13 research outputs found

    Management of an emerging pest, Tetranychus urticae Koch (Acari: Tetranychidae), with pesticides in eastern Ethiopia

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    Outbreak of two-spotted spider mite, Tetranychus urticae Koch, happened on potato ( Solanum tuberosum L.) in eastern Ethiopia in 2014 and effective pesticides as part of IPM practice were sought from greenhouse and laboratory experiments at Haramaya University, Ethiopia. The objective of the study was to identify pesticides with the highest efficacy against the mite. Potatoes infested with mites were used in the efficacy trial. Treatments, 9 pesticides and a control, were applied 2 times at weekly intervals. Mites per leaf before and after each spray were counted. Promising pesticides were further screened with leaf-disc spray, and dip methods. Adult mortality was recorded after 24 and 48 hours. Chlorantrniliprole + Lambda-cyhalothrin, Amitraz, Profenofos, Profenofos \u201cQ\u201d 720 g l-1, and Paraffin oil showed superior efficacy on eggs and mobile stages; though Paraffin\u2019s efficacy became clear 14 days later. Paraffin had the lowest mortality in leaf-disc sprays, but better mortality in the leaf-disc dip. This was attributed to complete wetting by the latter. Chlorantrniliprole + lambda-cyhalothrin, Profenofos, Profenofos \u201cQ\u201d and Paraffin were identified as promising pesticides for the two spotted spider mite management on potato.L\u2019explosion de t\ue9tranyque \ue0 deux points, Tetranychus urticae Koch, s\u2019est produite sur la patate ( Solanum tuberosum L.) dans l\u2019Est de l\u2019Ethiopie en 2014 et des pesticides effectifs comme une partie de de pratique IPM a \ue9t\ue9 recherch\ue9e \ue0 partir des exp\ue9rimentations sous serre et au laboratoire \ue0 l\u2019Universit\ue9 de Haramaya, Ethiopie. L\u2019objectif de l\u2019\ue9tude \ue9tait d\u2019identifier les pesticides avec de tr\ue8s grande efficacit\ue9 contre le t\ue9tranyque. Les patates infest\ue9es avec les t\ue9tranyques ont \ue9t\ue9 utilis\ue9es dans un essai d\u2019efficacit\ue9. Les traitements, 9 pesticides et un contr\uf4le, \ue9taient appliqu\ue9s deux fois \ue0 des intervalles d\u2019une semaine. Les t\ue9tranyques par feuille ont \ue9t\ue9 compt\ue9s avant et apr\ue8s chaque traitement. Des pesticidesprometteurs ont \ue9t\ue9 \ue9galement\ue9valu\ue9s avec le pulv\ue9riseur \ue0 disque sur les feuilles, et les m\ue9thodes d\u2019immersion. La mortalit\ue9 de l\u2019adulte\ue9tait evalu\ue9e apr\ue8s 24 et 48 heures. Chlorantrniliprole + Lambda-cyhalothrin, Amitraz, Profenofos, Profenofos \u201cQ\u201d 720 g l-1, et l\u2019huile du Paraffine ont montr\ue9 une efficacit\ue9 sup\ue9rieure sur les \u153ufs, stages mobiles\ua0; quoique l\u2019efficacit\ue9 de paraffine est devenue claire \ue0 14 jours apr\ue8s. Paraffine a eu la plus faible mortalit\ue9 avec le pulv\ue9riseur \ue0 disque sur la feuille, mais meilleure mortalit\ue9 avec l\u2019immersion de la feuille. Ceci a \ue9t\ue9 attribu\ue9 \ue0 la mouillure compl\ue8te de la deuxi\ue8me m\ue9thode. Chlorantrniliprole + lambda-cyhalothrin, Profenofos, profenofos \u201cQ\u201d et Paraffine ont \ue9t\ue9 identifi\ue9s comme pesticide prometteurs, pour la gestion du t\ue9tranyque \ue0 deux points sur la tomate

    Survey and identification of termites (Insecta, Isoptera) using morphological and molecular methods from eastern, central and western Ethiopia.

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    The subfamily Macrotermitinae are the largest members among the Family Termitidae which are the fungus growing sub-family and Odontotermes are the most abundant genus from the subfamily.  The taxonomy of termites is poorly described in Ethiopia. In the present study 168 termite samples were collected from eight locations of Eastern, Western and Central Ethiopia. The collected samples were identified based on morphological and molecular characteristics. Molecular identification was done based on the dna sequence of a portion of the mitochondrial 16S rrna gene. A phylogenetic analysis of the collected samples and the outgroup resulted in a consensus tree with four distinct groups. Geographical distribution of the samples also supported the resulting clades. Odontotermes were the most widely distributed termites from the collected samples. The genetic distance between the sample showed that Odontotermes zambesiensis, Babile 33 is more distantly related with the rest of the samples

    Biology of barley shoot fly Delia flavibasis Stein (Diptera: Anthomyiidae) on resistant and susceptible barley cultivars

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    The biology of barley shoot fly Delia flavibasis was studied using resistant (Dinsho and Harbu) and susceptible (Holker) barley cultivars at Sinana Agricultural Research Center, Ethiopia. A higher number of eggs was laid on Holker (17 eggs/female) than on Dinsho (11 eggs/female) or Harbu (12 eggs/female). However, there were no differences between cultivars in preoviposition and total reproductive periods. The shortest time required to complete larval, pupal and total developmental stages from egg to adult emergence occurred when the insect was reared on the cultivar Holker. Pupal weight, adult emergence and adult longevity did not differ between cultivars. The female to male sex ratio was 1:1. This study enabled us to understand the duration of each of the life stages of D.flavibasis, which will undoubtedly aid researchers and growers to design a sustainable management strategy against barley shoot fly

    Re-establishment of Spodoptera teferii Laporte in Rougeot (Lepidoptera: Noctuidae, Noctuinae), with an updated molecular phylogeny for the genus Spodoptera Guenee

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    International audienceThe genus Spodoptera Guenee (Lepidoptera: Noctuidae, Noctuinae) is a group of economic importance which encompasses several major pests of crops worldwide. Although this genus has been the focus of many studies, the status of several Spodoptera species is still unstable, especially in the light of recent molecular analyses. In 2015 five Spodoptera specimens collected in Ethiopia were first identified as S. apertura (Walker). However, preliminary studies suggested that these specimens belong to a distinct species, S. teferii Laporte in Rougeot, which has been previously synonymized with S. apertura. In this study, on the basis of morphological and molecular evidence, we re-establish the species status of S. teferii. We provide a supplemental description of S. teferii male and the first description of S. teferii female. We also conducted several molecular analyses. First, we reconstructed an updated phylogeny for the genus based on a multilocus dataset (four mitochondrial and three nuclear gene fragments) including S. teferii and 28 of the 31 currently recognized Spodoptera species; the results of phylogenetic analyses support the hypothesis that S. teferii is more closely related to the clade encompassing S. littoralis (Boisduval), S. litura (Fabricius), S. pectinicornis (Hampson) and S. picta (Guerin-Meneville) than to S. apertura. Second, we carried out molecular species delimitation analyses on a 683-specimen dataset that also clearly support the status of S. teferii as a species distinct to S. apertura

    Phylogeny and systematics of the Acrapex apicestriata (Bethune-Baker, 1911) species complex (Lepidoptera, Noctuidae, Noctuinae, Apameini, Sesamiina) with the description of eight new species from the Afrotropics

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    International audienceTwelve morphologically similar species of Acrapex Hampson 1894, (Lepidoptera, Noctuidae, Noctuinae, Apameini, Sesamiina), from Western, Central and Eastern Africa are reviewed. Eight of these species are new to science and are described: Acrapex akunamatatan. sp. and A. incrassata n. sp. from Kenya; A. gracilis n. sp., A. iringa n. sp., A. lukumbura n. sp. and A. rungwe n. sp. from Tanzania; A. soyema n. sp. from Ethiopia; and A. zoutoi n. sp. from Benin. All 12 species belong to a species complex that we hereby define as the Acrapex apicestriata group. Host-plants for three of the new species are recorded: Setaria incrassata (Hochst.) Hack. for Acrapex incrassata; Cymbopogon pospishilii (K. Schum.) C.E. Hubb. for A. rungwe; and Andropogon perligulatus Stapf. for A. zoutoi. We also conducted molecular phylogenetic analyses (using maximum likelihood and Bayesian inference) on a six gene multimarker molecular dataset (four mitochondrial and two nuclear gene fragments; 4581 nucleotides in length) consisting of 15 Acrapex species (including seven species from the apicestriata group) and four outgroups species from the subtribe Sesamiina (from genera Busseola Thurau 1904, Sciomesa Tams & Bowden 1953, Pirateolea Moyal, Le Ru, Conlong, Cugala, Defabachew, Matama-Kauma, Pallangyo & Van den Berg 2010 and Sesamia Boisduval & Guenee 1852). Both maximum likelihood and Bayesian inference analyses yield a similar and well-supported topology, which supports the monophyly of the apicestriata group

    Vers la comprehension de la systĂ©matique et de l’évolution du genre Acrapex Hampson, 1894 (Lepidoptera : Noctuidae : Apameini : Sesamiina) : phylogĂ©nie molĂ©culaire du genre et dĂ©finition du groupe Acrapex aenigma

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    International audienceSummary: With a species count reaching almost 100 species, the genus Acrapex is the most diverse genus of sesamiine stemborers (Lepidoptera: Noctuidae: Noctuinae: Apameini: Sesamiina). Acrapex species are mostly distributed in the Afrotropics and consist of several large clades corresponding to distinct species complexes. In this study, 45 morphologically similar species of Acrapex from sub-Saharan Africa are reviewed, including 22 new species that are described: Acrapex alemuran. sp., A. barnsin. sp., A. capelongon. sp., A. congoensisn. sp., A. elgonan. sp., A. elisabethianan. sp., A. eucanthan. sp., A. grandisn. sp., A. igominyin. sp., A. inexpectatan. sp., A. ketoman. sp., A. lilomwin. sp., A. mafingan. sp., A. maketen. sp., A. marungun. sp., A. mazoen. sp., A. mlanjen. sp., Acrapex muchingan. sp., A. ngorongoron. sp., A. obscuran. sp., A. ruirun. sp. and A. wittein. sp. Supplemental descriptions for previously described species are provided as well. These 45 species are assigned to the newly defined Acrapex aenigma species group. We also conduct molecular phylogenetic analyses and molecular species delimitation analyses on a multi-marker (four mitochondrial and two nuclear genes) molecular dataset encompassing 304 specimens (including 256 Acrapex specimens from 54 species of which 16 species belong to the A. aenigma group). Molecular phylogenetics analyses recover well-supported relationships within Acrapex and support the monophyly of the newly defined group. Results of molecular species delimitation analyses are mostly congruent and tend to corroborate the status of the sampled Acrapex species. Consistent with what has been previously found in other studies, the comparison of results from distinct methods and settings for molecular species delimitation analyses allows us to assess species boundaries with more confidence.Avec prĂšs d’une centaine d’espĂšces le genre Acrapex est le genre de noctuelles foreuses le plus diversifiĂ© de la sous-tribu des Sesamiina (Lepidoptera : Noctuidae : Noctuinae : Apameini). Les Acrapex sont majoritairement distribuĂ©s dans la rĂ©gion Afrotropicale et sont composĂ©s de plusieurs clades correspondant Ă  diffĂ©rents complexes d’espĂšces. Dans cette Ă©tude, 45 espĂšces morphologiquement proches d’Acrapex sub-sahariens sont Ă©tudiĂ©es, au rang desquelles figurent 22 nouvelles espĂšces que nous dĂ©crivons : Acrapex alemura n. sp., A. barnsi n. sp., A. capelongo n. sp., A. congoensis n. sp., A. elgona n. sp., A. elisabethiana n. sp., A. eucantha n. sp., A. grandis n. sp., A. igominyi n. sp., A. inexpectata n. sp., A. ketoma n. sp., A. lilomwi n. sp., A. mafinga n. sp., A. makete n. sp., A. marungu n. sp., A. mazoe n. sp., A. mlanje n. sp., A. muchinga n. sp., A. ngorongoro n. sp., A. obscura n. sp., A. ruiru n. sp., and A. wittei n. sp. Nous fournissons Ă©galement des descriptions supplĂ©mentaires pour des espĂšces dĂ©jĂ  dĂ©crites. Ces 45 espĂšces sont assignĂ©es au groupe d’espĂšces Acrapex aenigma, que nous dĂ©finissons. Nous avons Ă©galement rĂ©alisĂ© des analyses de reconstruction phylogĂ©nĂ©tique et des analyses de dĂ©limitation molĂ©culaire d’espĂšces sur un jeu de donnĂ©es molĂ©culaires multimarqueurs (quatre gĂšnes mitochondriaux et deux gĂšnes nuclĂ©aires) comprenant 304 spĂ©cimens (incluant 256 Acrapex de 54 espĂšces dont 16 appartiennent au groupe A. aenigma). Les analyses phylogĂ©nĂ©tiques retrouvent des topologies bien supportĂ©es au sein du genre Acrapex et soutiennent l’hypothĂšse de monophylie du groupe d’espĂšces nouvellement dĂ©fini. Les rĂ©sultats des analyses de dĂ©limitation molĂ©culaire d’espĂšces sont majoritaitement en accord et tendent Ă  soutenir le statut d’espĂšce des Acrapex Ă©chantillonnĂ©s. ConformĂ©ment Ă  ce qui a Ă©tĂ© mis en Ă©vidence dans d’autres Ă©tudes, la comparaison des rĂ©sultats de diffĂ©rentes mĂ©thodes et paramĂ©trages d’analyses de dĂ©limitation molĂ©culaire d’espĂšces permet ainsi d’estimer les contours des espĂšces avec plus de confiance

    Updated phylogenetic and systematics of the Acrapex albivena Hampson, 1910 and A. stygiata (Hampson, 1910) species groups (Lepidoptera, Noctuidae, Noctuinae, Apameini, Sesamiina), with the description of nine new species from the Afrotropics

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    International audienceThe genus Acrapex Hampson, 1891 (Lepidoptera, Noctuidae, Noctuinae, Apameini, Sesamiina) constitutes a speciose group of noctuid stemborers mostly distributed in the Afrotropics. In this study nine new Acrapex species are described: Acrapex abyssinica n. sp., Acrapex dabaga n. sp., Acrapex jansei n. sp., Acrapex kifanya n. sp., Acrapex lusinga n. sp., Acrapex ngwenya n. sp., Acrapex njombea n. sp., Acrapex vetiveria n. sp. and Acrapex zima n. sp. All species are assigned to the A. albivena group with the exception of A. lusinga which is assigned to the A. stygiata group. We also provide supplemental descriptions for two previously described species of the A. albivena group, A. punctosa Berio, 1973 and A. sysciodes Berio, 1973, and for one species belonging to the A. stygiata group: A. brunneella Le Ru, 2014. Host plants of three species are recorded; A. brunneella and Acrapex jansei were reared on Cymbopogon pospischilii (K.Schum.) C.E.Hubb and A. vetiveria on Chrysopogon zizanioides (L.). We also conducted molecular phylogenetic analyses (using both Bayesian inference and maximum likelihood) on a multi-marker (four mitochondrial and two nuclear genes) molecular dataset encompassing 138 specimens (including 98 specimens from the A. albivena group and 23 specimens from the A. stygiata group) from 48 stemborer species. The results of the corresponding analyses support the monophyly of the two groups of interest and the species status of all newly described taxa, except for A. lusinga that was not sequenced. The phylogenetic analyses also unravel several evolutionary lineages whose precise status is pending because their DNA was extracted from larval stages.Actualisation des connaissances de la phylogĂ©nie et de la systĂ©matique des groupes d’espĂšces Acrapex albivena Hampson, 1910 et A. stygiata (Hampson, 1910) (Lepidoptera, Noctuidae, Noctuinae, Apameini, Sesamiina), avec la description de neuf nouvelles espĂšces de la rĂ©gion Afrotropicale. Le genre Acrapex Hampson, 1891 (Lepidoptera, Noctuidae, Noctuinae, Apameini, Sesamiina) est un groupe diversifiĂ© de noctuelles foreuses, majoritairement distribuĂ© dans la rĂ©gion Afrotropicale. Dans cette Ă©tude neuf espĂšces nouvelles sont dĂ©crites : Acrapex abyssinica n. sp., Acrapex dabaga n. sp., Acrapex jansei n. sp., Acrapex kifanya n. sp., A. lusinga n. sp., Acrapex ngwenya n. sp., Acrapex njombea n. sp., Acrapex vetiveria n. sp. et Acrapex zima n. sp. Toutes ces espĂšces sont assignĂ©es au groupe d’espĂšce A. albivena Ă  l’exception d’A. lusinga qui est assignĂ©e au groupe d’espĂšce A. stygiata. Nous fournissons Ă©galement des descriptions supplĂ©mentaires pour deux espĂšces, A. punctosa Berio, 1973 et A. sysciodes, Berio 1973, prĂ©cedemment dĂ©crites dans le groupe A. albivena ainsi que pour A. brunneella Le Ru, 2014, une espĂšce qui appartient au groupe A. stygiata. Les plantes-hĂŽtes de trois espĂšces sont rĂ©pertoriĂ©es ; Acrapex brunneella et A. jansei ont Ă©tĂ© Ă©levĂ©es sur Cymbopogon pospischilii (K. Schum.) C. E. Hubb et A. vetiveria sur Chrysopogon zizanioides (L.). Nous avons Ă©galement rĂ©alisĂ© des analyses de reconstruction phylogĂ©nĂ©tique (utilisant Ă  la fois l’infĂ©rence BayĂ©sienne et le maximum de vraisemblance) sur un jeu de donnĂ©es molĂ©culaires multi-marqueurs (quatre gĂšnes mitochondriaux et deux gĂšnes nuclĂ©aires) comprenant 138 specimens (incluant 98 specimens du groupe A. albivena et 23 specimens du groupe A. stygiata) de 48 espĂšces de foreurs. Les rĂ©sultats de ces analyses soutiennent Ă  la fois l’hypothĂšse de monophylie des deux groupes d’intĂ©rĂȘt et le statut d’espĂšces des taxa nouvellement dĂ©cris, Ă  l’exception d’A. lusinga qui n’a pas Ă©tĂ© sĂ©quencĂ©. Les analyses phylogĂ©nĂ©tiques rĂ©vĂšlent Ă©galement l’existence de plusieurs lignĂ©es Ă©volutives distinctes dont le statut reste Ă  dĂ©finir car leur ADN a Ă©tĂ© extrait de stades larvaire

    Molecular phylogenetics and definition of the Acrapex minima Janse group (Lepidoptera, Noctuidae, Apameini, Sesamiina) with the description of four new species from the Afrotropics

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    International audienceFive morphologically similar species of Acrapex Hampson (Lepidoptera, Noctuidae, Noctuinae, Apameini), from sub-Saharan Africa are reviewed, including four new species that are described: Acrapex mondogeneta Le Ru n. sp., A. mubale Le Ru n. sp., A. robe Le Ru n. sp. and A. rubona Le Ru n. sp. These five species belong to a species complex that we hereby define as the Acrapex minima group. Host plants of three species are recorded; Acrapex minima is recorded for the first time on a host plant, Digitaria natalensis Stent; A. mondogeneta on Hyparrhenia hirta (L.) Stapf and A. rubona on Imperata cylindrica (L.) P. Beauv. We also conducted molecular phylogenetics (using both Bayesian inference and maximum likelihood) and molecular species delimitation analyses (Poisson tree processes) on a six gene multi-marker dataset (four mitochondrial and two nuclear gene fragments; 4582 nucleotides in length) of 42 specimens and 22 species, including 23 specimens from the Acrapex minima group. The results of the corresponding analyses support the monophyly of the group and the species status of the newly described taxa
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