Search results for "InSe"

Impacts of chitinase-transformed silver birch on leaf decomposition and soil organisms

2004

Genetically manipulated silver birch (Betula pendula) leaves were used in microcosms experiments to evaluate their impacts on different groups of decomposing soil fauna. Birches were transformed to produce chitinase IV from sugar beet. We compared decomposition rates of leaves, growth and reproduction of soil fauna deriving nutrition from these leaves. Population numbers of collembolans (Folsomia candida and Lepidocyrtus lignorum) and nematodes were measured and decomposition rates of the birch leaves were recorded. Woodlice (Porcellio scaber) juveniles living in the microcosms were weighed at 2- to 4-week intervals to determine growth rate. This study revealed that birch leaves manipulated…

Stream restorations with meanders increase dragonfly and damselfly diversity and abundance, including an endangered species.

2021

10 pages; International audience; This study presents examples of successful restoration projects for biodiversity conservation. In West France, the Pinail National Nature Reserve is a protected wetland interspersed with more than 6000 ponds. This wetland is inhabited by 50 species of Odonata and thus is a key biodiversity area for damselflies and dragonflies conservation. In the past, when the limestone was exploited, the streams of the plateau were artificially channeled rectilinearly, running to the Vienne River. Eventually streams were blocked by biomass and sediments resulting in water flowing mainly underground. In 2011, two restoration projects dug and recreated lost habitats such as…

Beta diversity of stream insects differs between boreal and subtropical regions, but land use does not generally cause biotic homogenization

2021

Made available in DSpace on 2021-06-25T10:17:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-01 Previous studies have found mixed results regarding the relationship between beta diversity and latitude. In addition, by influencing local environmental heterogeneity, land use maymodify spatial taxonomic and functional variability among communities causing biotic differentiation or homogenization. We tested 1) whether taxonomic and functional beta diversities among streams within watersheds differ between subtropical and boreal regions and 2) whether land use is related to taxonomic and functional beta diversities in both regions.Wesampled aquatic insects in 100 subtropical (Brazil…

2021

The social vespid wasps are common insect predators and several species behave in unison in the same biotopes. It is commonly accepted that social wasps are mainly opportunistic generalist predators without differences in prey selection and hence they compete for the same food resources. Trophic positions of six vespid wasp species and their potential prey from four sites in Finland and one in the UK were evaluated using carbon and nitrogen stable isotopes (δ 13 C and δ 15 N). The difference in isotope values indicated different trophic positions among species. In general, Dolichovespula spp. showed higher δ 15 N values than Vespula spp., which suggests that Dolichovespula forage on higher…

Springtails (Collembola) in meadows, pastures and road verges in Central Finland

2017

Understanding of species distribution, abundance and habitat affinities is crucial for red-list assessment, conservation and habitat management. In Central Finland, we studied Collembola in three habitat types, namely non-grazedmeadows, pastures and road verges using pitfall traps. Altogether, 9,630 Collembola individuals were recorded. These belonged to 12 families, 34 genera and 60 species. The number of specimens was clearly higher in meadows than in pastures or road verges. The number of species, however, was higher in meadows and road verges (40 and 39 species, respectively) than in pastures (33 species). The overall species number is comparable to other large-scale sampling schemes in…

Biology and Behaviour of Cirrospilus diallus and Cirrospilus pictus, Parasitoids of Phyllocnistis citrella

2005

International audience; Studies were carried out on some biological and behavioral aspects of Cirrospilus diallus Walker and Cirrospilus pictus (Nees) (Hymenoptera: Eulophidae) in relation to their host, the citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae). Adults of both species fed with sugar lived on average 4.45 +/- 0.19 days, whereas adults provided with honey survived on average 40.62 +/- 1.97 days. Rates of host mortality due to parasitoid stings without oviposition were as high as 31.25 and 37.73% for C. pictus and C. diallus, respectively. Both species showed arrhenotokous parthenogenesis. Sex ratios of parasitoids emerging from the 2nd and 3rd …

Characterization and evolution of two bacteriome-inhabiting symbionts in cixiid planthoppers (Hemiptera: Fulgoromorpha: Pentastirini).

2009

International audience; Like other plant sap-sucking insects, planthoppers within the family Cixiidae (Insecta: Hemiptera: Fulgoromorpha) host a diversified microbiota. We report the identification and first molecular characterization of symbiotic bacteria in cixiid planthoppers (tribe: Pentastirini). Using universal eubacterial primers we first screened the eubacterial 16S rRNA sequences in Pentastiridius leporinus (Linnaeus) with PCR amplification, cloning, and restriction fragment analysis. We identified three main 16S rRNA sequences that corresponded to a Wolbachia bacterium, a plant pathogenic bacterium, and a novel gammaproteobacterial symbiont. A fourth bacterial species affiliated w…

Redescription of the forgotten New Caledonian weevil genus Callistomorphus Perroud, 1865 (Coleoptera, Curculionidae, Eugnomini) with descriptions of …

2019

Callistomorphusis one of the “forgotten” genera of the tribe Eugnomini inhabiting rain forest in New Caledonia. In this paper, the genusCallistomorphusand the type speciesC.farinosusare redescribed. Eight new species,Callistomorphusfundatussp. n.,C.gibbussp. n.,C.malleussp. n.,C.minimussp. n.,C.rutaisp. n.,C.szoltysisp. n.,C.torosussp. n.andC.turbidussp. n., are described, originating from the main island of New Caledonia. Illustrations and SEM photographs of the external morphology and the male and female terminalia are provided, as well as dorsal habitus colour photographs of the adults, a key to the species, a distribution map, and a discussion of the systematic position ofCallistomorphu…

Sex versus parthenogenesis: A transcriptomic approach of photoperiod response in the model aphid Acyrthosiphon pisum (Hemiptera: Aphididae)

2007

International audience; Most aphids develop a cyclic parthenogenesis life-cycle. After several generations of viviparous parthenogenetic females, it follows a single annual generation of sexual individuals, usually in autumn, that mate and lay the sexual eggs. Shortening of photoperiod at the end of the summer is a key factor inducing the sexual response. With the survey here reported we aimed at identifying a collection of candidate genes to participate at some point in the cascade of events that lead to the sexual phenotypes. Following a suppression subtractive hybridization methodology (SSH) on the model aphid Acyrthosiphon pisum, we built and characterised two reciprocal cDNA libraries …

2021

Although insect herbivores are known to evolve resistance to insecticides through multiple genetic mechanisms, resistance in individual species has been assumed to follow the same mechanism. While both mutations in the target site insensitivity and increased amplification are known to contribute to insecticide resistance, little is known about the degree to which geographic populations of the same species differ at the target site in a response to insecticides. We tested structural (e.g., mutation profiles) and regulatory (e.g., the gene expression of Ldace1 and Ldace2, AChE activity) differences between two populations (Vermont, USA and Belchow, Poland) of the Colorado potato beetle, Lepti…