Search results for "Pest Analysis"
showing 10 items of 116 documents
RESUME:Studies on the Chemical Control of Aonidiella aurantii (Mask.)
1974
Aonidiella aurantii (Mask.) which was accidentally introduced in Sicily in 1968 has since become a dangerous pest requesting special treatments in citrus groves. Experiments have been carried out on Citrus lemon to evaluate the efficacy of several organophosphorous compounds partly in mixture with white oil and this latter applied sole (cf. table 1). The results obtained against young females are set out in table 2; they show excellent results with almost all compounds whereas the same pesticides had a rather poor effect on mature females (cf. table 3). It is concluded that the replacement of white oils by organophosphorous compounds is not justified providing that the control is directed a…
Toxicity of several d-endotoxins of Bacillus thuringiensis against Helicoverpa armigera (Lepidoptera: Noctuidae) from Spain
2005
Abstract Toxicity and larval growth inhibition of 11 insecticidal proteins of Bacillus thuringiensis were evaluated against neonate larvae of Helicoverpa armigera, a major pest of important crops in Spain and other countries, by a whole-diet contamination method. The most active toxins were Cry1Ac4 and Cry2Aa1, with LC50 values of 3.5 and 6.3 μg/ml, respectively. At the concentrations tested, Cry1Ac4, Cry2Aa1, Cry9Ca, Cry1Fa1, Cry1Ab3, Cry2Ab2, Cry1Da, and Cry1Ja1, produced a significant growth inhibition, whereas Cry1Aa3, Cry1Ca2, and Cry1Ea had no effect.
Esterase isoenzymes and insecticide resistance in Frankliniella occidentalis populations from the south-east region of Spain.
2008
BACKGROUND:Frankliniella occidentalis (Pergande) is among the most important crop pests in the south-east region of Spain; its increasing resistance to insecticides constitutes a serious problem, and understanding the mechanisms involved is therefore of great interest. To this end, F. occidentalis populations, collected from the field at different locations in south-east Spain, were studied in terms of total esterase activity and esterase isoenzyme pattern. RESULTS: Individual thrips extracts were analysed by native polyacrylamide gel electrophoresis (PAGE) and stained for esterase activity with the model substrate α-naphthyl acetate. Significant correlations were found between resistance t…
An assessment method for the quantification of Daktulosphaira vitifoliae (Fitch) (Hem., Phylloxeridae) populations in the field
2003
: Grape phylloxera is a plant parasite that has started to become a pest again in European viticulture in spite of the use of grafted rootstocks. Since the middle of the 1980s, there have been various reports of vine damage caused by phylloxera. It was shown that in some cases there is no direct correlation between the occurrence of phylloxera and vine damage. In this context, phytopathogenic microorganisms, especially fungi, are mentioned in literature. To investigate the possible interactions it is necessary to be able to assess phylloxera populations in the field, e.g. to correlate phylloxera abundance with the vigour of the vines. Because of the non-homogenous distribution of the grape…
Responses of Rhynchophorus ferrugineus adults to selected synthetic palm esters: electroantennographic studies and trap catches in an urban environme…
2010
BACKGROUND: The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier, accidentally introduced into the European countries facing the Mediterranean basin, is becoming the most serious pest for ornamental palms in the urban environment. In the present work, tests were conducted on the electroantennogram (EAG) and behavioural responses of RPW adults to five selected synthetic palm esters, ethyl propionate, ethyl butyrate, ethyl isobutyrate, ethyl lactate and ethyl acetate, to assess the application of a mass trapping technique in an urban environment. RESULTS: In the laboratory, EAG bioassays on RPW adults with the synthetic palm esters showed: (1) positive dose-dependent responses; (2) di…
Survey of the parasitoids of the European Sunflower MothHomoeosoma nebulella [Lep.: Pyralidae] in the palearctic region
1993
The European Sunflower MothHomoeosoma nebulella Denis & Schiffermuller is a potential pest on sunflower in France. The parasitoids of this moth are little known. We present here original data obtained in the south of France together with previous survey. Some parasitoids we found were new records onH. nebulella. The relative weakness of the parasite complex ofH. nebulella (less than 15 species) compared to that of the American Sunflower MothH. electellum (Hulst) is discussed.
Pre-release risk assessment of the egg-parasitoid Gryon pennsylvanicum for classical biological control of Leptoglossus occidentalis.
2013
Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae) is a North American conifer seed pest that was accidentally introduced to Europe. In the Mediterranean area, it threatens the production of Pinus pinea Linna- eus seeds. The egg-parasitoid Gryon pennsylvanicum (Ashmead) (Hymenop- tera: Platygastridae), the main natural enemy in the native range of L. occidentalis, was imported from British Columbia to Italy. Pre-release risk assessments were made under quarantine conditions by no-choice tests conducted with na€ıve and experienced G. pennsylvanicum offering single eggs of target and non-target species for varying exposure times (1, 4, 48 h). G. pennsylvanicum successfully parasitize…
Insecticidal Activity of Strains of Bacillus thuringiensis on Larvae and Adults of Bactrocera oleae Gmelin (Dipt. Tephritidae)
1999
The olive fly, Bactrocera oleae, is the key pest on olives in the Mediterranean area. The pest can destroy, in some cases, up to 70% of the olive production. Its control relies mainly on chemical treatments, sometimes applied by aircraft over vast areas, with their subsequent ecological and toxicological side effects. Bacillus thuringiensis is a spore-forming soil bacterium which produces a protein crystal toxic to some insects, including the orders of Lepidoptera, Diptera, and Coleoptera and other invertebrates. The aim of this study was to search for isolates toxic to B. oleae. Several hundred B. thuringiensis isolates were obtained from olive groves and olive presses in different areas o…
Interspecific extrinsic and intrinsic competitive interactions in egg parasitoids
2012
Interspecific competitive interactions can occur either between adult parasitoids searching/exploiting hosts (extrinsic competition) or between parasitoid larvae developing within the same host (intrinsic competition). Understanding how interspecific competition between parasitoids can affect pest suppression is important for improving biological pest control. The purpose of this work was to review both extrinsic and intrinsic competition between egg parasitoid species. These are organisms that are often candidates for biological control programs due to their ability to kill the pest before the crop feeding stage. We first reviewed the literature about interspecific competitive abilities of…
Assessment of synthetic chemicals for disruption of Rhynchophorus ferrugineus response to attractant-baited traps in an urban environment
2012
The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier (Coleoptera, Curculionidae), is one of the most severe pests of ornamental palm species in urban areas of Mediterranean countries. Aiming to discover inhibitory semiochemicals for RPW population management in urban environments, we conducted electroantennographic (EAG) screenings of 17 commercially available synthetic compounds, representing three groups of plant volatiles (isoprenoids, phenyl propanoid derivatives and fatty acid derivatives) known for their repellent effects toward insects. These tests were followed by trap-based screenings of EAG-active menthone, alpha-pinene and methyl salicylate, singly and in combination, und…