined, between October 2011 and July 2012. The prevalence of feather mites was 80.8%, corresponding to 139 infested individuals distributed into 30 species and 15 families of hosts. Fifteen feather mite taxa could be identified to the species level, sixteen to the genus level and three to the subfamily level, distributed into the families Analgidae, Proctophyllodidae, Psoroptoididae, Pteronyssidae, Xolalgidae, Trouessartiidae, Falculiferidae and Gabuciniidae. Hitherto unknown associations between feather mites and birds were recorded for eleven taxa identified to the species level, and nine taxa were recorded for the first time in Brazil. The number of new geographic records, as well as the hitherto unknown mite-host associations, supports the high estimates of diversity for feather mites of Brazil and show the need for research to increase knowledge of plumicole mites in the Neotropical region.

Widespread and evolutionary analysis of a MITE family Monkey King in Brassicaceae

OpenAIRE

Dai, Shutao; Hou, Jinna; Long, Yan; Wang, Jing; Li, Cong; Xiao, Qinqin; Jiang, Xiaoxue; Zou, Xiaoxiao; Zou, Jun; Meng, Jinling

2015-01-01

Background Miniature inverted repeat transposable elements (MITEs) are important components of eukaryotic genomes, with hundreds of families and many copies, which may play important roles in gene regulation and genome evolution. However, few studies have investigated the molecular mechanisms involved. In our previous study, a Tourist-like MITE, Monkey King, was identified from the promoter region of a flowering time gene, BnFLC.A10, in Brassica napus. Based on this MITE, the characteristics ...

Application of gamma radiation on longevity of some mites species (Acari: Tetranychidade)

Energy Technology Data Exchange (ETDEWEB)

Machi, Andre R., E-mail: rica_machi@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Arthur, Valter, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

2015-07-01

Mites are pests agricultural found in various environments accessible to animal life: soil, aerial parts of the plants, host insects. In this research the effects of gamma irradiation on longevity of mite pests of the tetranychidae family have been studied. The mites were irradiated in a source of Cobalt-60, Gammacell-220 type, at a dose rate of 0.486 kGy located in the CENA/USP, in the doses of 0 (control), 100, 200, 300, and 400 Gy with sixteen replicates per dose. After the irradiation, the mites were placed in petri dishes totalizing 5 treatments in 32 repetitions. The analysis of variance design with completely randomized design using the Statistical Analysis System (SAS) and the Tukey test, the verification of means. Were evaluated daily the adult mortality and longevity of irradiated mites. After 25 days was observed a mean longevity of mites, for O.ilicis, 100 Gy was equal the control dose (18.3 days), but to T. desertorum and T. urticae the larger longevity was observed in the dose of 200 Gy (19.0 days) being that this dose, obtained the larger longevity in comparison to control dose (18.5 days), in general the longevity decreased in relation to increased doses. Thus, only the dose of 100 Gy and 200 Gy stimulated an increased the longevity in O. ilicis and T. desertorum and T. urticae respectively. The exact mechanism by which the mites are tolerant to avoid damage caused by radicals when exposed to ionizing radiation is not fully understood. (author)

Application of gamma radiation on longevity of some mites species (Acari: Tetranychidade)

International Nuclear Information System (INIS)

Machi, Andre R.; Arthur, Valter

2015-01-01

Mites are pests agricultural found in various environments accessible to animal life: soil, aerial parts of the plants, host insects. In this research the effects of gamma irradiation on longevity of mite pests of the tetranychidae family have been studied. The mites were irradiated in a source of Cobalt-60, Gammacell-220 type, at a dose rate of 0.486 kGy located in the CENA/USP, in the doses of 0 (control), 100, 200, 300, and 400 Gy with sixteen replicates per dose. After the irradiation, the mites were placed in petri dishes totalizing 5 treatments in 32 repetitions. The analysis of variance design with completely randomized design using the Statistical Analysis System (SAS) and the Tukey test, the verification of means. Were evaluated daily the adult mortality and longevity of irradiated mites. After 25 days was observed a mean longevity of mites, for O.ilicis, 100 Gy was equal the control dose (18.3 days), but to T. desertorum and T. urticae the larger longevity was observed in the dose of 200 Gy (19.0 days) being that this dose, obtained the larger longevity in comparison to control dose (18.5 days), in general the longevity decreased in relation to increased doses. Thus, only the dose of 100 Gy and 200 Gy stimulated an increased the longevity in O. ilicis and T. desertorum and T. urticae respectively. The exact mechanism by which the mites are tolerant to avoid damage caused by radicals when exposed to ionizing radiation is not fully understood. (author)

Protective effect of the DNA vaccine encoding the major house dust mite allergens on allergic inflammation in the murine model of house dust mite allergy

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Lee Jaechun

2006-02-01

Full Text Available Abstract Background Vaccination with naked DNA encoding antigen induces cellular and humoral immunity characterized by the activation of specific Th1 cells. Objective To evaluate the effects of vaccination with mixed naked DNA plasmids encoding Der p 1, Der p 2, Der p 3, Der f 1, Der f 2, and Der f 3, the major house dust mite allergens on the allergic inflammation to the whole house dust mites (HDM crude extract. Methods Three hundred micrograms of these gene mixtures were injected into muscle of BALB/c mice. Control mice were injected with the pcDNA 3.1 blank vector. After 3 weeks, the mice were actively sensitized and inhaled with the whole house dust mite extract intranasally. Results The vaccinated mice showed a significantly decreased synthesis of total and HDM-specific IgE compared with controls. Analysis of the cytokine profile of lymphocytes after challenge with HDM crude extract revealed that mRNA expression of interferon-γ was higher in the vaccinated mice than in the controls. Reduced infiltration of inflammatory cells and the prominent infiltration of CD8+ T cells were observed in histology of lung tissue from the vaccinated mice. Conclusion Vaccination with DNA encoding the major house dust mite allergens provides a promising approach for treating allergic responses to whole house dust mite allergens.

Cheyletus eruditus (taurrus): an effective candidate for the biological control of the snake mite (Ophionyssus natricis).

Science.gov (United States)

Schilliger, Lionel H; Morel, Damien; Bonwitt, Jesse H; Marquis, Olivier

2013-09-01

The most commonly encountered ectoparasite in captive snakes is the hematophagous snake mite (Ophionyssus natricis). Infected snakes often exhibit lethargy, dysecdysis, pruritus, crusting dermatitis (sometimes progressing to abscesses), and behavioral changes (increased bathing time, rubbing against objects). Anemia and septicemia are occasional complications. Eliminating snake mites from a collection is frustrating. Insecticidal and acaricidal compounds used in mammals can be used against O. natricis infestation in reptiles, but they all are potentially neurotoxic to reptiles. The use of a biological agent to control the snake mite was first developed by using the predatory mites Hypoaspis miles and Hypoaspis aculeifer. However, no data are available regarding the potential of these mites to control O. natricis. Furthermore, the survival and predatory behavior of H. aculeifer and H. miles decreases above 28 degrees C, which is the lower value of the optimal temperature zone range required for rearing snakes. The aim of this study is to identify the ability of the predatory mite Cheyletus eruditus to control O. natricis. In the first experiment, 125 O. natricis mites where placed in separate plastic tubes together with the same number of C. eruditus mites. After 48 hr, the survival rate of snake mites was 6% compared with 92% in the control group (n = 125, P snake) ball pythons, with an average of 13 O. natricis per individual, were placed in separate cages with 1,000 C. eruditus mites + vermiculite After 15 days, only an average of two mites per snake remained, compared with 48 per snake in the control group (t-test, P < 0,01).

The effect of sub-floor heating on house-dust-mite populations on floors and in furniture.

Science.gov (United States)

de Boer, Rob

2003-01-01

It is well known that dehydrating conditions for house dust mites can be created by simply raising the temperature, causing loss of body water and eventually death. Thus, it can be expected that conditions for dust mites are less favourable on floors supplied with sub-floor heating. This was examined in a study of 16 houses with sub-floor heating and 21 without. The pattern of changes in air humidity and temperature on the floors was investigated and compared to known data of the tolerance of dust mites. Also the resident mite populations were compared. Floors with sub-floor heating had, on average, fewer mites, but the difference with unheated floors was small. It was remarkable that mite numbers were also lower in upholstered furniture. Another important observation was that some houses with sub-floor heating had high mite numbers, indicating that this type of heating is compatible with a thriving mite population. Temperature and humidity conditions of heated floors may allow mites not only to survive, but also to remain active in winter. A moderate increase in temperature, a moderate decrease in (absolute) air humidity, or a combination of both, will suffice to keep the humidity all winter below the Critical Equilibrium Humidity, the level of air humidity that is critical for mite growth and reproduction, hence for allergen production. However, it is argued that measures to suppress allergen production by house dust mites are likely to be far more effective if taken in summer rather than in winter.

Reproductive biology of varroa mites in colonies of Africanized honey bees

NARCIS (Netherlands)

Calderon Fallas, R.A.

2009-01-01

We investigated the reproductive biology of V. destructor in Africanized honeybees (AHB) in Central American conditions, specifically in Costa Rica. Attention was paid to mite fertility and production of viable female mites in worker and drone brood cells. Other reproduction parameters, like

Feather mites of Calidris fuscicollis (Aves: Scolopacidae) in Brazil

OpenAIRE

Gomes, S. N.; Pesenti, T. C.; Cirne, M. P.; Müller, G.

2015-01-01

Abstract During the period 2010-2012, eighty individuals of Calidris fuscicollis (Vieillot, 1819) were collected on the southern coast of Rio Grande do Sul, Brazil, with the objective of determining the presence of feather mites. Of the 80 birds examined, 32.5% were infested by mites, identified as Avenzoaria calidridis (Oudemans, 1904) (Avenzoariidae) (31.25%), Montchadskiana securicata (Megnin & Trouessart 1884) (Pterolichidae) (22.5%) and Alloptes limosae (Dubinin, 1951) (Alloptidae) (6.25...

Dermatitis due to Mixed Demodex and Sarcoptes Mites in Dogs

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B. Sudhakara Reddy

2014-01-01

Full Text Available In dogs, dermatitis due to mixed mite infestation is rare. During the five-year period of study, two dogs were identified suffering from dermatitis due to mixed Demodex and Sarcoptes mites. Upon clinical examination dogs had primary and secondary skin lesions on face, around the ears, chin, neck, fore limbs and lateral abdomen. Microscopic examination of skin scrapings revealed Demodex and Sarcoptes mites. Both dogs were treated with daily oral ivermectin at 100 to 400 μg/kg body weight as incremental doses, external application of amitraz and supportive treatments with topical antimicrobial shampoo. After completion of forty-two days of therapy, dogs were recovered from the dermatitis.

Detection and Host Range Study of Virus Associated with Pepper Yellow Leaf Curl Disease

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SRI SULANDARI

2006-03-01

Full Text Available High incidence of Pepper yellow leaf curl virus (PepYLCV was observed in Indonesia since early 2000. Disease incidence in Yogyakarta, Central and West Java reached 100% on Capsicum frutescens, but only 10-35% on C. annuum. As an exception, the disease incidence on C. annuum cv. TM 999 was in the range of 70-100%. The causal agent of the disease, PepYLCV, was detected by polymerase chain reaction. Viral specific DNA fragment of the size ~1600 bp and ~550 bp was amplified from infected plants using two pairs of geminivirus universal primers pAL1v1978/pAL1c715, and pAv494/pAc1048, respectively. The PepYLCV has an intermediate host range including plants belonging to the family of Solanaceae, Leguminosae, and Compositae. The species belonging to the families of Cucurbitaceae, Malvaceae, Chenopodiaceae, and Amaranthaceae were resistant to the virus. Physalis floridana, is very prospective as a propagation host for the geminivirus infecting pepper. Nicotiana spp., cucumber, watermelon, cotton, and Sida sp. could be used as a differential host. Besides, Capsicum frutescens cv. Cakra, tomato, N. benthamiana, N. glutinosa, and Ageratum conyzoides could be used as indicator plants for the geminivirus infecting pepper.

Seleção para alto teor de acilaçúcares em genótipos de tomateiro e sua relação com a resistência ao ácaro vermelho (Tetranychus evansi e à traça (Tuta absoluta Selection towards high acylsugar levels in tomato genotypes and its relationship with resistance to spider mite (Tetranychus evansi and to the South American pinworm (Tuta absoluta

Directory of Open Access Journals (Sweden)

Guilherme Victor Nippes Pereira

2008-06-01

Lycopersicon pennellii (Correll D'Arcy accession LA-716, acylsugars exsudated by type IV glandular trichomes present in all aerial parts of the plant reportedly mediate resistance to arthropod pests. This paper intended to study the levels of resistance to two arthropod pests, the South American tomato pinworm (Tuta absoluta and spider mites (Tetranychus evansi in tomato genotypes selected solely on the basis of their foliar acylsugar contents. Eleven plants with contrasting acylsugar contents were selected from population F3BC2 derived from the interespecific cross Lycopersicon esculentum 'TOM-584'x Lycopersicon pennellii 'LA-716'. These genotypes were used in tests for resistance/ repellence to the arthropod pests, along with parental checks TOM-584 and LA-716. In Tetranychus spp. mite repellence tests, plants selected for high acylsugar contents behaved similarly to the resistant parent LA-716. Negative and significative correlations between acylsugar contents and distances travelled by the mites onto the leaflet surface indicated an association between the allelochemical and the levels of mite repellence. In the assay with the South American pinworm, these genotypes were evaluated for leaflet lesion type and overall plant damage. The high acylsugar genotypes had good levels of insect resistance, similar to those found in LA-716. In all the evaluation date, acylsugars levels were highly and negatively correlated with pinworm damage. The results indicated that selection for high acylsugar contents was effective in increasing the levels of arthropod resistance of tomato genotypes.

Sequence characterization of cotton leaf curl virus from Rajasthan: phylogenetic relationship with other members of geminiviruses and detection of recombination.

Science.gov (United States)

Kumar, A; Kumar, J; Khan, J A

2010-04-01

Diseased cotton plants showing typical leaf curl symptoms were collected from experimental plot of Agriculture Research Station-Sriganganagar, Rajasthan. Complete DNA-A component from samples taken from two areas were amplified through rolling circle amplification (RCA) using templiphi kit (GE Healthcare) and characterized. DNA-A of one isolate consists of 2751 nucleotides and second isolate of 2759 nucleotide. Both sequences comprised six ORF's. Genome organization of DNA-A of one isolate shows high sequence similarity with other characterized local begomovirus isolates of Rajasthan, while other isolate shows high sequence similarity with CLCuV reported from Pakistan. The maximum similarity of first isolate, CLCuV-SG01, shows highest sequence identity with Cotton leaf curl Abohar (Rajasthan) virus, and second isolate, CLCuV-SG02, shows highest sequence identity with cotton leaf curl virus from Pakistan. Both isolates showed 85% similarities with each other. The sequence data revealed probable infiltration of some strains of Cotton leaf curl virus from Pakistan to India, or co-existence of different isolates under similar geographical conditions. While CLCuV-SG01 shows highest nt sequence similarity with CLCuV Rajasthan (Abohar), nt identity of V1 ORF (encoding coat protein) of SG01 shows the highest nt identity (100%) with CLCuV Multan (Bhatinda) and Abohar virus while AC1 region also showed difference. Complete nucleotide sequence of SG01 shows only 86% similarity with CLCuV Multan virus. Similarity search revealed significant difference in AV1 and AC1 regions with respect to DNA-A suggesting an evolutionary history of recombination. Computer based analysis, recombination detection Program (RDP) supports the recombination hypothesis, indicated that recombination with other begomoviruses had taken place within V1 ORF and AC1 ORF of CLCuV-SG01 and AC1 ORF of CLCuV-SG02 and also in noncoding intergenic region (IR).

Food stress causes sex-specific maternal effects in mites.

Science.gov (United States)

Walzer, Andreas; Schausberger, Peter

2015-08-01

Life history theory predicts that females should produce few large eggs under food stress and many small eggs when food is abundant. We tested this prediction in three female-biased size-dimorphic predatory mites feeding on herbivorous spider mite prey: Phytoseiulus persimilis, a specialized spider mite predator; Neoseiulus californicus, a generalist preferring spider mites; Amblyseius andersoni, a broad diet generalist. Irrespective of predator species and offspring sex, most females laid only one small egg under severe food stress. Irrespective of predator species, the number of female but not male eggs decreased with increasing maternal food stress. This sex-specific effect was probably due to the higher production costs of large female than small male eggs. The complexity of the response to the varying availability of spider mite prey correlated with the predators' degree of adaptation to this prey. Most A. andersoni females did not oviposit under severe food stress, whereas N. californicus and P. persimilis did oviposit. Under moderate food stress, only P. persimilis increased its investment per offspring, at the expense of egg number, and produced few large female eggs. When prey was abundant, P. persimilis decreased the female egg sizes at the expense of increased egg numbers, resulting in a sex-specific egg size/number trade-off. Maternal effects manifested only in N. californicus and P. persimilis. Small egg size correlated with the body size of daughters but not sons. Overall, our study provides a key example of sex-specific maternal effects, i.e. food stress during egg production more strongly affects the sex of the large than the small offspring. © 2015. Published by The Company of Biologists Ltd.

Isolation and sequence characterization of DNA-A genome of a new begomovirus strain associated with severe leaf curling symptoms of Jatropha curcas L.

KAUST Repository

Chauhan, Sushma

2018-04-22

Begomoviruses belong to the family Geminiviridae are associated with several disease symptoms, such as mosaic and leaf curling in Jatropha curcas. The molecular characterization of these viral strains will help in developing management strategies to control the disease. In this study, J. curcas that was infected with begomovirus and showed acute leaf curling symptoms were identified. DNA-A segment from pathogenic viral strain was isolated and sequenced. The sequenced genome was assembled and characterized in detail. The full-length DNA-A sequence was covered by primer walking. The genome sequence showed the general organization of DNA-A from begomovirus by the distribution of ORFs in both viral and anti-viral strands. The genome size ranged from 2844 bp–2852 bp. Three strains with minor nucleotide variations were identified, and a phylogenetic analysis was performed by comparing the DNA-A segments from other reported begomovirus isolates. The maximum sequence similarity was observed with Euphorbia yellow mosaic virus (FN435995). In the phylogenetic tree, no clustering was observed with previously reported begomovirus strains isolated from J. curcas host. The strains isolated in this study belong to new begomoviral strain that elicits symptoms of leaf curling in J. curcas. The results indicate that the probable origin of the strains is from Jatropha mosaic virus infecting J. gassypifolia. The strains isolated in this study are referred as Jatropha curcas leaf curl India virus (JCLCIV) based on the major symptoms exhibited by host J. curcas.

MITEE: A new nuclear engine concept for ultra fast, lightweight solar system exploration missions

Science.gov (United States)

Powell, James; Paniagua, John; Ludewig, Hans; Maise, George; Todosow, Michael

1998-01-01

A new ultra compact nuclear engine concept, MITEE (MIniature R_eactor E_nginE_), is described, and its performance evaluated for various solar system exploration missions. The MITEE concept is based on the Particle Bed Reactor (PBR), with modifications that enable a smaller, lighter nuclear engine. A range of MITEE Engine designs is described. Representative design parameters for the baseline MITEE reactor are: 75MW(th) power level, 1000 second Isp, 100 kilogram mass, 10 MW/Liter fuel element power density, 39 cm core diameter/height. Total engine mass, including turbo pump assembly, nozzles, controls, and contingency, is estimated to be 200 kilograms. Using the MITEE engine, ultra fast, lightweight solar system exploration missions are enabled. A range of such missions has been analyzed using the MULIMP code, and are described.

Vulnerability and behavioral response to ultraviolet radiation in the components of a foliar mite prey-predator system

Science.gov (United States)

Tachi, Fuyuki; Osakabe, Masahiro

2012-12-01

Ambient ultraviolet-B (UVB) radiation impacts plant-dwelling arthropods including herbivorous and predatory mites. However, the effects of UVB on prey-predator systems, such as that between the herbivorous spider mite and predatory phytoseiid mite, are poorly understood. A comparative study was conducted to determine the vulnerability and behavioral responses of these mites to ultraviolet (UV) radiation. First, we analyzed dose-response (cumulative irradiance-mortality) curves for the eggs of phytoseiid mites ( Neoseiulus californicus, Neoseiulus womersleyi, and Phytoseiulus persimilis) and the spider mite ( Tetranychus urticae) to UVB radiation from a UV lamp. This indicated that the phytoseiid mites were more vulnerable than the spider mite, although P. persimilis was slightly more tolerant than the other two phytoseiid mites. Second, we compared the avoidance behavior of adult female N. californicus and two spider mite species ( T. urticae, a lower leaf surface user; Panonychus citri, an upper leaf surface user) in response to solar UV and visible light. N. californicus actively avoided both types of radiation, whereas P. citri showed only minimal avoidance behavior. T. urticae actively avoided UV as well as N. californicus but exhibited a slow response to visible light as well as P. citri. Such variation in vulnerability and avoidance behavior accounts for differences in the species adaptations to solar UVB radiation. This may be the primary factor determining habitat use among these mites on host plant leaves, subsequently affecting accessibility by predators and also intraguild competition.

Egg hatching response to a range of ultraviolet-B (UV-B) radiation doses for four predatory mites and the herbivorous spider mite Tetranychus urticae.

Science.gov (United States)

Koveos, Dimitrios S; Suzuki, Takeshi; Terzidou, Anastasia; Kokkari, Anastasia; Floros, George; Damos, Petros; Kouloussis, Nikos A

2017-01-01

Egg hatchability of four predatory mites-Phytoseiulus persimilis Athias-Henriot, Iphiseius [Amblyseius] degenerans Berlese, Amblyseius swirskii Athias-Henriot, and Euseius finlandicus Oudemans (Acari: Phytoseiidae)-and the spider mite Tetranychus urticae Koch (Acari: Tetranychidae) was determined under various UV-B doses either in constant darkness (DD) or with simultaneous irradiation using white light. Under UV-B irradiation and DD or simultaneous irradiation with white light, the predator's eggs hatched in significantly lower percentages than in the control non-exposed eggs, which indicates deleterious effects of UV-B on embryonic development. In addition, higher hatchability percentages were observed under UV-B irradiation and DD in eggs of the predatory mites than in eggs of T. urticae. This might be caused by a higher involvement of an antioxidant system, shield effects by pigments or a mere shorter duration of embryonic development in predatory mites than in T. urticae, thus avoiding accumulative effects of UV-B. Although no eggs of T. urticae hatched under UV-B irradiation and DD, variable hatchability percentages were observed under simultaneous irradiation with white light, which suggests the involvement of a photoreactivation system that reduces UV-B damages. Under the same doses with simultaneous irradiation with white light, eggs of T. urticae displayed higher photoreactivation and were more tolerant to UV-B than eggs of the predatory mites. Among predators variation regarding the tolerance to UV-B effects was observed, with eggs of P. persimilis and I. degenerans being more tolerant to UV-B radiation than eggs of A. swirskii and E. finlandicus.

The Effect of High-Intensity Interval Cycling Sprints Subsequent to Arm-Curl Exercise on Upper-Body Muscle Strength and Hypertrophy.

Science.gov (United States)

Kikuchi, Naoki; Yoshida, Shou; Okuyama, Mizuki; Nakazato, Koichi

2016-08-01

Kikuchi, N, Yoshida, S, Okuyama, M, and Nakazato, K. The effect of high-intensity interval cycling sprints subsequent to arm-curl exercise on upper-body muscle strength and hypertrophy. J Strength Cond Res 30(8): 2318-2323, 2016-The purpose of this study was to examine whether lower limb sprint interval training (SIT) after arm resistance training (RT) influences training response of arm muscle strength and hypertrophy. Twenty men participated in this study. We divided subjects into RT group (n = 6) and concurrent training group (CT, n = 6). The RT program was designed to induce muscular hypertrophy (3 sets × 10 repetitions [reps] at 80% 1 repetition maximum [1RM] of arm-curl exercise) and was performed in an 8-week training schedule performed 3 times per week on nonconsecutive days. Subjects assigned to the CT group performed identical protocols as strength training and modified SIT (4 sets of 30-s maximal effort, separated in 4 m 30-s rest intervals) on the same day. Pretest and posttest maximal oxygen consumption (V[Combining Dot Above]O2max), muscle cross-sectional area (CSA), and 1RM were measured. Significant increase in V[Combining Dot Above]O2max from pretest to posttest was observed in the CT group (p = 0.010, effect size [ES] = 1.84) but not in the RT group (p = 0.559, ES = 0.35). Significant increase in CSA from pretest to posttest was observed in the RT group (p = 0.030, ES = 1.49) but not in the CT group (p = 0.110, ES = 1.01). Significant increase in 1RM from pretest to posttest was observed in the RT group (p = 0.021, ES = 1.57) but not in the CT group (p = 0.065, ES = 1.19). In conclusion, our data indicate that concurrent lower limb SIT interferes with arm muscle hypertrophy and strength.

Mite Pests in Plant Crops – Current Issues, Inovative Approaches and Possibilities for Controlling Them (1

Directory of Open Access Journals (Sweden)

Radmila Petanović

2010-01-01

Full Text Available In the middle of the last century, mites moved into the focus of attention as pests relevantto agriculture, forestry and landscape horticulture, presumably in direct reactionto the “green revolution” that involved plant cultivation in large-plot monocropping systems,improved methods of cultivation, selection of high-yielding cultivars and intensifieduse of pesticides and mineral fertilizers. Agroecosystems in which phytophagous miteshave become harmful organisms are primarily orchards, vineyards, greenhouses, urbangreeneries, plant nurseries and stored plant products, as well as annual field crops to asomewhat lesser degree. Phytophagous mite species belong to a variety of spider mites(Tetranychidae, false spider mites (Tenuipalpidae, gall and rust mites (Eriophyoidae, tarsonemidmites (Tarsonemidae and acarid mites (Acaridae. Most of these harmful speciesare widespread, some of them having more economic impact than others and being moredetrimental as depending on various specificities of each outdoor agroecosystem in anyparticular climatic region.The first segment of this overview focuses on the most significant mite pests ofagroecosystemsand urban horticultural areas in European countries, our own region andin Serbia today, primarily on species that have caused problems in recent years regardingplant production, and it also discusses various molecular methods available for investigatingdifferent aspects of the biology of phytophagous mites. Also, acaricides are discussedas a method of controlling mite pests in the light of the current situation and trends on pesticidemarkets in Serbia and the European Union member-countries

Behaviour of Coconut Mites Preceding Take-off to Passive Aerial Dispersal

NARCIS (Netherlands)

Melo, J.W.S.; Lima, D.B.; Sabelis, M.W.; Pallini, A.; Gondim Jr., M.G.C.

2014-01-01

For more than three decades the coconut mite Aceria guerreronis Keifer is one of the most important pests of coconut palms and has recently spread to many coconut production areas worldwide. Colonization of coconut palms is thought to arise from mites dispersing aerially after take-off from other

The influence of household pets on the composition and quantity of allergenic mite fauna within Irish homes: a preliminary investigation.

Science.gov (United States)

Clarke, D; Dix, E; Liddy, S; Gormally, M; Byrne, M

2016-03-01

Allergenic mites are responsible for inducing hypersensitive reactions in genetically predisposed people worldwide. Mites in dust from 30 Irish homes with pets (dogs, n = 23; cats, n = 7) were compared with those in 30 homes without pets. House dust mites constituted 78% of all mites recorded, with Dermatophagoides pteronyssinus (Acariformes: Pyroglyphidae) representing 57-72% of mites in furniture and mattresses in both home types compared with only 22% of mites in pet beds. Although storage mites accounted for just 13% of all mites recorded, they represented 46% of mites recorded in pet beds. Median levels of the dust mite allergen Der p 1 (µg/g) in dust samples from mattresses in homes without pets were significantly greater than in mattresses from homes with pets, reflecting the greater densities of D. pteronyssinus found in the former home category. Mite species richness was greater in homes with pets (17 species) than in homes without pets (13 species). This suggests that although the presence of pets can result in a wider variety of epidemiologically important mite species within households, increased competition among mite species may result in a more balanced mite fauna in the home, inhibiting the dominance of any one species and hence lowering allergen-associated risks. © 2015 The Royal Entomological Society.

Denegación y límite: Acerca de los llamados trastornos límites

OpenAIRE

Pereña, Francisco

2009-01-01

El estudio de los trastornos del límite revela que la neurosis y la psicosis sólo cubren un reducido campo de la psicopatología. Studies regarding disorders of borderline point out that neurosis and psychosis only cover a small field within psychopathology.

Involvement of Three Esterase Genes from Panonychus citri (McGregor in Fenpropathrin Resistance

Directory of Open Access Journals (Sweden)

Xiao-Min Shen

2016-08-01

Full Text Available The citrus red mite, Panonychus citri (McGregor, is a major citrus pest with a worldwide distribution and an extensive record of pesticide resistance. However, the underlying molecular mechanism associated with fenpropathrin resistance in this species have not yet been reported. In this study, synergist triphenyl phosphate (TPP dramatically increased the toxicity of fenpropathrin, suggesting involvement of carboxylesterases (CarEs in the metabolic detoxification of this insecticide. The subsequent spatiotemporal expression pattern analysis of PcE1, PcE7 and PcE9 showed that three CarEs genes were all over-expressed after insecticide exposure and higher transcripts levels were observed in different field resistant strains of P. citri. Heterologous expression combined with 3-(4,5-dimethyl-thiazol-2-yl-2,5-diphenyltetra-zolium bromide (MTT cytotoxicity assay in Spodoptera frugiperda (Sf9 cells revealed that PcE1-, PcE7- or PcE9-expressing cells showed significantly higher cytoprotective capability than parental Sf9 cells against fenpropathrin, demonstrating that PcEs probably detoxify fenpropathrin. Moreover, gene silencing through the method of leaf-mediated dsRNA feeding followed by insecticide bioassay increased the mortalities of fenpropathrin-treated mites by 31% (PcE1, 27% (PcE7 and 22% (PcE9, respectively, after individual PcE gene dsRNA treatment. In conclusion, this study provides evidence that PcE1, PcE7 and PcE9 are functional genes mediated in fenpropathrin resistance in P. citri and enrich molecular understanding of CarEs during the resistance development of the mite.

Tomato yellow leaf curl virus can be acquired and transmitted by Bemisia tabaci (Gennadius) from tomato fruits

NARCIS (Netherlands)

Delatte, H.; Dalmon, A.; Rist, D.; Soustrade, I.; Wuster, G.; Lett, J.M.; Goldbach, R.W.; Peterschmitt, M.; Reynaud, B.

2003-01-01

The whitefly Bemisia tabaci is an insect pest causing worldwide economic losses, especially as a vector of geminiviruses such as Tomato yellow leaf curl virus (TYLCV). Currently, imported and exported tomato fruit are not monitored for TYLCV infection because they are not considered to represent a

Global divergence of the human follicle mite Demodex folliculorum

DEFF Research Database (Denmark)

Palopoli, Michael F.; Fergus, Daniel J.; Minot, Samuel

2015-01-01

Microscopic mites of the genus Demodex live within the hair follicles of mammals and are ubiquitous symbionts of humans, but little molecular work has been done to understand their genetic diversity or transmission. Here we sampled mite DNA from 70 human hosts of diverse geographic ancestries...... American ancestry. To a great extent, the ancestral geography of hosts predicted the lineages of mites found on them; 27% of the total molecular variance segregated according to the regional ancestries of hosts. We found that D. folliculorum populations are stable on an individual over the course of years...... system for further understanding the history of human movement....

Morphometric variations of laelapine mite (Acari: Mesostigmata populations infesting small mammals (Mammalia in Brazil

Directory of Open Access Journals (Sweden)

F. Martins-Hatano

Full Text Available The goal of this study was to evaluate the morphometric variation of laelapine populations (Acari, Mesostigmata associated with neotropical oryzomyine rodents at different geographic localities in Brazil. Three nominal mite species were selected for study, all infesting the pelage of small mammals at different localities in Rio de Janeiro, Espírito Santo, Bahia, and the Federal District, Brazil. To analyse morphometric characteristics, thirty-seven morphological characters distributed across the whole body of each specimen were measured. We use the Analysis of Principal Components, extracting the three first axes and projecting each mite in these axes. Major species level changes in the taxonomy of the host mammals allows an independent examination of morphometric variation of mites infesting a set of distinctly different host species at different geographic localities. Gigantolaelaps vitzthumi and Laelaps differens are associated with oryzomyine rodents of the genus Cerradomys, and consistently showed a tendency to cluster by host phylogeny. Laelaps manguinhosi associated with Nectomys rattus in central Brazil is morphometrically distinct from mites infesting N. squamipes in the coastal restingas of Rio de Janeiro and Espírito Santo. The results obtained here indicate that laelapine mite populations can vary among geographic areas and among phylogenetically related host species. Clearly, the study of these mites at the population level can be an important tool for clarifying the taxonomy of both mites and hosts.

Morphometric variations of laelapine mite (Acari: Mesostigmata) populations infesting small mammals (Mammalia) in Brazil.

Science.gov (United States)

Martins-Hatano, F; Gettinger, D; Manhães, M L; Bergallo, H G

2012-08-01

The goal of this study was to evaluate the morphometric variation of laelapine populations (Acari, Mesostigmata) associated with neotropical oryzomyine rodents at different geographic localities in Brazil. Three nominal mite species were selected for study, all infesting the pelage of small mammals at different localities in Rio de Janeiro, Espírito Santo, Bahia, and the Federal District, Brazil. To analyse morphometric characteristics, thirty-seven morphological characters distributed across the whole body of each specimen were measured. We use the Analysis of Principal Components, extracting the three first axes and projecting each mite in these axes. Major species level changes in the taxonomy of the host mammals allows an independent examination of morphometric variation of mites infesting a set of distinctly different host species at different geographic localities. Gigantolaelaps vitzthumi and Laelaps differens are associated with oryzomyine rodents of the genus Cerradomys, and consistently showed a tendency to cluster by host phylogeny. Laelaps manguinhosi associated with Nectomys rattus in central Brazil is morphometrically distinct from mites infesting N. squamipes in the coastal restingas of Rio de Janeiro and Espírito Santo. The results obtained here indicate that laelapine mite populations can vary among geographic areas and among phylogenetically related host species. Clearly, the study of these mites at the population level can be an important tool for clarifying the taxonomy of both mites and hosts.

Isolation of oxalotrophic bacteria associated with Varroa destructor mites.

Science.gov (United States)

Maddaloni, M; Pascual, D W

2015-11-01

Bacteria associated with varroa mites were cultivated and genotyped by 16S RNA. Under our experimental conditions, the cultivable bacteria were few in number, and most of them proved to be fastidious to grow. Cultivation with seven different media under O2 /CO2 conditions and selection for colony morphology yielded a panel of species belonging to 13 different genera grouped in two different phyla, proteobacteria and actinobacteria. This study identified one species of actinobacteria that is a known commensal of the honey bee. Some isolates are oxalotrophic, a finding that may carry ramifications into the use of oxalic acid to control the number of phoretic mites in the managed colonies of honey bees. Oxalic acid, legally or brevi manu, is widely used to control phoretic Varroa destructor mites, a major drive of current honey bees' colony losses. Unsubstantiated by sanctioned research are rumours that in certain instances oxalic acid is losing efficacy, forcing beekeepers to increase the frequency of treatments. This investigation fathoms the hypothesis that V. destructor associates with bacteria capable of degrading oxalic acid. The data show that indeed oxalotrophy, a rare trait among bacteria, is common in bacteria that we isolated from V. destructor mites. This finding may have ramifications in the use of oxalic acid as a control agent. © 2015 The Society for Applied Microbiology.

House dust-mite allergen exposure is associated with serum specific IgE but not with respiratory outcomes.

Science.gov (United States)

Bakolis, I; Heinrich, J; Zock, J P; Norbäck, D; Svanes, C; Chen, C M; Accordini, S; Verlato, G; Olivieri, M; Jarvis, D

2015-06-01

Exposure to house dust has been associated with asthma in adults, and this is commonly interpreted as a direct immunologic response to dust-mite allergens in those who are IgE sensitized to house dust-mite. Mattress house dust-mite concentrations were measured in a population-based sample of 2890 adults aged between 27 and 56 years living in 22 centers in 10 countries. Generalized linear mixed models were employed to explore the association of respiratory symptoms with house dust-mite concentrations, adjusting for individual and household confounders. There was no overall association of respiratory outcomes with measured house dust-mite concentrations, even in those who reported they had symptoms on exposure to dust and those who had physician-diagnosed asthma. However, there was a positive association of high serum specific IgE levels to HDM (>3.5 kUA /l) with mattress house dust-mite concentrations and a negative association of sensitization to cat with increasing house dust-mite concentrations. In conclusion, there was no evidence that respiratory symptoms in adults were associated with exposure to house dust-mite allergen in the mattress, but an association of house mite with strong sensitization was observed. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Size of predatory mites and refuge entrance determine success of biological control of the coconut mite

NARCIS (Netherlands)

da Silva, F.R.; de Moraes, G.J.; Lesna, I.; Sato, Y.; Vasquez, C.; Hanna, R.; Sabelis, M.W.; Janssen, A.

2016-01-01

Predators face the challenge of accessing prey that live in sheltered habitats. The coconut mite Aceriaguerreronis Keifer (Acari: Eriophyidae) lives hidden beneath the perianth, which is appressed to the coconut fruit surface, where they feed on the meristematic tissue. Its natural enemy, the

Isolation and sequence characterization of DNA-A genome of a new begomovirus strain associated with severe leaf curling symptoms of Jatropha curcas L.

Science.gov (United States)

Chauhan, Sushma; Rahman, Hifzur; Mastan, Shaik G; Pamidimarri, D V N Sudheer; Reddy, Muppala P

2018-07-20

Begomoviruses belong to the family Geminiviridae are associated with several disease symptoms, such as mosaic and leaf curling in Jatropha curcas. The molecular characterization of these viral strains will help in developing management strategies to control the disease. In this study, J. curcas that was infected with begomovirus and showed acute leaf curling symptoms were identified. DNA-A segment from pathogenic viral strain was isolated and sequenced. The sequenced genome was assembled and characterized in detail. The full-length DNA-A sequence was covered by primer walking. The genome sequence showed the general organization of DNA-A from begomovirus by the distribution of ORFs in both viral and anti-viral strands. The genome size ranged from 2844 bp-2852 bp. Three strains with minor nucleotide variations were identified, and a phylogenetic analysis was performed by comparing the DNA-A segments from other reported begomovirus isolates. The maximum sequence similarity was observed with Euphorbia yellow mosaic virus (FN435995). In the phylogenetic tree, no clustering was observed with previously reported begomovirus strains isolated from J. curcas host. The strains isolated in this study belong to new begomoviral strain that elicits symptoms of leaf curling in J. curcas. The results indicate that the probable origin of the strains is from Jatropha mosaic virus infecting J. gassypifolia. The strains isolated in this study are referred as Jatropha curcas leaf curl India virus (JCLCIV) based on the major symptoms exhibited by host J. curcas. Copyright © 2018 Elsevier B.V. All rights reserved.

Infection of the whitefly Bemisia tabaci with Rickettsia spp. alters its interactions with Tomato yellow leaf curl virus

Science.gov (United States)

Numerous animal and plant viruses are transmitted by arthropod vectors in a persistent, circulative manner. Tomato yellow leaf curl virus (TYLCV) is transmitted by the sweet potato whitefly Bemisia tabaci. Here we report that infection with Rickettsia spp., a facultative endosymbiont of whiteflies...

Behavioural responses of two-spotted spider mites induced by predator-borne and prey-borne cues.

Science.gov (United States)

Gyuris, Enikő; Szép, Erna; Kontschán, Jenő; Hettyey, Attila; Tóth, Zoltán

2017-11-01

Applying predatory mites as biological control agents is a well established method against spider mites which are major pests worldwide. Although antipredator responses can influence the outcome of predator-prey interactions, we have limited information about what cues spider mites use to adjust their behavioural antipredator responses. We experimentally exposed two-spotted spider mites (Tetranychus urticae) to different predator-borne cues (using a specialist predator, Phytoseiulus persimilis, or a generalist predator, Amblyseius swirskii), conspecific prey-borne cues, or both, and measured locomotion and egg-laying activity. The reactions to predator species compared to each other manifested in reversed tendencies: spider mites increased their locomotion activity in the presence of P. persimilis, whereas they decreased it when exposed to A. swirskii. The strongest response was triggered by the presence of a killed conspecific: focal spider mites decreased their locomotion activity compared to the control group. Oviposition activity was not affected by either treatment. Our results point out that spider mites may change their behaviour in response to predators, and also to the presence of killed conspecifics, but these effects were not enhanced when both types of cues were present. The effect of social contacts among prey conspecifics on predator-induced behavioural defences is discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Environmental Engineering Approaches toward Sustainable Management of Spider Mites.

Science.gov (United States)

Suzuki, Takeshi

2012-10-26

Integrated pest management (IPM), which combines physical, biological, and chemical control measures to complementary effect, is one of the most important approaches to environmentally friendly sustainable agriculture. To expand IPM, we need to develop new pest control measures, reinforce existing measures, and investigate interactions between measures. Continued progress in the development of environmental control technologies and consequent price drops have facilitated their integration into plant production and pest control. Here I describe environmental control technologies for the IPM of spider mites through: (1) the disturbance of photoperiod-dependent diapause by artificial light, which may lead to death in seasonal environments; (2) the use of ultraviolet radiation to kill or repel mites; and (3) the use of water vapor control for the long-term cold storage of commercially available natural enemies. Such environmental control technologies have great potential for the efficient control of spider mites through direct physical effects and indirect effects via natural enemies.

Social familiarity modulates group living and foraging behaviour of juvenile predatory mites

Science.gov (United States)

Strodl, Markus A.; Schausberger, Peter

2012-04-01

Environmental stressors during early life may have persistent consequences for phenotypic development and fitness. In group-living species, an important stressor during juvenile development is the presence and familiarity status of conspecific individuals. To alleviate intraspecific conflicts during juvenile development, many animals evolved the ability to discriminate familiar and unfamiliar individuals based on prior association and use this ability to preferentially associate with familiar individuals. Assuming that familiar neighbours require less attention than unfamiliar ones, as predicted by limited attention theory, assorting with familiar individuals should increase the efficiency in other tasks. We assessed the influence of social familiarity on within-group association behaviour, development and foraging of juvenile life stages of the group-living, plant-inhabiting predatory mite Phytoseiulus persimilis. The observed groups consisted either of mixed-age familiar and unfamiliar juvenile mites or of age-synchronized familiar or unfamiliar juvenile mites or of pairs of familiar or unfamiliar larvae. Overall, familiar mites preferentially grouped together and foraged more efficiently, i.e. needed less prey at similar developmental speed and body size at maturity, than unfamiliar mites. Preferential association of familiar mites was also apparent in the inter-exuviae distances. Social familiarity was established by imprinting in the larval stage, was not cancelled or overridden by later conspecific contacts and persisted into adulthood. Life stage had an effect on grouping with larvae being closer together than nymphal stages. Ultimately, optimized foraging during the developmental phase may relax within-group competition, enhance current and future food supply needed for optimal development and optimize patch exploitation and leaving under limited food.

Viral epidemiology of the adult Apis Mellifera infested by the Varroa destructor mite.

Science.gov (United States)

Bernardi, Sara; Venturino, Ezio

2016-05-01

The ectoparasitic mite Varroa destructor has become one of the major worldwide threats for apiculture. Varroa destructor attacks the honey bee Apis mellifera weakening its host by sucking hemolymph. However, the damage to bee colonies is not strictly related to the parasitic action of the mite but it derives, above all, from its action as vector increasing the transmission of many viral diseases such as acute paralysis (ABPV) and deformed wing viruses (DWV), that are considered among the main causes of CCD (Colony Collapse Disorder). In this work we discuss an [Formula: see text] model that describes how the presence of the mite affects the epidemiology of these viruses on adult bees. The acronym [Formula: see text] means that the disease affects both populations. In fact it accounts for the bee and mite populations, that are each divided among the S (susceptible) and I (infected) states. We characterize the system behavior, establishing that ultimately either only healthy bees survive, or the disease becomes endemic and mites are wiped out. Another dangerous alternative is the Varroa invasion scenario with the extinction of healthy bees. The final possible configuration is the coexistence equilibrium in which honey bees share their infected hive with mites. The analysis is in line with some observed facts in natural honey bee colonies. Namely, these diseases are endemic. Further, if the mite population is present, necessarily the viral infection occurs. The findings of this study indicate that a low horizontal transmission rate of the virus among honey bees in beehives will help in protecting bee colonies from Varroa infestation and viral epidemics.

Complete sequence analysis of 18S rDNA based on genomic DNA extraction from individual Demodex mites (Acari: Demodicidae).

Science.gov (United States)

Zhao, Ya-E; Xu, Ji-Ru; Hu, Li; Wu, Li-Ping; Wang, Zheng-Hang

2012-05-01

The study for the first time attempted to accomplish 18S ribosomal DNA (rDNA) complete sequence amplification and analysis for three Demodex species (Demodex folliculorum, Demodex brevis and Demodex canis) based on gDNA extraction from individual mites. The mites were treated by DNA Release Additive and Hot Start II DNA Polymerase so as to promote mite disruption and increase PCR specificity. Determination of D. folliculorum gDNA showed that the gDNA yield reached the highest at 1 mite, tending to descend with the increase of mite number. The individual mite gDNA was successfully used for 18S rDNA fragment (about 900 bp) amplification examination. The alignments of 18S rDNA complete sequences of individual mite samples and those of pooled mite samples ( ≥ 1000mites/sample) showed over 97% identities for each species, indicating that the gDNA extracted from a single individual mite was as satisfactory as that from pooled mites for PCR amplification. Further pairwise sequence analyses showed that average divergence, genetic distance, transition/transversion or phylogenetic tree could not effectively identify the three Demodex species, largely due to the differentiation in the D. canis isolates. It can be concluded that the individual Demodex mite gDNA can satisfy the molecular study of Demodex. 18S rDNA complete sequence is suitable for interfamily identification in Cheyletoidea, but whether it is suitable for intrafamily identification cannot be confirmed until the ascertainment of the types of Demodex mites parasitizing in dogs. Copyright © 2012 Elsevier Inc. All rights reserved.

Limits to ambulatory displacement of coconut mites in absence and presence of food-related cues.

Science.gov (United States)

Melo, J W S; Lima, D B; Sabelis, M W; Pallini, A; Gondim, M G C

2014-04-01

Ambulatory movement of plant-feeding mites sets limits to the distances they can cover to reach a new food source. In absence of food-related cues these limits are determined by survival, walking activity, walking path tortuosity and walking speed, whereas in presence of food the limits are also determined by the ability to orient and direct the path towards the food source location. For eriophyoid mites such limits are even more severe because they are among the smallest mites on earth, because they have only two pairs of legs and because they are very sensitive to desiccation. In this article we test how coconut mites (Aceria guerreronis Keifer) are constrained in their effective displacement by their ability to survive in absence of food (meristematic tissue under the coconut perianth) and by their ability to walk and orient in absence or presence of food-related cues. We found that the mean survival time decreased with increasing temperature and decreasing humidity. Under climatic conditions representative for the Tropics (27 °C and 75 % relative humidity) coconut mites survived on average for 11 h and covered 0.4 m, representing the effective linear displacement away from the origin. Within a period of 5 h, coconut mites collected from old fruits outside the perianth moved further away from the origin than mites collected under the perianth of young fruits. However, in the presence of food-related cues coconut mites traveled over 30 % larger distances than in absence of these cues. These results show that ambulatory movement of eriophyoid mites may well bring them to other coconuts within the same bunch and perhaps also to other bunches on the same coconut palm, but it is unlikely to help them move from palm to palm, given that palms usually do not touch each other.

The single-leg Roman chair hold is more effective than the Nordic hamstring curl in improving hamstring strength-endurance in Gaelic footballers with previous hamstring injury.

Science.gov (United States)

Macdonald, Ben; O'Neill, John; Pollock, Noel; Van Hooren, Bas

2018-03-06

Poor hamstring strength-endurance is a risk factor for hamstring injuries. This study investigated the effectiveness of the single-leg Roman hold and Nordic hamstring curl in improving hamstring strength-endurance. Twelve Gaelic footballers (mean ± standard deviation age, height and mass were 25.17 ± 3.46 years, 179.25 ± 5.88 cm, 85.75 ± 4.75 kilo) with a history of hamstring injury were randomized into 2 groups that performed 6 weeks of either Nordic hamstring curl, or single-leg Roman chair hold training. The single-leg hamstring bridge (SLHB) was measured pre- and post- intervention. The Roman chair group showed a very likely moderate magnitude improvement on SLHB performance for both legs (23.7% for the previously injured leg [90% confidence interval 9.6% to 39.6%] and 16.9% for the non-injured leg [6.2% to 28.8%]). The Nordic curl group showed a likely trivial change in SLHB performance for the non-injured leg (-2.1% [-6.7% to 2.6%]) and an unclear, but possibly trivial change for the previously injured leg (0.3% [-5.6% to 6.6%]). The Roman chair group improved very likely more with a moderate magnitude in both the non-injured (19.5% [8.0% to 32.2%]) and the previously injured leg (23.3% [8.5% to 40.0%]) compared to the Nordic curl group. This study demonstrated that 6-weeks single-leg Roman chair training substantially improved SLHB performance, suggesting that it may be an efficacious strategy to mitigate hamstring (re-) injury risk. Conversely, 6-weeks Nordic curl training did not substantially improve SLHB performance, suggesting this may not be the intervention of choice for modifying this risk factor.

A lost world disease: Copra itch outbreak caused by Tyrophagus longior mite

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Prakit Sarathep

Full Text Available An outbreak investigation of copra itch revealed a cluster of six suspected cases with skin dermatitis, with 11–32 years of age, belonging to a single family, between June and July 2016 in Phang Nga province, Southern Thailand. Epidemiologic investigation of these suspected cases revealed five probable cases developing multiple discrete erythematous papules with intense pruritus on the body rather than the extremities and one confirmed case whose skin was infested with domestic mite, Tyrophagus longior (Gervais (Ascari: Ascaridae. This mite was also found in unused coir mattresses outside their bedrooms. Household infestation with T. longior mites rendered these family members to become more susceptible to expose indoor biting of T. longior adult mites that were adapted well to the domestic environments with poor hygienic conditions. Human exposure to mite bites was more likely to be a direct contact than an indirect contact. Findings from this copra itch outbreak investigation provided understanding of natural disease of copra itch and factors that favored the outbreak, and could guide diagnosis for physicians, surveillance and response for surveillance and rapid response teams (SRRTs, and prevention and control for entomologists and public health personnel. Keywords: Copra itch, Tyrophagus longior, Erythematous papules, Domestic environments

Trophic habits of mesostigmatid mites associated with bark beetles in Mexico

Science.gov (United States)

M. Patricia Chaires-Grijalva; Edith G. Estrada-Venegas; Armando Equihua-Martinez; John C. Moser; Stacy R. Blomquist

2016-01-01

Samples of bark and logs damaged by bark beetles were collected from 16 states of Mexico from 2007 to 2012. Fifteen bark beetle species were found within the bark and log samples and were examined for phoretic mites and arthropod associates. Thirty-three species of mesostigmatid mites were discovered within the samples. They were identified in several trophic guilds...

Social environment affects the life history tactic of a phoretic mite

DEFF Research Database (Denmark)

Nehring, Volker; Müller, Josef K

2009-01-01

Phoretic animals use their hosts for travelling to habitat patches suitable for reproduction. Some species, such as the mite Poecilochirus carabi, are phoretic as juveniles and cannot leave their habitat once they reach adulthood. Previous work has shown that mites exercise choice over the habitat...... influence of the social environment on a phoretic's habitat choice and life history....

Active optical sensor assessment of spider mite damage on greenhouse beans and cotton.

Science.gov (United States)

Martin, Daniel E; Latheef, Mohamed A

2018-02-01

The two-spotted spider mite, Tetranychus urticae Koch, is an important pest of cotton in mid-southern USA and causes yield reduction and deprivation in fiber fitness. Cotton and pinto beans grown in the greenhouse were infested with spider mites at the three-leaf and trifoliate stages, respectively. Spider mite damage on cotton and bean canopies expressed as normalized difference vegetation index indicative of changes in plant health was measured for 27 consecutive days. Plant health decreased incrementally for cotton until day 21 when complete destruction occurred. Thereafter, regrowth reversed decline in plant health. On spider mite treated beans, plant vigor plateaued until day 11 when plant health declined incrementally. Results indicate that pinto beans were better suited as a host plant than cotton for rearing T. urticae in the laboratory.

Control of Varroa Mite (Varroa destructor on Honeybees by Aromatic Oils and Plant Materials

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I.K. Nazer

2003-01-01

Full Text Available The effect of several volatile plant oils, plant materials and fluvalinate (Apistan® strips on the control of the mite Varroa destructor on honeybee (Apis mellifera L. colonies was studied. The volatile oils were: clove, lavender, peppermint, sage, and thyme. The plant materials were: cumin fruits, eucalyptus leaves, and worm wood flowers. For each tested material, three treatment periods were carried out. Each period lasted for 24 days followed by eight days no-treatment. Within each treatment period, an average of three to six treatments were applied. Dead mites were counted one hour before and after each treatment. An increase in dead mites was recorded for the three treatment periods. It indicated that worm wood flowers, peppermint oil and clove oil treatments gave the best results in the control of Varroa mites but not significantly different than the control. The overall increase in the dead mites was 3.92, 3.62 and 3.34 fold, respectively.

Mites associated with sugarcane crop and with native trees from adjacent Atlantic forest fragment in Brazil.

Science.gov (United States)

Duarte, Mércia E; Navia, Denise; dos Santos, Lucas R; Rideiqui, Pedro J S; Silva, Edmilson S

2015-08-01

In some Brazilian regions the Atlantic forest biome is currently restrict to fragments occurring amid monocultures, as sugarcane crops in the Northeast region. Important influence of forest remnants over mite fauna of permanent crops have been showed, however it has been poorly explored on annual crops. The first step for understanding ecological relationship in an agricultural systems is known its composition. The objective of this study was to investigate the plant-inhabiting mite fauna associated with sugarcane crop (Saccharum officinarum L.) (Poaceae) and caboatã (Cupania oblongifolia Mart.) (Sapindaceae) trees in the state of Alagoas, Brazil. Sugarcane stalks and sugarcane and caboatã apical, middle and basal leaves were sampled. A total of 2565 mites were collected from sugarcane and classified into seven families of Trombidiformes and Mesostigmata orders, with most individuals belonging to the Eriophyidae, Tetranychidae and Tarsonemidae families. Among predatory mites, the Phytoseiidae were the most common. A total of 1878 mites were found on C. oblongifolia and classified into 13 families of Trombidiformes and Mesostigmata orders. The most abundant phytophagous mite family on caboatã was also Eriophyidae. In contrast to sugarcane, Ascidae was the most common predatory mite family observed in caboatã. No phytophagous species were common to both sugarcane and C. oblongifolia. However two predatory mites were shared between host plants. Although mites associated with only one native species in the forest fragment were evaluated in this study, our preliminary results suggest Atlantic forest native vegetation can present an important role in the sugarcane agricultural system as a source of natural enemies.

Prey Preference of the Predatory Mite, Amblyseius swirskii between First Instar Western Flower Thrips Frankliniella occidentalis and Nymphs of the Twospotted Spider Mite Tetranychus urticae

OpenAIRE

Xu, Xuenong; Enkegaard, Annie

2010-01-01

The prey preference of polyphagous predators plays an important role in suppressing different species of pest insects. In this study the prey preference of the predatory mite, Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) was examined between nymphs of the twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) and first instar larvae of the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), as well as between active and chrysa...

House Dust Mite Prevalence in the House of Patients with Atopic Dermatitis in Mashhad, Iran

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Toktam Ziyaei

2017-06-01

Full Text Available Background: Being exposed to house dust mites intensifies atopic dermatitis. This study has investigated the con­tamination rate with Dermatophagoides mites in patient's residential home with atopic dermatitis.Methods: In this cross-sectional study, 40 patients took part with atopic dermatitis (positive or negative for mites by prick Dermal Test. Samples were collected from 3 locations (living room, bedroom and bed by vacuum cleaner. Dust samples (transferred to freezer -20 ˚C were examined by direct method and flotation. The data were analyzed using statistical SPSS vr.20 software.Results: Twenty patients of positive prick test included 8 (40% male and 12 (60% female. The results of direct observation of mites: 7 cases (35% in bedding sheets, 6 cases (30% bedrooms' carpet, 3 cases (15% living room's carpet. Twenty patients of negative prick test included 8 (40% male and 12 (60% female. Only mites were found (5% in living room's carpets of negative prick test patients. Dermatophagoides pteronyssinus was more frequent than Dermatophagoides farinae. (98% vs 83%.Conclusion: Fifty-five percent of residential homes of prick test positive patients and only 5% of residential homes of prick test negative patients were positive for mite. Sunshine provided home had fewer mites than home where sunshine is not provided. Prick test positive patients used handmade carpets more than machine made ones. In posi­tive prick test patients, mites were found in bed sheet and bedroom’s carpet more than negative prick test patient's sheets and carpets.

Bee Mite ID - an online resource on identification of mites associated with bees of the World

Science.gov (United States)

Parasitic mites are known to be a factor in recent declines in bee pollinator populations. In particular, Varroa destructor, an introduced parasite and disease vector, has decimated colonies of the western honey bee, one of the most important agricultural pollinators in the world. Further, global tr...

The effect of queen pheromone status on Varroa mite removal from honey bee colonies with different grooming ability.

Science.gov (United States)

Bahreini, Rassol; Currie, Robert W

2015-07-01

The objective of this study was to assess the effects of honey bees (Apis mellifera L.) with different grooming ability and queen pheromone status on mortality rates of Varroa mites (Varroa destructor Anderson and Trueman), mite damage, and mortality rates of honey bees. Twenty-four small queenless colonies containing either stock selected for high rates of mite removal (n = 12) or unselected stock (n = 12) were maintained under constant darkness at 5 °C. Colonies were randomly assigned to be treated with one of three queen pheromone status treatments: (1) caged, mated queen, (2) a synthetic queen mandibular pheromone lure (QMP), or (3) queenless with no queen substitute. The results showed overall mite mortality rate was greater in stock selected for grooming than in unselected stock. There was a short term transitory increase in bee mortality rates in selected stock when compared to unselected stock. The presence of queen pheromone from either caged, mated queens or QMP enhanced mite removal from clusters of bees relative to queenless colonies over short periods of time and increased the variation in mite mortality over time relative to colonies without queen pheromone, but did not affect the proportion of damaged mites. The effects of source of bees on mite damage varied with time but damage to mites was not reliably related to mite mortality. In conclusion, this study showed differential mite removal of different stocks was possible under low temperature. Queen status should be considered when designing experiments using bioassays for grooming response.

The First Report of Eustigmaeus Johnstoni (Acari: Stigmaeidae Parasitic Mite of Phlebotominae Sand Flies from Iran

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Mehdi Badakhshan

2013-03-01

Full Text Available Background: Stigmaeids mites have been recorded only on Phlebotominae sand flies up to now. Five species of Eustigmaeus, and three of Stigmaeus were reported on infested sandflies in different country up to the present.Methods: Sand flies collection was done using CDC light trap and sticky paper. The mites were isolated from in­fested specimens, mounted in Puri’s medium and identified using reliable keys.Results: A mite infested Phlebotomus papatasi was observed during a study on sandflies of one of the southern provinces of Iran, near to the Persian Gulf. Several scars resulting from mite attachment were found on abdominal tergites of this female sand fly. The mites were identified as Eustigmaeus johnstoni.Conclusion: This parasitic mite is one of the eyeless species, which has a great distribution over the world, reported from Tunisia, Saudi Arabia, Pakistan, Yemen, Cyprus and Palestine. But, this is the first record of this species from Iran.

Genetic diversity and distribution of a distinct strain of Chili leaf curl virus and associated betasatellite infecting tomato and pepper in Oman.

Science.gov (United States)

Khan, Akhtar J; Akhtar, Sohail; Al-Zaidi, Amal M; Singh, Achuit K; Briddon, Rob W

2013-10-01

Tomato and pepper are widely grown in Oman for local consumption. A countrywide survey was conducted during 2010-2011 to collect samples and assess the diversity of begomoviruses associated with leaf curl disease of tomato and pepper. A virus previously only identified on the Indian subcontinent, chili leaf curl virus (ChLCV), was found associated with tomato and pepper diseases in all vegetable grown areas of Oman. Some of the infected plant samples were also found to contain a betasatellite. A total of 19 potentially full-length begomovirus and eight betasatellite clones were sequenced. The begomovirus clones showed >96% nucleotide sequence identity, showing them to represent a single species. Comparisons to sequences available in the databases showed the highest levels of nucleotide sequence identity (88.0-91.1%) to isolates of the "Pakistan" strain of ChLCV (ChLCV-PK), indicating the virus from Oman to be a distinct strain, for which the name Oman strain (ChLCV-OM) is proposed. An analysis for recombination showed ChLCV-OM likely to have originated by recombination between ChLCV-PK (the major parent), pepper leaf curl Lahore virus and a third strain of ChLCV. The betasatellite sequences obtained were shown to have high levels of identity to isolates of tomato leaf curl betasatellite (ToLCB) previous shown to be present in Oman. For the disease in tomato Koch's postulates were satisfied by Agrobacterium-mediated inoculation of virus and betasatellites clones. This showed the symptoms induced by the virus in the presence of the betasatellite to be enhanced, although viral DNA levels were not affected. ChLCV-OM is the fourth begomovirus identified in tomato in Oman and the first in Capsicum. The significance of these findings is discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

Mite fauna and fungal flora in house dust from homes of asthmatic children.

Science.gov (United States)

Ishii, A; Takaoka, M; Ichinoe, M; Kabasawa, Y; Ouchi, T

1979-12-01

Mite fauna and fungal flora in the house dust from homes of asthmatic children with positive and negative skin test to house dust allergen and non-asthmatic controls were examined. There was no conspicuous difference in mite species distribution among the three groups. Pyroglyphid mites dominate the mite fauna in house dust more than half of which being Dermatophagoides: D. pteronyssinus and D. farinae. There was no statistically significant difference in numbers between the two species and either species could dominate depending on the conditions of the individual houses. The average number of acarina in 0.5 g of fine dust did not differ statistically among the three groups; however, mite number per square meter floor differed between patients with positive skin test and negative skin test. The results suggest that house-cleaning might influence the possible sensitization of children. The genetic distribution of mould fungi in house dust was largely similar to that of airborne fungi. The average number of fungal colonies detected in 0.5 g of dust did not differ statistically among the three groups. Wallemia with its minute spores may cause sensitization but has so far been insufficiently investigated.

From repulsion to attraction: species- and spatial context-dependent threat sensitive response of the spider mite Tetranychus urticae to predatory mite cues

Science.gov (United States)

Fernández Ferrari, M. Celeste; Schausberger, Peter

2013-06-01

Prey perceiving predation risk commonly change their behavior to avoid predation. However, antipredator strategies are costly. Therefore, according to the threat-sensitive predator avoidance hypothesis, prey should match the intensity of their antipredator behaviors to the degree of threat, which may depend on the predator species and the spatial context. We assessed threat sensitivity of the two-spotted spider mite, Tetranychus urticae, to the cues of three predatory mites, Phytoseiulus persimilis, Neoseiulus californicus, and Amblyseius andersoni, posing different degrees of risk in two spatial contexts. We first conducted a no-choice test measuring oviposition and activity of T. urticae exposed to chemical traces of predators or traces plus predator eggs. Then, we tested the site preference of T. urticae in choice tests, using artificial cages and leaves. In the no-choice test, T. urticae deposited their first egg later in the presence of cues of P. persimilis than of the other two predators and cue absence, indicating interspecific threat-sensitivity. T. urticae laid also fewer eggs in the presence of cues of P. persimilis and A. andersoni than of N. californicus and cue absence. In the artificial cage test, the spider mites preferred the site with predator traces, whereas in the leaf test, they preferentially resided on leaves without traces. We argue that in a nonplant environment, chemical predator traces do not indicate a risk for T. urticae, and instead, these traces function as indirect habitat cues. The spider mites were attracted to these cues because they associated them with the existence of a nearby host plant.

Chemical and cultural control of Tropilaelaps mercedesae mites in honeybee (Apis mellifera colonies in Northern Thailand.

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Jeffery S Pettis

Full Text Available At least two parasitic mites have moved from Asian species of honeybees to infest Apis mellifera. Of these two, Varroa destructor is more widespread globally while Tropilaelaps mercedesae has remained largely in Asia. Tropilaelaps mites are most problematic when A. mellifera is managed outside its native range in contact with Asian species of Apis. In areas where this occurs, beekeepers of A. mellifera treat aggressively for Tropilaelaps and Varroa is either outcompeted or is controlled as a result of the aggressive treatment regime used against Tropilaelaps. Many mite control products used worldwide may in fact control both mites but environmental conditions differ globally and thus a control product that works well in one area may be less or ineffective in other areas. This is especially true of volatile compounds. In the current research we tested several commercial products known to control Varroa and powdered sulfur for efficacy against Tropilaelaps. Additionally, we tested the cultural control method of making a hive division to reduce Tropilaelaps growth in both the parent and offspring colony. Making a split or nucleus colony significantly reduced mite population in both the parent and nucleus colony when compared to un-manipulated control colonies. The formic acid product, Mite-Away Quick Strips®, was the only commercial product that significantly reduced mite population 8 weeks after initiation of treatment without side effects. Sulfur also reduced mite populations but both sulfur and Hopguard® significantly impacted colony growth by reducing adult bee populations. Apivar® (amitraz strips had no effect on mite or adult bee populations under the conditions tested.

Long term dynamics of dermanyssus gallinae in relation to mite control measures in aviary systems for layers.

Science.gov (United States)

Nordenfors, H; Höglund, J

2000-12-01

1. The dynamics of the poultry red mite, Dermanyssus gallinae, in aviary systems for layers were studied in an empirical study in Sweden between 1994 and 1997. Fluctuations were monitored with mite traps at monthly intervals during 3 laying cycles at each of 2 commercial poultry farms. 2. When mites were first detected in the system it then took about 5 months for the populations to reach equilibrium levels around which they fluctuated. Within flocks when the population growth was unaffected by temporary control activities, it was demonstrated that the mite populations were significantly denser in summer than in winter. 3. Current control methods had limited effects as mite populations were only temporarily suppressed. One exception was the control achieved with permethrin impregnated plastic strips, which reduced the population at equilibrium level to approximately 22%, compared with the previous flock. 4. The distribution of mites was patchy horizontally, along the aviary system, at low burden wlhereas it became more evenly dispersed at equilibrium. 5. Significant differences in vertical mite distributions that correlated with the hybrids used and their rearing conditions were also observed. In flocks with brown hens, mites gathered at the lower tiers, whereas they were found at the highest tiers in association with white hens. As the hens are attacked mainly at night-time the most likely explanation is that the mites adjust their behavioural pattern to the birds' roosting behaviour.

Lower virus infections in Varroa destructor-infested and uninfested brood and adult honey bees (Apis mellifera) of a low mite population growth colony compared to a high mite population growth colony.

Science.gov (United States)

Emsen, Berna; Hamiduzzaman, Mollah Md; Goodwin, Paul H; Guzman-Novoa, Ernesto

2015-01-01

A comparison was made of the prevalence and relative quantification of deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), black queen cell virus (BQCV), Kashmir bee virus (KBV), acute bee paralysis virus (ABPV) and sac brood virus (SBV) in brood and adult honey bees (Apis mellifera) from colonies selected for high (HMP) and low (LMP) Varroa destructor mite population growth. Two viruses, ABPV and SBV, were never detected. For adults without mite infestation, DWV, IAPV, BQCV and KBV were detected in the HMP colony; however, only BQCV was detected in the LMP colony but at similar levels as in the HMP colony. With mite infestation, the four viruses were detected in adults of the HMP colony but all at higher amounts than in the LMP colony. For brood without mite infestation, DWV and IAPV were detected in the HMP colony, but no viruses were detected in the LMP colony. With mite infestation of brood, the four viruses were detected in the HMP colony, but only DWV and IAPV were detected and at lower amounts in the LMP colony. An epidemiological explanation for these results is that pre-experiment differences in virus presence and levels existed between the HMP and LMP colonies. It is also possible that low V. destructor population growth in the LMP colony resulted in the bees being less exposed to the mite and thus less likely to have virus infections. LMP and HMP bees may have also differed in susceptibility to virus infection.

Geometric classification of scalp hair for valid drug testing, 6 more reliable than 8 hair curl groups.

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K Mkentane

Full Text Available Curly hair is reported to contain higher lipid content than straight hair, which may influence incorporation of lipid soluble drugs. The use of race to describe hair curl variation (Asian, Caucasian and African is unscientific yet common in medical literature (including reports of drug levels in hair. This study investigated the reliability of a geometric classification of hair (based on 3 measurements: the curve diameter, curl index and number of waves.After ethical approval and informed consent, proximal virgin (6cm hair sampled from the vertex of scalp in 48 healthy volunteers were evaluated. Three raters each scored hairs from 48 volunteers at two occasions each for the 8 and 6-group classifications. One rater applied the 6-group classification to 80 additional volunteers in order to further confirm the reliability of this system. The Kappa statistic was used to assess intra and inter rater agreement.Each rater classified 480 hairs on each occasion. No rater classified any volunteer's 10 hairs into the same group; the most frequently occurring group was used for analysis. The inter-rater agreement was poor for the 8-groups (k = 0.418 but improved for the 6-groups (k = 0.671. The intra-rater agreement also improved (k = 0.444 to 0.648 versus 0.599 to 0.836 for 6-groups; that for the one evaluator for all volunteers was good (k = 0.754.Although small, this is the first study to test the reliability of a geometric classification. The 6-group method is more reliable. However, a digital classification system is likely to reduce operator error. A reliable objective classification of human hair curl is long overdue, particularly with the increasing use of hair as a testing substrate for treatment compliance in Medicine.

Selection of Apis mellifera workers by the parasitic mite Varroa destructor using host cuticular hydrocarbons.

Science.gov (United States)

Del Piccolo, F; Nazzi, F; Della Vedova, G; Milani, N

2010-05-01

The parasitic mite, Varroa destructor, is the most important threat for apiculture in most bee-keeping areas of the world. The mite is carried to the bee brood cell, where it reproduces, by a nurse bee; therefore the selection of the bee stage by the parasite could influence its reproductive success. This study investigates the role of the cuticular hydrocarbons of the European honeybee (Apis mellifera) in host-selection by the mite. Preliminary laboratory bioassays confirmed the preference of the varroa mite for nurse bees over pollen foragers. GC-MS analysis of nurse and pollen bees revealed differences in the cuticular hydrocarbons of the two stages; in particular, it appeared that pollen bees have more (Z)-8-heptadecene than nurse bees. Laboratory experiments showed that treatment of nurse bees with 100 ng of the pure compound makes them repellent to the varroa mite. These results suggest that the mite can exploit the differences in the cuticular composition of its host for a refined selection that allows it to reach a brood cell and start reproduction. The biological activity of the alkene encourages further investigations for the development of novel control techniques based on this compound.

Diversity and significance of eriophyoid mites (Acari: Eriophyoidea associated with coniferous trees in Poland: a review

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Kiedrowicz Agnieszka

2016-06-01

Full Text Available Among the approximately 200 eriophyoid mite species associated with coniferous trees worldwide, 33 species (of the families Eriophyidae and Phytoptidae infest conifers in Poland, and 24 of them can cause visible feeding symptoms. In this paper we discuss the importance of eriophyoid mites to coniferous plants in Poland and their potential impact on the decorative value of ornamental plants. We emphasize the general lack of knowledge about the diversity of eriophyoid mites associated with coniferous trees and its role in the management and control of this economically important mite group.

Evidence for passive chemical camouflage in the parasitic mite Varroa destructor.

Science.gov (United States)

Kather, Ricarda; Drijfhout, Falko P; Shemilt, Sue; Martin, Stephen J

2015-02-01

Social insect colonies provide a stable and safe environment for their members. Despite colonies being heavily guarded, parasites have evolved numerous strategies to invade and inhabit these hostile places. Two such strategies are (true) chemical mimicry via biosynthesis of host odor, and chemical camouflage, in which compounds are acquired from the host. The ectoparasitic mite Varroa destructor feeds on hemolymph of its honey bee host, Apis mellifera. The mite's odor closely resembles that of its host, which allows V. destructor to remain undetected as it lives on the adult host during its phoretic phase and while reproducing on the honeybee brood. During the mite life cycle, it switches between host adults and brood, which requires it to adjust its profile to mimic the very different odors of honey bee brood and adults. In a series of transfer experiments, using bee adults and pupae, we tested whether V. destructor changes its profile by synthesizing compounds or by using chemical camouflage. We show that V. destructor required direct access to host cuticle to mimic its odor, and that it was unable to synthesize host-specific compounds itself. The mite was able to mimic host odor, even when dead, indicating a passive physico-chemical mechanism of the parasite cuticle. The chemical profile of V. destructor was adjusted within 3 to 9 h after switching hosts, demonstrating that passive camouflage is a highly efficient, fast and flexible way for the mite to adapt to a new host profile when moving between different host life stages or colonies.

Inheritance and heritability of resistance to citrus leprosis.

Science.gov (United States)

Bastianel, Marinês; de Oliveira, Antonio Carlos; Cristofani, Mariângela; Filho, Oliveiro Guerreiro; Freitas-Astúa, Juliana; Rodrigues, Vandeclei; Astúa-Monge, Gustavo; Machado, Marcos Antônio

2006-10-01

ABSTRACT The genetic inheritance of resistance to leprosis, the most important viral disease of citrus in Brazil, was characterized through the phenotypic assessment of 143 hybrids resulting from crosses between tangor 'Murcott' (Citrus sinensis x C. reticulata) and sweet orange 'Pêra' (C. sinensis), considered to be resistant and susceptible to the disease, respectively. All plants were grafted onto Rangpur lime (C. limonia) and inoculated with Citrus leprosis virus, cytoplasmic type through the infestation with viruliferous mites, Brevipalpus phoenicis. The experiments were arranged in a completely randomized block design with 10 replicates. Incidence and severity of the disease in leaves and stems as well as plant growth parameters (plant height and stem diameter) were recorded for 3 years after the infestation with the viruliferous mites. The average values of all variables were analyzed using principal component analysis, discriminant factorial analysis, estimation of the clonal repeatability coefficients, and frequency of the distributions of the average values for each measured variable. The principal component analysis resulted in the identification of at least two groups with resistance and susceptibility to leprosis, respectively. About 99% of all hybrids were correctly classified according to the discriminant factorial analysis. The broad-sense heritability coefficients for characteristics associated with incidence and severity of leprosis ranged from 0.88 to 0.96. The data suggest that the inheritance of resistance to leprosis may be controlled by only a few genes.

Temperature preference and respiration of acaridid mites

Czech Academy of Sciences Publication Activity Database

Hubert, J.; Pekár, S.; Nesvorná, M.; Šustr, Vladimír

2010-01-01

Roč. 103, č. 6 (2010), s. 2249-2257 ISSN 0022-0493 Institutional research plan: CEZ:AV0Z60660521 Keywords : mites * temperature * acclimation Subject RIV: EH - Ecology, Behaviour Impact factor: 1.489, year: 2010

Selection of VSH-derived “Pol-line” honey bees and evaluation of their Varroa-resistance characteristics

OpenAIRE

Danka , Robert G.; Harris , Jeffery W.; Dodds , Garrett E.

2016-01-01

International audience; AbstractHoney bees with Varroa sensitive hygiene (VSH) have good resistance to Varroa destructor. We bred “Pol-line” bees by outcrossing VSH queens to US commercial stocks from 2008 to 2014 and then selecting colonies with low mite infestations. Beginning in 2011, field performance of colonies with outcrossed Pol-line queens was compared to colonies with outcrossed VSH queens. Mite infestations after one season were comparable in colonies of the two bee types. Queens f...

Inoculate Release of Stethorus gilvifrons Mulsan (Coleoptera: Coccinellidae for Biological Control of Date Palm Spider Mite, Oligonychus afrasiaticusMcGregor (Prostigmata: Tetranychidae

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M. Latifian

2017-12-01

Full Text Available Introduction: The spider mite, Oligonychus afrasiaticus feeds by sucking the sap from the immature fruits tissue. The natural color of fruits changes to pale yellow or gray by mite's feeding. Damaged fruit are cracked and its damage can dry out the fruits. Because of resistance to pesticides, resurgence of date palm spider mite causes to disrupt the natural balance of their population. Tiny black ladybird beetle, Stethorous gilvifrons is the most important and active lady beetle species in Khuzestan province and is very effective on biological control of the spider mite. Determination of the amount and release time of the lady beetles are the most important factors in the implementation of biological control programs of date palm spider mite. So, careful monitoring, time of the release and the ability of deployment of predatory ladybird are essential steps to success in the programs of biological control. Materials and Methods: This research was conducted in Shadegan region of Khuzestan province. The nested design was used to compare the efficiency of different inoculate release methods of the predator, S. gilvifrons. The main niches include three release times which were at the time of emergence, three days and one week after emergence of date palm spider mite in date palm plantation. Sub nesting including three different levels of predator release including minimum, moderate and maximum release with 0.5, 1 and 3 predator /m2 per day and were continued for two weeks. The two or three-days ladybirds were used to release. First, the infected clusters were covered by mesh fabric and ladybirds were released under them. After a week, mantles were opened up to the establishment of ladybird run on the normal condition of date palm plantations. This experiment was repeated three times, and each replication consists of a quarter- hectare plantation with dominant cultivar Sayer.Three date Palm trees from each release and control were randomly selected

Morphology of the olfactory system in the predatory mite Phytoseiulus persimilis.

Science.gov (United States)

van Wijk, Michiel; Wadman, Wytse J; Sabelis, Maurice W

2006-01-01

The predatory mite Phytoseiulus persimilis locates its prey, the two-spotted spider mite, by means of herbivore-induced plant volatiles. The olfactory response to this quantitatively and qualitatively variable source of information is particularly well documented. The mites perform this task with a peripheral olfactory system that consists of just five putative olfactory sensilla that reside in a dorsal field at the tip of their first pair of legs. The receptor cells innervate a glomerular olfactory lobe just ventral of the first pedal ganglion. We have made a 3D reconstruction of the caudal half of the olfactory lobe in adult females. The glomerular organization as well as the glomerular innervation appears conserved across different individuals. The adult females have, by approximation, a 1:1 ratio of olfactory receptor cells to olfactory glomeruli.

A SHORT-TERM CIRCUIT RESISTANCE PROGRAMME REDUCED EPICARDIAL FAT IN OBESE AGED WOMEN.

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Rosety, Miguel Angel; Pery, Maria Teresa; Rodriguez-Pareja, Maria Antonia; Diaz, Antonio; Rosety, Jesus; Garcia, Natalia; Brenes-Martin, Francisco; Rosety-Rodríguez, Manuel; Toro, Rocío; Ordoñez, Francisco Javier; Rosety, Ignacio

2015-11-01

this study was conducted to ascertain the effects of resistance circuit training on epicardial adipose tissue (EAT) in obese aged women. A secondary objective was to assess muscle damage induced by supervised resistance training to confirm the intervention program was effective and safe. in the present interventional study, a total of 48 obese aged women were recruited from the community. Twenty-four of them were randomly assigned to perform a 12-week resistance circuit training programme, 3-days per week. This training was circularly performed in 6 stations: arm curl, leg extension, seated row, leg curl, triceps extension and leg press. The Jamar handgrip electronic dynamometer was used to assess maximal handgrip strength of the dominant hand. Two experienced observers assessed EAT by transthoracic two-dimensional echocardiography. Lastly, serum samples were analysed using one-step sandwich assays for creatine kinase activity (CK) and myoglobin (MB) concentration. as was hypothesized, resistance training significantly reduced EAT thickness (8.4 ± 1.0 vs. 7.3 ± 1.3 mm; p = 0.014; d = 0.76) in the experimental group. Resistance training induced no significant changes in markers of muscle damage such as CK (181.6 ± 36.9 vs. 194.2 ± 37.8 U/l; p = 0.31) and MB (62.4 ± 7.1 vs. 67.3 ± 7.7 ng/ml; p = 0.26). No significant changes in any of the tested outcomes were found in the control group. resistance training reduced EAT in aged obese women. A secondary finding was that the training program was effective and safe. While current results are promising, future studies are still required to consolidate this approach in clinical application. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Mites associated to Xylopia aromatica (Lam. Mart. (Annonaceae in urban and rural fragments of semidecidual forest

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Felipe M. Nuvoloni

2011-12-01

Full Text Available Mites associated to Xylopia aromatica (Lam. Mart. (Annonaceae in urban and rural fragments of semidecidual forest. Native plants can shelter a great diversity of mites. Notwithstanding, the conservation of the forest fragments where the plants are located can influence the structure of the mites community. Generally, in homogenous environments the diversity is lower due to the dominance of one or a few species. In this work, we studied the mite community on Xylopia aromatica (Lam. Mart. (Annonaceae in two fragments of semidecidual forest: one on rural and other on urban area. Seven individuals of X. aromatica were monthly sampled from April 2007 to March 2008, in each of these fragments. Descriptive indexes of diversity, dominance and evenness were applied to verify the ecological patterns of the mite community, besides the Student's t-test to compare the abundance between the fragments. We collected 27,365 mites of 37 species belonging to 11 families. Calacarus sp. (Eriophyidae was the most abundant species, representing 73% of the total sampled. The abundance was greater in the urban fragment (67.7%, with the diversity index reaching only 25% of the theoretical maximum expected. Probably, these values might have been influenced by the location of this fragment in the urban area, being more homogeneous and submitted directly to the presence of atmospheric pollution. In this manner, X. aromatica is able to shelter a higher diversity of mites when inserted in preserved ecosystems, since the highest diversity of available resources allows the establishment of richer and most diverse mite community.

State-dependent and odour-mediated anemotactic responses of the predatory mite Phytoseiulus persimilis in a wind tunnel.

Science.gov (United States)

Van Tilborg, Merijn; Sabelis, Maurice W; Roessingh, Peter

2004-01-01

Anemotaxis in the predatory mite Phytoseiulus persimilis (both well-fed and starved), has previously been studied on a wire grid under slight turbulent airflow conditions yielding weak, yet distinct, gradients in wind speed and odour concentration (Sabelis and Van der Weel 1993). Such conditions might have critically influenced the outcome of the study. We repeated these experiments, under laminar airflow conditions on a flat surface in a wind tunnel, thereby avoiding variation in wind speed and odour concentration. Treatments for starved and well-fed mites were (1) still-air without herbivore-induced plant volatiles (HIPV) (well-fed mites only), (2) an HIPV-free air stream, and (3) an air stream with HIPV (originating from Lima bean plants infested by two-spotted spider mites, Tetranychus urticae). Well-fed mites oriented in random directions in still-air without HIPV. In an air stream, starved mites always oriented upwind, whether plant odours were present or not. Well-fed mites oriented downwind in an HIPV-free air stream, but in random directions in an air stream with HIPV. Only under the last treatment our results differed from those of Sabelis and Van der Weel (1993).

Characterization of a New World Monopartite Begomovirus Causing Leaf Curl Disease of Tomato in Ecuador and Peru Reveals a New Direction in Geminivirus Evolution

Science.gov (United States)

Melgarejo, Tomas A.; Kon, Tatsuya; Rojas, Maria R.; Paz-Carrasco, Lenin; Zerbini, F. Murilo

2013-01-01

All characterized whitefly-transmitted geminiviruses (begomoviruses) with origins in the New World (NW) have bipartite genomes composed of a DNA-A and DNA-B component. Recently, an NW begomovirus lacking a DNA-B component was associated with tomato leaf curl disease (ToLCD) in Peru, and it was named Tomato leaf deformation virus (ToLDeV). Here, we show that isolates of ToLDeV associated with ToLCD in Ecuador and Peru have a single, genetically diverse genomic DNA that is most closely related to DNA-A components of NW bipartite begomoviruses. Agroinoculation of multimeric clones of the genomic DNA of three ToLDeV genotypes (two variants and a strain) resulted in the development of tomato leaf curl symptoms indistinguishable from those of ToLCD in Ecuador and Peru. Biological properties of these ToLDeV genotypes were similar to those of Old World (OW) monopartite tomato-infecting begomoviruses, including lack of sap transmissibility, phloem limitation, a resistance phenotype in tomato germplasm with the Ty-1 gene, and functional properties of the V1 (capsid protein) and C4 genes. Differences in symptom phenotypes induced by the ToLDeV genotypes in tomato and Nicotiana benthamiana plants were associated with a highly divergent left intergenic region and C4 gene. Together, these results establish that ToLDeV is an emergent NW monopartite begomovirus that is causing ToLCD in Ecuador and Peru. This is the first report of an indigenous NW monopartite begomovirus, and evidence is presented that it emerged from the DNA-A component of a NW bipartite progenitor via convergent evolution and recombination. PMID:23468482

Lower Virus Infections in Varroa destructor-Infested and Uninfested Brood and Adult Honey Bees (Apis mellifera) of a Low Mite Population Growth Colony Compared to a High Mite Population Growth Colony

Science.gov (United States)

Emsen, Berna; Hamiduzzaman, Mollah Md.; Goodwin, Paul H.; Guzman-Novoa, Ernesto

2015-01-01

A comparison was made of the prevalence and relative quantification of deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), black queen cell virus (BQCV), Kashmir bee virus (KBV), acute bee paralysis virus (ABPV) and sac brood virus (SBV) in brood and adult honey bees (Apis mellifera) from colonies selected for high (HMP) and low (LMP) Varroa destructor mite population growth. Two viruses, ABPV and SBV, were never detected. For adults without mite infestation, DWV, IAPV, BQCV and KBV were detected in the HMP colony; however, only BQCV was detected in the LMP colony but at similar levels as in the HMP colony. With mite infestation, the four viruses were detected in adults of the HMP colony but all at higher amounts than in the LMP colony. For brood without mite infestation, DWV and IAPV were detected in the HMP colony, but no viruses were detected in the LMP colony. With mite infestation of brood, the four viruses were detected in the HMP colony, but only DWV and IAPV were detected and at lower amounts in the LMP colony. An epidemiological explanation for these results is that pre-experiment differences in virus presence and levels existed between the HMP and LMP colonies. It is also possible that low V. destructor population growth in the LMP colony resulted in the bees being less exposed to the mite and thus less likely to have virus infections. LMP and HMP bees may have also differed in susceptibility to virus infection. PMID:25723540

Widespread and evolutionary analysis of a MITE family Monkey King in Brassicaceae.

Science.gov (United States)

Dai, Shutao; Hou, Jinna; Long, Yan; Wang, Jing; Li, Cong; Xiao, Qinqin; Jiang, Xiaoxue; Zou, Xiaoxiao; Zou, Jun; Meng, Jinling

2015-06-19

Miniature inverted repeat transposable elements (MITEs) are important components of eukaryotic genomes, with hundreds of families and many copies, which may play important roles in gene regulation and genome evolution. However, few studies have investigated the molecular mechanisms involved. In our previous study, a Tourist-like MITE, Monkey King, was identified from the promoter region of a flowering time gene, BnFLC.A10, in Brassica napus. Based on this MITE, the characteristics and potential roles on gene regulation of the MITE family were analyzed in Brassicaceae. The characteristics of the Tourist-like MITE family Monkey King in Brassicaceae, including its distribution, copies and insertion sites in the genomes of major Brassicaceae species were analyzed in this study. Monkey King was actively amplified in Brassica after divergence from Arabidopsis, which was indicated by the prompt increase in copy number and by phylogenetic analysis. The genomic variations caused by Monkey King insertions, both intra- and inter-species in Brassica, were traced by PCR amplification. Genomic sequence analysis showed that most complete Monkey King elements are located in gene-rich regions, less than 3kb from genes, in both the B. rapa and A. thaliana genomes. Sixty-seven Brassica expressed sequence tags carrying Monkey King fragments were also identified from the NCBI database. Bisulfite sequencing identified specific DNA methylation of cytosine residues in the Monkey King sequence. A fragment containing putative TATA-box motifs in the MITE sequence could bind with nuclear protein(s) extracted from leaves of B. napus plants. A Monkey King-related microRNA, bna-miR6031, was identified in the microRNA database. In transgenic A. thaliana, when the Monkey King element was inserted upstream of 35S promoter, the promoter activity was weakened. Monkey King, a Brassicaceae Tourist-like MITE family, has amplified relatively recently and has induced intra- and inter-species genomic

Breeding cassava for multiple pest resistance in Africa | Mahungu ...

African Journals Online (AJOL)

The green spider mite and cassava mealybug are by far the most economically important arthropod pests. The long growing period and diverse agroecologies in which cassava cultivars are grown expose them to one or more of these problems and the losses can be devastating. Multiple pest resistance helps to ensure ...

Neonicotinoid Insecticides Alter Induced Defenses and Increase Susceptibility to Spider Mites in Distantly Related Crop Plants

Science.gov (United States)

Szczepaniec, Adrianna; Raupp, Michael J.; Parker, Roy D.; Kerns, David; Eubanks, Micky D.

2013-01-01

Background Chemical suppression of arthropod herbivores is the most common approach to plant protection. Insecticides, however, can cause unintended, adverse consequences for non-target organisms. Previous studies focused on the effects of pesticides on target and non-target pests, predatory arthropods, and concomitant ecological disruptions. Little research, however, has focused on the direct effects of insecticides on plants. Here we demonstrate that applications of neonicotinoid insecticides, one of the most important insecticide classes worldwide, suppress expression of important plant defense genes, alter levels of phytohormones involved in plant defense, and decrease plant resistance to unsusceptible herbivores, spider mites Tetranychus urticae (Acari: Tetranychidae), in multiple, distantly related crop plants. Methodology/Principal Findings Using cotton (Gossypium hirsutum), corn (Zea mays) and tomato (Solanum lycopersicum) plants, we show that transcription of phenylalanine amonia lyase, coenzyme A ligase, trypsin protease inhibitor and chitinase are suppressed and concentrations of the phytohormone OPDA and salicylic acid were altered by neonicotinoid insecticides. Consequently, the population growth of spider mites increased from 30% to over 100% on neonicotinoid-treated plants in the greenhouse and by nearly 200% in the field experiment. Conclusions/Significance Our findings are important because applications of neonicotinoid insecticides have been associated with outbreaks of spider mites in several unrelated plant species. More importantly, this is the first study to document insecticide-mediated disruption of plant defenses and link it to increased population growth of a non-target herbivore. This study adds to growing evidence that bioactive agrochemicals can have unanticipated ecological effects and suggests that the direct effects of insecticides on plant defenses should be considered when the ecological costs of insecticides are evaluated. PMID

Long conduction time POs experiments on MITE

International Nuclear Information System (INIS)

Woodall, H.N.; McDaniel, D.H.; Mendel, C.W.; Rochau, G.E.; Zagar, D.M.; Simpson, W.W.; Zuchowski, N.P.

1990-01-01

MITE is a power flow test bed that has been modified to conduct experiments in high power plasma opening switch (POS) technology and apply this technology to Inertial Confinement Fusion. The goal of the experiment is to develop a plasma opening switch that conducts megampere currents for 300 ns, then opens in 5--10 ns. MITE/POS is an advanced power flow experiment that uses a magnetically insulated transmission line (MITL) as the inductive energy store and as a means to shape the output pulse. This experiment demonstrates that a simplified, lower-cost facility can be built by eliminating water pulse-forming lines and water-switching. Another advantage of this approach is that high energy efficiency at peak power can be achieved. The disadvantage is that a new technology, the triggered POS, must be implemented. The triggered POS is necessary for synchronization of multiple modules with a long conduction-time POS. The MITE facility has been modified to drive a 250 nH, 16.6 Ohm MITL at 0.9 MA to accommodate this power flow experiment. A MITL inductive energy storage of 101 kJ is available for POS switching to a matched load. Experiments have been conducted using segmented flashboards and magnetic-field controlled plasma sources. These experiments will lead to the development of the triggered POS. The initial experiments with plasma conduction times of 120 ns to 800 ns are discussed

Acaricidal activity of Cymbopogon citratus and Azadirachta indica against house dust mites.

Science.gov (United States)

Hanifah, Azima Laili; Awang, Siti Hazar; Ming, Ho Tze; Abidin, Suhaili Zainal; Omar, Maizatul Hashima

2011-10-01

To examine the acaricidal effects of the essential oil of Cymbopogon citratus leaf extract (lemongrass) and ethanolic Azadirachta indica leaf extract (neem) against house dust mites Dermatophagoides farinae (D. farinae) and Dermatophagoides pteronyssinus (D. pteronyssinus). Twenty-five adults mites were placed onto treated filter paper that is soaked with plant extract and been tested at different concentrations (50.00%, 25.00%, 12.50%, 6.25% and 3.13%) and exposure times (24hrs, 48hrs, 72hrs and 96 hrs). All treatments were replicated 7 times, and the experiment repeated once. The topical and contact activities of the two herbs were investigated. Mortalities from lemongrass extract were higher than neem for both topical and contact activities. At 50 % concentration, both 24 hrs topical and contact exposures to lemongrass resulted in more than 91% mortalities for both species of mites. At the same concentration and exposure time, neem resulted in topical mortalities of 40.3% and 15.7% against D. pteronyssinus and D. farinae respectively; contact mortalities were 8.0% and 8.9% against the 2 mites, respectively. There was no difference in topical mortalities of D. pteronyssinus from exposure to concentrations of lemongrass and neem up to 12.50%; lemongrass was more effective than neem at the higher concentrations. Generally, topical mortalities of D. farinae due to lemongrass are higher than that due to neem. Contact mortalities of lemongrass are always higher that neem against both species of mites.

Aphid transmission of Lettuce necrotic leaf curl virus, a member of atentative new subgroup within the genus Torradovirus

NARCIS (Netherlands)

Verbeek, M.; Dullemans, A.M.; Vlugt, van der R.A.A.

2017-01-01

Lettuce necrotic leaf curl virus (LNLCV) was described as the first non-tomato-infecting member of the genus Torradovirus. Until today, the virus was found only in The Netherlands in two different areas in open field crops of lettuce. In 2015, LNLCV was accepted by the ICTV as a new member of the

A randomised clinical trial of the efficacy of drop squats or leg extension/leg curl exercises to treat clinically diagnosed jumper's knee in athletes: pilot study

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Cannell, L; Taunton, J; Clement, D; Smith, C; Khan, K

2001-01-01

Objectives—To compare the therapeutic effect of two different exercise protocols in athletes with jumper's knee. Methods—Randomised clinical trial comparing a 12 week programme of either drop squat exercises or leg extension/leg curl exercises. Measurement was performed at baseline and after six and 12 weeks. Primary outcome measures were pain (visual analogue scale 1–10) and return to sport. Secondary outcome measures included quadriceps and hamstring moment of force using a Cybex II isokinetic dynamometer at 30°/second. Differences in pain response between the drop squat and leg extension/curl treatment groups were assessed by 2 (group) x 3 (time) analysis of variance. Two by two contingency tables were used to test differences in rates of return to sport. Analysis of variance (2 (injured versus non-injured leg) x 2 (group) x 3 (time)) was also used to determine differences for secondary outcome measures. Results—Over the 12 week intervention, pain diminished by 2.3 points (36%) in the leg extension/curl group and 3.2 points (57%) in the squat group. There was a significant main effect of both exercise protocols on pain (psquat group returned to sporting activity by 12 weeks, but five of those subjects still had low level pain. Six of nine of the leg extension/curl group returned to sporting activity by 12 weeks and four patients had low level pain. There was no significant difference between groups in numbers returning to sporting activity. There were no differences in the change in quadriceps or hamstring muscle moment of force between groups. Conclusions—Progressive drop squats and leg extension/curl exercises can reduce the pain of jumper's knee in a 12 week period and permit a high proportion of patients to return to sport. Not all patients, however, return to sport by that time. Key Words: knee; patellar tendon; tendinopathy; tendinosis; eccentric strengthening; strength training PMID:11157465

Mutation Breeding of Dendrobium Orchids For Insect Resistance

International Nuclear Information System (INIS)

Zaiton Ahmad; Sakinah Ariffin; Ros Anita Ahmad Ramli; Mohd Nazir Basiran; Affrida Abu Hassan

2010-01-01

This project was a collaborative FNCA project involving Malaysia, Thailand, Indonesia and Japan. The objective was to jointly produce new orchid mutants that resistant/tolerant to insect infestation. It focused on commercial hybrids or species of Dendrobium orchids; namely Dendrobium Sonia 17 Red from Thailand, Dendrobium jayakarta from Indonesia and Dendrobium mirbellianum from Malaysia. In this project, tissue culture orchid materials (proto corm-like-bodies or PLBs) were exchanged among the participated countries early in the project. The Malaysian research team had irradiated these PLBs with two ionizing mutagens; gamma rays and ion beams (JAEA). Following irradiation, regenerated plant lets were randomly selected from each dose and subjected to in vitro infestation with mites and thrips, to analyse their resistance towards these pests. The main aim of in vitro infestation was to pre-select potential mutants for secondary screening at flowering stage. Potential insect resistant orchid mutants were then selected and subsequently planted in the glass house. Secondary screenings were carried out at flowering stage by challenge-infestation with the target insects. This project, which was completed in December 2009, has successfully generated two D. jayakarta mutants tolerant to thrips, and one D. mirbellianum tolerant to both mite and thrips. (author)

Orthotropic conductivity reconstruction with virtual-resistive network and Faraday's law

KAUST Repository

Lee, Min-Gi

2015-06-01

We obtain the existence and the uniqueness at the same time in the reconstruction of orthotropic conductivity in two-space dimensions by using two sets of internal current densities and boundary conductivity. The curl-free equation of Faraday\\'s law is taken instead of the elliptic equation in a divergence form that is typically used in electrical impedance tomography. A reconstruction method based on layered bricks-type virtual-resistive network is developed to reconstruct orthotropic conductivity with up to 40% multiplicative noise.

Effects of Nitrogen Fertilization on Potato Leafhopper (Hemiptera: Cicadellidae) and Maple Spider Mite (Acari: Tetranychidae) on Nursery-Grown Maples.

Science.gov (United States)

Prado, Julia; Quesada, Carlos; Gosney, Michael; Mickelbart, Michael V; Sadof, Clifford

2015-06-01

Although leaf nitrogen (N) has been shown to increase the suitability of hosts to herbivorous arthropods, the responses of these pests to N fertilization on susceptible and resistant host plants are not well characterized. This study determined how different rates of N fertilization affected injury caused by the potato leafhopper (Empoasca fabae Harris) and the abundance of maple spider mite (Oligonychus aceris (Shimer)) on 'Red Sunset' red maple (Acer rubrum) and 'Autumn Blaze' Freeman maple (Acer×freemanii) during two years in Indiana. N fertilization increased leaf N concentration in both maple cultivars, albeit to a lesser extent during the second year of the study. Overall, Red Sunset maples were more susceptible to E. fabae injury than Autumn Blaze, whereas Autumn Blaze maples supported higher populations of O. aceris. Differences in populations of O. aceris were attributed to differences between communities of stigmaeid and phytoseiid mites on each cultivar. Injury caused by E. fabae increased with N fertilization in a dose-dependent manner in both cultivars. Although N fertilization increased the abundance of O. aceris on both maple cultivars, there was no difference between the 20 and 40 g rates. We suggest the capacity of N fertilization to increase O. aceris on maples could be limited at higher trophic levels by the community of predatory mites. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

``Sleeping with the enemy''—predator-induced diapause in a mite

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Kroon, Annemarie; Veenendaal, René L.; Bruin, Jan; Egas, Martijn; Sabelis, Maurice W.

2008-12-01

Diapause in arthropods is a physiological state of dormancy that is generally thought to promote survival during harsh seasons and dispersal, but it may also serve to avoid predation in space and time. Here, we show that predation-related odours induce diapause in female adult spider mites. We argue that this response allows them to move into an area where they are free of enemies, yet forced to survive without food. Spider mites are specialised leaf feeders, but—in late summer—they experience severe predation on leaves. Hence, they face a dilemma: to stay on the leaf and risk being eaten or to move away from the leaf and risk death from starvation and thirst. Female two-spotted spider mites solve this dilemma by dramatically changing their physiology when exposed to predation-associated cues. This allows them to disperse away from leaves and to survive in winter refuges in the bark of trees or in the soil. We conclude that the mere presence of predation-associated cues causes some herbivorous mites to seek refuge, thereby retarding the growth rate of the population as a whole: a trait-mediated indirect effect that may have consequences for the stability of predator prey systems and for ecosystem structure.

Genome organization of Tobacco leaf curl Zimbabwe virus, a new, distinct monopartite begomovirus associated with subgenomic defective DNA molecules.

Science.gov (United States)

Paximadis, M; Rey, M E

2001-12-01

The complete DNA A of the begomovirus Tobacco leaf curl Zimbabwe virus (TbLCZWV) was sequenced: it comprises 2767 nucleotides with six major open reading frames encoding proteins with molecular masses greater than 9 kDa. Full-length TbLCZWV DNA A tandem dimers, cloned in binary vectors (pBin19 and pBI121) and transformed into Agrobacterium tumefaciens, were systemically infectious upon agroinoculation of tobacco and tomato. Efforts to identify a DNA B component were unsuccessful. These findings suggest that TbLCZWV is a new member of the monopartite group of begomoviruses. Phylogenetic analysis identified TbLCZWV as a distinct begomovirus with its closest relative being Chayote mosaic virus. Abutting primer PCR amplified ca. 1300 bp molecules, and cloning and sequencing of two of these molecules revealed them to be subgenomic defective DNA molecules originating from TbLCZWV DNA A. Variable symptom severity associated with tobacco leaf curl disease and TbLCZWV is discussed.

Soil oribatid mite communities under three species of legumes in an ultisol in Brazil.

Science.gov (United States)

Badejo, M Adetola; Espindola, Jose Antonio Azevedo; Guerra, Jose Guilherme Marinho; De Aquino, Adriana Maria; Correa, Maria Elizabeth Fernandes

2002-01-01

Oribatid mite densities in the topsoil and their activity at the soil surface were monitored under three species of perennial legume cover crops namely, Arachis pintoi, Macroptilium atropupureum and Pueraria phaseoloides, grass (Panicum maximum) and bare plots on three occasions in 1998 and 1999 in a derived savanna zone in Brazil. Both densities and activity at the soil surface were higher in the early but cool dry season in April 1998 than in the early wet but warm season in November 1998 and 1999. Three taxonomic groups of macropyline oribatid mites, namely Nothrus, Archegozetes and Masthermannia as well as a brachypyline taxon, Scheloribates were suggested as possible indicators of effect of legumes on soil biota because their populations increased under the legumes and/or the irresidues. Nothrus in particular increased in abundance more than any other taxon in the presence of residues of A. pintoi. Each legume supported a unique oribatid mite community in terms of species composition and relative abundance. The large numbers of Archegozeres trapped from all the legume and grass plots in April and November 1998 were also attributed to highly conducive conditions provided by the vegetation cover and their residues. The results suggest that the oribatid mite community of the study area was numerically stable as the peak populations of different species were not synchronized. Many taxonomic groups of pycnonotic brachypyline mites were absent. Legume cover crops, especially A. pintoi, and their residues have potential in restoring oribatid mite populations to precultivation levels.

The Tropilaelaps mites threat: An examination of the injuries inflicted on Apis mellifera

Science.gov (United States)

Tropilaelaps spp. are the most serious parasites of Apis mellifera in Asia. However, much of their biology and ecology are largely unexplored (de Guzman et al., 2017 J. Econ. Entomol. 1-14). Like varroa mites, tropilaelaps mites puncture through the integuments of their bee hosts to feed on hemolymp...

Differences among plant species in acceptance by the spider mite Tetranychus urticae Koch

NARCIS (Netherlands)

Boom, van den C.E.M.; Beek, van T.A.; Dicke, M.

2003-01-01

The spider mite Tetranychus urticae Koch has a broad range of host plants. However, the spider mite does not accept all plants to the same degree because of differences in nutritive and toxic constituents. Other factors, such as the induction of secondary metabolites, the morphology of a leaf

Analytical solutions of the electrostatically actuated curled beam problem

KAUST Repository

Younis, Mohammad I.

2014-07-24

This works presents analytical expressions of the electrostatically actuated initially deformed cantilever beam problem. The formulation is based on the continuous Euler-Bernoulli beam model combined with a single-mode Galerkin approximation. We derive simple analytical expressions for two commonly observed deformed beams configurations: the curled and tilted configurations. The derived analytical formulas are validated by comparing their results to experimental data and numerical results of a multi-mode reduced order model. The derived expressions do not involve any complicated integrals or complex terms and can be conveniently used by designers for quick, yet accurate, estimations. The formulas are found to yield accurate results for most commonly encountered microbeams of initial tip deflections of few microns. For largely deformed beams, we found that these formulas yield less accurate results due to the limitations of the single-mode approximation. In such cases, multi-mode reduced order models are shown to yield accurate results. © 2014 Springer-Verlag Berlin Heidelberg.

Association of an alphasatellite with tomato yellow leaf curl virus and ageratum yellow vein virus in Japan is suggestive of a recent introduction.

Science.gov (United States)

Shahid, Muhammad Shafiq; Ikegami, Masato; Waheed, Abdul; Briddon, Rob W; Natsuaki, Keiko T

2014-01-14

Samples were collected in 2011 from tomato plants exhibiting typical tomato leaf curl disease symptoms in the vicinity of Komae, Japan. PCR mediated amplification, cloning and sequencing of all begomovirus components from two plants from different fields showed the plants to be infected by Tomato yellow leaf curl virus (TYLCV) and Ageratum yellow vein virus (AYVV). Both viruses have previously been shown to be present in Japan, although this is the first identification of AYVV on mainland Japan; the virus previously having been shown to be present on the Okinawa Islands. The plant harboring AYVV was also shown to contain the betasatellite Tomato leaf curl Java betasatellite (ToLCJaB), a satellite not previously shown to be present in Japan. No betasatellite was associated with the TYLCV infected tomato plants analyzed here, consistent with earlier findings for this virus in Japan. Surprisingly both plants were also found to harbor an alphasatellite; no alphasatellites having previously been reported from Japan. The alphasatellite associated with both viruses was shown to be Sida yellow vein China alphasatellite which has previously only been identified in the Yunnan Province of China and Nepal. The results suggest that further begomoviruses, and their associated satellites, are being introduced to Japan. The significance of these findings is discussed.

Association of an Alphasatellite with Tomato Yellow Leaf Curl Virus and Ageratum Yellow Vein Virus in Japan Is Suggestive of a Recent Introduction

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Muhammad Shafiq Shahid

2014-01-01

Full Text Available Samples were collected in 2011 from tomato plants exhibiting typical tomato leaf curl disease symptoms in the vicinity of Komae, Japan. PCR mediated amplification, cloning and sequencing of all begomovirus components from two plants from different fields showed the plants to be infected by Tomato yellow leaf curl virus (TYLCV and Ageratum yellow vein virus (AYVV. Both viruses have previously been shown to be present in Japan, although this is the first identification of AYVV on mainland Japan; the virus previously having been shown to be present on the Okinawa Islands. The plant harboring AYVV was also shown to contain the betasatellite Tomato leaf curl Java betasatellite (ToLCJaB, a satellite not previously shown to be present in Japan. No betasatellite was associated with the TYLCV infected tomato plants analyzed here, consistent with earlier findings for this virus in Japan. Surprisingly both plants were also found to harbor an alphasatellite; no alphasatellites having previously been reported from Japan. The alphasatellite associated with both viruses was shown to be Sida yellow vein China alphasatellite which has previously only been identified in the Yunnan Province of China and Nepal. The results suggest that further begomoviruses, and their associated satellites, are being introduced to Japan. The significance of these findings is discussed.

Analysis of basophil activation by flow cytometry in pediatric house dust mite allergy.

Science.gov (United States)

González-Muñoz, Miguel; Villota, Julian; Moneo, Ignacio

2008-06-01

Detection of allergen-induced basophil activation by flow cytometry has been shown to be a useful tool for allergy diagnosis. The aim of this study was to assess the potential of this technique for the diagnosis of pediatric house dust mite allergy. Quantification of total and specific IgE and basophil activation test were performed to evaluate mite allergic (n = 24), atopic (n = 23), and non-allergic children (n = 9). Allergen-induced basophil activation was detected as a CD63-upregulation. Receiver operating characteristics (ROC) curve analysis was performed to calculate the optimal cut-off value of activated basophils discriminating mite allergic and non-allergic children. ROC curve analysis yielded a threshold value of 18% activated basophils when mite-sensitized and atopic children were studied [area under the curve (AUC) = 0.99, 95% confidence interval (CI) = 0.97-1.01, p 43 kU/l) values for Dermatophagoides pteronyssinus allergen. They also showed positive prick (wheal diameter >1.0 cm) and basophil activation (>87%) tests and high specific IgE (>100 kU/l) with shrimp allergen. Shrimp sensitization was demonstrated by high levels of Pen a 1-specific IgE (>100 kU/l). Cross-reactivity between mite and shrimp was confirmed by fluorescence enzyme immunoassay (FEIA-CAP) inhibition study in these two cases. This study demonstrated that the analysis of allergen-induced CD63 upregulation by flow cytometry is a reliable tool for diagnosis of mite allergy in pediatric patients, with sensitivity similar to routine diagnostic tests and a higher specificity. Furthermore, this method can provide additional information in case of disagreement between in vivo and in vitro test results.

House dust mite reduction and avoidance measures for treating eczema.

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Nankervis, Helen; Pynn, Emma V; Boyle, Robert J; Rushton, Lesley; Williams, Hywel C; Hewson, Deanne M; Platts-Mills, Thomas

2015-01-19

Eczema is an inflammatory skin disease that tends to involve skin creases, such as the folds of the elbows or knees; it is an intensely itchy skin condition, which can relapse and remit over time. As many as a third of people with eczema who have a positive test for allergy to house dust mite have reported worsening of eczema or respiratory symptoms when exposed to dust. To assess the effects of all house dust mite reduction and avoidance measures for the treatment of eczema. We searched the following databases up to 14 August 2014: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library (2014, Issue 8), MEDLINE (from 1946), Embase (from 1974), LILACS (from 1982), and the GREAT database. We also searched five trials registers and checked the reference lists of included and excluded studies for further references to relevant studies. We handsearched abstracts from international eczema and allergy meetings. Randomised controlled trials (RCTs) of any of the house dust mite reduction and avoidance measures for the treatment of eczema, which included participants of any age diagnosed by a clinician with eczema as defined by the World Allergy Organization. We included all non-pharmacological and pharmacological interventions that sought to reduce or avoid exposure to house dust mite and their allergenic faeces. The comparators were any active treatment, no treatment, placebo, or standard care only. Two authors independently checked the titles and abstracts identified, and there were no disagreements. We contacted authors of included studies for additional information. We assessed the risk of bias using Cochrane methodology. We included seven studies of 324 adults and children with eczema. Overall, the included studies had a high risk of bias. Four of the seven trials tested interventions with multiple components, and three tested a single intervention. Two of the seven trials included only children, four included children and adults, and one

El Concepto de Límite como Indicador de la Maduración de la Lógica Hegeliana

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Leonardo Mattana

2017-02-01

Full Text Available El presente texto expone una confrontación entre tres autores fundamentales del idealismo alemán (Kant, Fichte y Hegel sobre un tema de vital importancia tanto para las propuestas de estos autores como para el actual debate filosófico: el concepto de límite. Este problema atraviesa la filosofía alemana de los siglos XVIII y XIX y encuentra en Hegel una elaboración particularmente interesante. Nos ocuparemos por lo tanto de la figura del límite en la Ciencia de la Lógica, donde en pocas y densas páginas, Hegel invierte la dinámica kantiana del límite y también trasfigura la aportación fichteana. Si bien la posición hegeliana resulta en nuestra opinión más interesante, recorrer las problemáticas de Kant y Fichte resulta imprescindible para demostrar el contexto y los desafíos filosóficos a los que Hegel se enfrentaba. El problema del límite, por tanto, se articula en el de la construcción de la identidad, ya que, como vemos en el mismo Kant, el límite implica siempre un sujeto con el que él se relaciona. Justamente es la problematicidad del sujeto en Kant que causa un límite excluyente: un límite que divide las facultades del sujeto sin tener claro lo que es el sujeto. Ya Fichte invierte este punto, a través de la autoposición del sujeto como acción de hecho, dando lugar mediante el límite a la determinidad. Pero es Hegel quien revela cómo el límite tiene un gran potencial a la hora de elaborar el concepto de identidad, trasfigurando las identidades fijas y dando lugar a otras nuevas. Hegel, además de dar un importante giro al problema del límite dentro del idealismo alemán, nos muestra cómo el límite, incluso para la filosofía política, puede constituir un dispositivo teórico esencial para comprender las realidades complejas y entramadas que pueblan nuestro mundo global actual.

Parasitism of wild Gouldian finches (Erythrura gouldiae) by the air-sac mite Sternostoma tracheacolum.

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Tidemann, S C; McOrist, S; Woinarski, J C; Freeland, W J

1992-01-01

Sixty-two percent of 26 wild caught Gouldian finches (Erythrura gouldiae) were infected with Sternostoma tracheacolum, a parasitic rhinonyssid mite. The intensity of infection was higher in adult finches than juveniles, and higher in juvenile females than juvenile males. Histopathological investigation of wild Gouldian Finches revealed bronchopneumonia and air sacculitis associated with mite infection. Although this mite may not have contributed to the decline of Gouldian finch populations in the wild during the past 20 yr, it may be suppressing the return of the finch to its former status.

The hair follicle mites (Demodex spp.). Could they be vectors of pathogenic microorganisms?

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Wolf, R; Ophir, J; Avigad, J; Lengy, J; Krakowski, A

1988-01-01

The hair follicle mites Demodex folliculorum and D. brevis are the most common permanent ectoparasites of Man. Ordinarily they are harmless to their human host and appear to be of no medical significance. We present, however, an unusual finding regarding this mite, namely, that in a potassium hydroxide mount of a skin scraping from a mycotic plaque we found numerous Demodex mites containing inside them spores of Microsporum canis. This could mean that the putatively inoffensive Demodex has the potential to ingest various microorganisms that are found in its niche and transport them to other areas of the skin or possibly to other individuals.

Phoretic mites and their hyperphoretic fungi associated with flying Ips typographus japonicus Niijima (Col., Scolytidae) in Japan

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J.C. Moser; T.J. Perry; K. Furuta

1997-01-01

Flying Ips typographus japonicus from Hokkaido (Japan) carried 12 species of phoretic mites, three of which were not previously recorded in Europe. The mite biologies were diverse, including specialists feeding on microorganisms, beetle eggs, and nematodes which were common under beetle elytra. Hyperphoretic on these mites were seven distinct species of fungal spores...

Feather mites (Acari, Astigmata) associated with birds in an Atlantic Forest fragment in Northeastern Brazil

OpenAIRE

Silva, HM; Hernandes, FA; Pichorim, M

2015-01-01

AbstractThe present study reports associations between feather mites (Astigmata) and birds in an Atlantic Forest fragment in Rio Grande do Norte state, in Brazil. In the laboratory, mites were collected through visual examination of freshly killed birds. Overall, 172 individuals from 38 bird species were examined, between October 2011 and July 2012. The prevalence of feather mites was 80.8%, corresponding to 139 infested individuals distributed into 30 species and 15 families of hosts. Fiftee...

Guanine as a hygienic index for allergological relevant mite infestation in mattress dust

NARCIS (Netherlands)

Bronswijk, van J.E.M.H.

1986-01-01

Since guanine is not only an essential constituent of vital nucleic acids, but also the main end product of nitrogenous waste excretion in arachnids, it is a potential candidate for a hygienic index for mite activity in house dust. The public health significance of these mites is based on their

Active optical sensor assessment of spider mite damage on greenhouse beans and cotton

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The two-spotted spider mite, Tetranychus urticae Koch is an important pest of cotton in mid-southern United States and causes yield reduction, and deprivation in fiber fitness. A greenhouse colony of the spider mite was used to infest cotton and pinto beans at the three-leaf and trifoliate stages, r...

Catalogue of ptyctimous mites (Acari, Oribatida) of the world.

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NiedbaŁa, Wojciech; Liu, Dong

2018-03-11

As important representatives of Oribatida (Acari), ptyctimous mites comprise more than 1400 described species in 40 genera and subgenera, with nearly cosmopolitan distribution except for the Arctic and Antarctic Regions. They are capable of folding the aspidosoma under the opisthosoma to protect their appendages, and are primarily soil and litter inhabitants, feeding on fungi and decaying plant remains with various levels of specificity. Our purpose was to provide a detailed catalogue of all known ptyctimous mite species in the world with information of distribution, taxonomic issues and some remarks. Data of known juvenile  instars of ptyctimous mites which were not included in Norton Ermilov (2014) were added. We hope that our catalogue with bibliography will be helpful in taxonomic and ecological studies.        The catalogue presents taxonomic information and geographic distribution of 1431 known species of the world belonging to 42 genera and eight families (not including data of genus and species inquirenda, nomina nuda and species without author name). Among them, 261 species are listed as synonyms, 43 species inquirenda, nine homonyms, 17 new synonyms, one new subgenus Mahuntritia subgenus nov. and three new names are included in the catalogue.

A study on the prevalence of house dust mites in Al-Arish city, North Sinai Governorate, Egypt.

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El-Sherbiny, Gihad T; El-Sherbini, Eman T; Saled, Nagla Mostafa K; Haridy, Fouad M; Morsy, Ayman T A

2010-04-01

Free living mites comprise a huge and various groups of tiny arthropods in the class Arachida, mainly of the Pyroglyphidae family. Exposure to allergens derived from house dust mite (HDM) feces is a postulated risk factor for allergic sensitization, asthma development and asthma morbidity. However, practical and effective method to mitigate these allergens in low-income, urban home environments remains elusive. It well known that (HDM) physiology is greatly affected by hydrothermal microclimatic condition. El Arish has subtropical climate and warm humid summer, such situation are favourable to proliferate house dust mites. As no valid data are available for house dust mites fauna of El Arish, this study was carried out to determine the prevalence and contamination rates of homes in El Arish city. Samples of house dust collected in 2008 from 50 houses in El Arish city were subjected to acarological examination. Acri were found in (34.6 %) of the samples collected from these homes. Results indicated that dust mites were present in all humid environments. Also, hypersensitivity to dust mites was common among patients with asthma.

Límites de esbeltez en soportes de hormigón armado

OpenAIRE

Río, O.; Morán, F.

1987-01-01

Se presenta una propuesta racional de límites de esbeltez para soportes de hormigón armado, que tiene en cuenta los principales parámetros conocidos en el dimensionamiento: el esfuerzo axil, la excentricidad relativa y la relación de excentricidades en los extremos del soporte. En función de estos parámetros se define la esbeltez límite equivalente X^, que permite calibrar la importancia de los efectos de segundo orden.

Regional factors rather than forest type drive the community structure of soil living oribatid mites (Acari, Oribatida).

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Erdmann, Georgia; Scheu, Stefan; Maraun, Mark

2012-06-01

Most European forests are managed by humans. However, the manner and intensity of management vary. While the effect of forest management on above-ground communities has been investigated in detail, effects on the below-ground fauna remain poorly understood. Oribatid mites are abundant microarthropods in forest soil and important decomposers in terrestrial ecosystems. Here, we investigated the effect of four forest types (i.e., managed coniferous forests; 30 and 70 years old managed beech forests; natural beech forests) on the density, diversity and community structure of oribatid mites (Acari). The study was replicated at three regions in Germany: the Swabian Alb, the Hainich and the Schorfheide. To relate changes in oribatid mite community structure to environmental factors, litter mass, pH, C and N content of litter, fine roots and C content of soil were measured. Density of oribatid mites was highest in the coniferous forests and decreased in the order 30 years old, 70 years old, and natural beech forests. Mass of the litter layer and density of oribatid mites were strongly correlated indicating that the litter layer is an important factor regulating oribatid mite densities. Diversity of oribatid mites was little affected by forest type indicating that they harbor similar numbers of niches. Species composition differed between the forest types, suggesting different types of niches. The community structure of oribatid mites differed more strongly between the three regions than between the forest types indicating that regional factors are more important than effects associated with forest type.

Intercropping With Fruit Trees Increases Population Abundance and Alters Species Composition of Spider Mites on Cotton.

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Li, Haiqiang; Pan, Hongsheng; Wang, Dongmei; Liu, Bing; Liu, Jian; Zhang, Jianping; Lu, Yanhui

2018-05-05

With the recent increase in planting of fruit trees in southern Xinjiang, the intercropping of fruit trees and cotton has been widely adopted. From 2014 to 2016, a large-scale study was conducted in Aksu, an important agricultural area in southern Xinjiang, to compare the abundance and species composition of spider mites in cotton fields under jujube-cotton, apple-cotton, and cotton monocrop systems. The abundance of spider mites in cotton fields under both intercropping systems was generally higher than in the cotton monocrop. The species composition of spider mites also differed greatly between cotton intercropped with apple or jujube compared to the cotton monocrop. The relative proportion of Tetranychus truncates Ehara (Acari: Tetranychidae) in the species complex generally increased while that of another spider mite, Tetranychus dunhuangensis Wang (Acari: Tetranychidae), decreased under fruit tree-cotton systems. More attention should be paid to the monitoring and management of spider mites, especially T. truncates in this important region of China.

Allergen sensitivity (mites, insects, and pets) in a Puerto Rican population.

Science.gov (United States)

Nazario, Sylvette; Zaragoza, Rafael; Velázquez, Vylma; Ramos-Valencia, Gilberto; Acantilado, Carmen; Rodríguez, Ray; Rivera, Angel M; Alvarez, María M; López-Almodóvar, Carlos; López-Malpica, Fernando

2012-03-01

The people of Puerto Rico have one of the highest asthma prevalence and morbidity rates in the U.S.A. Limited information is available on the most common allergy sensitivities among island residents. The aims of the study were to determine the most common inhalant allergen sensitivities among a convenience sample in Puerto Rico and determine as well their relationship to an asthma or a rhinitis diagnosis. In August of 2008, we evaluated a cohort of subjects visiting ambulatory clinics offering health screening; the clinics were located in two of the island's biggest cities: Guaynabo in the north and Ponce in the south. Subjects over three years of age (or their parents) visiting the clinics answered a survey on asthma and rhinitis and were skin tested for reactivity to common aeroallergens. The survey included 395 subjects with a mean age of 29 years. Thirty-six percent reported a history of asthma, of whom 83% (30% of the total participants) reported still having asthma, and 76% reported having rhinitis. Sixty-five percent of the subjects were sensitive to at least one antigen. Subjects sensitive to mites were 53% more likely to have suffered from asthma than were non-mite-sensitized subjects (OR = 1.53, p < 0.05) sensitivity to mosquitoes (OR = 2.25, p < 0.02), mites (OR = 2.53, p < 0.00001), feathers (OR = 2.72, p < 0.03), dogs (OR = 3.02, p < 0.01), or cats (OR = 3.42, p < 0.001) increased an individual's likelihood of suffering from rhinitis. The most common sensitivities identified were to mites and insects. Mite sensitivity was associated with rhinitis and asthma. Sensitivity to animal dander as well as to mosquitoes was associated to with rhinitis. Further studies are warranted to explore the relevance of allergen sensitivity in terms of asthma and rhinitis prevalence and morbidity among residents of Puerto Rico.

Indoor mite allergens in patients with respiratory allergy living in Porto, Portugal.

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Plácido, J L; Cuesta, C; Delgado, L; da Silva, J P; Miranda, M; Ventas, P; Vaz, M

1996-09-01

We investigated the levels of mite allergens (Der p 1, Der f 1, Der 2, and Lep d 1) in dust samples from the homes of 59 patients with asthma, 36 sensitized to house-dust mites (HDM) and 23 to grass pollen (controls), living in Porto, northern Portugal. The relationship between exposure and sensitization to HDM and the influence of housing conditions on mite-allergen levels were also evaluated. Der p 1 (median 9.2 micrograms/g) and Der 2 (4.6 micrograms/g) were the main allergens, while Der f 1 and Lep d 1 levels were always 2 micrograms/g and their homes contained significantly higher levels of Der p 1 (median 12.5 vs 6.4 micrograms/g; P = 0.008) and Der 2 (6.2 vs 3.0 micrograms/g; P = 0.004) when compared to the control group. A significant correlation was observed between the exposure to Der p 1 and the wheal area at skin testing with the Dermatophagoides pteronyssinus (Dp) extract (P = 0.01) as well as with serum specific IgE levels to Dp (P = 0.03). Patients with higher levels of serum specific IgE (> or = 17.5 HRU/ml) were also more frequently exposed to Der p 1 levels > or = 10 micrograms/g (P = 0.002). Old homes, presence of carpets, and signs of dampness were conditions associated with significantly higher levels of mite allergens. In conclusion, we found high levels of Der p 1 and Der 2 particularly in the homes of HDM-sensitized patients and we confirm the relationship between exposure and sensitization to HDM, assessed by both in vivo and in vitro methods. In additional to a favorable outdoor climate, we found in our region housing conditions propitious to mite growth, suggesting that specific geographic characteristics must also be taken into account for the correct planning of mite-avoidance measures.

Birefringent Crystals and Abdominal Discoloration in the Predatory Mite Phytoseiulus persimilis (Acari: Phytoseiidae)

Science.gov (United States)

Bjørnson; Steiner; Keddie

1997-03-01

In response to grower complaints of poor performance of Phytoseiulus persimilis, mites from 14 commercial insectaries and research colonies were examined for pathogens. Some were found to have abdominal discolorations, manifested initially as two white stripes along the dorsal sides of the body within the Malpighian tubules. Advanced signs appeared as a large, centrally located, white spot or U-shaped discoloration in the distal opisthosoma within the rectum/anal atrium. White material often accumulated and hardened within the anus and formed a rectal plug that inhibited further excretion. Most affected mites were lethargic. Adults and immatures with abdominal discoloration contained numerous densely packed, birefringent, dumbbell-shaped entities. Though occasionally observed in the colon, they occurred most frequently within the Malpighian tubules and/or rectum and anal atrium. Dumbbells measured 2-4 &mgr;m long and contained prominent concentric rings. When observed by transmission electron microscopy, the entities lacked cellular organelles. Asymptomatic mites contained few or no such entities. Dumbbell-shaped inclusions were observed in P. persimilis from all sources examined. High levels of potassium, low levels of phosphorous and sulfur, and traces of chlorine were detected by energy-dispersive X-ray analysis. Guanine and uric acid, known nitrogenous wastes of arachnids, do not contain these elements. The chemical composition and structure indicate that the dumbbells are crystals. Both asymptomatic mites and those specimens exhibiting abdominal discoloration were examined for pathogens using light and transmission electron microscopy. Microsporidia, virus-like particles, and a rickettsia (genus Wolbachia) were observed in some mites but showed no correlation with white abdominal discoloration or associated crystal formation. Neither were pathogens always detected in symptomatic mites. Although birefringent crystals may be naturally occurring excretory

Tomato yellow leaf curl virus infection mitigates the heat stress response of plants grown at high temperatures

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Ghandi, Anfoka; Adi, Moshe; Lilia, Fridman; Linoy, Amrani; Or, Rotem; Mikhail, Kolot; Mouhammad, Zeidan; Henryk, Czosnek; Rena, Gorovits

2016-01-01

Cultured tomatoes are often exposed to a combination of extreme heat and infection with Tomato yellow leaf curl virus (TYLCV). This stress combination leads to intense disease symptoms and yield losses. The response of TYLCV-susceptible and resistant tomatoes to heat stress together with viral infection was compared. The plant heat-stress response was undermined in TYLCV infected plants. The decline correlated with the down-regulation of heat shock transcription factors (HSFs) HSFA2 and HSFB1, and consequently, of HSF-regulated genes Hsp17, Apx1, Apx2 and Hsp90. We proposed that the weakened heat stress response was due to the decreased capacity of HSFA2 to translocate into the nuclei of infected cells. All the six TYLCV proteins were able to interact with tomato HSFA2 in vitro, moreover, coat protein developed complexes with HSFA2 in nuclei. Capturing of HSFA2 by viral proteins could suppress the transcriptional activation of heat stress response genes. Application of both heat and TYLCV stresses was accompanied by the development of intracellular large protein aggregates containing TYLCV proteins and DNA. The maintenance of cellular chaperones in the aggregated state, even after recovery from heat stress, prevents the circulation of free soluble chaperones, causing an additional decrease in stress response efficiency. PMID:26792235

Impact of ectohumus application in birch and pine nurseries on the presence of soil mites (Acari, Oribatida in particular

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Klimek Andrzej

2016-03-01

Full Text Available Intensively used forest nurseries are characterised by degradation processes that lead to a drop in the quality of seedlings. The main reason of this problem is a decrease in biological soil diversity. Therefore, an attempt of nursery soil enrichment by introducing ectohumus – as compost and fresh litter – from the pine forest was carried out. The research was carried out in 2009–2011 in the Bielawy forest nursery near the city of Toruń, Poland. The objective of the study was to determine the impact of organic fertilisation (compost made up of forest humus and mulching using fresh ectohumus on the density and community composition of Acari mites and on species composition of oribatid mites (Oribatida in the nurseries of silver birch and Scots pine. Mites, especially oribatid mites, were treated as bioindicators of soil biological activity. Research has shown that mulching using fresh ectohumus caused a multiple increase in the density of mites, especially in saprophagous mites Oribatida. Oribatid mites were clearly more numerous in birch cultivation than in that of pine. Overall, 27 species of oribatid mites were found. Mulching resulted in a significant growth in species diversity in both cultivations. The most numerous oribatid mite in the area under the study was Oribatula tibialis. This species was present in all plots and showed clear preference for birch cultivation. Tectocepheus velatus and Oppiella nova, common and known to be present in a variety of environments, were slightly less numerous.

Fine-scale linkage mapping reveals a small set of candidate genes influencing honey bee grooming behavior in response to Varroa mites.

Directory of Open Access Journals (Sweden)

Miguel E Arechavaleta-Velasco

Full Text Available Populations of honey bees in North America have been experiencing high annual colony mortality for 15-20 years. Many apicultural researchers believe that introduced parasites called Varroa mites (V. destructor are the most important factor in colony deaths. One important resistance mechanism that limits mite population growth in colonies is the ability of some lines of honey bees to groom mites from their bodies. To search for genes influencing this trait, we used an Illumina Bead Station genotyping array to determine the genotypes of several hundred worker bees at over a thousand single-nucleotide polymorphisms in a family that was apparently segregating for alleles influencing this behavior. Linkage analyses provided a genetic map with 1,313 markers anchored to genome sequence. Genotypes were analyzed for association with grooming behavior, measured as the time that individual bees took to initiate grooming after mites were placed on their thoraces. Quantitative-trait-locus interval mapping identified a single chromosomal region that was significant at the chromosome-wide level (p<0.05 on chromosome 5 with a LOD score of 2.72. The 95% confidence interval for quantitative trait locus location contained only 27 genes (honey bee official gene annotation set 2 including Atlastin, Ataxin and Neurexin-1 (AmNrx1, which have potential neurodevelopmental and behavioral effects. Atlastin and Ataxin homologs are associated with neurological diseases in humans. AmNrx1 codes for a presynaptic protein with many alternatively spliced isoforms. Neurexin-1 influences the growth, maintenance and maturation of synapses in the brain, as well as the type of receptors most prominent within synapses. Neurexin-1 has also been associated with autism spectrum disorder and schizophrenia in humans, and self-grooming behavior in mice.

Challenges in devising economic spray thresholds for a major pest of Australian canola, the redlegged earth mite (Halotydeus destructor).

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Arthur, Aston L; Hoffmann, Ary A; Umina, Paul A

2015-10-01

A key component for spray decision-making in IPM programmes is the establishment of economic injury levels (EILs) and economic thresholds (ETs). We aimed to establish an EIL for the redlegged earth mite (Halotydeus destructor Tucker) on canola. Complex interactions between mite numbers, feeding damage and plant recovery were found, highlighting the challenges in linking H. destructor numbers to yield. A guide of 10 mites plant(-1) was established at the first-true-leaf stage; however, simple relationships were not evident at other crop development stages, making it difficult to establish reliable EILs based on mite number. Yield was, however, strongly associated with plant damage and plant densities, reflecting the impact of mite feeding damage and indicating a plant-based alternative for establishing thresholds for H. destructor. Drawing on data from multiple field trials, we show that plant densities below 30-40 plants m(-2) could be used as a proxy for mite damage when reliable estimates of mite densities are not possible. This plant-based threshold provides a practical tool that avoids the difficulties of accurately estimating mite densities. The approach may be applicable to other situations where production conditions are unpredictable and interactions between pests and plant hosts are complex. © 2015 Society of Chemical Industry.

Neoseiulus paspalivorus, a predator from coconut, as a candidate for controlling dry bulb mites infesting stored tulip bulbs.

Science.gov (United States)

Lesna, Izabela; da Silva, Fernando R; Sato, Yukie; Sabelis, Maurice W; Lommen, Suzanne T E

2014-06-01

The dry bulb mite, Aceria tulipae, is the most important pest of stored tulip bulbs in The Netherlands. This tiny, eriophyoid mite hides in the narrow space between scales in the interior of the bulb. To achieve biological control of this hidden pest, candidate predators small enough to move in between the bulb scales are required. Earlier experiments have shown this potential for the phytoseiid mite, Neoseiulus cucumeris, but only after the bulbs were exposed to ethylene, a plant hormone that causes a slight increase in the distance between tulip bulb scales, just sufficient to allow this predator to reach the interior part of the bulb. Applying ethylene, however, is not an option in practice because it causes malformation of tulip flowers. In fact, to prevent this cosmetic damage, bulb growers ventilate rooms where tulip bulbs are stored, thereby removing ethylene produced by the bulbs (e.g. in response to mite or fungus infestation). Recently, studies on the role of predatory mites in controlling another eriophyoid mite on coconuts led to the discovery of an exceptionally small phytoseiid mite, Neoseiulus paspalivorus. This predator is able to move under the perianth of coconuts where coconut mites feed on meristematic tissue of the fruit. This discovery prompted us to test N. paspalivorus for its ability to control A. tulipae on tulip bulbs under storage conditions (ventilated rooms with bulbs in open boxes; 23 °C; storage period June-October). Using destructive sampling we monitored predator and prey populations in two series of replicated experiments, one at a high initial level of dry bulb mite infestation, late in the storage period, and another at a low initial dry bulb mite infestation, halfway the storage period. The first and the second series involved treatment with N. paspalivorus and a control experiment, but the second series had an additional treatment in which the predator N. cucumeris was released. Taking the two series of experiments together

Higher glandular trichome density in tomato leaflets and repellence to spider mites Alta densidade de tricomas glandulares em tomateiro e aumento da repelência a ácaros rajados

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Wilson Roberto Maluf

2007-09-01

Full Text Available The objective of this work was to evaluate the feasibility of selection for higher glandular trichome densities, as an indirect criterion of selection for increasing repellence to spider mites Tetranychus urticae, in tomato populations derived from an interspecific cross between Lycopersicon esculentum x L. hirsutum var. glabratum PI 134417. Trichome densities were evaluated in 19 genotypes, including 12 from advanced backcross populations, derived from the original cross L. esculentum x L. hirsutum var. glabratum PI 134417. Counts were made both on the adaxial and abaxial leaf surfaces, and trichomes were classified into glandular types IV and VI, other glandular types (types I+VII, and nonglandular types. Mite repellence was measured by distances walked by mites onto the tomato leaf surface after 20, 40 and 60 min. Spider mite repellence biotests indicated that higher densities of glandular trichomes (especially type VI decreased the distances walked by the mites onto the tomato leaf surface. Selection of plants with higher densities of glandular trichomes can be an efficient criterion to obtain tomato genotypes with higher resistance (repellence to spider mites.O objetivo deste trabalho foi avaliar a eficiência da seleção para maior densidade de tricomas glandulares na resistência (repelência ao ácaro Tetranychus urticae, em populações de tomate derivadas do cruzamento interespecífico Lycopersicon esculentum x L. hirsutum var. glabratum PI 134417. Foram avaliados 19 genótipos quanto à densidade de tricomas, que incluíram 12 derivados de populações avançadas de retrocruzamentos, obtidos a partir do cruzamento original L. esculentum x L. hirsutum var. glabratum PI 134417. Nas faces abaxial e adaxial dos folíolos, realizaram-se as contagens e os tricomas foram classificados em glandulares tipo IV e VI, outros glandulares (tipo I e VII e não glandulares. A repelência aos ácaros foi medida pela distância média, percorrida pelo

Immunogene and viral transcript dynamics during parasitic Varroa destructor mite infection of developing honey bee (Apis mellifera) pupae.

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Kuster, Ryan D; Boncristiani, Humberto F; Rueppell, Olav

2014-05-15

The ectoparasitic Varroa destructor mite is a major contributor to the ongoing honey bee health crisis. Varroa interacts with honey bee viruses, exacerbating their pathogenicity. In addition to vectoring viruses, immunosuppression of the developing honey bee hosts by Varroa has been proposed to explain the synergy between viruses and mites. However, the evidence for honey bee immune suppression by V. destructor is contentious. We systematically studied the quantitative effects of experimentally introduced V. destructor mites on immune gene expression at five specific time points during the development of the honey bee hosts. Mites reproduced normally and were associated with increased titers of deformed wing virus in the developing bees. Our data on different immune genes show little evidence for immunosuppression of honey bees by V. destructor. Experimental wounding of developing bees increases relative immune gene expression and deformed wing virus titers. Combined, these results suggest that mite feeding activity itself and not immunosuppression may contribute to the synergy between viruses and mites. However, our results also suggest that increased expression of honey bee immune genes decreases mite reproductive success, which may be explored to enhance mite control strategies. Finally, our expression data for multiple immune genes across developmental time and different experimental treatments indicates co-regulation of several of these genes and thus improves our understanding of the understudied honey bee immune system. © 2014. Published by The Company of Biologists Ltd.

Influence of environmental characteristics and climatic factors on mites in the dust of air-conditioner filters.

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Wu, J; Liu, Z G; Ran, P X; Wang, B

2009-12-01

To investigate mites in the dust of air-conditioner filters (MACF) in China, a total of 652 dust samples were collected from six cities: Guangzhou (n = 129), Nanchang (n = 127), Shanghai (n = 113), Xian (n = 93), Beijing (n = 93), and Shenyang (n = 79). Tarsonemus granarius was the most dominant species (87.2%). Dermatophagoides pteronyssinus and Dermatophagoides farinae only represented 7.0 and 3.0% of total mites, respectively. With latitude increasing, both mite occurrence rate (P air-conditioner age, utilization time and power. Wall and window type air-conditioner had higher risk of finding MACF than the floor type air-conditioner. As far as the cleaning interval time of ACF was concerned, higher risk ratio and the highest density of MACF were found in the time stage of >3, air-conditioner filters are potential indoor threat to asthma and allergy sufferers. In this study, we find that the storage mite Tarsonemus granarius is the predominant species of mites in the dust of air-conditioner filters (MACF). Thus, the possible clinical importance of T. granarius should cause more our attentions in the future. The abundance and distribution of MACF are also found significantly varied in different climatic regions of China. When we try to assess the possible risk of MACF, more attentions should be focused on subtropical region than temperate region. The influence analysis of environmental characteristics on the prevalence of MACF will shed light on the establishment of mite control strategy and the design of mite defense air-conditioner.

Skin mites in mice (Mus musculus): high prevalence of Myobia sp. (Acari, Arachnida) in Robertsonian mice.

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Sastre, Natalia; Calvete, Oriol; Martínez-Vargas, Jessica; Medarde, Nuria; Casellas, Joaquim; Altet, Laura; Sánchez, Armand; Francino, Olga; Ventura, Jacint

2018-05-04

Myobia sp. and Demodex sp. are two skin mites that infest mice, particularly immunodeficient or transgenic lab mice. In the present study, wild house mice from five localities from the Barcelona Roberstonian system were analysed in order to detect skin mites and compare their prevalence between standard (2n = 40) and Robertsonian mice (2n > 40). We found and identified skin mites through real-time qPCR by comparing sequences from the mitochondrial 16S rRNA and the nuclear 18S rRNA genes since no sequences are available so far using the mitochondrial gene. Fourteen positive samples were identified as Myobia musculi except for a deletion of 296 bp out to 465 bp sequenced, and one sample was identified as Demodex canis. Sampling one body site, the mite prevalence in standard and Robertsonian mice was 0 and 26%, respectively. The malfunction of the immune system elicits an overgrowth of skin mites and consequently leads to diseases such as canine demodicosis in dogs or rosacea in humans. In immunosuppressed mice, the probability of developing demodicosis is higher than in healthy mice. Since six murine toll-like receptors (TLRs) are located in four chromosomes affected by Robertsonian fusions, we cannot dismiss that differences in mite prevalence could be the consequence of the interruption of TLR function. Although ecological and/or morphological factors cannot be disregarded to explain differences in mite prevalence, the detection of translocation breakpoints in TLR genes or the analysis of TLR gene expression are needed to elucidate how Robertsonian fusions affect the immune system in mice.

The predatory mite Phytoseiulus persimilis does not perceive odor mixtures as strictly elemental objects.

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van Wijk, Michiel; de Bruijn, Paulien J A; Sabelis, Maurice W

2010-11-01

Phytoseiulus persimilis is a predatory mite that in absence of vision relies on the detection of herbivore-induced plant odors to locate its prey, the two-spotted spider-mite Tetranychus urticae. This herbivorous prey is feeding on leaves of a wide variety of plant species in different families. The predatory mites respond to numerous structurally different compounds. However, typical spider-mite induced plant compounds do not attract more predatory mites than plant compounds not associated with prey. Because the mites are sensitive to many compounds, components of odor mixtures may affect each other's perception. Although the response to pure compounds has been well documented, little is known how interactions among compounds affect the response to odor mixtures. We assessed the relation between the mites' responses elicited by simple mixtures of two compounds and by the single components of these mixtures. The preference for the mixture was compared to predictions under three conceptual models, each based on one of the following assumptions: (1) the responses elicited by each of the individual components can be added to each other; (2) they can be averaged; or (3) one response overshadows the other. The observed response differed significantly from the response predicted under the additive response, average response, and overshadowing response model in 52, 36, and 32% of the experimental tests, respectively. Moreover, the behavioral responses elicited by individual compounds and their binary mixtures were determined as a function of the odor concentration. The relative contribution of each component to the behavioral response elicited by the mixture varied with the odor concentration, even though the ratio of both compounds in the mixture was kept constant. Our experiments revealed that compounds that elicited no response had an effect on the response elicited by binary mixtures that they were part of. The results are not consistent with the hypothesis that P

Draft genome of the honey bee ectoparasitic mite, Tropilaelaps mercedesae, is shaped by the parasitic life history.

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Dong, Xiaofeng; Armstrong, Stuart D; Xia, Dong; Makepeace, Benjamin L; Darby, Alistair C; Kadowaki, Tatsuhiko

2017-03-01

The number of managed honey bee colonies has considerably decreased in many developed countries in recent years and ectoparasitic mites are considered as major threats to honey bee colonies and health. However, their general biology remains poorly understood. We sequenced the genome of Tropilaelaps mercedesae, the prevalent ectoparasitic mite infesting honey bees in Asia, and predicted 15 190 protein-coding genes that were well supported by the mite transcriptomes and proteomic data. Although amino acid substitutions have been accelerated within the conserved core genes of two mites, T. mercedesae and Metaseiulus occidentalis, T. mercedesae has undergone the least gene family expansion and contraction between the seven arthropods we tested. The number of sensory system genes has been dramatically reduced, but T. mercedesae contains all gene sets required to detoxify xenobiotics. T. mercedesae is closely associated with a symbiotic bacterium (Rickettsiella grylli-like) and Deformed Wing Virus, the most prevalent honey bee virus. T. mercedesae has a very specialized life history and habitat as the ectoparasitic mite strictly depends on the honey bee inside a stable colony. Thus, comparison of the genome and transcriptome sequences with those of a tick and free-living mites has revealed the specific features of the genome shaped by interaction with the honey bee and colony environment. Genome and transcriptome sequences of T. mercedesae, as well as Varroa destructor (another globally prevalent ectoparasitic mite of honey bee), not only provide insights into the mite biology, but may also help to develop measures to control the most serious pests of the honey bee. © The Author 2017. Published by Oxford University Press.

Characterization of the complete mitochondrial genome of the storage mite pest Tyrophagus longior (Gervais) (Acari: Acaridae) and comparative mitogenomic analysis of four acarid mites.

Science.gov (United States)

Yang, Banghe; Li, Chaopin

2016-02-01

Mites of the genus Tyrophagus are economically important polyphagous pest commonly living on stored products and also responsible for allergic reactions to humans. Complete mitochondrial genomes (mitogenomes) and the gene features therein are widely used as molecular markers in the study of population genetics, phylogenetics as well as molecular evolution. However, scarcity on the sequence data has greatly impeded the studies in these areas pertaining to the Acari (mites and ticks). Information on the Tyrophagus mitogenomes is quite critical for phylogenetic evaluation and molecular evolution of the mitogenomes within Acariformes. Herein, we reported the complete mitogenome of the allergenic acarid storage mite Tyrophagus longior (Astigmata: Acaridae), an important member of stored food pests, and compared with those of other three acarid mites. The complete mitogenome of T. longior was a circular molecule of 13,271 bp. Unexpectedly, only 19 transfer RNA genes (tRNAs) were present, lacking trnF, trnS1 and trnQ. Furthermore, it also contained 13 protein-coding genes (PCGs) and 2 genes for rRNA (rrnS and rrnL) commonly detected in metazoans. The four mitogenomes displayed similar characteristics with respect to the gene content, nucleotide comparison, and codon usages. Yet, the gene order of T. longior was different from that in other Acari. The J-strands of the four mitogenomes possessed high A+T content (67.4-70.0%), and exhibited positive GC-skews and negative AT-skews. Most inferred tRNAs of T. longior were extremely truncated, lacking either a D- or T-arm, as found in other acarid mites. In T. longior mitogenome the A+T-rich region was just 50 bp in length and can be folded as a stable stem-loop structure, whereas in the region some structures of microsatellite-like (AT)n and palindromic sequences was not present. Besides, reconstructing of the phylogenetic relationship based on concatenated amino acid sequences of 13 PCGs supported that monophyly of the family

The predatory mite Phytoseiulus persimilis does not perceive odor mixtures as strictly elemental objects

NARCIS (Netherlands)

van Wijk, M.; de Bruijn, P.J.A.; Sabelis, M.W.

2010-01-01

Phytoseiulus persimilis is a predatory mite that in absence of vision relies on the detection of herbivore-induced plant odors to locate its prey, the two-spotted spider-mite Tetranychus urticae. This herbivorous prey is feeding on leaves of a wide variety of plant species in different families. The

Scabies Mites Alter the Skin Microbiome and Promote Growth of Opportunistic Pathogens in a Porcine Model

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Swe, Pearl M.; Zakrzewski, Martha; Kelly, Andrew; Krause, Lutz; Fischer, Katja

2014-01-01

Background The resident skin microbiota plays an important role in restricting pathogenic bacteria, thereby protecting the host. Scabies mites (Sarcoptes scabiei) are thought to promote bacterial infections by breaching the skin barrier and excreting molecules that inhibit host innate immune responses. Epidemiological studies in humans confirm increased incidence of impetigo, generally caused by Staphylococcus aureus and Streptococcus pyogenes, secondary to the epidermal infestation with the parasitic mite. It is therefore possible that mite infestation could alter the healthy skin microbiota making way for the opportunistic pathogens. A longitudinal study to test this hypothesis in humans is near impossible due to ethical reasons. In a porcine model we generated scabies infestations closely resembling the disease manifestation in humans and investigated the scabies associated changes in the skin microbiota over the course of a mite infestation. Methodology/Principal Findings In a 21 week trial, skin scrapings were collected from pigs infected with S. scabies var. suis and scabies-free control animals. A total of 96 skin scrapings were collected before, during infection and after acaricide treatment, and analyzed by bacterial 16S rDNA tag-encoded FLX-titanium amplicon pyrosequencing. We found significant changes in the epidermal microbiota, in particular a dramatic increase in Staphylococcus correlating with the onset of mite infestation in animals challenged with scabies mites. This increase persisted beyond treatment from mite infection and healing of skin. Furthermore, the staphylococci population shifted from the commensal S. hominis on the healthy skin prior to scabies mite challenge to S. chromogenes, which is increasingly recognized as being pathogenic, coinciding with scabies infection in pigs. In contrast, all animals in the scabies-free cohort remained relatively free of Staphylococcus throughout the trial. Conclusions/Significance This is the first

Scabies mites alter the skin microbiome and promote growth of opportunistic pathogens in a porcine model.

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Pearl M Swe

Full Text Available BACKGROUND: The resident skin microbiota plays an important role in restricting pathogenic bacteria, thereby protecting the host. Scabies mites (Sarcoptes scabiei are thought to promote bacterial infections by breaching the skin barrier and excreting molecules that inhibit host innate immune responses. Epidemiological studies in humans confirm increased incidence of impetigo, generally caused by Staphylococcus aureus and Streptococcus pyogenes, secondary to the epidermal infestation with the parasitic mite. It is therefore possible that mite infestation could alter the healthy skin microbiota making way for the opportunistic pathogens. A longitudinal study to test this hypothesis in humans is near impossible due to ethical reasons. In a porcine model we generated scabies infestations closely resembling the disease manifestation in humans and investigated the scabies associated changes in the skin microbiota over the course of a mite infestation. METHODOLOGY/PRINCIPAL FINDINGS: In a 21 week trial, skin scrapings were collected from pigs infected with S. scabies var. suis and scabies-free control animals. A total of 96 skin scrapings were collected before, during infection and after acaricide treatment, and analyzed by bacterial 16S rDNA tag-encoded FLX-titanium amplicon pyrosequencing. We found significant changes in the epidermal microbiota, in particular a dramatic increase in Staphylococcus correlating with the onset of mite infestation in animals challenged with scabies mites. This increase persisted beyond treatment from mite infection and healing of skin. Furthermore, the staphylococci population shifted from the commensal S. hominis on the healthy skin prior to scabies mite challenge to S. chromogenes, which is increasingly recognized as being pathogenic, coinciding with scabies infection in pigs. In contrast, all animals in the scabies-free cohort remained relatively free of Staphylococcus throughout the trial. CONCLUSIONS

Tomato whole genome transcriptional response to Tetranychus urticae identifies divergence of spider mite-induced responses between tomato and Arabidopsis

NARCIS (Netherlands)

Martel, C.; Zhurov, V.; Navarro, M.; Martinez, M.; Cazaux, M.; Auger, P.; Migeon, A.; Santamaria, M.E.; Wybouw, N.; Diaz, I.; Van Leeuwen, T.; Navajas, M.; Grbic, M.; Grbic, V.

2015-01-01

The two-spotted spider mite Tetranychus urticae is one of the most significant mite pests in agriculture, feeding on more than 1,100 plant hosts, including model plants Arabidopsis thaliana and tomato, Solanum lycopersicum. Here, we describe timecourse tomato transcriptional responses to spider mite

Driving factors of the communities of phytophagous and predatory mites in a physic nut plantation and spontaneous plants associated.

Science.gov (United States)

Cruz, Wilton P; Sarmento, Renato A; Teodoro, Adenir V; Neto, Marçal P; Ignacio, Maíra

2013-08-01

Seasonal changes in climate and plant diversity are known to affect the population dynamics of both pests and natural enemies within agroecosystems. In Brazil, spontaneous plants are usually tolerated in small-scale physic nut plantations over the year, which in turn may mediate interactions between pests and natural enemies within this agroecosystem. Here, we aimed to access the influence of seasonal variation of abiotic (temperature, relative humidity and rainfall) and biotic (diversity of spontaneous plants, overall richness and density of mites) factors on the communities of phytophagous and predatory mites found in a physic nut plantation and its associated spontaneous plants. Mite sampling was monthly conducted in dicotyledonous and monocotyledonous leaves of spontaneous plants as well as in physic nut shrubs over an entire year. In the dry season there was a higher abundance of phytophagous mites (Tenuipalpidae, Tarsonemidae and Tetranychidae) on spontaneous plants than on physic nut shrubs, while predatory mites (Phytoseiidae) showed the opposite pattern. The overall density of mites on spontaneous plants increased with relative humidity and diversity of spontaneous plants. Rainfall was the variable that most influenced the density of mites inhabiting physic nut shrubs. Agroecosystems comprising spontaneous plants associated with crops harbour a rich mite community including species of different trophic levels which potentially benefit natural pest control due to increased diversity and abundance of natural enemies.

A New Stubby Species of Demodectic Mite (Acari: Demodicidae) From the Domestic Dog (Canidae).

Science.gov (United States)

Morita, Tatsushi; Ohmi, Aki; Kiwaki, Akihito; Ike, Kazunori; Nagata, Katsuyuki

2018-02-28

A new species of Demodex was detected in the earwax of a dog with otitis externa in Saitama Prefecture, Japan, in July 2010. The opisthosoma length of the mite was slightly shorter than 1/2 of its body length, which was different from the other species in domestic dogs, D. canis and D. injai, but was similar to the form of mites termed "short-bodied species", including D. cornei. However, the stubby external form was morphologically different from those of "short-bodied species", excluding a case without a species description reported from Greece. Among known species, the mite was similar to D. equi and D. acutipes.

Electron-beam irradiation as a quarantine treatment against red mite on exported cut flower of Chrysanthemum

International Nuclear Information System (INIS)

Doan Thi The; Nguyen Thi Ly; Vo Thi Kim Lang; Cao Van Chung

2016-01-01

Utilization of phytosanitary irradiation as a potential treatment to disinfest agricultural commodities in trade has expanded rapidly in the recent years. In this study, red mites (Tetranychus sp) isolated from cut Chrysanthemums were treated by electron beam irradiation at doses of 100, 200, 300 and 400 Gy. After irradiation, they were kept at room temperature to determine the effects of electron beam irradiation on red mite at different developmental stages (eggs, nymphs and adults) and the reproduction of female adults. The results showed that the pattern of tolerance to irradiation in red mite was eggs < 2nd instars < adults, in which the adults were the most tolerance stage. The number of eggs laid by the irradiated female mites and the hatching rate significantly decreased when the irradiation dose increased. The hatching rate of eggs at 300 Gy was 4.25% and no larvae F_1 survived during observation time. It could be concluded that 300 Gy is the effective quarantine dose for red mite infesting on cut chrysanthemums. (author)

Factors affecting the prevalence of mange-mite infestations in stray dogs of Yucatán, Mexico.

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Rodriguez-Vivas, R I; Ortega-Pacheco, A; Rosado-Aguilar, J A; Bolio, G M E

2003-07-10

The aim of the present study was to determine the factors affecting the prevalence of mange-mite infestations in stray dogs of Yucatán, Mexico. The study was carried out in 200 stray dogs of Mérida capital city of Yucatán, Mexico. Four samples (head, thoracic-abdominal area, extremities and ear) were taken from each animal by skin scraping and examined microscopically in 10% KOH solution to detect the presence of mites. Mites were also collected from the external ear canal of dogs using cotton-tipped swabs. The prevalence of different mite species was calculated. A primary screening was performed using 2xK contingency tables of exposure variables. All variables with PDemodex canis (23.0%) was the most frequent mite, followed by Sarcoptes scabei var. canis (7.0%) and Otodectes cynotis (3.5%). The following factors were found: body condition (bad, OR: 5.35, CI 95%: 1.66-17.3; regular, OR: 3.72, CI 95%: 1.39-9.99) and the presence of macroscopic lesions of dermatosis (OR: 42.80, CI 95%: 13.65-134.24).

The SQ House Dust Mite SLIT-Tablet Is Well Tolerated in Patients with House Dust Mite Respiratory Allergic Disease

DEFF Research Database (Denmark)

Emminger, Waltraud; Hernández, María Dolores; Cardona, Victòria

2017-01-01

BACKGROUND: The SQ house dust mite (HDM) SLIT-tablet (ALK, Denmark) addresses the underlying cause of HDM respiratory allergic disease, and a clinical effect has been demonstrated for both HDM allergic rhinitis and allergic asthma. Here, we present pooled safety data from an adult population with...

Immunoinformatics and Similarity Analysis of House Dust Mite Tropomyosin

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Mohammad Mehdi Ranjbar

2015-10-01

Full Text Available Background: Dermatophagoides farinae and Dermatophagoides pteronyssinus are house dust mites (HDM that they cause severe asthma and allergic symptoms. Tropomyosin protein plays an important role in mentioned immune and allergic reactions to HDMs. Here, tropomyosin protein from Dermatophagoides spp. was comprehensively screened in silico for its allergenicity, antigenicity and similarity/conservation.Materials and Methods: The amino acid sequences of D. farinae tropomyosin, D. pteronyssinus and other mites were retrieved. We included alignments and evaluated conserved/ variable regions along sequences, constructed their phylogenetic tree and estimated overall mean distances. Then, followed by with prediction of linear B-cell epitope based on different approaches, and besides in-silico evaluation of IgE epitopes allergenicity (by SVMc, IgE epitope, ARPs BLAST, MAST and hybrid method. Finally, comparative analysis of results by different approaches was made.Results: Alignment results revealed near complete identity between D. farina and D. pteronyssinus members, and also there was close similarity among Dermatophagoides spp. Most of the variations among mites' tropomyosin were approximately located at amino acids 23 to 80, 108 to 120, 142 to 153 and 220 to 230. Topology of tree showed close relationships among mites in tropomyosin protein sequence, although their sequences in D. farina, D. pteronyssinus and Psoroptes ovis are more similar to each other and clustered. Dermanyssus gallinae (AC: Q2WBI0 has less relationship to other mites, being located in a separate branch. Hydrophilicity and flexibility plots revealed that many parts of this protein have potential to be hydrophilic and flexible. Surface accessibility represented 7 different epitopes. Beta-turns in this protein are with high probability in the middle part and its two terminals. Kolaskar and Tongaonkar method analysis represented 11 immunogenic epitopes between amino acids 7-16. From

Ex-ante analysis of economic returns from biological control of coconut mite in Tanzania

NARCIS (Netherlands)

Oleke, J.M.; Manyong, V.; Mignouna, D.; Isinika, A.; Mutabazi, K.; Hanna, R.; Sabelis, M.

2013-01-01

The coconut mite, Aceria guerreronis Keifer, has been identified as one of the pests that pose a threat to the coconut industry in Benin. The study presents the simulation results of the economic benefits of the biological control of coconut mites in Benin using a standard economic surplus model. In

Isolation and sequence characterization of DNA-A genome of a new begomovirus strain associated with severe leaf curling symptoms of Jatropha curcas L.

KAUST Repository

Chauhan, Sushma; Rahman, Hifzur; Mastan, Shaik G.; Sudheer, Pamidimarri D.V.N.; Reddy, Muppala P.

2018-01-01

Begomoviruses belong to the family Geminiviridae are associated with several disease symptoms, such as mosaic and leaf curling in Jatropha curcas. The molecular characterization of these viral strains will help in developing management strategies

Ectoparasites of medical and veterinary importance: drug resistance and the need for alternative control methods.

Science.gov (United States)

McNair, Carol M

2015-03-01

Despite multiple attempts at eradication, many ectoparasites of humans and domestic livestock remain a persistent problem in the modern world. For many years, a range of pesticide drugs including organophosphates, organochlorides and synthetic pyrethroids provided effective control of these parasites; but intensive use of these drugs has led to the evolution of resistance in many target species. This paper aims to review the effectiveness of current control methods and discuss potential alternatives for the long term sustainable control of ectoparasites. Important medical ectoparasites such as scabies mites, head lice and bed bugs present a significant public health problem, and so adequate control methods are essential. Ectoparasites of domestic livestock and farmed fish (for example sheep scab mites, poultry mites and sea lice) are also of concern given the increasing strain on the world's food supply. These parasites have become resistant to several classes of pesticide, making control very difficult. Recently, an increasing amount of research has focussed on alternative control methods such as insect growth regulators, biological control using essential oils or fungi, as well as vaccine development against some ectoparasites of medical and veterinary importance. Drug resistance is prevalent in all of the ectoparasites discussed in this review. A wide variety of alternative control methods have been identified, however further research is necessary in order for these to be used to successfully control ectoparasitic diseases in the future. © 2015 Royal Pharmaceutical Society.

[Investigation on Cheyletoidea mites breeding in culture environment of Eupolyphaga sinensis and morphologic observation of Eucheyletia reticulate Cunliffe].

Science.gov (United States)

Ning, Tao; Wei, Guo; Shao-Sheng, Wang; Chao-Pin, Li

2016-01-27

To investigate the species of Cheyletoidea mites breeding in the culture environment of Eupolyphaga sinensis and to observe the morphology of Eucheyletia reticulata Cunliffe. The soil samples from an E. sinensis farm in northern Anhui were collected. The mites in the soil samples were separated directly under a microscope and the glass specimens were made to observe the morphological feature of the mites under a light microscope, then the mites species were identified and classified based on the morphological characteristics. In the culture soil of E. sinensis , totally 7 kinds of Cheyletoidea mites were isolated, namely Eucheyletia reticulata Cunliffe, Cheyletus eruditus Schrank, Cheyletus malaccensis Oudemans, Cheyletus troussarti Oudemans, Cheyletus aveisor Rohdendorz, Acaropsis sollers Rohdendorz and Cheletomorpha lepidopterorum Shaw. They belonged to genera Eucheyletia , Cheletomorpha , Acaropsis and Cheyletus of Cheyletidae Leach family. The Eucheyletia reticulata Cunliffe was firstly found in the culture environment of E. sinensis , and its gnathosoma was large, the pedipalpal femurs were expanding and there were two strips of comb hair and two smooth bristles on the pedipalpal tarsus, and the back of the body was covered with two pieces of tergum, which were decorated with reticular pattern. The body and foot setae were fan-shape. There are various of Cheyletoidea mites found in the breeding environment of E. sinensis . These mites are important species for pest control in the culture environments of E. sinensis . Related measures should be taken to prevent the excessive growth of Cheyletoidea mites, so as to avoid the adverse effects on the quality and quantity of E. sinensis .

ACTIVITY OF SOME BRAZILIAN ISOLATES OF ENTOMOPATHOGENIC FUNGI AGAINST THE POULTRY RED MITE DERMANYSSUS GALLINAE DE GEER (ACARI: DERMANYSSIDAE

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CR Kasburg

Full Text Available ABSTRACT Poultry red mite Dermanyssus gallinae is a cosmopolitan and hematophagous species commonly found in layer houses around the world. Poultry mite infestations may cause anemia, stress, low body weight and egg production, and mortality. Mite control is typically based on chemical products, but they are not effective and leave residues in eggs; therefore, alternative control methods, such as entomopathogenic fungi, need to researched. This study aimed at evaluating, in the laboratory, the activity of Brazilian isolates of entomopathogenic fungi against D. gallinae. The mites were collected from a commercial layer house and were sprayed with conidial suspensions (1 × 108 conidia/mL of five isolates of Beauveria bassiana and Metarhizium anisopliae. All tested isolates were pathogenic for the red mite, with confirmed mortality ranging from 22.9 to 52.4%. This demonstrate the potential of the tested entomopathogenic fungi isolates for mite control, and reinforces the need for further studies with other isolates, application strategies, and with fungal formulations.

Real-time PCR protocols for the quantification of the begomovirus tomato yellow leaf curl Sardinia virus in tomato plants and in its insect vector.

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Noris, Emanuela; Miozzi, Laura

2015-01-01

Tomato yellow leaf curl Sardinia virus (TYLCSV) (Geminiviridae) is an important pathogen, transmitted by the whitefly Bemisia tabaci, that severely affects the tomato production in the Mediterranean basin. Here, we describe real-time PCR protocols suitable for relative and absolute quantification of TYLCSV in tomato plants and in whitefly extracts. Using primers and probe specifically designed for TYLCSV, the protocols for relative quantification allow to compare the amount of TYLCSV present in different plant or whitefly samples, normalized to the amount of DNA present in each sample using endogenous tomato or Bemisia genes as internal references. The absolute quantification protocol allows to calculate the number of genomic units of TYLCSV over the genomic units of the plant host (tomato), with a sensitivity of as few as ten viral genome copies per sample. The described protocols are potentially suitable for several applications, such as plant breeding for resistance, analysis of virus replication, and virus-vector interaction studies.

Citrus leprosis transmission by Brevipalpus yothersi mites through non citrus hosts

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Guillermo León M.

2017-05-01

Full Text Available Citrus leprosis virus (C i LV was detected in Colombia at the eastern plains in 2004; it is a threat the disease spreads to other regions of the country. The main vector is Brevipalpus yothersi Baker (formerly identified as Brevipalpus phoenicis. This research determined the viability of B. yothersi to transmit C i LV to citrus plants, after been hosted in non-citrus plants. To virus acquisition, mites spent three days on symptomatic orange (Citrus x sinensis leaves positives to C i LV-C2; then mites were placed on six non-citrus plants (Dieffenbachia sp., Hibiscus rosa-sinensis,Codiaeum variegatum, Swinglea glutinosa, Sida acutaand Stachytarpheta cayennensis. A randomized design with 6 treatments and 4 replicates was carried out. After scheduled time in non-citrus plants, mites were three days relocated on C. x sinensis healthy plants. Leaves of receptor plants, were evaluated to the occurrence or absence of symptoms and collected for RT-PCR tests. B. yothersi mites were able to transmit the C i LV virus over 85 % of Valencia orange plants (Citrus x sinensis L., after feeding from 2-20 days on non-citrus host plants. The first leprosis symptoms on C. x sinensis leaves was confirmed from 14 to 51 days after transmission. The present research work further established that C i LV-C2 is a persistently transmitted virus. The implement quarantine diagnostic measures to prevent spread of CiLV to disease-free zones is suggested.

Spatial distribution of phytophagous mites (Aca ri: Tetranychidae) on strawberry plants

International Nuclear Information System (INIS)

Fadini, Marcos A.M.; Venzon, Madelaine; Oliveira, Hamilton G.; Pallini, Angelo; Vilela, Evaldo F.

2007-01-01

Many phytophagous mites can attack strawberry plants, Fragaria x ananassa, among them the southern red mite, Oligonychus ilicis McGregor, and the two-spotted spider mite, Tetranychus urticae Koch. They are found together feeding on the same plant on the upper and underside of the leaves, respectively. Here we studied the choice for feeding sites of O. ilicis and T. urticae on strawberry plants. The first hypothesis tested whether the feeding site choice would be related to the fitness of the species. The second hypothesis dealt whether the feeding site would be determined by the presence of a heterospecific mite. We evaluated the preference, biology and reproductive success of O. ilicis and T. urticae on the under and upper side surface of strawberry leaves infested or not by the heterospecific. O. ilicis preferred to stay on the upper side surface while T. urticae preferred the underside. The preference for the leaf surface correlated with the reproductive success of the species (measured by the intrinsic growth rate). The choice pattern of feeding sites did not alter when the choice test was applied using sites previously infested by heterospecific. Although O. ilicis and T. urticae, apparently, do not interact directly for feeding sites, there is a chance that the first species induces defenses in strawberry plant enabling to reduce the fitness of the second species. The possibility of those species stay together on strawberry plant increases the damage capacity to the culture. (author)

A rapid method to assess grape rust mites on leaves and observations from case studies in western Oregon vineyards

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A rapid method for extracting eriophyoid mites was adapted from previous studies to provide growers and IPM consultants with a practical, efficient, and reliable tool to monitor for rust mites in vineyards. The rinse in bag (RIB) method allows quick extraction of mites from collected plant parts (sh...

Varroa Sensitive Hygiene contributes to naturally selected varroa resistance in honey bees

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Panziera, Delphine; Langevelde, van Frank; Blacquière, Tjeerd

2017-01-01

The parasitic mite Varroa destructor is a serious threat for western honey bee colonies and beekeepers are compelled to control it to keep their colonies healthy. Yet, by controlling varroa no resistance to the parasite can evolve. As a trial, honey bee colonies have been left untreated in

Concepto de límite funcional : aprendizaje y memoria

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Tomás Ortega del Rincón

2013-05-01

Full Text Available El presente artículo forma parte de un proyecto de investigación sobre el concepto de límite funcional en el que se viene trabajando desde hace varios años. En este caso, se contrasta si la noción de límite ligada a la definición métrica perdura en la memoria de los alumnos más que la definición como aproximación óptima dada por Blázquez y Ortega en 2002. Se trata de un estudio empírico realizado con alumnos de Ingeniería de la Universidad Nacional de San Luis (Argentina, que en cursos anteriores habían estudiado ambas conceptualizaciones.

Free living astigmatid mites (Astigmatina): new taxa, rearing and use for mesostigmatid (Mesostigmata) predatory mite production

OpenAIRE

Marina Ferraz de Camargo Barbosa

2016-01-01

The cohort Astigmatina is divided in two major groups: Psoroptidia, composed mainly by feather and fur mites, and Non-psoroptidia, a dominant component of the acarofauna in ephemeral habitats. In these environments Astigmatina usually are saprophages or feed on fungi or bacteria. Astigmatina protonymphs undergo a complete reorganization of the body structure leading to the production of heteromorphic deutonymphs, generally specialized for dispersion through phoresy using arthropods and verteb...

Preventing Severe Asthma Exacerbations in Children. A Randomized Trial of Mite-Impermeable Bedcovers.

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Murray, Clare S; Foden, Philip; Sumner, Helen; Shepley, Elizabeth; Custovic, Adnan; Simpson, Angela

2017-07-15

Allergen exposure in sensitized individuals with asthma interacts with viruses to increase the risk of asthma exacerbation. To evaluate the use of house dust mite-impermeable bedding and its impact on severe asthma exacerbations in children. We randomized mite-sensitized children with asthma (ages 3-17 yr) after an emergency hospital attendance with an asthma exacerbation to receive mite-impermeable (active group) or control (placebo group) bed encasings. Over a 12-month intervention period, the occurrence of severe asthma exacerbations was investigated. Of 434 children with asthma who consented, 286 (mean age, 7.7 yr; male sex, 65.8%) were mite sensitized, and 284 were randomized (146 to the active group and 138 to the placebo group). At 12 months, significantly fewer children in the active group than in the placebo group had attended the hospital with an exacerbation (36 [29.3%] of 123 vs. 49 [41.5%] of 118; P = 0.047). In the multivariable analysis, the risk of emergency hospital attendance was 45% lower in the active group (hazard ratio, 0.55; 95% confidence interval [CI], 0.36-0.85; P = 0.006) than in the placebo group. The annual rate of emergency hospital attendance with exacerbations was 27% lower in the active group than in the placebo group, but this did not reach significance (estimated marginal mean [95% CI], active, 0.38 [0.26-0.56] vs. placebo, 0.52 [0.35-0.76]; P = 0.18). No difference between the groups in the risk of prednisolone use for exacerbation was found (hazard ratio, 0.82; 95% CI, 0.58-1.17; P = 0.28). Mite-impermeable encasings are effective in reducing the number of mite-sensitized children with asthma attending the hospital with asthma exacerbations but not the number requiring oral prednisolone. This simple measure may reduce the health care burden of asthma exacerbations in children. Clinical trial registered with www.isrctn.com (ISRCTN 69543196).

Phenomenon of Rickettsiella phytoseiuli in Phytoseiulus persimilis mite.

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Sutáková, G

1994-01-01

An unknown microorganism occurring in a predaceous mite Phytoseiulus persimilis was described by the author in 1977 as a new species Rickettsiella phytoseiuli. Some new results on the relation between this agent and its hosts are presented in this paper.

The underlying processes of a soil mite metacommunity on a small scale

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Guo, Chuanwei; Lin, Lin; Wu, Donghui; Zhang, Limin

2017-01-01

Metacommunity theory provides an understanding of how ecological processes regulate local community assemblies. However, few field studies have evaluated the underlying mechanisms of a metacommunity on a small scale through revealing the relative roles of spatial and environmental filtering in structuring local community composition. Based on a spatially explicit sampling design in 2012 and 2013, this study aims to evaluate the underlying processes of a soil mite metacommunity on a small spatial scale (50 m) in a temperate deciduous forest located at the Maoershan Ecosystem Research Station, Northeast China. Moran’s eigenvector maps (MEMs) were used to model independent spatial variables. The relative importance of spatial (including trend variables, i.e., geographical coordinates, and broad- and fine-scale spatial variables) and environmental factors in driving the soil mite metacommunity was determined by variation partitioning. Mantel and partial Mantel tests and a redundancy analysis (RDA) were also used to identify the relative contributions of spatial and environmental variables. The results of variation partitioning suggested that the relatively large and significant variance was a result of spatial variables (including broad- and fine-scale spatial variables and trend), indicating the importance of dispersal limitation and autocorrelation processes. The significant contribution of environmental variables was detected in 2012 based on a partial Mantel test, and soil moisture and soil organic matter were especially important for the soil mite metacommunity composition in both years. The study suggested that the soil mite metacommunity was primarily regulated by dispersal limitation due to broad-scale and neutral biotic processes at a fine-scale and that environmental filtering might be of subordinate importance. In conclusion, a combination of metacommunity perspectives between neutral and species sorting theories was suggested to be important in the

The underlying processes of a soil mite metacommunity on a small scale.

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Chengxu Dong

Full Text Available Metacommunity theory provides an understanding of how ecological processes regulate local community assemblies. However, few field studies have evaluated the underlying mechanisms of a metacommunity on a small scale through revealing the relative roles of spatial and environmental filtering in structuring local community composition. Based on a spatially explicit sampling design in 2012 and 2013, this study aims to evaluate the underlying processes of a soil mite metacommunity on a small spatial scale (50 m in a temperate deciduous forest located at the Maoershan Ecosystem Research Station, Northeast China. Moran's eigenvector maps (MEMs were used to model independent spatial variables. The relative importance of spatial (including trend variables, i.e., geographical coordinates, and broad- and fine-scale spatial variables and environmental factors in driving the soil mite metacommunity was determined by variation partitioning. Mantel and partial Mantel tests and a redundancy analysis (RDA were also used to identify the relative contributions of spatial and environmental variables. The results of variation partitioning suggested that the relatively large and significant variance was a result of spatial variables (including broad- and fine-scale spatial variables and trend, indicating the importance of dispersal limitation and autocorrelation processes. The significant contribution of environmental variables was detected in 2012 based on a partial Mantel test, and soil moisture and soil organic matter were especially important for the soil mite metacommunity composition in both years. The study suggested that the soil mite metacommunity was primarily regulated by dispersal limitation due to broad-scale and neutral biotic processes at a fine-scale and that environmental filtering might be of subordinate importance. In conclusion, a combination of metacommunity perspectives between neutral and species sorting theories was suggested to be important

Draft genome of the honey bee ectoparasitic mite, Tropilaelaps mercedesae, is shaped by the parasitic life history

OpenAIRE

Dong, Xiaofeng; Armstrong, Stuart D.; Xia, Dong; Makepeace, Benjamin L.; Darby, Alistair C.; Kadowaki, Tatsuhiko

2017-01-01

Abstract The number of managed honey bee colonies has considerably decreased in many developed countries in recent years and ectoparasitic mites are considered as major threats to honey bee colonies and health. However, their general biology remains poorly understood. We sequenced the genome of Tropilaelaps mercedesae, the prevalent ectoparasitic mite infesting honey bees in Asia, and predicted 15?190 protein-coding genes that were well supported by the mite transcriptomes and proteomic data....

Vitamin A deficiency modifies response of predatory mite Amblyseius potentillae to volatile kairomone of two-spotted spider mite, Tetranychus urticae.

NARCIS (Netherlands)

Dicke, M.; Sabelis, M.W.; Groeneveld, A.

1986-01-01

volatile kairomone of the two-spotted spider mite,Tetranychus urticae, elicits a searching response of the phytoseiid predatorAmblyseius potentillae, only when the predator is reared on a carotenoid-free diet. However, after addition of crystalline betta-carotene or vitamin A acetate to the

Predatory Mite Attraction to Herbivore-induced Plant Odors is not a Consequence of Attraction to Individual Herbivore-induced Plant Volatiles

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De Bruijn, Paulien J. A.; Sabelis, Maurice W.

2008-01-01

Predatory mites locate herbivorous mites, their prey, by the aid of herbivore-induced plant volatiles (HIPV). These HIPV differ with plant and/or herbivore species, and it is not well understood how predators cope with this variation. We hypothesized that predators are attracted to specific compounds in HIPV, and that they can identify these compounds in odor mixtures not previously experienced. To test this, we assessed the olfactory response of Phytoseiulus persimilis, a predatory mite that preys on the highly polyphagous herbivore Tetranychus urticae. The responses of the predatory mite to a dilution series of each of 30 structurally different compounds were tested. They mites responded to most of these compounds, but usually in an aversive way. Individual HIPV were no more attractive (or less repellent) than out-group compounds, i.e., volatiles not induced in plants fed upon by spider-mites. Only three samples were significantly attractive to the mites: octan-1-ol, not involved in indirect defense, and cis-3-hexen-1-ol and methyl salicylate, which are both induced by herbivory, but not specific for the herbivore that infests the plant. Attraction to individual compounds was low compared to the full HIPV blend from Lima bean. These results indicate that individual HIPV have no a priori meaning to the mites. Hence, there is no reason why they could profit from an ability to identify individual compounds in odor mixtures. Subsequent experiments confirmed that naive predatory mites do not prefer tomato HIPV, which included the attractive compound methyl salicylate, over the odor of an uninfested bean. However, upon associating each of these odors with food over a period of 15 min, both are preferred. The memory to this association wanes within 24 hr. We conclude that P. persimilis possesses a limited ability to identify individual spider mite-induced plant volatiles in odor mixtures. We suggest that predatory mites instead learn to respond to prey

Spatial distribution patterns of soil mite communities and their relationships with edaphic factors in a 30-year tillage cornfield in northeast China.

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Liu, Jie; Gao, Meixiang; Liu, Jinwen; Guo, Yuxi; Liu, Dong; Zhu, Xinyu; Wu, Donghui

2018-01-01

Spatial distribution is an important topic in community ecology and a key to understanding the structure and dynamics of populations and communities. However, the available information related to the spatial patterns of soil mite communities in long-term tillage agroecosystems remains insufficient. In this study, we examined the spatial patterns of soil mite communities to explain the spatial relationships between soil mite communities and soil parameters. Soil fauna were sampled three times (August, September and October 2015) at 121 locations arranged regularly within a 400 m × 400 m monitoring plot. Additionally, we estimated the physical and chemical parameters of the same sampling locations. The distribution patterns of the soil mite community and the edaphic parameters were analyzed using a range of geostatistical tools. Moran's I coefficient showed that, during each sampling period, the total abundance of the soil mite communities and the abundance of the dominant mite populations were spatially autocorrelated. The soil mite communities demonstrated clear patchy distribution patterns within the study plot. These patterns were sampling period-specific. Cross-semivariograms showed both negative and positive cross-correlations between soil mite communities and environmental factors. Mantel tests showed a significant and positive relationship between soil mite community and soil organic matter and soil pH only in August. This study demonstrated that in the cornfield, the soil mite distribution exhibited strong or moderate spatial dependence, and the mites formed patches with sizes less than one hundred meters. In addition, in this long-term tillage agroecosystem, soil factors had less influence on the observed pattern of soil mite communities. Further experiments that take into account human activity and spatial factors should be performed to study the factors that drive the spatial distribution of soil microarthropods.

Patterns of infestation by the trombiculid mite Eutrombicula alfreddugesi in four sympatric lizard species (genus Tropidurus) in northeastern Brazil.

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Rocha, C F D; Cunha-Barros, M; Menezes, V A; Fontes, A f; Vrcibradic, D; Van Sluys, M

2008-06-01

We studied the parasitism by the chigger mite Eutrombicula alfreddugesi on four sympatric lizard species of the genus Tropidurus in Morro do Chapéu, Bahia state, Brazil: T. hispidus, T. cocorobensis, T. semitaeniatus and T. erythrocephalus. For each species, we investigated the patterns of infestation and analyzed to which extent they varied among the hosts. We calculated the spatial niche breadth of the chigger mite on the body of each host species and the distribution of mites along the hosts' bodies for each Tropidurus species. All four species of Tropidurus at Morro do Chapéu were parasited by the chigger mite, with high (97-100%) prevalences. Host body size significantly explained the intensity of mite infestation for all species, except T. erythrocephalus. The body regions with highest intensity of infestation in the four lizard species were the mite pockets. The spacial niche width of the chigger varied consistently among the four lizards species studied being highest for T. erytrocephalus and lowest for T. cocorobensis. We conclude that the distribution and intensity with which lizards of the genus Tropidurus are infested by Eutrombicula alfreddugesi larvae results from the interaction between aspects of host morphology (such as body size and the occurrence and distribution of mite pockets) and ecology (especially microhabitat use).

Patterns of infestation by the trombiculid mite Eutrombicula alfreddugesi in four sympatric lizard species (genus Tropidurus in northeastern Brazil

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Rocha C.F.D.

2008-06-01

Full Text Available We studied the parasitism by the chigger mite Eutrombicula alfreddugesi on four sympatric lizard species of the genus Tropidurus in Morro do Chapéu, Bahia state, Brazil: T. hispidus, T. cocorobensis, T. semitaeniatus and T. erythrocephalus. For each species, we investigated the patterns of infestation and analyzed to which extent they varied among the hosts. We calculated the spatial niche breadth of the chigger mite on the body of each host species and the distribution of mites along the hosts’ bodies for each Tropidurus species. All four species of Tropidurus at Morro do Chapéu were parasited by the chigger mite, with high (97-100% prevalences. Host body size significantly explained the intensity of mite infestation for all species, except T. erythrocephalus. The body regions with highest intensity of infestation in the four lizard species were the mite pockets. The spacial niche width of the chigger varied consistently among the four lizards species studied being highest for T. erytrocephalus and lowest for T. cocorobensis. We conclude that the distribution and intensity with which lizards of the genus Tropidurus are infested by Eutrombicula alfreddugesi larvae results from the interaction between aspects of host morphology (such as body size and the occurrence and distribution of mite pockets and ecology (especially microhabitat use.

Detection, Prevalence and Phylogenetic Relationships of Demodex spp and further Skin Prostigmata Mites (Acari, Arachnida) in Wild and Domestic Mammals.

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Sastre, Natalia; Francino, Olga; Curti, Joseph N; Armenta, Tiffany C; Fraser, Devaughn L; Kelly, Rochelle M; Hunt, Erin; Silbermayr, Katja; Zewe, Christine; Sánchez, Armand; Ferrer, Lluís

2016-01-01

This study was conceived to detect skin mites in social mammals through real-time qPCR, and to estimate taxonomic Demodex and further Prostigmata mite relationships in different host species by comparing sequences from two genes: mitochondrial 16S rRNA and nuclear 18S rRNA. We determined the mite prevalence in the hair follicles of marmots (13%) and bats (17%). The high prevalence found in marmots and bats by sampling only one site on the body may indicate that mites are common inhabitants of their skin. Since we found three different mites (Neuchelacheles sp, Myobia sp and Penthaleus sp) in three bat species (Miotis yumanensis, Miotis californicus and Corynorhinus townsendii) and two different mites (both inferred to be members of the Prostigmata order) in one marmot species (Marmota flaviventris), we tentatively concluded that these skin mites 1) cannot be assigned to the same genus based only on a common host, and 2) seem to evolve according to the specific habitat and/or specific hair and sebaceous gland of the mammalian host. Moreover, two M. yumanensis bats harbored identical Neuchelacheles mites, indicating the possibility of interspecific cross-infection within a colony. However, some skin mites species are less restricted by host species than previously thought. Specifically, Demodex canis seems to be more transmissible across species than other skin mites. D. canis have been found mostly in dogs but also in cats and captive bats. In addition, we report the first case of D. canis infestation in a domestic ferret (Mustela putorius). All these mammalian hosts are related to human activities, and D. canis evolution may be a consequence of this relationship. The monophyletic Demodex clade showing closely related dog and human Demodex sequences also supports this likely hypothesis.

Detection, Prevalence and Phylogenetic Relationships of Demodex spp and further Skin Prostigmata Mites (Acari, Arachnida in Wild and Domestic Mammals.

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Natalia Sastre

Full Text Available This study was conceived to detect skin mites in social mammals through real-time qPCR, and to estimate taxonomic Demodex and further Prostigmata mite relationships in different host species by comparing sequences from two genes: mitochondrial 16S rRNA and nuclear 18S rRNA. We determined the mite prevalence in the hair follicles of marmots (13% and bats (17%. The high prevalence found in marmots and bats by sampling only one site on the body may indicate that mites are common inhabitants of their skin. Since we found three different mites (Neuchelacheles sp, Myobia sp and Penthaleus sp in three bat species (Miotis yumanensis, Miotis californicus and Corynorhinus townsendii and two different mites (both inferred to be members of the Prostigmata order in one marmot species (Marmota flaviventris, we tentatively concluded that these skin mites 1 cannot be assigned to the same genus based only on a common host, and 2 seem to evolve according to the specific habitat and/or specific hair and sebaceous gland of the mammalian host. Moreover, two M. yumanensis bats harbored identical Neuchelacheles mites, indicating the possibility of interspecific cross-infection within a colony. However, some skin mites species are less restricted by host species than previously thought. Specifically, Demodex canis seems to be more transmissible across species than other skin mites. D. canis have been found mostly in dogs but also in cats and captive bats. In addition, we report the first case of D. canis infestation in a domestic ferret (Mustela putorius. All these mammalian hosts are related to human activities, and D. canis evolution may be a consequence of this relationship. The monophyletic Demodex clade showing closely related dog and human Demodex sequences also supports this likely hypothesis.

Mites fluctuation population on peach tree (Prunus persica (L. Batsch and in associated plants

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Carla Rosana Eichelberger

2011-09-01

Full Text Available Despite the importance of peach (Prunus persica (L. Batsch in Rio Grande do Sul, little is known about mites fluctuation population considered important to this crop. The objective of this study was to know the population diversity and fluctuation of mite species associated with Premier and Eldorado varieties in Roca Sales and Venâncio Aires counties, Rio Grande do Sul. The study was conducted from July 2008 to June 2009 when 15 plants were randomly chosen in each area. The plants were divided in quadrants and from each one a branch was chosen from which three leaves were removed: one collected in the apical region, another in the medium and the other in the basal region, totalizing 180 leaves/area. Five of the most abundant associated plants were collected monthly in enough amounts for the screening under the stereoscopic microscope during an hour. A total of 1,124 mites were found belonging to 14 families and 28 species. Tetranychus ludeni Zacher, 1913, Panonychus ulmi (Koch, 1836 and Mononychellus planki (McGregor, 1950 were the most abundant phytophagous mites, whereas Typhlodromalus aripo Deleon, 1967 and Phytoseiulus macropilis (Banks, 1904 the most common predatory mites. The period of one hour under stereoscopic microscope was enough to get a representative sample. In both places evaluated the ecologic indices were low, but little higherin Premier (H' 0.56; EqJ: 0.43 when compared to Eldorado (H' 0.53; EqJ 0.40. In Premier constant species were not observed and accessory only Brevipalpus phoenicis (Geijskes, 1939, T. ludeni and T. aripo. Higher abundance was observed in December and January and bigger amount in April. Already in Eldorado, T. ludeni and P. ulmi were constants. Greater abundance was observed in November and December, whereas grater richness in December and January. In both orchards were not found mites in buds. Tetranychus ludeni is the most abundant phytophagous mites with outbreak population in November, December and

Phytoseiid mites from tropical fruit trees in Bahia State, Brazil (Acari, Phytoseiidae).

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de Souza, Izabel Vieira; Sá Argolo, Poliane; Júnior, Manoel Guedes Correa Gondim; de Moraes, Gilberto José; Bittencourt, Maria Aparecida Leão; Oliveira, Anibal Ramadan

2015-01-01

The cultivation of tropical fruit trees has grown considerably in the state of Bahia, northeastern Brazil. Some of these have been severely attacked by phytophagous mites, which are usually controlled by the use of chemical pesticides. However, there is today a growing interest for the adoption of less aggressive measures of pest control, as for example the use of predatory mites. Most of the plant-inhabiting predatory mites belong to the family Phytoseiidae. The objective of this paper is to report the phytoseiid species found in an intensive survey conducted on cultivated tropical fruit trees in fifteen localities of the southern coast of Bahia. Measurements of relevant morphological characters are provided for each species, to complement the understanding of the morphological variation of these species. Twenty-nine species of sixteen genera were identified. A key was elaborated to assist in the separation of these species. Fifteen species are reported for the first time in the state, raising to sixty-six the number of species of this family now known from Bahia. Seventy-two percent of the species collected belong to Amblyseiinae, followed by Typhlodrominae (21%) and Phytoseiinae (7%). The most diverse genus was Amblyseius. Amblyseius operculatus De Leon was the most frequent and abundant species. Studies should be conducted to evaluate the possible role of the most common predators as control agents of the phytophagous mites co-occurring with them.

[Efficacy of the dust mites drops sublingual immunotherapy in pediatric allergic rhinitis].

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Xie, Lisheng; Jiang, Yinzhu; Li, Qi

2016-03-01

To observe the role of the dust mites drops sublingual immunotherapy(SLIT) in pediatric allergic rhiriitis caused by dust mites and compare its efficacy between monosensitized and polysensitized children. A total of 77 pediatric allergic rhinitis patients received Dermatophagoides farina extracts sublingual immunotherapy for 2 years were enrolled as desensitization group and were allocated into monosensitized group (41 cases) and polysensitized group (36 cases) according to the number of coexisting allergens. Meanwhile another 33 allergic rhinitis children treated by pharmacotherapy during the period were collected as control group. The total symptom scores (TNSS), total medication scores (TMS) and visual analogue scale(VAS) were assessed at the beginning, six months, 1 year and 2 years of the treatment. SPSS 13. 0 software was used to analyze the data. the score of TNSS and VAS in desensitization was slightly higher than the control after six months treatment, but without difference at l year and 2 years; the score of TMS had significantly improved in desensitization compared with the corresponding points in control. All the parameters in monosensitized group were equivalent with polysensitizend group, except the score of TMS was slightly lower than the polysensitizend group at six months. Dust mite drops sublingual immunotherapy is effective for the allergic rhinitis children caused by mites. And it has similar immunotherapy efficacy between monosensitized and polysensitized children.

Within-host dynamics of the emergence of Tomato yellow leaf curl virus recombinants.

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Cica Urbino

Full Text Available Tomato yellow leaf curl virus (TYLCV is a highly damaging begomovirus native to the Middle East. TYLCV has recently spread worldwide, recombining with other begomoviruses. Recent analysis of mixed infections between TYLCV and Tomato leaf curl Comoros begomovirus (ToLCKMV has shown that, although natural selection preserves certain co-evolved intra-genomic interactions, numerous and diverse recombinants are produced at 120 days post-inoculation (dpi, and recombinant populations from different tomato plants are very divergent. Here, we investigate the population dynamics that lead to such patterns in tomato plants co-infected with TYLCV and ToLCKMV either by agro-inoculation or using the natural whitefly vector Bemisia tabaci. We monitored the frequency of parental and recombinant genotypes independently in 35 plants between 18 and 330 dpi and identified 177 recombinants isolated at different times. Recombinants were detected from 18 dpi and their frequency increased over time to reach about 50% at 150 dpi regardless of the inoculation method. The distribution of breakpoints detected on 96 fully sequenced recombinants was consistent with a continuous generation of new recombinants as well as random and deterministic effects in their maintenance. A severe population bottleneck of around 10 genomes was estimated during early systemic infection-a phenomenon that could account partially for the heterogeneity in recombinant patterns observed among plants. The detection of the same recombinant genome in six of the thirteen plants analysed beyond 30 dpi supported the influence of selection on observed recombination patterns. Moreover, a highly virulent recombinant genotype dominating virus populations within one plant has, apparently, the potential to be maintained in the natural population according to its infectivity, within-host accumulation, and transmission efficiency - all of which were similar or intermediate to those of the parent genotypes. Our

Predatory mites avoid ovipositing near counter-attacking prey

NARCIS (Netherlands)

Faraji, F.; Janssen, A.; Sabelis, M.W.

2001-01-01

Attacking prey is not without risk; predators may endure counterattackby the prey. Here, we study the oviposition behaviour of a predatory mite(Iphiseius degenerans) in relation to its prey, thewesternflower thrips (Frankliniella occidentalis). This thrips iscapable of killing the eggs of the

Comparative morphological analysis of apple blister mite, Eriophyes mali Nal., a new pest in Serbia

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Biljana Vidović

2014-06-01

Full Text Available The apple blister mite, Eriophyes mali Nalepa, 1926 (Acari: Prostigmata: Eriophyoidea, has been recently found in Serbia as a new pest of apple. The history of its research, the results of a morphological analysis and degree of infestation are presented. A comparison of the main morphological features of mites from different populations of remote geographical origin has shown that the apple blister mite from Serbia is most similar to another European population (Bulgarian [or Austrian?] while it differs from E. mali originating from the USA and New Zealand. The percentage of infestation varied from 1.6% to 87.6%, with an average of 22.4%.

Origins of asexuality in Bryobia mites (Acari: Tetranychidae)

NARCIS (Netherlands)

Ros, V.I.D.; Breeuwer, J.A.J.; Menken, S.B.J.

2008-01-01

Background Obligate asexual reproduction is rare in the animal kingdom. Generally, asexuals are considered evolutionary dead ends that are unable to radiate. The phytophagous mite genus Bryobia contains a large number of asexual species. In this study, we investigate the origin and evolution of

Varroa destructor virus 1: a new picorna-like virus in Varroa mites as well as honey bees

OpenAIRE

Ongus, J.R.

2006-01-01

Varroa destructor mite is an ectoparasite of the honey bee Apis mellifera. This species was recently differentiated from Varroa jacobsoni species which infests the Asian bee Apis cerana. Varroa mites feed entirely on the bee's haemolymph and have been associated with the spread of a number of viruses. Since the mites were first observed in Java, Indonesia in 1904, they have been reported in most regions of the world except Australia and the equatorial regions of Africa. V. destructor severely...

The role of methyl salicylate in prey searching behavior of the predatory mite phytoseiulus persimilis.

Science.gov (United States)

De Boer, Jetske G; Dicke, Marcel

2004-02-01

Many carnivorous arthropods use herbivore-induced plant volatiles to locate their prey. These plant volatiles are blends of up to hundreds of compounds. It is often unknown which compounds in such a complex volatile blend represent the signal to the foraging carnivore. We studied the role of methyl salicylate (MeSA) as part of the volatile blend in the foraging behavior of the predatory mite Phytoseiulus persimilis by using a Y-tube olfactometer. MeSA is one of the compounds released by lima bean, infested with Tetranychus urticae--a prey species of the predatory mite. MeSA attracted satiated predatory mites in a dose-dependent way with optimum attraction at a dose of 0.2 microg. Predatory mites did not discriminate between a prey-induced lima bean volatile blend (that contains MeSA) and a prey-induced volatile blend to which an extra amount of synthetic MeSA had been added. However, they preferred a MeSA-containing volatile blend (induced by T. urticae) to an otherwise similar but MeSA-free blend (induced by jasmonic acid). Adding synthetic MeSA to the MeSA-free blend significantly increased the mites' choice for this odor, suggesting an important role for MeSA. This study is a new step toward unraveling the role of herbivore-induced plant volatiles in the foraging behavior of predatory arthropods.

Composition of fatty acids in the Varroa destructor mites and their hosts, Apis mellifera drone-prepupae.

Science.gov (United States)

Dmitryjuk, Małgorzata; Zalewski, Kazimierz; Raczkowski, Marek; Żółtowska, Krystyna

2015-01-01

The fatty acid (FA) profile of lipids extracted from the Varroa destructor parasitic mite and its host, drone-prepupae of Apis mellifera, was determined by gas chromatography (GC). The percentages of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were generally similar in parasites and their hosts. Fatty acids were arranged in the following descending order based on their content: MUFAs (ca. 52-55%), SFAs (ca. 41%) and PUFAs (ca. 3%). The predominant fatty acids were oleic acid (46% in mites, 44% in prepupae) and palmitic acid (23% and 30%, respectively). Varroa parasites differed from their hosts in the quantity of individual FAs and in their FA profiles. Three PUFAs noted in the host were not observed in parasitic mites, whereas the presence of C21:0, C24:0 and C22:1 FAs was reported in mites, but not in drones.

Norwegian honey bees surviving Varroa destructor mite infestations by means of natural selection

OpenAIRE

Oddie, Melissa AY; Dahle, Bjørn Steinar; Neumann, Peter

2017-01-01

Background Managed, feral and wild populations of European honey bee subspecies, Apis mellifera, are currently facing severe colony losses globally. There is consensus that the ectoparasitic mite Varroa destructor, that switched hosts from the Eastern honey bee Apis cerana to the Western honey bee A. mellifera, is a key factor driving these losses. For >20 years, breeding efforts have not produced European honey bee colonies that can survive infestations without the need for mite control....

Effects of azadirachtin on Tetranychus urticae (Acari: Tetranychidae) and its compatibility with predatory mites (Acari: Phytoseiidae) on strawberry.

Science.gov (United States)

Bernardi, Daniel; Botton, Marcos; da Cunha, Uemerson Silva; Bernardi, Oderlei; Malausa, Thibaut; Garcia, Mauro Silveira; Nava, Dori Edson

2013-01-01

The spider mite, Tetranychus urticae, is the major strawberry pest in Brazil. The main strategies for its control comprise synthetic acaricides and predatory mites. The recent register of a commercial formula of azadirachtin (Azamax(®) 12 g L(-1) ) can be viable for control of T. urticae. In this work, the effects of azadirachtin on T. urticae and its compatibility with predatory mites Neoseiulus californicus and Phytoseiulus macropilis in the strawberry crop were evaluated. Azadirachtin was efficient against T. urticae, with a mortality rate similar to that of abamectin. In addition, the azadirachtin showed lower biological persistence (7 days) than abamectin (21 days). Azadirachtin did not cause significant mortality of adult predatory mites (N. californicus and P. macropilis), but it did reduce fecundity by 50%. However, egg viability of the azadirachtin treatments was similar to that of the control (>80% viability). The use of azadirachtin and predatory mites is a valuable tool for controlling T. urticae in strawberry crop. Azadirachtin provided effective control of T. urticae and is compatible with the predatory mites N. californicus and P. macropilis. It is an excellent tool to be incorporated into integrated pest management for strawberry crop in Brazil. Copyright © 2012 Society of Chemical Industry.

The crystal structure of recombinant proDer p 1, a major house dust mite proteolytic allergen

DEFF Research Database (Denmark)

Meno, Kåre; Thorsted, Peter B; Ipsen, Henrik

2005-01-01

Allergy to house dust mite is among the most prevalent allergic diseases worldwide. Most house dust mite allergic patients react to Der p 1 from Dermatophagoides pteronyssinus, which is a cysteine protease. To avoid heterogeneity in the sample used for crystallization, a modified recombinant...

Introduction of Astigmatina and Oribatida Mites (Acari: Sarcoptiformes associated with Stored Food Products in Mashhad county

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Zohre Khaleghabadian

2016-09-01

Full Text Available Introduction: The occurrence and activity of mites in stored foods cause a variety of qualitative and quantitative damages, including reduction in the germinating power of the grains, bronchial asthma and allergic skin reactions. Among the mites associated with stored products, species of order Sarcoptiformes especially some species of Astigmatina including the genera Acarus, Suidasia and Tyrophagousare have economic importance and a worldwide distribution. The members of family Histiosomatidae also are cosmopolitan and often found in moist organic materials. In Iran, there have been a considerable number of studies on astigmatic mites. Kamali et al. have provided a list of stored product mites. fthe work of Bahrami et al. on species diversity of Acaroidea in Tehran, Ardeshir on population of stored grains in different seasons in Iran;Sayedi et al. on mites associated with stored rice in Guilan can be mentioned. Reviewing the literature revealed that in the only study that has been carried out in the study area, only 6 species of storage mites have previously been reported from Khorasan-e- +Razavi province. Literature review showed that although Oribatida consists of 9000 known species in the world, the number of recorded species from Iran is not considerable. Iranian studies on oribatid mites have limited to a few specific areas and recent years. By considering the limitation of knowledge on species diversity of stored product mites in the study area, the present study aimed to improve our knowledge on the mite associated with the stored food products in Mashhad city and the vicinity. Material and Methods: During years 2011−2012 a variety of food storages in Mashhad region were visited and sampled. These stored food products included wheat, barley, wheat bran, rice, flour mill, factories of pasta and bakeries, stockpiles of livestock’s food, and potato and onion storages in different parts of Mashhad. Mite specimens were extracted from

Allergic asthma induced in rhesus monkeys by house dust mite (Dermatophagoides farinae).

Science.gov (United States)

Schelegle, E S; Gershwin, L J; Miller, L A; Fanucchi, M V; Van Winkle, L S; Gerriets, J P; Walby, W F; Omlor, A M; Buckpitt, A R; Tarkington, B K; Wong, V J; Joad, J P; Pinkerton, K B; Wu, R; Evans, M J; Hyde, D M; Plopper, C G

2001-01-01

To establish whether allergic asthma could be induced experimentally in a nonhuman primate using a common human allergen, three female rhesus monkeys (Macaca mulatta) were sensitized with house dust mite (Dermatophagoides farinae) allergen (HDMA) by subcutaneous injection, followed by four intranasal sensitizations, and exposure to allergen aerosol 3 hours per day, 3 days per week for up to 13 weeks. Before aerosol challenge, all three monkeys skin-tested positive for HDMA. During aerosol challenge with HDMA, sensitized monkeys exhibited cough and rapid shallow breathing and increased airway resistance, which was reversed by albuterol aerosol treatment. Compared to nonsensitized monkeys, there was a fourfold reduction in the dose of histamine aerosol necessary to produce a 150% increase in airway resistance in sensitized monkeys. After aerosol challenge, serum levels of histamine were elevated in sensitized monkeys. Sensitized monkeys exhibited increased levels of HDMA-specific IgE in serum, numbers of eosinophils and exfoliated cells within lavage, and elevated CD25 expression on circulating CD4(+) lymphocytes. Intrapulmonary bronchi of sensitized monkeys had focal mucus cell hyperplasia, interstitial infiltrates of eosinophils, and thickening of the basement membrane zone. We conclude that a model of allergic asthma can be induced in rhesus monkeys using a protocol consisting of subcutaneous injection, intranasal instillation, and aerosol challenge with HDMA.

Seasonal exposure to drought and air warming affects soil Collembola and mites.

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