Search results for " pest"
showing 10 items of 253 documents
Microbiological control of soil-borne phytopathogenic fungi with special emphasis on wilt-inducing Fusarium oxysporum
2009
Contents Summary 529 I. Biological control of plant diseases: state of the art 530 II. Main modes of action of biological control agents 530 III. The protective strains of F. oxysporum: an unexplored model 532 IV. Future directions for the study of the protective capacity of strains of F. oxysporum 539 V. How to make biological control successful in the field? 540 References 541 Summary Plant diseases induced by soil-borne plant pathogens are among the most difficult to control. In the absence of effective chemical control methods, there is renewed interest in biological control based on application of populations of antagonistic micro-organisms. In addition to Pseudomonas spp. a…
Quantitative structure-activity relationships for the toxicity of organophosphorus and carbamate pesticides to the Rainbow trout Onchorhyncus mykiss.
2006
This study has investigated the development of quantitative structure-activity relationships (QSARs) for the toxicity to rainbow trout Onchorhyncus mykiss Walbaum of 75 organophosphorus and carbamate pesticides. The toxicity data were obtained from an openly available toxicological database and were selected to be representative of a single endpoint. A large number of physicochemical and structural descriptors were calculated for the pesticides. QSAR models were developed using multiple linear regression and partial least-squares analyses. Following the removal of a small number of outliers, predictive QSARs were developed on small numbers of mechanistically relevant descriptors. Applying m…
Invasive and native populations of common ragweed exhibit strong tolerance to foliar damage.
2013
8 pages; International audience; Tolerance and resistance are defence strategies evolved by plants to cope with damage due to herbivores. The introduction of exotic species to a new biogeographical range may alter the plant herbivore interactions and induce selection pressures for new plant defence strategies with a modified resource allocation. To detect evolution in tolerance to herbivory in common ragweed, we compared 3 native (North America) and 3 introduced (France) populations, grown in a common garden environment. We explored the effect of leaf herbivory on plant vegetative and reproductive traits. Plants were defoliated by hand, simulating different degrees of insect grazing by remo…
Bacillus thuringiensis treatment modulate the HSP70 expression in larva and adult brain of Rhynchophorus ferrugineus
2013
To study the pathogen-host relationship, we used the model of the entomopathogenic bacterium Bacillus thuringiensis (Bt) and Rhynchophorus ferrugineus, a quarantine pest that attacks palm trees. In particular, we focused on the Bt stress-induced infections. We studied the effect of Bt on larval and adult growth, and on the expression of the heat shock proteins (HSPs), rapidly synthesized in the cell after exposure to stress including pathogens. Bt has negative effects on larval and adult growth, on total hemocytes counts and on the hemocyte type. HSP70 was evaluated in the supernatant of the brain lysate obtained from larvae and adults fed with sublethal doses of Bt. HSP70 expression was mo…
Analysis of Pesticide Residues in Milk, Eggs, and Meat
2009
This handbook provides a systematic description of the principles, procedures, and technology of the modern analytical techniques used in the detection, extraction, clean up, and determination of pesticide residues present in the environment. This book provides the historical background of pesticides and emerging trends in pesticide regulation. The text discusses various techniques for analysis, including supercritical fluid extraction, disposable electrochemical biosensors, matrix solid-phase dispersion, volatmetric methods, and liquid chromatography. The authors also address the scope and limitation of NEEM products in plant protection as well as the analysis of medicinal plants.
Antimicrobial activity of the red palm weevil Rhynchophorus ferrugineus
2011
The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera Dryophthoridae), is an important pest of palms. Knowl- edge of both its natural enemies and its defensive mechanisms against predators and microorganisms is important to develop methods for an integrated pest control. Antimicrobial activity of the cuticular surface of adults and larvae, as well as of eggs, of this invasive species was investigated. This activity was tested against the Gram-positive bacteria Bacillus subtilis (Ehrenberg) Cohn and Bacillus thuringiensis Berliner, the Gram-negative bacterium Escherichia coli Escherich, and the entomopathogenic fungi Beauveria bassiana (Balsamo) Vuillemin and Metarhizium aniso…
Pythium perplexum isolated from soil in France: morphology, molecular characterisation and biological control.
2001
Pythium perplexum (F-926) was isolated from a soil sample taken in the Burgundy region in France. In 1907, it was mistakenly described by Bulter as P. vexans. Despite morphological resemblance, the comparison between the internal transcribed spacer 1 regions of the ribosomal DNA of the two fungi leaves no doubt of their different identities. P. perplexum was found to be highly pathogenic to cucumber seedlings. Damping-off disease of cucumber caused by P. perplexum can effectively be controlled by using the soil bacterium Serratia plymuthica (B-781). The details of the morphology and the molecular characterisation of P. perplexum and its biological control with S. plymuthica are described he…
Oviposition deterrence and repellent activities of selected essential oils against Tuta absoluta Meyrick (Lepidoptera: Gelechiidae): laboratory and g…
2022
AbstractTuta absoluta, an invasive pinworm characterized by high reproductive potential and adaptation to different agroecological conditions, cause serious damage to tomato crops. Chemical control with synthetic insecticides is widely used to control this pest, although pesticides exhibit side effects on non-target organisms and negatively impact the environment, with the occurrence of resistance to some active substances in the target pest. The use of essential oils (EOs) from aromatic or officinal plants could represent an environmentally safe control method, alternative to synthetic insecticide application. In this work we investigated the effect of EOs from Spanish oregano, laurel, bas…
Bacillus thuringiensis treatment alters larval growth, hemocytes and modulation of Hsp70 in Rhynchophorus ferrugineus
2011
To study the pathogen-host relationship, we used the model of the entomopathogenic bacterium Bacillus thuringiensis (Bt) and Rhynchophorus ferrugineus, a quarantine pest that attacks the palm trees. In particular, we focused on the Bt stress-induced infections. We studied the effect of Bt on larval growth, on hemocytes and on the expression of the heat shock proteins (Hsp70). HSPs are rapidly synthesized in the cells after a stress exposition including pathogens. The Hsp70 was evaluated in the supernatant of the hemocyte lysate (HLS) obtained from larvae fed with Bt. This is the first time that the presence of Hsp70 has been recorded in R. ferrugineus. Bt has negative effects on larval grow…
Pesticides: Chemical and Biological.
2013
There is a requirement by World Health Organization (WHO), Food and Agriculture Organization (FAO) and other International Organizations to develop environmentally sustainable systems for controlling pests that are less reliant on chemical pesticides as the primary management tool. However biological control alone cannot at the moment solve all pest problems and must be considered instrument to be used in combination with other methods. Compatibility of chemical pesticides (CP) and biological pesticides (BP) is one of the key for the implementation of Integrated Pest Management (IPM) programs. Testing the compatibility of CP and BP is necessary if these two agents are to be applied together…