Search results for "herbivore"
showing 10 items of 126 documents
Oxygen isotope composition of North American bobcat (Lynx rufus) and puma (Puma concolor) bone phosphate: implications for provenance and climate rec…
2015
Feline carnivores are threatened by illegal wildlife trade. Tracing the provenance of unknown felid tissues via stable isotope analysis could provide important information in wildlife crime investigations. The oxygen isotope composition of mammalian skeletal phosphate (δ(18)Op) is widely applied to trace the origin of animal remains and to reconstruct migratory patterns in palaeontological, archaeological, ecological and wildlife forensic applications. Teeth and bones of terrestrial mammals form at constant body temperature in isotope equilibrium with body water, which is predominantly controlled by ingested meteoric water (δ(18)Ow) that varies systematically with latitude, altitude and cli…
The Impact of Environmental Conditions on Efficiency of Host Plant DNA Barcoding for Polyphagous Beetles.
2015
Recently, several papers were published dealing with host plant identification for selected species of insects, including beetles. These studies took advantage of the DNA barcoding approach and generally showed that it is possible to identify diet composition from plant DNA present in insect guts. However, none of these studies considered how the impact of environmental conditions affected the likelihood of insect feeding and, therefore, the presence of host plant DNA that could be amplified and sequenced. In the present study, individuals of the polyphagous weevil Centricnemus leucogrammus (Germar, 1824) (Curculionidae: Entiminae) were used to test the hypothesis that harsh environmental c…
Seasonal diet-based resistance to anticoagulant rodenticides in the fossorial water vole (Arvicola amphibius)
2021
International audience; Anticoagulant rodenticides (AR) resistance has been defined as "a major loss of efficacy due to the presence of a strain of rodent with a heritable and commensurately reduced sensitivity to the anticoagulant". The mechanism that supports this resistance has been identified as based on mutations in the Vkorc1 gene leading to severe resistance in rats and mice. This study evaluates the validity of this definition in the fossorial water vole and explores the possibility of a non-genetic diet-based resistance in a strict herbivorous rodent species. Genetic support was explored by sequencing the Vkorc1 gene and the diet-based resistance was explored by the dosing of vitam…
Predicting future thermal habitat suitability of competing native and invasive fish species: From metabolic scope to oceanographic modelling
2015
Global increase in sea temperatures has been suggested to facilitate the incoming and spread of tropical invaders. Here, we determined the effect of temperature on the aerobic metabolic scope of two competing fish species, one native and one invasive, and we predicted their future thermal habitat suitability.
Stable isotope analysis of well-preserved 120,000-year-old herbivore bone collagen from the Middle Palaeolithic site of Neumark-Nord 2, Germany revea…
2012
Abstract Herbivores from the Neumark-Nord 2 archaeological site, Germany, were analysed for bone collagen stable carbon (δ 13 C) and nitrogen (δ 15 N) isotope ratios in order to investigate feeding ecology at this early Last Interglacial (Eemian) shallow-lake site. Of 42 faunal samples selected, 23 yielded collagen, demonstrating remarkable preservation for material of this age. The results indicate clear inter-specific differences in δ 15 N and δ 13 C values, notably between equids ( Equus ) and bovids ( Bos/Bison ), with mean difference Δ 15 N of + 2‰ measured in the bovids compared to the equids. The potential reasons for these differences are explored, including physiology, herbivore fe…
Individual and combined effects of disturbance and N addition on understorey vegetation in a subarctic mountain birch forest
2011
Questions: What are the effects of repeated disturbance and N-fertilization on plant community structure in a mountain birch forest? What is the role of enhanced nutrient availability in recovery of understorey vegetation after repeated disturbance? How are responses of soil micro-organisms to disturbance and N-fertilization reflected in nutrient allocation patterns and recovery of understorey vegetation after disturbance? Location: Subarctic mountain birch forest, Finland. Methods: We conducted a fully factorial experiment with annual treatments of disturbance (two levels) and N-fertilization (four levels) during 1998‐2002. We monitored treatment effects on above-ground plant biomass, plan…
The Ecology of Hyperparasitoids.
2021
Hyperparasitoids are some of the most diverse members of insect food webs. True hyperparasitoids parasitize the larvae of other parasitoids, reaching these larvae with their ovipositor through the herbivore that hosts the parasitoid larva. During pupation, primary parasitoids also may be attacked by pseudohyperparasitoids that lay their eggs on the parasitoid (pre)pupae. By attacking primary parasitoids, hyperparasitoids may affect herbivore population dynamics, and they have been identified as a major challenge in biological control. Over the past decades, research, especially on aphid- and caterpillar-associated hyperparasitoids, has revealed that hyperparasitoids challenge rules on nutri…
Impact of parasitoid-associated polydnaviruses on plant-mediated herbivore interactions
2022
Insect herbivores interact via plant-mediated interactions in which one herbivore species induces changes in plant quality that affects the performance of a second phytophagous insect that shares the food plant. These interactions are often asymmetric due to specificity in induced plant responses to herbivore attack, amount of plant damage, elicitors in herbivore saliva and plant organ damaged by herbivores. Parasitoids and their symbiotic polydnaviruses alter herbivore physiology and behaviour and may influence how plants respond to parasitized herbivores. We argue that these phenomena affect plant-mediated interactions between herbivores. We identify that the extended phenotype of parasit…
Synopsis of the helminth communities of the lacertid lizards from the Balearic and Canary Islands
2012
Helminth communities of reptiles have usually been considered as depauperate and isolationist, with low abundance and species richness when compared to other vertebrates. Nevertheless there are some insular reptile populations in which this general rule is not fulfilled. In this study, we compare helminth faunas from two groups of lizards living in two different archipelagos and having different feeding habits. Lacertid lizards from Canary Islands, belonging to the endemic genus Gallotia, showed by contrast with other lacertids, a tendency to high consumption of plant matter and to rich and diverse helminth communities. Differences were found even between the lizards living in different isl…
Glyphosate-based herbicide has soil-mediated effects on potato glycoalkaloids and oxidative status of a potato pest
2020
Glyphosate is the most used herbicide worldwide, targeting physiological pathways in plants. Recent studies have shown that glyphosate can also cause toxic effects in animals. We investigated the glyphosate-based herbicide (GBH)-induced changes in potato (Solanum tuberosum) plant chemistry and the effects of a GBH on the survival rate and oxidative status of the Colorado potato beetle (Leptinotarsa decemlineata). The beetles were reared on potato plants grown in pots containing soil treated with a GBH (Roundup Gold, 450 g/l) or untreated soil (water control). The 2nd instar larvae were introduced to the potato plants and then collected in 2 phases: as 4th instar larvae and as adults. The ma…