Vidal, Stefan

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Insects"],["dc.bibliographiccitation.lastpage","12"],["dc.bibliographiccitation.volume","9"],["dc.contributor.author","Sann, Christina"],["dc.contributor.author","Wemheuer, Franziska"],["dc.contributor.author","Beaurepaire, Alexis"],["dc.contributor.author","Daniel, Rolf"],["dc.contributor.author","Erler, Silvio"],["dc.contributor.author","Vidal, Stefan"],["dc.date.accessioned","2019-07-09T11:45:05Z"],["dc.date.available","2019-07-09T11:45:05Z"],["dc.date.issued","2018"],["dc.description.abstract","Ongoing intensification of rice production systems in Southeast Asia is causing devastating yield losses each year due to rice hoppers. Their continuing development of immunity to resistant rice varieties and pesticide applications further complicates this problem. Hence, there is a high demand for biological control agents of rice hoppers. Egg parasitoid wasps are among the most important natural enemies of rice hoppers, such asNilaparvata lugensandNephotettixspp. However, our knowledge of their diversity is still very limited, due to their small size and the lack of available morphological information. Classifying these parasitoids is the first step to properly understanding their role in the rice agroecosystem. We used traditional morphological identification, as well as DNA sequencing of the 28S rRNA and the COI genes, to investigate the diversity of four important hopper egg parasitoid genera in the Philippines. Parasitoids of the generaAnagrus,Oligosita,Gonatocerus, andParacentrobiawere collected in eight study landscapes located in Luzon. Our findings illustrate that characterization of species diversity using morphological and molecular analyses were concordant only for the genusParacentrobia. The generaAnagrusandGonatocerusexhibited more genetic diversity than estimated with the morphological analysis, while the opposite was observed forOligosita. This is the first study investigating the molecular diversity of rice hopper parasitoids in the Philippines. More research combining morphological, behavioral, and molecular methods, as well as the establishment of a comprehensive DNA database, are urgently needed to assess the performance and suitability of these organisms as biocontrol agents."],["dc.identifier.doi","10.3390/insects9010019"],["dc.identifier.pmid","29425132"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15032"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59158"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.publisher","MDPI"],["dc.relation.eissn","2075-4450"],["dc.relation.issn","2075-4450"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.subject.ddc","630"],["dc.title","Preliminary Investigation of Species Diversity of Rice Hopper Parasitoids in Southeast Asia."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","5937"],["dc.bibliographiccitation.issue","21"],["dc.bibliographiccitation.journal","African Journal of Biotechnology"],["dc.bibliographiccitation.lastpage","5943"],["dc.bibliographiccitation.volume","8"],["dc.contributor.author","Abebe, Fikremariam"],["dc.contributor.author","Tefera, Tadele"],["dc.contributor.author","Mugo, Stephen"],["dc.contributor.author","Beyene, Yoseph"],["dc.contributor.author","Vidal, Stefan"],["dc.date.accessioned","2019-07-10T08:13:17Z"],["dc.date.available","2019-07-10T08:13:17Z"],["dc.date.issued","2009"],["dc.description.abstract","This study aimed at evaluating commonly used maize varieties, collected from Melkasa and Bako Agricultural Research Centers and Haramaya University, Ethiopia, against the maize weevil Sitophilus zeamais Motsch., one of the most important cosmopolitan stored product pests in maize. A total of 13 improved maize varieties were screened for their relative susceptibility to S. zeamais. The Dobie index of susceptibility was used to group the varieties. The variety, ‘BHQP-542’, had the least index of susceptibility and was regarded as resistant. The varieties, ‘Katumani’, ‘Melkasa-I’, ‘Melkasa-II’, ‘Melkasa-III’, ‘Coree’, ‘BH-541’, ‘BH-660’, ‘BH-540’, ‘Rare-I’, ‘Awasa-511’, ‘ACV3’ and ‘ACV6’, were moderately resistant. Weevils fed with the resistant variety produced low numbers of F1 progeny, had a high median developmental time and a low percentage of seed damage and seed weight loss. Maize varieties with a high F1 progeny tended to have a short median developmental time. An increasing number of F1 progeny resulted in an increasing seed damage and seed weight loss. We found an inverse relationship between the susceptibility index and percent mortality and median developmental time; however, the numbers of F1 progeny, percent seed damage and seed weight loss were positively related with the susceptibility index. The use of resistant varieties should be promoted in managing S. zeamais in stored maize under subsistence farming conditions in Africa."],["dc.identifier.fs","503022"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/5840"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/61197"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.orgunit","Fakultät für Agrarwissenschaften"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.subject.ddc","630"],["dc.title","Resistance of maize varieties to the maize weevil Sitophilus zeamais (Motsch.) (Coleoptera: Curculionidae)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","e0180807"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","PloS one"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Schaefer, Heike L"],["dc.contributor.author","Brandes, Haiko"],["dc.contributor.author","Ulber, Bernd"],["dc.contributor.author","Becker, Heiko C"],["dc.contributor.author","Vidal, Stefan"],["dc.date.accessioned","2019-07-09T11:43:31Z"],["dc.date.available","2019-07-09T11:43:31Z"],["dc.date.issued","2017"],["dc.description.abstract","The rape stem weevil, Ceutorhynchus napi Gyll., is a serious pest of winter oilseed rape (Brassica napus L.) crops in Europe causing severe yield loss. In currently used oilseed rape cultivars no resistance to C. napi has been identified. Resynthesized lines of B. napus have potential to broaden the genetic variability and may improve resistance to insect pests. In this study, the susceptibility to C. napi of three cultivars, one breeding line and five resynthesized lines of oilseed rape was compared in a semi-field plot experiment under multi-choice conditions. Plant acceptance for oviposition was estimated by counting the number of C. napi larvae in stems. The larval instar index and the dry body mass were assessed as indicators of larval performance. The extent of larval feeding within stems was determined by the stem injury coefficient. Morphological stem traits and stem contents of glucosinolates were assessed as potential mediators of resistance. The resynthesized line S30 had significantly fewer larvae than the cultivars Express617 and Visby and the resynthesized lines L122 and L16. The low level of larval infestation in S30 was associated with a low larval instar and stem injury index. Low numbers of larvae were not correlated with the length or diameter of stems, and the level of stem glucosinolates. As indicated by the low larval infestation and slow larval development the resistance of S30 to C. napi is based on both antixenotic and antibiotic properties of the genotypes. The resynthesized line S30 should therefore be introduced into B. napus breeding programs to enhance resistance against C. napi."],["dc.identifier.doi","10.1371/journal.pone.0180807"],["dc.identifier.pmid","28686731"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/14549"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/58900"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","1932-6203"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0/"],["dc.subject.ddc","630"],["dc.title","Evaluation of nine genotypes of oilseed rape (Brassica napus L.) for larval infestation and performance of rape stem weevil (Ceutorhynchus napi Gyll.)."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]