Search results for "Pest Analysis"
showing 10 items of 116 documents
An Egg Parasitoid Efficiently Exploits Cues From a Coevolved Host But Not Those From a Novel Host
2019
Egg parasitoids have evolved adaptations to exploit host-associated cues, especially oviposition-induced plant volatiles and odors of gravid females, when foraging for hosts. The entire host selection process is critical for successful parasitism and relevant in defining host specificity of parasitoids. We hypothesized that naïve egg parasitoid females reared on their coevolved host are able to exploit cues related to the coevolved host but not those from a novel host. We used the egg parasitoid Trissolcus japonicus, its coevolved host Halyomorpha halys, and the non-coevolved host Podisus maculiventris to evaluate this hypothesis. H. halys, a polyphagous pest native from Eastern Asia, has i…
Genetic variation in the behavioural mechanisms involved in the response of the egg parasitoid Trissolcus brochymenae to contact chemical cues left b…
2021
International audience; 1. The ability of parasitoid females to perceive chemical traces left by theirhosts is of utmost importance in the host location process. The behaviours involved insuch ability have thus most likely been promoted by natural selection in the course ofthe evolutionary time. For this to happen, however, there must be signicant geneticvariation in natural populations on which natural selection could act.2. Using the isofemale line method and motion analysis, we detected signicantintra-population genetic variation for several walking behaviour traits of the eggparasitoid Trissolcus brochymenae (Hymenoptera: Scelionidae) females responding tochemical traces left by its h…
2016
Bacillus thuringiensis Cry3Aa and Cry3Ca proteins have been reported to be toxic against the African sweetpotato pest Cylas puncticollis. In the present work, the binding sites of these proteins in C. puncticollis brush border vesicles suggest the occurrence of different binding sites, but only one of them is shared. Our results suggest that pest resistance mediated by alteration of the shared Cry-receptor binding site might not render both Cry proteins ineffective.
Insecticidal Activity and Synergistic Combinations of Ten Different Bt Toxins against Mythimna separata (Walker)
2018
The oriental armyworm (OAW), Mythimna separata (Walker), is a destructive pest of agricultural crops in Asia and Australia. Commercialized Bt crops have performed very well against their target pests
The Gut Entomotype of Red Palm Weevil Rhynchophorus ferrugineus Olivier (Coleoptera: Dryophthoridae) and Their Effect on Host Nutrition Metabolism
2017
For invasive insects, the potential roles of gut microbiota in exploiting new food resources and spreading remain elusive. Red palm weevil (RPW), Rhynchophorus ferrugineus Olivier, is an invasive destructive pest which feeds on nutrient-poor tender tissues and has caused extensive mortality of palm trees. The microbes associated with insects can improve their nutrition assimilation. However, experimental evidence on the interactions between RPW and its gut microbiota is still absent. The aim of this study is to determine the dynamics changes and the bacterial entomotype in the RPW gut and its potential physiological roles. Here, we confirmed RPW harbors a complex gut microbiota mainly const…
Evaluating Resistance to Bt Toxin Cry1Ab by F<SUB>2</SUB> Screen in European Populations of Ostrinia nubilalis (Lepidoptera: Crambidae)
2010
ABSTRACT The large-scale cultivation of transgenic crops producing Bacillus thuringiensis (Bt) toxins have already lead to the evolution of Bt resistance in some pest populations targeted by these crops. We used the F2 screening method for further estimating the frequency of resistance alleles of the European corn borer, Ostrinia nubilalis (Hubner) (Lepidoptera: Crambidae), to Bt maize, Zea mays L., producing the CrylAb toxin. In France, Germany, and Italy, 784, 455, and 80 lines of European corn borer were screened for resistance to Mon810 maize, respectively. In Slovakia, 26 lines were screened for resistance to the CrylAb toxin. The cost of F2 screen performed in the four countries varie…
The transposable element-rich genome of the cereal pest Sitophilus oryzae
2021
AbstractBackgroundThe rice weevil Sitophilus oryzae is one of the most important agricultural pests, causing extensive damage to cereal in fields and to stored grains. S. oryzae has an intracellular symbiotic relationship (endosymbiosis) with the Gram-negative bacterium Sodalis pierantonius and is a valuable model to decipher host-symbiont molecular interactions.ResultsWe sequenced the Sitophilus oryzae genome using a combination of short and long reads to produce the best assembly for a Curculionidae species to date. We show that S. oryzae has undergone successive bursts of transposable element (TE) amplification, representing 72% of the genome. In addition, we show that many TE families a…
Researches Regarding the Species Diabrotica Virgifera Virgifera Le Conte in Sibiu County
2010
From the very beginning of the recording of its appearance in Europe as well as in
 our country the published material emphasized the harmful potential of the pest Diabrotica virgifera
 virgifera also drawing the attention to the scientific world and to the farmers as well upon this factor
 of reduction of the production of corn.
 In Sibiu County this species was first recorded in 2001, coming from West, at the border with
 Alba County. The first gatherings were done in Miercurea Sibiului. The investigation was done during
 2001–2009 concerning in: monitoring the adults and the larvae, the identification of the attacked
 plants, the way of harming both for…
Production and characterization of Bacillus thuringiensis Cry1Ac-resistant cotton bollworm Helicoverpa zea (Boddie).
2007
ABSTRACT Laboratory-selected Bacillus thuringiensis -resistant colonies are important tools for elucidating B. thuringiensis resistance mechanisms. However, cotton bollworm, Helicoverpa zea , a target pest of transgenic corn and cotton expressing B. thuringiensis Cry1Ac (Bt corn and cotton), has proven difficult to select for stable resistance. Two populations of H. zea (AR and MR), resistant to the B. thuringiensis protein found in all commercial Bt cotton varieties (Cry1Ac), were established by selection with Cry1Ac activated toxin (AR) or MVP II (MR). Cry1Ac toxin reflects the form ingested by H. zea when feeding on Bt cotton, whereas MVP II is a Cry1Ac formulation used for resistance se…
Microbial Diversity in the Midguts of Field and Lab-Reared Populations of the European Corn Borer Ostrinia nubilalis
2011
Background: Insects are associated with microorganisms that contribute to the digestion and processing of nutrients. The European Corn Borer (ECB) is a moth present world-wide, causing severe economical damage as a pest on corn and other crops. In the present work, we give a detailed view of the complexity of the microorganisms forming the ECB midgut microbiota with the objective of comparing the biodiversity of the midgut-associated microbiota and explore their potential as a source of genes and enzymes with biotechnological applications. Methodological/Principal Findings: A high-throughput sequencing approach has been used to identify bacterial species, genes and metabolic pathways, parti…