La casside de la betterave (Cassida vittata Wild, Col., Chrysomelidae) au Gharb : Cycle de développement et stratégie de lutte

In the Gharb and Loukkos regions, the Tortoise Beetle (Cassida vittata Vill) develops a single annual generation due to obligatory imaginal dormancy induced by summer conditions. The weekly counts of the various stages of the insect made during two campaigns, reveal a homogeneous life cycle for all areas covered by the study: arrival of adults on fields of sugar beet from early January, feeding and spawning starting from late February to early March, straddling larval development, adult of the year generation and migration to sites of aestivation. The influence of these sites of aestivating on the infestation of adjacent beet crops has been sought. Depending on the method of analysis used, it seems not to be clear correlation. At their awakening, the Tortoise Beetle likely scatter freely on the fields.   Keywords : Cassida vittata, Tortoise Beetle, sugar beet, life cycle, control strategy, Morocco Dans la région du Gharb-Loukkos, la Casside (Cassida vittata Vill) développe une seule génération annuelle en raison d’une diapause imaginale de type obligatoire induite par les conditions estivales. Les comptages hebdomadaires des différents stades de l’insecte, réalisés durant deux campagnes, révèlent un cycle homogène pour toutes les zones concernées par l’étude: arrivage des imagos sur les champs de betterave dès début janvier, prise de nourriture et démarrage de la ponte dès fin février - début mars, développement larvaire chevauchant, formation des adultes de l’année et émigration vers les sites d’estivation. L’influence de ces gîtes d’estivation sur l’infestation des cultures betteravières limitrophes a été recherchée. Selon le procédé d’analyse utilisé, il ne semble pas y avoir de corrélation nette. A leur éveil, les cassides s’éparpillent vraisemblablement de manière libre sur les champs. Mots clés: Cassida vittata, Casside, Betterave, cycle de développement, stratégie de lutte, Maroc &nbsp

Lutte contre les trois bruches Acanthoscelides obtectus (Say, 1893), Bruchus rufimanus Boheman, 1833 et Collosobruchus maculatus (Fabricius, 1775) (Coleoptera: Chrysomelidae : Bruchinae) par les huiles essentielles extraites d'Origanum glandulosum (Lamiacées)

Els olis essencials extrets per destiŀlació del vapor de la planta aromàtica Origanum glandulosum (Lamiacées) han estat testats a diferents dosis en els adults de tres espècies de brúquids, Acanthoscelides obtectus (brúquid del fesol), Bruchus rufimanus (brúquid de la fava) i Callosobruchus maculatus (brúquid dels cigrons), a una temperatura de 27 ºC i a una humitat relativa del 75 %. Aquests olis tenen activitat insecticida i hem observat a més una reducció significativa de la posta d?ous en comparació amb el control a les femelles de les tres espècies de brúquids estudiats. Els valors DL50 calculats després de 48 h d?exposició mostren que els olis essencials testats són molt tòxics en A. obtectus, amb una DL50 = 1,44 μl/ 30 g de llavors, presenten una toxicitat una mica variable en C. maculatus, amb una DL50 = 2,06 μl/ 30 g de llavors, i són menys tòxics en B. rufimanus, amb una DL50 = 7,72 μl/ 30 g de llavors. L?anàlisi de la composició química mostra la riquesa dels olis essencials en compostos coneguts per les seves propietats insecticides com l?α-pinè, limonè, el carvacrol i el timol, la qual cosa explica els resultats obtinguts.The essential oils extracted by hydrodistillation from the aromatic plant Origanum glandulosum (Lamiacées) were tested with various amounts on the adults of three beetles Acanthoscelides obtectus (bruchid of bean), Bruchus rufimanus, (bruchid of broad bean) and Callosobruchus maculatus (bruchid of chickpea), at a temperature of 27 ºC and a relative humidity of 75 %. These oils present an insecticidal activity and induce in the females of the three studied beetles a significant reduction of the laying compared with that in the control. The DL50 calculated after 48h of exposure, show the essential oils tested are very toxic on A. obtectus with DL 50 = 1,44 μl/ 30 g of seeds, have a little variable toxicity on C. maculatus with DL 50 = 2.06 μl/ 30 g of seeds, and less toxic on B. rufimanus with DL 50 = 7.72 μl/ 30 g of seeds. The analysis of the chemical composition shows the richness of essential oils in compounds known for their insecticidal properties like the α-pinene, limonene, carvacrol, and the thymol, which explains the results obtained

Biological Synthesis of Nanoparticles Using Endophytic Microorganisms: Current Development

Nanotechnology is a new emerging interdisciplinary approach created by pairing of engineering, chemical, and biological approaches. This technology produces nanoparticles using different methods of traditional physical and chemical processes; however, the outlook in this field of research is to use ecofriendly, nontoxic, and clean methods for the synthesis of nanoparticles. Biological entities, such as plants, bacteria, fungi, algae, yeast, and actinomycetes, are the best candidate to achieve this goal. Among the biological route, those involve endophtic microorganisms to reduce metallic ions into nanoparticles. This method is considered as an attractive option and can open a new horizon on the interface of biology and nanotechnology. The present chapter highlights the latest research about endophytic microorganisms and their application in the synthesis of nanoparticles, as well as the mechanisms involved in the formation of nanoparticles

La casside de la betterave (Cassida vittata Wild, Col., Chrysomelidae) au Gharb : Cycle de développement et stratégie de lutte

In the Gharb and Loukkos regions, the Tortoise Beetle (Cassida vittata Vill) develops a single annual generation due to obligatory imaginal dormancy induced by summer conditions. The weekly counts of the various stages of the insect made during two campaigns, reveal a homogeneous life cycle for all areas covered by the study: arrival of adults on fields of sugar beet from early January, feeding and spawning starting from late February to early March, straddling larval development, adult of the year generation and migration to sites of aestivation. The influence of these sites of aestivating on the infestation of adjacent beet crops has been sought. Depending on the method of analysis used, it seems not to be clear correlation. At their awakening, the Tortoise Beetle likely scatter freely on the fields.   Keywords : Cassida vittata, Tortoise Beetle, sugar beet, life cycle, control strategy, Morocco Dans la région du Gharb-Loukkos, la Casside (Cassida vittata Vill) développe une seule génération annuelle en raison d’une diapause imaginale de type obligatoire induite par les conditions estivales. Les comptages hebdomadaires des différents stades de l’insecte, réalisés durant deux campagnes, révèlent un cycle homogène pour toutes les zones concernées par l’étude: arrivage des imagos sur les champs de betterave dès début janvier, prise de nourriture et démarrage de la ponte dès fin février - début mars, développement larvaire chevauchant, formation des adultes de l’année et émigration vers les sites d’estivation. L’influence de ces gîtes d’estivation sur l’infestation des cultures betteravières limitrophes a été recherchée. Selon le procédé d’analyse utilisé, il ne semble pas y avoir de corrélation nette. A leur éveil, les cassides s’éparpillent vraisemblablement de manière libre sur les champs. Mots clés: Cassida vittata, Casside, Betterave, cycle de développement, stratégie de lutte, Maroc &nbsp

Carcinome métaplasique du sein avec différenciation osseuse extensive: À propos d’un cas

Le carcinome métaplasique du sein est une entité rare et bien individualisé par l'OMS. Il représente moins de 1 % des cancers invasifs du sein et constitue un groupe tumoral hétérogène soit purement épithélial soit à doublecontingent épithélial et mésenchymateuse. Le carcinome métaplasique avec différenciation osseuse extensive est très rare. Il représente 0.2% des carcinomes du sein. Nous rapportant un cas exceptionnel d'un carcinome métaplasique du sein avec différenciation osseuse extensive chez une patiente de 53 ans. A travers ce cas et une revue de la littérature, les caractéristiques anatomo-cliniques, radiologique, thérapeutiques et évolutives seront discutées

Relationships between crystalline structure and dielectric properties in Sr2Sm(1-x)NdxTi2Nb3O15 ceramics

In this study, tungsten-bronze type materials of Sr2Sm(1-x)NdxTi2Nb3O15 composition (x=0; 0,25; 0,5; 0,75 and 1) were elaborated by classical solid-state reaction. The structural characterization demonstrate that these compounds present tetragonal symmetry, using two space groups P4bm (N°100) and P4/mbm (N°127) respectively. The lattice parameters are a=b≈12,2Ǻ; c≈3,8Ǻ; V≈579,03Ǻ and Z=2. In this compounds, Ti and Nb cations show obvious off-center displacements along the c axis in both the Ti/Nb(1)O6 and the Ti/Nb(2)O6 octahedra. Besides, the unequal Ti/Nb(2)–O bonds length in the equatorial plane of Ti/Nb(2)O6 octahedra indicates the displacement of the Ti/Nb(2) cations in the ab plane, and no displacement of the Ti/Nb(1) cations exists in the ab plane. The results show that this material has two types of octahedral, first octahedron with little deformation around the Ti1/Nb1 and the second octahedron are more distorted around the Ti2/Nb2. The measurements of permittivity and dielectric losses of the ceramic samples performed between 25°C and 700°C (100Hz to 1MHz), high dielectric constants (εr=127 ~ 194) and low dielectric losses (tan(δ) around 10-4 at 1MHz) were found. The maximum value of the dielectric constant is obtained for x=0 (εr=194). The Curie temperature Tc decreases from 332 to 246°C as a function of the substitution of the samarium by neodymium. Detailed microstructural analysis by scanning electron microscope (SEM) and (EDS) for this compounds are also investigated

A study on the essential oil Ferulago campestris. How much does exstraction method influence the oil composition?

The essential oil of different parts of Ferulago campestris (Bess.) collected in Sicily has been extracted by microwave-assisted hydrodistillation (MAHD) and by classic hydrodistillation (HD). A comparative qualitative–quantitative study on the composition of the oils was carried out. A total of 100 compounds were identified in the oils obtained by MAHD, whereas 88 compounds characterized the HD oils. The most prominent components were, in all different parts of F. campestris and in both extraction methods, 2,4,5-trimethylbenzaldehyde and 2,4,6-trimethylbenzaldehyde isomers; the latter was not previously found. The attempt to evaluate where the oil components are located in all parts of the plant was carried out by means of a kinetic study. Then, electron microscopy observation on the different parts before and after MAHD and HD was performed

Pesticide exposure in honey bees results in increased levels of the gut pathogen Nosema

Global pollinator declines have been attributed to habitat destruction, pesticide use, and climate change or some combination of these factors, and managed honey bees, Apis mellifera, are part of worldwide pollinator declines. Here we exposed honey bee colonies during three brood generations to sub-lethal doses of a widely used pesticide, imidacloprid, and then subsequently challenged newly emerged bees with the gut parasite, Nosema spp. The pesticide dosages used were below levels demonstrated to cause effects on longevity or foraging in adult honey bees. Nosema infections increased significantly in the bees from pesticide-treated hives when compared to bees from control hives demonstrating an indirect effect of pesticides on pathogen growth in honey bees. We clearly demonstrate an increase in pathogen growth within individual bees reared in colonies exposed to one of the most widely used pesticides worldwide, imidacloprid, at below levels considered harmful to bees. The finding that individual bees with undetectable levels of the target pesticide, after being reared in a sub-lethal pesticide environment within the colony, had higher Nosema is significant. Interactions between pesticides and pathogens could be a major contributor to increased mortality of honey bee colonies, including colony collapse disorder, and other pollinator declines worldwide