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31.
32.
Anne Villemey William E. Peterman Murielle Richard Annie Ouin Inge van Halder Virginie M. Stevens Michel Baguette Philip Roche Frédéric Archaux 《Landscape Ecology》2016,31(7):1629-1641
Context
Anthropogenic activities readily result in the fragmentation of habitats such that species persistence increasingly depends on their ability to disperse. However, landscape features that enhance or limit individual dispersal are often poorly understood. Landscape genetics has recently provided innovative solutions to evaluate landscape resistance to dispersal.Objectives
We studied the dispersal of the common meadow brown butterfly, Maniola jurtina, in agricultural landscapes, using a replicated study design and rigorous statistical analyses. Based on existing behavioral and life history research, we hypothesized that the meadow brown would preferentially disperse through its preferred grassy habitats (meadows and road verges) and avoid dispersing through woodlands and the agricultural matrix.Methods
Samples were collected in 18 study landscapes of 5 × 5 km in three contrasting agricultural French regions. Using circuit theory, least cost path and transect-based methods, we analyzed the effect of the landscape on gene flow separately for each sex.Results
Analysis of 1681 samples with 6 microsatellites loci revealed that landscape features weakly influence meadow brown butterfly gene flow. Gene flow in both sexes appeared to be weakly limited by forests and arable lands, whereas grasslands and grassy linear elements (road verges) were more likely to enhance gene flow.Conclusion
Our results are consistent with the hypothesis of greater dispersal through landscape elements that are most similar to suitable habitat. Our spatially replicated landscape genetics study allowed us to detect subtle landscape effects on butterfly gene flow, and these findings were reinforced by consistent results across analytical methods.33.
Cline Tixier Philippe Bogaerts Martine Sancelme Frdrique Bonnemoy Landoald Twagilimana Annie Cuer Jacques Bohatier Henri Veschambre 《Pest management science》2000,56(5):455-462
Microbial degradation, organic synthesis and ecotoxicology were used to investigate the fate of diuron after spreading on soils. Quantitative biodegradation assays were performed with fungal strains, showing that diuron was degraded but not entirely mineralized. The modifications observed consisted in demethylation of the terminal nitrogen atom. The identified metabolites were synthesized in sufficient amounts to confirm their structures and determine their non‐target toxicity using four biotests. The two metabolites exhibited higher effects than parent diuron. This limited biodegradability and potential aquatic toxicity suggest that diuron is of higher environmental concern than previously recognized. © 2000 Society of Chemical Industry 相似文献
34.
Annie J Krueger Kathryn Hanford Thomas J Weissling Ana M Vlez Troy D Anderson 《Journal of insect science (Online)》2021,21(2)
Insecticide exposure has been identified as a contributing stressor to the decline in the North American monarch butterfly Danaus plexippus L. (Lepidoptera: Nymphalidae) population. Monarch toxicity data are currently limited and available data focuses on lethal endpoints. This study examined the 72-h toxicity of two pyrethroid insecticides, bifenthrin and β-cyfluthrin, and their effects on growth and diet consumption. The toxicity of bifenthrin to caterpillars was lower than β-cyfluthrin after 72 h. Survival was the most sensitive endpoint for bifenthrin, but diet consumption and caterpillar growth were significantly reduced at sublethal levels of β-cyfluthrin. Using AgDRIFT spray drift assessment, the aerial application of bifenthrin or β-cyfluthrin is predicted to pose the greatest risk to fifth-instar caterpillars, with lethal insecticide deposition up to 28 m for bifenthrin and up to 23 m for β-cyfluthrin from treated edges of fields. Low boom ground applications are predicted to reduce distances of lethal insecticide exposure to 2 m from the treated field edge for bifenthrin and β-cyfluthrin. Growth and survival of fifth-instar monarch caterpillars developing within the margins of a treated field may be significantly impacted following foliar applications of bifenthrin or β-cyfluthrin. These findings provide evidence that pyrethroid insecticides commonly used for soybean pest control are a potential risk to monarch caterpillars in agricultural landscapes. 相似文献
35.
Alexandra J. Tomlinson Annie Rayner Ashleigh Bright David P. Cowan Kate E. Littin Ruth Layton 《国际虫害防治杂志》2018,64(3):271-278
Anticoagulant rodenticides (ARs) are considered inhumane, show increasingly limited efficacy due to acquired resistance, and carry environmental consequences associated with non-target species uptake. In a questionnaire study of 499 UK farms that all deployed chemical rodenticide we found a high mean reliance (79%), on second generation ARs with just over half of the respondents using no other rodent control methods. Additional methods where deployed, alone or in combination, included predation (41%), kill-trap deployment (16%) and shooting (1%). Nearly 40% of all respondents deployed rodenticides year-round. There was no evidence to suggest that “tidy-farm” measures, such as clearing food spills and minimising on-farm rodent harbourage sites aimed at minimising rodent-associated problems, were associated with a lower likelihood of year-round deployment; in fact trends in our analyses suggested the opposite. We therefore encourage operators to fully evaluate the true necessity of rodenticide deployment before AR use. 相似文献
36.
Milagros R. de la Peña Annie Villa Franco Hermoso P. IgcasanJr Mary Dianne Grace N. Arnaldo Ramil M. Piloton Soledad S. Garibay Vicente T. Balinas 《Aquaculture International》2018,26(4):1119-1134
The optimum culture conditions of the local strain Chaetoceros calcitrans were determined to improve biomass and reduce cost of production. Under outdoor culture conditions, higher cell density was attained when the cultures were enriched with Tungkang Marine Research Laboratory (TMRL) medium composed of cheap technical grade reagents and cultured at 25 g L?1 salinity. The cultures were lighted with two 40 W cool-white GE fluorescent tubes (24–35 μmol photon m?2 s?1). Using semi-continuous culture system under established optimum culture conditions, C. calcitrans can be re-cultured thrice and concentrated at each culture cycle using electrolytic flocculation method to produce 4.6 kg m?3 of diatom paste. The viability of concentrated C. calcitrans after 3 months of storage was comparable to live diatom cells. Simple preservation technique by low-temperature storage is convenient for storing algal concentrates for use as starter cultures and for feeding invertebrates. The paste costs USD 8.24 kg?1 inclusive of the assets and flocculation materials for culturing and harvesting the diatom, respectively. This study established the suitable conditions for mass culture of C. calcitrans and produced concentrated diatoms in paste form that is readily available for aquaculture hatcheries at a lower cost. 相似文献
37.
Effects of thyroxine,cod liver oil and potassium iodide on growth and survival of juvenile seahorse,Hippocampus barbouri
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Fatihah Abd Halid Nur Annie Christianus Abd Rahim Abdullah Muta Harah Zakaria Che Roos Saad 《Aquaculture Research》2018,49(2):867-873
Low survival at early stage is the bottleneck in seahorse aquaculture, particularly in the feeding aspect since newborn seahorses must feed immediately upon birth to sustain themselves. Seahorses are visual predator, therefore preferred live feed such as zooplankton. In aquaculture, the most common live feed used is Artemia. In this study, two experiments were conducted to determine the effect of different Artemia enrichment on the growth and survival of newborn Hippocampus barbouri. In the first experiment, six treatments using Artemia enriched with Culture Selco Plus? (SELCO), thyroxine (T4), potassium iodide (KI), cod liver oil (CLO), cod liver oil in combination with thyroxine (CLO + T4) and potassium iodide (CLO+KI) were fed to newborn H. barbouri. Newly hatched Artemia were used as control. At the end of first experiment, treatments using CLO + T4 produced juvenile H. barbouri with the best (p < .05) wet weight (0.142 ± 0.000 g), while juvenile in treatment CLO+KI recorded the highest (p < .05) standard length (3.947 ± 0.014 cm). Subsequently, a second experiment was carried out using the two best enrichment (CLO + T4 and CLO + KI) from the first experiment, but given at different frequency (daily, twice a week, once a week, once in 2 weeks). Daily enrichment using both CLO + T4 and CLO + KI showed no significant (p > .05) difference in growth performance and survival of juvenile of H. barbouri. Interestingly, juvenile fed CLO + T4 enriched Artemia at frequency of twice a week also has no significant difference (p > .05) in survival and growth performance (except for final standard length) when compared with treatment CLO + T4 at daily frequency. 相似文献
38.
39.
Chlamydophila pecorum found in the intestine and vaginal mucus of asymptomatic ruminants has also been associated with different pathological conditions in ruminants, swine and koalas. Some endangered species such as water buffalos and bandicoots have also been found to be infected by C. pecorum. The persistence of C. pecorum strains in the intestine and vaginal mucus of ruminants could cause long-term sub-clinical infection affecting the animal’s health. C. pecorum strains present many genetic and antigenic variations, but coding tandem repeats have recently been found in some C. pecorum genes, allowing C. pecorum strains isolated from sick animals to be differentiated from those isolated from asymptomatic animals. This review provides an update on C. pecorum infections in different animal hosts and the implications for animal health. The taxonomy, typing and genetic aspects of C. pecorum are also reviewed. 相似文献
40.
Because of their highly polymorphic shell patterns, Cepaea land snails have been the subject of numerous studies in ecological genetics. Here, we investigated the spatial structure
of polychromatism in Cepaea hortensis in agricultural landscapes with zones from low to high hedgerow densities. Our main purpose was to search for a relationship
between landscape composition and spatial structuring of chromatism. Despite significant spatial heterogeneity in the three
landscapes sampled, only the high hedgerow density landscape showed a significant spatial structuring of shell polymorphism.
In order to understand this result, an investigation of daily movement patterns in relation to habitat form was carried out
on a mark-release experiment under semi-artificial conditions. This experiment revealed a strong influence of a linear corridor
on snail dispersal. In the field, spatial heterogeneity of shell polymorphism, related to the effects of genetic drift, was
shaped by restricted dispersal in narrow corridors. In the more enclosed one, i.e. where hedgerow density was the highest,
the significant spatial structure we detected involved a balance between local genetic drift and environmentally mediated
gene flow. This isolation-by-distance pattern resulted from direct gene exchange through fields between neighbouring populations.
When applying landscape distances based on hedgerow length, no significant spatial correlation with polychromatism was found.
In the more fragmented sites, random genetic drift seemed to be the prevailing force and, at the scale of the whole sampled
area, selective pressures potentially interfere with these genetic drift-dispersal events. 相似文献