TETRANYCHUS EVANSI

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Uncertainties in predicting species distributions under climate change: a case study using Tetranychus evansi (Acari: Tetranychidae), a widespread agricultural pest

Uncertainties in predicting species distributions under climate change: a case study using Tetranychus evansi (Acari: Tetranychidae), a widespread agricultural pest

potential prevalence is absent, a factor that has been widely recognized to affect model predictions [21,22,23,24]. The tomato red spider mite Tetranychus evansi is a small arthropod, first recorded in Brazil in 1952 [25] under the name of Tetranychus marianae and described in 1960 from Mauritius [26]. It was only after it caused significant agricultural damage in tomato cultures in the early 1980 s in Africa and Brazil that the species started being considered as a significant agricultural pest [27]. Outbreaks were said to cause up to 90% loss in tomato cultures in South-East and West Africa [28,29]. Outbreaks were then recorded in Europe, especially around the Mediterranean basin where it has spread significantly in the last decades. The mite was later reported in Asia, mainly Japan and China (see [30] for a complete list of reports). The species is inconspicuous, with a rapid growth cycle (10 days under optimal conditions) and high tolerance to hot and dry conditions, making it a challenging pest in many agricultural systems. The species has also been misidentified in several occasions (e.g. [31]), causing a slow response to its outbreaks in newly invaded areas, an issue often reported for spider mites (e.g. [32]). Detailed recent genetic studies of different populations of T. evansi around the world suggest that the species is native to South America, and show that two main distinct clades, both coming from Brazil, and genetically charac- terized as clade 1 and 2, explain current patterns of species genetic diversity [33,34]. The most likely scenario for the species spread involves an initial introduction of clade 1 from Brazil into Africa, and invasion of this population into the Mediterranean, with later reports in Asia. A second introduction of clade 2 occurred into a restricted area of the Mediterranean basin, with a subsequent mixture of both clades [33]. Therefore the two clades have invaded distinct geographic areas worldwide. The question that remains to be answered is whether or not this current differential distribution is solely the result of introduction events, or whether it reflects large-scale environmental niche differentiation between clades. These two scenarios have important consequences for climate change analysis, since in the absence of niche differenti- ation mites of the two clades of T. evansi would have the same invasive potential when introduced into a new area. This would be an important issue to take into account when designing strategies to prevent future pest expansion or when proposing quarantine policies.
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Recent emergence and worldwide spread of the red tomato spider mite, [i]Tetranychus evansi[/i]: genetic variation and multiple cryptic invasions

Recent emergence and worldwide spread of the red tomato spider mite, [i]Tetranychus evansi[/i]: genetic variation and multiple cryptic invasions

Discussion Origins of invasive Tetranychus evansi A common assumption, though not always correct, is that the geographical natal range of a species contains the oldest populations which will therefore have the greatest genetic diversity (Lozier et al. 2009 ; Nardi et al. 2005 ; Roderick 2004 ). In this study, patterns of genetic variation of T. evansi are consistent with the hypothesis of a South American origin of the species. Populations in South America were found to contain six out of the ten identified mitochondrial haplotypes and the single variant (T3) of the most common ITS sequence (T1), despite a relatively small sample size (the cumulative number of individuals analyzed in the other continents was approximately three times as great). Although the measured genetic diversity of T. evansi would certainly increase with a greater number of populations examined (as modeled for several invasive species, Puillandre et al. 2008 ), the sample from South America comprises collections from Recife (Brazil) to Tucuman (Northern Argen- tina), covering more than 3,800 km, spanning the distribution area of the pest. Tetranychus evansi is not evenly distributed in Brazil and geographical predic- tions based on climatic modelling pinpointed the Atlantic coast and South Brazil as the most suitable geographical areas for the species (Migeon et al.
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First record of two insects preying on the red tomato spider mite Tetranychus evansi (Acari: Tetranychidae) in Latakia governorate, Syria

First record of two insects preying on the red tomato spider mite Tetranychus evansi (Acari: Tetranychidae) in Latakia governorate, Syria

Navajas M., de Moraes G.J., Auger P., Migeon A. 2013. Review of the invasion of Tetranychus evansi: biology, colonization pathways, potential expansion and prospects for biological control. Exp. Appl. Acarol., 59: 43­65. doi:10.1007/s10493-012-9590-5 Perumalsamy K., Selvasundaram R., Roobakkumar A., Rahman V.J., Muraleedharan N. 2010. Life table and predatory efficiency of Stethorus gilvifrons (Coleoptera: Coccinellidae), an important predator of the red spider mite, Oligonychus coffeae (Acari: Tetranychidae), infesting tea. Exp. Appl. Acarol., 50: 141­150. doi:10.1007/s10493-009-9290-y
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Dispersal Behavior of Tetranychus evansi and T. urticae on Tomato at Several Spatial Scales and Densities: Implications for Integrated Pest Management

Dispersal Behavior of Tetranychus evansi and T. urticae on Tomato at Several Spatial Scales and Densities: Implications for Integrated Pest Management

appeared that T. evansi dispersed mainly after the destruction of food shortage of lower leaves. Tetranychus evansi’s population grew exponentially and destroyed the tomato plant in 15 days while T. urticae caused moderate damage on tomato leaves due to its distribution on the plant and total plant destruction was recorded 21 days after initial infestation. Our result confirms previous studies showing higher reproductive rates of T. evansi compared to T. urticae on tomato plants [20,21,23]. The high distribution of T. urticae on whole tomato plant, evidenced by the moderate damage on leaves and its low population growth rate compared to T. evansi could explain a better resilience of tomato plant to T. urticae compared with T. evansi infestations. This gregarious behavior of T. evansi combined with its rapid population growth rate, may explain why tomato plants can be severely damaged by T. evansi infestations and how suddenly a tomato crop can be highly infested by them. The dispersal behavior of T. evansi makes it easy the localisation of infested tomato plants appearing highly damaged. The early control of T. evansi on these high spots could reduce the risk of outbreaks in the crop. The different dispersal behavior of T. evansi and T. urticae (density-dependent and density- independent, respectively) indicate these two species are not exposed to the same stresses and have different dynamics. T. evansi has to face food shortages and host plant desiccation for dispersal [33,34]. But T. urticae females disperse by walking to new leaves even at low densities when food is not scarce [35]. Yano [36] reported that females of T. urticae can disperse alone and start new colonies, after which sib-mating occurs among their offspring. In both species, when populations grow to the extent that individuals face both food limitations and host plant desiccation mites often build dense silk webs [35,36] further aggregate to form silk balls involved in long-range dispersal and the colonisation of distant plants [37,38].
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Test of colonisation scenarios reveals complex invasion history of the red tomato spider mite <em>tetranychus evansi</em>

Test of colonisation scenarios reveals complex invasion history of the red tomato spider mite <em>tetranychus evansi</em>

1 INRA, UMR CBGP (INRA/IRD/Cirad/Montpellier SupAgro), CS 30016, Montferrier-sur-Lez, France, 2 Environmental Science Policy and Management, University of California, 3 Faculdade de Cieˆncias, Centro de Biologia Ambiental, Universidade de Lisboa, Lisbon, Portugal Abstract The spider mite Tetranychus evansi is an emerging pest of solanaceous crops worldwide. Like many other emerging pests, its small size, confusing taxonomy, complex history of associations with humans, and propensity to start new populations from small inocula, make the study of its invasion biology difficult. Here, we use recent developments in Approximate Bayesian Computation (ABC) and variation in multi-locus genetic markers to reconstruct the complex historical demography of this cryptic invasive pest. By distinguishing among multiple pathways and timing of introductions, we find evidence for the ‘‘bridgehead effect’’, in which one invasion serves as source for subsequent invasions. Tetranychus evansi populations in Europe and Africa resulted from at least three independent introductions from South America and involved mites from two distinct sources in Brazil, corresponding to highly divergent mitochondrial DNA lineages. Mites from southwest Brazil (BR- SW) colonized the African continent, and from there Europe through two pathways in a ‘‘bridgehead’’ type pattern. One pathway resulted in a widespread invasion, not only to Europe, but also to other regions in Africa, southern Europe and eastern Asia. The second pathway involved the mixture with a second introduction from BR-SW leading to an admixed population in southern Spain. Admixture was also detected between invasive populations in Portugal. A third introduction from the Brazilian Atlantic region resulted in only a limited invasion in Europe. This study illustrates that ABC methods can provide insights into, and distinguish among, complex invasion scenarios. These processes are critical not only in understanding the biology of invasions, but also in refining management strategies for invasive species. For example, while reported observations of the mite and outbreaks in the invaded areas were largely consistent with estimates of geographical expansion from the ABC approach, historical observations failed to recognize the complex pathways involved and the corresponding effects on genetic diversity.
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Plant inhabiting phytoseiid predators of midwestern Brazil, with emphasis on those associated with the tomato red spider mite, Tetranychus evansi (Acari: Phytoseiidae, Tetranychidae)

Plant inhabiting phytoseiid predators of midwestern Brazil, with emphasis on those associated with the tomato red spider mite, Tetranychus evansi (Acari: Phytoseiidae, Tetranychidae)

Montferrier-sur-Lez cedex, France. kreiter@supagro.inra.fr, tixier@supagro.inra.fr 4 ICIPE, P.O. Box 30772-00100 Nairobi, Kenya; current address Koppert Biological Systems, R&D Entomology, P.O. Box 155, 2650 AD Berkel en Rodenrijs, The Netherlands. mknapp@koppert.nl A BSTRACT — The fauna of phytoseiid mites in the state of Mato Grosso do Sul, in midwestern Brazil, is poorly known. The tomato red spider mite, Tetranychus evansi Baker and Pritchard, is an important pest of Solanaceae in several coun- tries, but it is usually found in low densities in Brazil. It has been hypothesized that this is due to the effect of natural enemies. The objective of this study was to identify phytoseiid mites from Mato Grosso do Sul associated with T. evansi, to identify promising biological control agents for T. evansi in Africa. A survey was conducted in October – November 2002, sampling more than 70 plant species of 30 families, including 16 solanaceous species. The results of this survey provide some additional information to the scant knowledge on the phytoseiids from Mato Grosso do Sul. In total, 471 phytoseiids were collected, belonging to 12 Amblyseiinae and two Phytoseiinae species. The most frequent and abundant species was Euseius citrifolius Denmark and Muma, followed by Euseius concordis (Chant). Also, 3,493 tetranychids were found. Tetranychus evansi was found in Aquidauna on Solanum americanum (Miller), associated with E. citrifolius and Ty- phlodromalus aripo De Leon; in Corumbá, on S. americanum associated with E. concordis and Neoseiulus idaeus Denmark and Muma; and in Dourados, on Solanum lycopersicum (L.), associated with E. citrifolius, Proprioseiopsis mexicanus (Garman) and Proprioseiopsis ovatus (Garman). However, none of the phytoseiids found are considered to be a promising biological control agent of T. evansi, based on both their inconsistent association with the pest and on available information about each species.
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Traits leading to invasion: how did the tomato spider mite Tetranychus evansi colonize Europe?

Traits leading to invasion: how did the tomato spider mite Tetranychus evansi colonize Europe?

P40/03 Titre : Traits leading to invasion: how did the tomato spider mite Tetranychus evansi colonize Europe? Angham Boubou - Philippe Auger - Alain Migeon - Ruth Hufbauer - Maria Navajas What allows a species or population to invade once a propagule arrives to a new geographical area, remains poorly understood. There is much research focused on differences in the traits possessed by invasive species relative to non-invasive introduced species. However, the different evolutionary histories of the species, and often differences in the environments they invade, make difficult to know which traits play a large role in invasion. We are studying the invasion history and biology of the tomato spider mite, Tetranychus evansi, a mite that originates from South America and has recently emerged as a new threat to solanaceous crops in Africa and in the Mediterranean basin. Our research has revealed that two main lineages are present in Europe. Differences in their geographical distribution and population dynamics suggest that they differ dramatically in invasive potential. This provides an excellent opportunity to evaluate what biological traits differ between more invasive and less invasive lineage. We investigate two biological traits that appear likely to be key for the success of the invasion of T. evansi in newly colonized temperate climates: cold tolerance and host range. The species is not able to diapause, thus its invasion of a temperate environment is likely to rely upon its ability to tolerate cold. Additionally, though considered to be a specialist, as with many herbivorous insects, and its ability to exploit different species of plants is not equal, and the range of plants in the new environment likely differs from the native area. We experimentally compare life-history parameters of mites from the more and less invasive lineages and submitted them to different temperatures and host plants. We find that the more invasive lineages is more cold tolerant and has a broader host range. This supports the idea that ‘general purpose genotypes’ are particularly suited to invasion.
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Apport de l'approche évolutive pour l'étude de l'invasion de l'acarien rouge de la tomate, Tetranychus evansi

Apport de l'approche évolutive pour l'étude de l'invasion de l'acarien rouge de la tomate, Tetranychus evansi

1 Résumé L‟acarien rouge de la tomate Tetranychus evansi (Acari: Tetranychidae) est considéré comme une espèce invasive à fort impact économique sur les cultures de solanacées. Il a été découvert pour la première fois en 1954 au Brésil, d‟où il est probablement originaire. Historiquement, T. evansi a d‟abord été signalé en Afrique et plus récemment en Europe et en Asie. L‟objectif de cette thèse était de reconstruire les routes de colonisation de T. evansi et de dégager le scénario évolutif décrivant le mieux l‟histoire de l‟invasion. Nous avons d‟abord analysé des échantillons collectés dans son aire actuelle de distribution, à l‟aide des séquences d‟un fragment du gène codant pour la sous-unité I de la Cytochrome Oxydase (COI) de l‟ADN mitochondrial et de la région ITS1-5,8S-ITS2 de l‟ADN nucléaire ribosomique. Les données soutiennent l‟hypothèse d‟une origine sud américaine de cette espèce et ont révélé que des événements d‟invasions multiples et cryptiques ont eu lieu lors de la colonisation de l‟Europe. L‟invasion résulte de deux lignées génétiquement divergentes et originaires de deux régions géographiques distantes au Brésil. Ces deux lignées semblent avoir des potentiels invasifs contrastés. Elles s‟hybrident en laboratoire ainsi que dans la nature. Grâce à 16 locus microsatellites que nous avons développés et utilisés comme marqueurs, nous avons déterminé les zones géographiques de cette hybridation. Nous avons également pu estimer des paramètres historiques de l‟invasion et confronter différents scénarios d‟introduction, par la comparaison de la composition génétique des populations récemment introduites avec celles de l‟aire d‟origine de T evansi, et par l‟utilisation de la méthode d‟inférence bayésienne (Approximate Bayesian Computation, ABC). Les résultats ABC contredisent partiellement le scénario d‟invasion basé uniquement sur des données historiques. Ils suggèrent que T. evansi serait d‟abord arrivé en Europe dans le sud de l'Espagne (en Andalousie) bien avant les signalements historiques. Ainsi, l‟Andalousie semble avoir servi de source de colonisation pour des nouvelles zones d‟Afrique, d‟autres régions méditerranéennes et d‟Asie. Les résultats de cette thèse ouvrent des perspectives d‟étude visant à comprendre pourquoi certaines populations d‟une espèce allochtone réussissent à s‟établir et à envahir un nouvel écosystème.
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Performance of Metarhizium anisopliae-treated foam in combination with Phytoseiulus longipes Evans against Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae)

Performance of Metarhizium anisopliae-treated foam in combination with Phytoseiulus longipes Evans against Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae)

www.soci.org GY Azandémè Hounmalon et al. association with T. evansi 17 and has been reported to be effective against T. evansi in the laboratory and greenhouse. 17–19 These two biological control agents could therefore be integrated as com- ponents of a tomato spider mite management strategy. Further- more, young females of T. evansi during the day shows gregarious behaviour and spreads on the tomato plant when its resources become limited 20 . This behaviour could therefore be exploited to

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Selection of strawberry cultivars with tolerance to Tetranychus urticae (Acari: Tetranychidae) and high yield under different managements.

Selection of strawberry cultivars with tolerance to Tetranychus urticae (Acari: Tetranychidae) and high yield under different managements.

Tetranychus urticae (TSSM) Koch (Acari: Tetranychidae) (Svensson, 2006). TSSM is polyphagous mite species and important pest of agricultural and ornamental crops in the world (Greco et al., 2005). It is one of the most important pests in Brazilian strawberry (Iwassaki et al., 2015) and its control is based on the use of chemicals (Sato et al., 2002; Fadini et al., 2004). Its damages are caused by the mobile forms that cause the appearance of chlorotic points on the upper face of the leaves, which develop into yellowish spots until completely reddish leaves. New leaves may be infested and this depends on the pest infestation; however, their occurrence is greater in older leaves and close to the plastic cover of the beds, especially in longer dry periods. Higher temperatures are favored by the heat emanating from the plastic mulching and can shorten the TSSM cycle (Fornazier and Pratissoli, 2006).
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Comparison of serological and molecular tests for detection of Trypanosoma evansi in domestic animals from Ghardaïa district, South Algeria

Comparison of serological and molecular tests for detection of Trypanosoma evansi in domestic animals from Ghardaïa district, South Algeria

Trypanosoma evansi (T. evansi) is a hemoflagellate parasite that affects a broad range of mammalian hosts and that causes a disease called surra. Diagnosis of surra based on clinical symptoms alone is inaccurate. Therefore, a variety of serological and molecular diagnostic tests are used to assist in the detection of T. evansi infections.

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Isolation, characterization and PCR multiplexing of microsatellite loci for a mite crop pest, Tetranychus urticae (Acari: Tetranychidae)

Isolation, characterization and PCR multiplexing of microsatellite loci for a mite crop pest, Tetranychus urticae (Acari: Tetranychidae)

Findings Tetranychus urticae (the two spotted spider mite) is a cosmopolitan and highly polyphagous species. This mite has been reported from about 1059 host plants and is a major pest for 100 crops [ 1 ]. Despite the worldwide dis- tribution and high agricultural relevance of the species, the extent of its genetic diversity still lacks of informa- tion. The evolutionary history of T. urticae, while only partially explored, indicates high biodiversity. Analyses

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Reaching the Ball or Missing the Flight? Collective Dispersal in the Two-Spotted Spider Mite Tetranychus urticae

Reaching the Ball or Missing the Flight? Collective Dispersal in the Two-Spotted Spider Mite Tetranychus urticae

When plants became exhausted and overcrowded (about 15 days after Collective Dispersal in Tetranychus urticae.. infestation of the bean plant), a part of the individuals gathered[r]

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Acaricidal activities of Santolina africana and Hertia cheirifolia essential oils against the two-spotted spidermite (Tetranychus urticae)

Acaricidal activities of Santolina africana and Hertia cheirifolia essential oils against the two-spotted spidermite (Tetranychus urticae)

b Laboratoire d'Entomologie-acarologie, Institut National Agronomique de Tunisie, Tunis, Tunisia c Université de Liège Gembloux Agro-Bio Tech Unité de Chimie Analytique, Gembloux, Belgium Abstract BACKGROUND: Many plant essential oils show a broad spectrum of activity against pests. This study investigated the effects of two essential oils on Tetranychus urticae, one of the most serious pests in the world. RESULTS: The chemical composition of the two oils was characterised by GC-MS. The most abundant component in the Santolina africana (Jord. & Fourr) oil was terpinen-4-ol (54.96%), while thymol (61%) was prevalent in the Hertia cheirifolia (L.) oil. Mortality and fecundity were measured upon treatment with oil concentrations ranging from 0.07 to 6.75 mg L -1 with a Potter spray tower. Mite mortality increased with oil
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Selection of strawberry cultivars with tolerance to Tetranychus urticae (Acari: Tetranychidae) and high yield under different managements.

Selection of strawberry cultivars with tolerance to Tetranychus urticae (Acari: Tetranychidae) and high yield under different managements.

Tetranychus urticae (TSSM) Koch (Acari: Tetranychidae) (Svensson, 2006). TSSM is polyphagous mite species and important pest of agricultural and ornamental crops in the world (Greco et al., 2005). It is one of the most important pests in Brazilian strawberry (Iwassaki et al., 2015) and its control is based on the use of chemicals (Sato et al., 2002; Fadini et al., 2004). Its damages are caused by the mobile forms that cause the appearance of chlorotic points on the upper face of the leaves, which develop into yellowish spots until completely reddish leaves. New leaves may be infested and this depends on the pest infestation; however, their occurrence is greater in older leaves and close to the plastic cover of the beds, especially in longer dry periods. Higher temperatures are favored by the heat emanating from the plastic mulching and can shorten the TSSM cycle (Fornazier and Pratissoli, 2006).
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Eficiência de produtos naturais no controle de Tetranychus urticae Koch, 1836 (Acari: Tetranychidae) e efeito em predadores em morangueiro.

Eficiência de produtos naturais no controle de Tetranychus urticae Koch, 1836 (Acari: Tetranychidae) e efeito em predadores em morangueiro.

REFERÊNCIAS ABBOTT, W.S. A method for computing the effectiveness of insecticides. Journal of Economic Entomology, v. 18, n. 15, p. 265-267, 1925. CALZA, R.; SUPLICY, N. Estudos sobre o “ácaro do morangueiro” Tetranychus telarius (L.). Biológico, v.33, p. 137-143, 1967.

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Prevalence of Trypanosoma evansi in horses (Equus caballus) and donkeys (Equus asinus) in El-Bayadh district, southwestern Algeria

Prevalence of Trypanosoma evansi in horses (Equus caballus) and donkeys (Equus asinus) in El-Bayadh district, southwestern Algeria

si in horses and donkeys in Algeria. It has shown that the seroprevalence of Trypanosoma evansi in horses was 45.2% (CI 95%, 37.8-52.5%) and 62.1% (CI 95%, 44.4-79.7%) in donkeys. The results indicate that El- Bayadh district is a highly endemic area. Gender, high plains zone, promiscuity with dromedaries, presence of animals near than watering points and vegetation are risk factors to be infected by Trypanosoma evansi. Other characteristics like breed, purpose and housing are not revealed as risk factors for the infection by try- panosomiosis. However, physicals and environmental characteristics were not significantly associated with the infection by Trypanosoma evansi in donkeys.
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An analysis of potential resistance of the phytophagous mite, Tetranychus urticae Koch (Acari: Tetranychidae) to four botanical pesticides

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

However, the repeated application of essential oils for pest control could also potentially induce the acquisition of resistance. It is therefore necessary to test that possibility even if it is less likely that mites will evolve resistance to essential oils as they are a mixture of different active compounds. This low acquisition of resistance linked to the complexity of essential oil composition was already shown in insects (Liu et al., 2004) but has never been explored in mites. The purpose of this study is to analyze the emergence of the resistance of a Tetranychus urticae population to repeated applications of Deverra scoparia Coss. & Durieu, Santolina africana Jord. & Fourr., Hertia cheirifolia (L.) Kuntze essential oils and of a garlic extract, Allium sativum L. This selection of plants is based on previous works (Attia et al., 2011a; Attia et al., 2011b; Attia et al., 2011c; Attia et al., 2012) where we examined the effect of different concentrations of S. africana, H. cheirifolia, D. scoparia essential oils and garlic extract A. sativum against T. urticae. We showed that they caused significant T. urticae mortality after 24 h at low concentrations, with LC 50 values of 2.35 mg.l -1 for S. africana, 3.43 mg.l -1 for H. cheirifolia, 1.79 mg.l -1 for D. scoparia and 7.49 mg.l -1 for A. sativum (Attia et al., 2011a; Attia et al., 2011b; Attia et al., 2011c; Attia et al., 2012). In addition, fecundity decreased after treatments with sublethal concentrations of extracts corresponding for D. scoparia to 0.07, 0.09, 0.29 mg.l -1 , H. cheirifolia and S. africana oils to 0.064, 0.08, 0.26 mg.l -1 respectively and for the garlic distillate, A. sativum, to 0.36 and 0.74 mg.l -1 (Attia et al., 2011b; Attia et al., 2011c; Attia et al., 2012). In the present study, emergence of resistance experiments was performed on 20 generations. Our study is the first to evaluate the emergence of resistance to some natural biopesticides of one of the most important pest in the world, T. urticae.
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Microsatellites reveal a strong subdivision of genetic structure in Chinese populations of the mite Tetranychus urticae Koch (Acari: Tetranychidae)

Microsatellites reveal a strong subdivision of genetic structure in Chinese populations of the mite Tetranychus urticae Koch (Acari: Tetranychidae)

Microsatellites reveal a strong subdivision of genetic structure in Chinese populations of the mite Tetranychus urticae Koch (Acari: Tetranychidae)... The population genetic diversity an[r]

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Seroprevalence and risk factors for Trypanosoma evansi, the causative agent of surra, in the dromedary camel (Camelus dromedarius) population in Southeastern Algeria

Seroprevalence and risk factors for Trypanosoma evansi, the causative agent of surra, in the dromedary camel (Camelus dromedarius) population in Southeastern Algeria

T. evansi seroprevalence were reported in the African nations of Ethiopia (between 18.2% and 24.9%; Aregawi et al. 2015; Bogale, Kelemework & Chanie 2012; Fikru et al. 2015; Hagos et al. 2009), Mauritania (24%, Dia et al. 1997), Niger (12%, Pacholek et al. 2000) and Tanzania (8.3%, Njiru et al. 2002). Others reports of low T. evansi seroprevalence came from UAE (10.67%, Chaudhary & Iqbal 2000), Iran (10%, Zarif-Fard & Hashemi-Fesharki 2000) and Pakistan (4%, Hasan et al. 2006). The heterogeneity between seroprevalence rates in different parts of the world is likely because of the differences in density of camel rearing, animal husbandry systems, climatic conditions, density of mechanical vectors, local herd management practices, study sample sizes, as well as cut-off values and sensitivity differences in the serological tests employed. Moreover, in our study location, poor-quality veterinary service, divagation and migration of camels to humid area and northland areas in search of feed (Benaissa et al. 2012) might have additionally contributed to the high seroprevalence. Under such production conditions, it will be important to educate camel farmers how to mitigate risks of
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