15 research outputs found

    Spatio‐temporal partitioning and sharing of parasitoids by fall armyworm and maize stemborers in Cameroon

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    Biological invasion is a global concern with species deployed out of native range, the most recent in Africa being the invasion by fall armyworm (FAW) Spodoptera frugiperda J.E. Smith (Lepidoptera: Noctuidae). One of the most mentioned ecological consequences is the capacity of invaders to change native communities' structure. Busseola fusca Fuller (Lepidoptera: Noctuidae) has long been the most destructive pests of maize in Africa. Few or no studies have attempted to look at the interaction between FAW and native maize pests over a cropping cycle for sustainable management. Maize trials were established over two cropping cycles in Cameroon to investigate the nature of such interactions and eventual sharing of parasitoids. FAW incidence decreased with maize growth, while the reverse was observed for stemborers. Few cases of co‐occurrence were recorded at the later maize growth stage. There was a clear indication that FAW infestation was associated with vegetative stages, while stemborers were associated with reproductive stages. Only FAW eggs were found on abaxial and adaxial leaf surfaces, while only stemborer eggs were inside leaf sheaths. Similarly, while larvae of both groups were found in maize whorl and on ears, only FAW larvae were found in closed tassels, while only stemborers were found inside stems. These results are in favour of segregation in time and space in plant colonization by native and invasive pests, which may limit competition and exacerbates damage if no control is provided. The same egg, larval and pupal parasitoids respectively Telenomus remus, Cotesia icipe and Procerochasmias nigromaculatus emerged from isolated FAW and B. fusca eggs, larvae, and pupae. The sharing of parasitoids by both species provides a unique opportunity for augmentative biocontrol

    Гранитоиды обрамления Криворожской структуры. Проблемы корреляции геологических тел и комплексов

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    Current population genetic models fail to cope with genetic differentiation for species with large, contiguous and heterogeneous distribution. We show that in such a case, genetic differentiation can be predicted at equilibrium by circuit theory, where conductance corresponds to abundance in species distribution models (SDM). Circuit-SDM approach was used for the phylogeographic study of the lepidopteran cereal stemborer Busseola fusca Füller (Noctuidae) across sub-Saharan Africa. Species abundance was surveyed across its distribution range. SDM models were optimized and selected by cross validation. Relationship between observed matrices of genetic differentiation between individuals, and matrices of resistance distance was assessed through Mantel tests and redundancy discriminant analyses (RDA). A total of 628 individuals from 130 localities in 17 countries were genotyped at 7 microsatellite loci. Six population clusters were found based on a Bayesian analysis. The eastern margin of Dahomey Gap between East and West Africa was the main factor of genetic differentiation. The SDM projections at present, last interglacial and last glacial maximum periods were used for estimation of circuit resistance between locations of genotyped individuals. For all periods of time, when using either all individuals or only East-African individuals, partial Mantel r and RDA analyses conditioning on geographic distance were found significant. Under future projections (year 2080), partial r and RDA significance were different. From this study, it is concluded that analytical solutions provided by circuit theory are useful for the evolutionary management of populations and for phylogeographic analysis when coalescence times are not accessible by approximate Bayesian simulations

    Révision du genre Poeonoma Tams & Bowden (Lepidoptera : Noctuidae : Apameiini : Sesamiina) avec la description d’un nouveau genre et de deux nouvelles espèces de Sesamiina de la région afrotropicale

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    The genus Poeonoma (Tams & Bowden, 1953) is revised to include two species P. serrata (Hampson, 1910) and P. ugandensis Le Run. sp., from the Congolian bioregion. Several new synonyms are introduced for Poeonoma serrata: Conicofrontia sjoestedti (Aurivillius, 1925) n. syn. for Poeonoma serrata (Hampson, 1910), Poeonoma similis (Tams & Bowden, 1953) n. syn. for Poeonoma serrata (Hampson, 1910), and Poeonoma nigribasis (Laporte, 1974) n. syn. for Poeonoma serrata (Hampson, 1910). A new genus, Nyaluteme Le Run. gen., is proposed for two species formerly included in Poeonoma, N. acantha (Tams & Bowden, 1953) n. comb. and N. inermis (Laporte, 1973) n. comb., and N. nigra Le Run. sp., described from the Congolian bioregion. Host-plants for three of the species are recorded:Pennisetum purpureum Schumach. for P. serrata and P. ugandensis, and Miscanthus violaceus (K. Schum) Pilg. for N. nigra. A key to species, descriptions, illustrations of adults and genitalia, and distribution maps are included. Results of previously published phylogenetic analyses also allow the status of the new genus to be confirmed and to infer the phylogenetic placement of the two genera.Le genre Poeonoma (Tams & Bowden, 1953) est révisé ; deux espèces, P. serrata (Hampson, 1910) et P. ugandensis Le Ru n. sp., de la biorégion Congolaise, y sont incluses et plusieurs nouvelles synonymies sont proposées pour Poeonoma serrata : Conicofrontia sjoestedti (Aurivillius, 1925) n. syn. de Poeonoma serrata (Hampson, 1910), Poeonoma similis (Tams & Bowden, 1953) n. syn. de Poeonoma serrata (Hampson, 1910), et Poeonoma nigribasis (Laporte, 1974) n. syn. de Poeonoma serrata (Hampson, 1910). Un nouveau genre, Nyaluteme Le Ru n. gen., de la biorégion Congolaise, est proposé pour deux espèces précédemment décrites dans le genre Poeonoma, N. acantha (Tams & Bowden, 1953) n. comb., et N. inermis (Laporte, 1973) n. comb., et une espèce nouvellement décrite N. nigra Le Ru n. sp. Les plantes-hôtes de trois espèces sont répertoriées : Pennisetum purpureum Schumach. pour P. serrata et P. ugandensis, et Miscanthus violaceus (K. Schum) Pilg. pour N. nigra. Une clé de détermination des espèces est présentée ainsi que l’illustration des adultes et des génitalia et, des cartes de distribution. Les résultats d’analyses de reconstruction phylogénétique déjà publiées permettent également de confirmer le statut du nouveau genre et d’inférer la position phylogénétique des deux genres. http://www.zoobank.org/urn:lsid:zoobank.org:pub:6ED4AC9E-043C-4A04-A92D-80706694300

    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

    Phylogenetic analysis and systematics of the Acrapex unicolora Hampson species complex (Lepidoptera, Noctuidae, Apameini), with the description of five new species from the Afrotropics

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    Ten morphologically similar species of Acrapex Hampson, 1891 (Lepidoptera, Noctuidae, Noctuinae, Apameini) from Central and Eastern Africa are reviewed, including five new species: Acrapex kafula le Ru sp. nov., A. kavumba le Ru sp. nov., A. kiakouama le Ru sp. nov., A. miscantha le Ru sp. nov. and A. simillima le Ru sp. nov. Evidence is provided to transfer the monotypic genus Poecopa Bowden, 1956 to the genus Acrapex. Host plants of five species are recorded, some of them for the first time. Acrapex kavumba sp. nov., A. miscantha sp. nov. and A. simillima sp. nov. were found on one host plant each. Acrapex mediopuncta, previously reported in West Africa from Pennisetum purpureum Schumach., Rottboellia compressa L., Setaria megaphylla (Steud) Dur. & Schinz. and Sorghum arundinaceum (Desv.) Stapf, was only found from S. megaphylla in Central Africa. Larvae of Acrapex unicolora were collected on Andropogon gayanus Kunth, Chrysopogon zizanoides (L.) Roberty, Cymbopogon schoenanthus subsp. proximus (Hochst. ex A.Rich.) Maire & Weller, Cymbopogon pospischiilii (K.Schum.) C.E.Hubb., Hyparrhenia diplandra (Hack.) Stapf and Setaria sphacelata (Schumach.) Moss. We also conducted molecular phylogenetic analyses (using maximum likelihood) and molecular species delimitation analyses on a comprehensive sample of 61 specimens belonging to eight of the studied species. Molecular phylogenetic analyses provided additional evidence of the synonymy of Acrapex and Poecopa, whereas molecular species delimitation analyses support the validity of the five newly described species and unravel another potential new species, only collected in the larval stage
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