Search results for "INS"
showing 10 items of 35719 documents
Defense strategies used by two sympatric vineyard moth pests.
2014
8 pages; International audience; Natural enemies including parasitoids are the major biological cause of mortality among phytophagous insects. In response to parasitism, these insects have evolved a set of defenses to protect themselves, including behavioral, morphological, physiological and immunological barriers. According to life history theory, resources are partitioned to various functions including defense, implying trade-offs among defense mechanisms. In this study we characterized the relative investment in behavioral, physical and immunological defense systems in two sympatric species of Tortricidae (Eupoecilia ambiguella, Lobesia botrana) which are important grapevine moth pests. …
Species diversity of larval parasitoids of the European grapevine moth (Lobesia botrana, Lepidoptera: Tortricidae): the influence of region and culti…
2010
7 pages; International audience; The European grapevine moth, Lobesia botrana (Denis & Schiffermüller, 1775) (Lepidoptera: Tortricidae) is a major pest of grapevines responsible for great economic losses and frequent insecticide applications. Nevertheless, the use of parasitoids as potential biological control agents has received very little attention. In this study, we present results from a survey on parasitoid species collected from French and Swiss vineyards over a period of 2 years. Over 2000 larvae of L. botrana were collected from six grape cultivars out of which a total of 118 parasitoids emerged. Ten species were identified. Exochus notatus (Holmgren, 1858) (Hymenoptera: Ichneumoni…
Differences in nutritional quality of parts of Vitis vinifera berries affect fitness of the European grapevine moth
2006
International audience; The European grapevine moth, Lobesia botrana (Denis & Schiffermuller) (Lepidoptera: Tortricidae), is a major grapevine pest in Europe. The larva is polyphagous and able to develop on more than 25 plant species, several of them being more suitable than Vitaceae for the fitness of L. botrana. Larvae normally eat the pulp of the berry, but may also consume the seeds according to the development stage of the berry and the larval density per bunch. Understanding the effect on individual fitness of such feeding behaviour is important to assess how suitable the different berry tissues are for this insect. We offered to the larvae either entire berries, seeds, or pulp with s…
Immigrant Tortricidae: Holarctic versus Introduced Species in North America
2020
In support of a comprehensive update to the checklist of the moths of North America, we attempt to determine the status of 151 species of Tortricidae present in North America that may be Holarctic, introduced, or sibling species of their European counterparts. Discovering the natural distributions of these taxa is often difficult, if not impossible, but several criteria can be applied to determine if a species that is present in both Europe and North America is natively Holarctic, introduced, or represented by different but closely related species on each continent. We use DNA barcodes (when available), morphology, host plants, and historical records (literature and museum specimens) to mak…
Is maternal thyroid hormone deposition subject to a trade-off between self and egg because of iodine?
2021
ABSTRACT Maternal hormones constitute a key signalling pathway for mothers to shape offspring phenotype and fitness. Thyroid hormones (THs; triiodothyronine, T3; and thyroxine, T4) are metabolic hormones known to play crucial roles in embryonic development and survival in all vertebrates. During early developmental stages, embryos exclusively rely on exposure to maternal THs, and maternal hypothyroidism can cause severe embryonic maldevelopment. The TH molecule includes iodine, an element that cannot be synthesised by the organism. Therefore, TH production may become costly when environmental iodine availability is low. This may yield a trade-off for breeding females between allocating the …
Transcription of two blue copper-binding protein isogenes is highly correlated with arbuscular mycorrhizal development in Medicago truncatula.
2010
International audience; Expression profiling of two paralogous arbuscular mycorrhizal (AM)-specific blue copper-binding gene (MtBcp1a and MtBcp1b) isoforms was performed by real-time quantitative polymerase chain reaction in wild-type Medicago truncatula Jemalong 5 (J5) during the mycorrhizal development with Glomus intraradices for up to 7 weeks. Time-course analysis in J5 showed that expression of both MtBcp1 genes increased continuously and correlated strongly with the colonization intensity and arbuscule content. MtPT4, selected as a reference gene of the functional plant-fungus association, showed a weaker correlation to mycorrhizal development. In a second experiment, a range of mycor…
Consequences of gene flow between transgenic, insect-resistant crops and their wild relatives
2015
Concerns have been raised about the possibility of the negative impact of transgenic crops on the environment. If wild plants accidentally pick up transgenes through pollen exchange with genetically modified crops, they could gain new environmental advantages or conversely suffer genetic homogenization and loss of biodiversity. This could cause weeds that might create new problems in farmers' fields and wild habitats and change biological equilibriums. Examples of gene flow are given for several cases of crop/ancestor pairs and two cases of more distantly related species. The main concern is that introgression between transgenic, insect-resistant crops and their wild relatives could lead to…
Mating Status of an Herbivorous Stink Bug Female Affects the Emission of Oviposition-Induced Plant Volatiles Exploited by an Egg Parasitoid
2019
Insect parasitoids are under selection pressure to optimize their host location strategy in order to maximize fitness. In parasitoid species that develop on host eggs, one of these strategies consists in the exploitation of oviposition-induced plant volatiles (OIPVs), specific blends of volatile organic compounds released by plants in response to egg deposition by herbivorous insects. Plants can recognize insect oviposition via elicitors that trigger OIPVs, but very few elicitors have been characterized so far. In particular, the source and the nature of the elicitor responsible of egg parasitoid recruitment in the case of plants induced with oviposition by stink bugs are still unknown. In …
How to Deal with Uninvited Guests in Wine: Copper and Copper-containing Oxidases
2020
Copper is one of the most frequently occurring heavy metals in must and wine. It is introduced by pesticides, brass fittings, and as copper sulphate for treatment of reductive off-flavors. At higher concentrations, copper has harmful effects on the wine. It contributes to the oxidation of wine ingredients, browning reactions, cloudiness, inhibition of microorganisms, and wine fermentation. Last but not least, there is also a danger to the consumer. At present, some physicochemical methods exist to reduce the copper content in must and wine, but they all have their shortcomings. A possible solution is the biosorption of metals by yeasts or lactobacilli. Copper can also reach must and wine in…
Research priorities for freshwater mussel conservation assessment
2018
Freshwater mussels are declining globally, and effective conservation requires prioritizing research and actions to identify and mitigate threats impacting mussel species. Conservation priorities vary widely, ranging from preventing imminent extinction to maintaining abundant populations. Here, we develop a portfolio of priority research topics for freshwater mussel conservation assessment. To address these topics, we group research priorities into two categories: intrinsic or extrinsic factors. Intrinsic factors are indicators of organismal or population status, while extrinsic factors encompass environmental variables and threats. An understanding of intrinsic factors is useful in monitor…