Search results for "systematics."
showing 10 items of 4966 documents
Habitat Preference of German Mantis religiosa Populations (Mantodea: Mantidae) and Implications for Conservation.
2015
In Germany, the thermophilic European mantid ( Mantis religiosa L.) is endangered. Here, we study habitat requirements during its life, and discuss the applicability of the two conservation measures grazing and mowing to this insect species . At two study sites in south-western Germany, which were each subject to one of these measures, we recorded structural and climatic conditions within different microhabitats. We also conducted capture–mark–recapture studies for adult M. religiosa , and mapped adult roosting, oothecae deposition, egg hatching, and imaginal molting in microhabitats over two vegetation periods. In order to assess microhabitat preference of M. religiosa during its life, and…
Coupling transcriptomics and behaviour to unveil the olfactory system of Spodoptera exigua larvae
2020
AbstractChemoreception in insects is crucial for many aspects related to food seeking, enemy avoidance, and reproduction. Different families of receptors and binding proteins interact with chemical stimuli, including odorant receptors (ORs), ionotropic receptors (IRs), gustatory receptors (GRs), odorant binding proteins (OBPs) and chemosensory proteins (CSPs). In this work, we describe the chemosensory-related gene repertoire of the worldwide spread pest Spodoptera exigua (Lepidoptera: Noctuide) focusing on the transcripts expressed in larvae, which feed on many horticultural crops producing yield losses. A comprehensive de novo assembly that includes reads from chemosensory organs of larva…
Reproductive site selection: evidence of an oviposition cue in a highly adaptive dipteran, Drosophila suzukii (Diptera: Drosophilidae)
2020
Abstract Drosophila suzukii (Matsumura) is a vinegar fly species that originates from Eastern Asia and has spread throughout Europe and the Americas since its initial detection in United States in 2008. Its relatively large, sclerotized, and serrated ovipositor enables the ability to penetrate ripening fruits, providing a protected environment for its egg and larval stages. Because the mechanism of oviposition site selection of D. suzukii is a matter of hypothesis, the aim of the present study was to elucidate behavioral and chemical aspects of short-range ovipositional site selection within the context of D. suzukii reproductive biology. The preference of D. suzukii to lay eggs on artifici…
Dynamics of PHA-induced immune response and plasma carotenoids in birds: should we have a closer look?
2009
SUMMARY Allocation trade-offs of limited resources are thought to ensure the honesty of sexual signals and are often studied using controlled immune challenges. One such trade-off between immunity and ornaments is that involving carotenoids. Phytohemagglutinin (PHA)-induced immune response is a widely used immune challenge, yet more details on the underlying physiological mechanisms and potential costs are needed. We investigated the temporal dynamics of PHA-induced immune response and associated changes in blood carotenoids, body mass and a carotenoid-based coloured signal. We found variation in individual response patterns to PHA after peak swelling was reached, with birds showing either …
Does evolution of iteroparous and semelparous reproduction call for spatially structured systems?
2000
A persistent question in the evolution of life histories is the fitness trade-off between reproducing only once (semelparity) in a lifetime or reproducing repeated times in different seasons (iteroparity). The problem can be formulated into a research agenda by assuming that one reproductive strategy is resident (has already evolved) and by asking whether invasion (evolution) of an alternative reproductive strategy is possible. For a spatially nonstructured system, Bulmer (1994) derived the relationship v + PA1 (PA is adult survival; vbS and bS are offspring numbers for iteroparous and semelparous breeding strategies, respectively) at which semelparous population cannot be invaded by an ite…
EPIDEMIOLOGY OF PLASMODIUM RELICTUM INFECTION IN THE HOUSE SPARROW.
2014
International audience; : Abstract In vertebrates, multiple host characteristics and environmental factors are known to influence infectious disease dynamics. Here, we investigated variability in prevalence and parasitemia of Plasmodium relictum in the house sparrow (Passer domesticus), across a large number of rural and urban populations (n = 16). We found that prevalence was not predicted by any of the host traits investigated (age, sex, body mass or wing length). However, parasitemia was significantly higher in females when compared to males and in 1-yr-olds as compared to older individuals. Neither prevalence nor parasitemia differed according to habitat type (urban vs. rural). These re…
Elevated oxidative stress in pied flycatcher nestlings of eumelanic foster fathers under low rearing temperatures
2019
Striking variation in melanin coloration within natural populations is likely due to the different fitness outcomes of alternative phenotypes in varying environmental conditions. There are two types of melanin: eumelanins yield blackish hues, whereas pheomelanins yield reddish hues. The production of eumelanins requires low levels of glutathione (GSH), which is the most important intracellular antioxidant, whereas the production of pheomelanins requires high levels of GSH. We investigated the oxidative status of male pied flycatchers (Ficedula hypoleuca) with different degrees of melanin coloration under different temperatures during the nestling period. Moreover, we assessed the oxidative …
Avoiding perceived past resource use of potential competitors affects niche dynamics in a bird community
2014
Abstract. Background: Social information use is usually considered to lead to ecological convergence among involved con- or heterospecific individuals. However, recent results demonstrate that observers can also actively avoid behaving as those individuals being observed, leading to ecological divergence. This phenomenon has been little explored so far, yet it can have significant impact on resource use, realized niches and species co-existence. In particular, the time-scale and the ecological context over which such shifts can occur are unknown. We examined with a long-term (four years) field experiment whether experimentally manipulated, species-specific, nest-site feature preferences (sy…
The evolution of sperm morphometry in pheasants
2007
7 pages; International audience; Post-copulatory sexual selection is thought to be a potent evolutionary force driving the diversification of sperm shape and function across species. In birds, insemination and fertilization are separated in time and sperm storage increases the duration of sperm-female interaction and hence the opportunity for sperm competition and cryptic female choice. We performed a comparative study of 24 pheasant species (Phasianidae, Galliformes) to establish the relative importance of sperm competition and the duration of sperm storage for the evolution of sperm morphometry (i.e. size of different sperm traits). We found that sperm size traits were negatively associat…
Co-variation between the intensity of behavioural manipulation and parasite development time in an acanthocephalan-amphipod system.
2010
8 pages; International audience; Pomphorhynchus laevis, a fish acanthocephalan parasite, manipulates the behaviour of its gammarid intermediate host to increase its trophic transmission to the definitive host. However, the intensity of behavioural manipulation is variable between individual gammarids and between parasite populations. To elucidate causes of this variability, we compared the level of phototaxis alteration induced by different parasite sibships from one population, using experimental infections of Gammarus pulex by P. laevis. We used a naive gammarid population, and we carried out our experiments in two steps, during spring and winter. Moreover, we also investigated co-variati…