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The process of local adaptation involves differential changes in fitness over time across different environments. Although experimental evolution studies have extensively tested for patterns of local adaptation at a single time point, there is relatively little research that examines fitness more than once during the time course of adaptation. We allowed replicate populations of the fruit pest Drosophila suzukii to evolve in one of eight different fruit media. After five generations, populations with the highest initial levels of maladaptation had mostly gone extinct, whereas experimental populations evolving on cherry, strawberry and cranberry media had survived. We measured the fitness of each surviving population in each of the three fruit media after five and after 26 generations of evolution. After five generations, adaptation to each medium was associated with increased fitness in the two other media. This was also true after 26 generations, except when populations that evolved on cranberry medium developed on cherry medium. These results suggest that, in the theoretical framework of a fitness landscape, the fitness optima of cherry and cranberry media are the furthest apart. Our results show that studying how fitness changes across several environments and across multiple generations provides insights into the dynamics of local adaptation that would not be evident if fitness were analysed at a single point in time. By allowing a qualitative mapping of an experimental fitness landscape, our approach will improve our understanding of the ecological factors that drive the evolution of local adaptation in D. suzukii., Using fitness landscape theory to study adaptation and correlated fitness responses over two time scales in Drosophila suzukii populations evolving in different fruit environments.

International audience; Orthoptera are infected by about 60 species of gregarines assigned to the genus Gregarina Dufour, 1828. Among these species, Gregarina garnhami Canning, 1956 from Schistocerca gregaria (Forsskål, 1775) was considered by Lipa et al. in 1996 to be synonymous with Gregarina acridiorum (Léger 1893), a parasite of several orthopteran species including Locusta migratoria (Linné, 1758). Here, a morphological study and molecular analyses of the SSU rDNA marker demonstrate that specimens of S. gregaria and specimens of L. migratoria are infected by two distinct Gregarina species, G. garnhami and G. acridiorum, respectively. Validation of the species confirms that molecular analyses provide useful taxonomical information. Phenotypic plasticity was clearly observed in the case of G. garnhami: the morphology of its trophozoites, gamonts and syzygies varied according to the geographical location of S. gregaria and the subspecies infected.; Les orthoptères sont parasités par environ soixante espèces de grégarines affiliées au genre Gregarina (Dufour, 1828). Parmi ces espèces Gregarina garnhami (Canning, 1956), décrite chez Schistocerca gregaria (Forskål,1775), a été mise en synonymie par Lipa et al. en 1996 avec Gregarina acridiorum (Léger 1893), parasite de plusieurs espèces d’orthoptères dont Locusta migratoria (Linné, 1758). Ici, une étude morphologique et des analyses moléculaires du marqueur SSU rDNA démontrent que les spécimens de S. gregariaet ceux de L. migratorias ont infectés par 2 espèces distinctes de grégarines, Gregarina garnhami et Gregarina acridiorum, respectivement. La validation de ces espèces confirme l’importance des informations fournies par les analyses moléculaires dans les études taxonomiques. Une plasticité phénotypique a été clairement observée dans le cas de G. garnhami :la morphologie de ses trophozoïtes, gamontes et syzygies varie selon la localisation géographique et la sous-espèce de S. gregaria infectée.

International audience; Puumala virus (PUUV) in Europe causes nephropathia epidemica (NE), a mild form of hemorrhagic fever with renal syndrome (HFRS). The incidence of NE is highly heterogeneous spatially, whereas the geographic distribution of the wild reservoir of PUUV, the bank vole, is essentially homogeneous. Our understanding of the processes driving this heterogeneity remains incomplete due to gaps in knowledge. Little is known about the current distribution and genetic variation of PUUV in the areas outside the well-identified zones of NE endemicity. We trapped bank voles in four forests in French regions in which NE is considered non-endemic, but sporadic NE cases have been reported recently. We tested bank voles for anti-PUUV IgG and characterized the S segment sequences of PUUV from seropositive animals. Phylogenetic analyses revealed specific amino-acid signatures and genetic differences between PUUV circulating in non-endemic and nearby NE-endemic areas. We also showed, in temporal surveys, that the amino-acid sequences of PUUV had undergone fewer recent changes in areas non-endemic for NE than in endemic areas. The evolutionary history of the current French PUUV clusters was investigated by phylogeographic approaches, and the results were considered in the context of the history of French forests. Our findings highlight the need to monitor the circulation and genetics of PUUV in a larger array of bank vole populations, to improve our understanding of the risk of NE.

Adaptation to divergent environments can result in ecological specialization. The detection of trade-offs across environments (i.e., negative correlations in performance between different environments) is the hallmark of specialization. Although such trade-offs are predicted by theory, experimental evidence that trade-offs can readily evolve in the laboratory remains scarce. Here, we investigated the evolution of adaptation to distinct environments, including potential fitness trade-offs by maintaining populations of the generalist fruit pest, Drosophila suzukii , for 26 generations on media made with different fruits. We measured the performance and preference of each evolved population on the different fruits using reciprocal transplant experiments after five generations and at the end of our experiment. After five generations, experimental populations on most fruits had gone extinct, but they had adapted to three test fruit media, without exhibiting trade-offs. By generation 26 on these three fruits, specific adaptation to each fruit media had evolved, with trade-offs across media for some populations. The evolution of fruit-specific performance did not drive the evolution of corresponding preferences (i.e., preferences for the evolution fruit). This study suggests that ecological specialization can evolve in generalist species, even if only transiently, when hosts or habitats are heterogeneous over time and space.

The systematics of the genus Calliptamus mainly relies on the shape of the wing and phallic complex, and on color pattern of hind femora of males only. However, geographical variation in these morphological characters hinders species determination. These difficulties may explain why the species delimitation within the genus Calliptamus has been controversial, with numerous confusions, descriptions, synonymies and subspecies. The purpose of this research is to provide a taxonomic review of the genus Calliptamus, based on an integrative approach including morphological, molecular and biological data. Beyond laying the foundations for a revised classification, this project will unravel the historical biogeography of the genus. The Orthoptera Species File currently counts twelve species whose type depositories are known for the Palaearctic genus Calliptamus. We collected with success 9 species, represented by an average of 10 (from 1 to 25) individuals and 6 (from 1 to 17) localities. Since a phylogeny based on a few nuclear genes only may fail to resolve the basal relationships, we used the method of Restrictionsite- associated DNA sequencing (RAD-seq), which showed promises to infer shallow relationships in insects. We showed a success of the method, despite the huge size for the genomes of Calliptamus sp., which we estimated to be ~7.65- 8.39 Gb. We confirmed the two clades defined on the basis of genitalia shape: a Northern group includes species from the cold and wet temperate regions of Eurasia (e.g. C. italicus) and a southern group includes species from the warm and dry mediterranean region (e.g. c. barbarus). we interpreted diversification within these two clades as the result of biogeographic factors, such as isolation in high mountain ranges and islands. We discovered that the species C. barbarus was not monophyletic and we used finer-scale sampling and the COI barcode to understand further its evolutionary history. Morphological analyses of numerous characters, including the hind wing, hind femur, shape of the pronotum and internal and external structures of the male genitalia, are in process to supplement genetic analyses.

The use of cameras to analyze locust activity, attraction / repulsion is an innovation that is increasingly used in behavioral studies. It allows to simultaneously collect information without interacting with the locusts and to observe more discrete behaviors which are not visually noticeable. Although the technique is complementary to the one focused on the analysis of the individual response to a group of stimuli, it offers an improvement in the observation methods of groups of individuals through the application of spatial statistics. In our present study, we did laboratory analysis of locust spatial distribution patterns in a circular arena for characterizing phase status. With spatial statistics, we examined the temporal variations of nearest neighbor distances as a criterion of attraction / repulsion between individuals raised either in isolation or in groups in order to induce phase behavior. Also, the successive changes of position of the individuals because of their activity in the circular arena were interpreted as criterion of differentiation between solitarious and gregarious locust phases. Tests were carried out, first with the sequences of photographs taken at regular intervals on 3rd instar hoppers of Desert Locust, Schistocerca gregaria, and secondly with the help of video tracking on 3rd instar hoppers of the Migratory Locust, Locusta migratoria. Making inferences on the underlying process that generates the temporal variations of the positions of the hoppers in the arena, we found that there was a larger nearest neighbor distance between isolated-rearedhoppers (indicating repulsion) in contrast to crowd-rearedhoppers, which showed an attraction with their conspecifics. From the analysis of walked distances in both tests, we found a greater activity of crowd-rearedhoppers compared to isolated-rearedhoppers. This method of quantitative analysis of locust phase differences appears to be more effective in saving time and providing more insight into as yet unclear aspects of behavioral phase studies.

National audience; Theory predicts that adaptive trade-offs across environments promote the evolution of specialized genotypes. However, generalist genotypes that are not better adapted to a specific environment are often observed in nature. Generalists can be maintained despite trade-offs between environments under two circumstances: when environmental conditions are variable spatially or temporally or when there is no genetic variability to evolve toward specialized genotypes. Drosophila suzukii is an insect pest that attacks the fruits of a wide range of host plants. The availability of each type of host is restricted to a certain time of the year, which might prevent the evolution of specialist genotypes. We can hypothesize that if flies were able to develop on the same host for multiple generations, increased specialization should arise. We tested this hypothesis using an experimental evolution approach. We maintained replicate populations of flies in three different fruit environments. After five generations of experimental selection, each population evolved increased fitness on the fruit it was maintained on as well as on the two other fruits. In addition, preference tests showed that lines did not prefer their own fruit environment. These results indicate that the populations adapted to laboratory conditions, and that there was no response to potential trade-offs across environments. This suggests, that such trade-offs are weak or that there is no genetic variation for specialization to evolve. To confirm this finding, we are maintaining the experimental lines for another five additional generations. Our preliminary results highlight the difficulty of studying the evolution of specialization.

National audience; Theory predicts that adaptive trade-offs across environments promote the evolution of specialized genotypes. However, generalist genotypes that are not better adapted to a specific environment are often observed in nature. Generalists can be maintained despite trade-offs between environments under two circumstances: when environmental conditions are variable spatially or temporally or when there is no genetic variability to evolve toward specialized genotypes. Drosophila suzukii is an insect pest that attacks the fruits of a wide range of host plants. The availability of each type of hast is restricted to a certain time of the year, which might prevent the evolution of specialist genotypes. We can hypothesize that if flies were able to develop on the same hast for multiple generations, increased specialization should arise. We tested this hypothesis using an experimental evolution approach. We maintained replicate populations of flies in three different fruit environments. After five generations of experimental selection, each population evolved increased fitness on the fruit it was maintained on as well as on the two other fruits. In addition, preference tests showed that lines did not prefer their own fruit environment. These results indicate that the populations adapted to laboratory conditions, and that there was no response to potential trade-offs across environments. This suggests, that such trade-offs are weak or that there is no genetic variation for specialization to evolve. To confirm this finding, we are maintaining the experimental lines for another five additional generations. Our preliminary results highlight the difficulty of studying the evolution of specialization.

The easy leaching of boron in wood preservation formulations has allowed to use this fungicide only for short term applications. The recently discovered adduct with flavonoids allows boron to resist longer periods of time within wood and consequently extend its life. Two different leaching treatments were compared and the fungal and termite decay was examined. The biological tests have shown extremely high resistance of the leached samples against both, fungus (Coriolus versicolor and Coniophora puteana). The resistance towards termites (Reticulitermes flavipes ex. santonensis) was also evaluated. A threshold concentration for the efficacy of boron as wood preservative was determined. Furthermore, the solid state 13C-NMR analysis of the tannin resin has permitted to prove the anchorage of boron to flavonoids.

Biochemical and physiological process which occurred during heartwood formation have consequences on wood properties such as colour, natural durability and some mechanical properties. However, it is very time-consuming to take measurements of extractives contents. Teak has been reported to contain 1-hydroxy- 2-methyl-anthraquinone, 2-hydroxy-methyl-anthraquinone, 2-methyl- anthraquinone, lapachol, 1,4-naphthoquinone for the main compounds. In teak, natural durability is ascribed to extractives. Consequently, it's possible to estimate natural durability by measurement of extractives indirectly. For the purposes of selection for the production of improved varieties, the number of samples to be measured rapidly exceeds the capacity of a traditional laboratory. Near-infrared spectroscopy approach, based on spectral data and reference data, is a tool enabling many of the chemical properties of wood to be predicted and the number of laboratory measurements to be reduced exponentially. The issue here is a question of checking the effectiveness of NIRS tool to build models and predict the main extractive compounds of teak wood from Ivory Coast. We try to calibrate these chemical properties with Nirs spectral information measured on grounded wood. The results show the possible use of NIRS to predict total phenol content and some main extractive compounds of teak heartwood as tectoquinone, 2-hydroxymethylanthraquinone,Consequently, after verification on other sets of teak samples, which may or may not be included in the prediction model, NIRS can be used to predict extractive compounds accurately for a large number of samples, making it possible to estimate natural durability indirectly and to include these characteristics in the selection criteria for classifying wood and high throughput phenotyping.

The implication of quinones in decay resistance of teak wood is controversial. To better understand the role of individual quinone in this property, we studied the correlations between this latter and the content of 2-(hydroxymethyl)anthraquinone, tectoquinone, anthraquinone-2-carboxylic acid, 1,4-naphthoquinone, lapachol and the new compound 4',5'-dihydroxy-epiisocatalponol found in teak wood. Then, we studied the fungicidal activities of these quinones in comparison to acetone/water extracts from teak heartwood and sapwood and also with the commercial biocide tebuconazole. Broth dilution technique was used to assess the toxicity of these compounds against #Trametes versicolor# and #Poria placenta#. Decay resistance was measured according to curent standards and individual quinones content were quantified by high performance liquid chromatography. High positive correlations were found between teak decay resistance and the content of 4',5'-dihydroxy-epiisocatalponol, tectoquinone, 2-(hydroxymethyl)anthraquinone. Whereas no correlation was found with anthraquinone-2-carboxylic acid, lapachol and 1,4-naphthoquinone. Concerning the fungicidal activities of teak wood extractives, acetone/water heartwood extract was toxic against the two fungi while that of acetone/water sapwood was only fungistatic. 1,4-naphthoquinone and 4',5'-dilydroxy-epiisocatalponol from the naphthoquinones family were fungicide. However, lapachol and all studied anthraquinones (2-(hydroxymethyl)anthraquinone, anthraquinone-2-carboxylic acid and tectoquinone) were fungistatic or not toxic. In the present study, 1,4-naphthoquinone was found the more toxic with a fungicidal activity 1000-times lower than that of the commercial biocide and over 2000-times lower than that of acetone/water heartwood extracts. These results show that decay resistance of teak wood could be mostly due to the content of naphthoquinone, particularly to that of 1,4-naphthoquinone indicating that it could be used as a potential wood preservative for lesser durable species.