Biologie deVespa orientalis. Les premiers stades de développement

Sommaire Ce travail ne présente que quelques observations sur les premiers stades de dévelopment des colones deVespa orientalis. Les résultats ne sont que fragmentaires, mais permettent tout de même quelques comparaisons intéressantes avec d'autres espèces de Vespides.Nous avons observé que: 1^o les reines de la Guêpe orientale sont très facilement élevées au laboratoire et y construisent et y pondent aisément. 2^o les reines et les ouvrières dévorent leurs larves pour se nourrir ou pour alimenter les plus grosses larves; 3^oles premières cellules d'un rayon sont assez irrégulières, elles ne prennent leur forme hexagonale que lorsqu'elles sont entourées de cellules voisines; 4^o le matériau utilisé pour édifier les cellules est assez divers; 5^o les reines ne réparent pas les trous effectués dans les parois des cellules; 6^o les reines ne s'intéressent au petites brèches du bord des cellules que lorsqu'elles sont en train d'allonger les parois des cellules voisines; 7^o les ouvrières ont un comportement comparable à celui des reines lorsqu'elles se nourrissent ou nourrissent les larves ou lorsqu'elles construisent; 8^o les reines, les larves et les ouvrières échangent de la nourriture, du liquide; 9^o la seule division du travail dans la colonie est celle qui existe entre la reine qui ne fait plus que pondre et les ouvrières qui s'affairent à toutes les occupations; 10^o le cycle évolutif du développement du couvain que nous décrivons peut être variable, suivant les colonies, dans les mêmes conditions expérimentales.

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Summary These first observations only deal with the early growing of new colonies in an israelian laboratory: the building of the first comb, the queen's hatching and behavior, the first workers' behavior have been observed.1^o The breeding of the queens and the workers is easy: they build fine combs, where the queens lay their eggs; 2^o Queens and workers cannibalism has been pointed out; 3^o The first cells are very odd; they become hexagonal when they are surrounded with other ones; 4^o The materials used into the combs are various, paper, earth ; 5^o Many little holes has been observed inside the walls of the cells; they are never closed; 6^o The experimental gaps in the cells are only repaired when the wasps lengthen the neighbour cells; 7^o The building and breeding bekavior of the queens and the workers are similar; 8^o The queens, the larvae, the workers exchange food, liquids; 9^o There is no division of the work between the first workers, but between the queens and the first workers; 10^o In our experiments, the brood's evolutive cycle is different from one colony to the other one.

     

Etude des premiers stades de développement de la Coccidie Coelotropha durchoni

Summary This study considers the earlier growth stages of Coccidium Coelotropha durchoni in its host, Nereis diversicolor. Before evolving into free trophozoites and gamontes in coeliac fluid, the parasites remain in muscular and coeliac cells in microscopic intracellular form. Electron microscope reveals that these stages show an intermediary fine structure between that of a sporozoite — from which they keep some typical characteristics such as the conoid, the fibers and the involuted tubuli — and that of the future free trophozoites. The wall consisting in two clear membrans is provided with one or several micropores. The classical cytoplasmic organites clearly stand out: dictyosomes show constant relationship with ergastoplasm, the mitochondria contain short inner tubuli. Besides the paraglycogen granules and lipoid vacuoles, at least three types of vacuoles may be observed. Peculiar topographic relationship connects mitochondria and paraglycogen granules probably in formation. In the nucleus with classical membrane and heterogeneous structure, a rather voluminous nucleolus may be seen.     

Émission de rayonnement par les œufs de Discoglosse en cours de développement

Sans résumé     

Les levures,dans les stations d'épuration des eaux usées

Résumé Les auteurs étudient l'influence des stations d'épuration sur la population de levures dans les eaux usées d'origine urbaine. Quantitativement, le nombre de microorganismes diminue de 90% lors du traitement. 49 espèces ont été identifiées. Les témoins de pollution d'origine humaine ont été plus particulièrement recherchés. Les auteurs indiquent les modes de détection du Candida albicans.The authors have studied the influence of sewage treatment plants over the yeast population in the waste waters coming from towns. Quantitatively, the number of microorganisms shows a 90% decrease in the process of the treatment. 49 different species have been identified. Evidence of pollution coming from human being has been particularly looked for. The authors point out the different ways of detecting the Candida albicans.     

Etude preliminaire de stades de la méiose humaine dans les spermatocytes et les ovocytes

Summary Human meiotic chromosomes, from spermatocytes and ovocytes, are described after observations of whole mount preparations under E.M. Small testicular and ovarian fragments are put in distillated water, then macerated; the cell suspension is spread on the surface of sheet copper grids covered with formvar plus collodion films. After dehydratation interesting stages are selected under L.M. before observations under E.M.Zygotene and pachytene are the most common stages. During pachytene the chromomeres are well individualized; the synaptonemal complex may be observed; chromatin fibers connect the chromosomes to nuclear pores, interchromosomal fibers joint the bivalents. Zygotene and pachytene bivalents are very similar in the male and the feminine germ cells.     

Anomalies postnatales du développement de la spermatogenèse associées aux troubles de la migration testiculaire

Cryptorchidism, a non-descended testis in its physiological intrascrotal location, is one of the most frequent congenital anomalies of the male genital system. The mechanisms of the normal descent of the testis are still unclear. Several etiological hypotheses have been proposed for cryptorchidism. Cryptorchidism is associated with a greater risk of testis cancer, and is also a cause of impairment in sperm parameters and fertility in the adult age. In this article, we review the cellular and hormonal events occurring from birth to puberty in isolated cases of congenital cryptorchidism that will later, in adulthood, alter both spermatogenesis and fertility.     

Altérations environnementales du développement du testicule foetal: zoom sur les phtalates

There are great concerns about the increasing incidence of abnormalities in male reproductive function. Human sperm counts have markedly dropped, and the rate of testicular cancer has clearly increased over the past four decades. Moreover, the prevalence rates of cryptorchidism and hypospadias are also probably increasing. It has been hypothesized that all these adverse trends in male reproduction result from abnormalities in the development of the testis during foetal and neonatal life. Furthermore, many recent epidemiological, clinical and experimental data suggest that these male reproductive disorders could be due to xenobiotics termed endocrine disruptors, which are becoming more and more concentrated and prevalent in our environment. Among these endocrine disruptors, we chose to focus this review on phthalates for different reasons: 1) they are widespread in the environment; 2) their concentrations in many human biological fluids have been measured; 3) the experimental data using rodent models suggesting a reprotoxicity are numerous and are the most convincing; 4) their deleterious effects on the development and function of the rat foetal testis have been largely studied; 5) some epidemiological data in humans suggest a reprotoxic effect at environmental concentrations at least during neonatal life. However, the direct effects of phthalates on human foetal testis have never been explored. Thus, as we did for the rat in the 1990s, we recently developed and validated an organotypic culture system, which allows maintenance of the development of the different cell types of human foetal testis. In this system, the addition of 10^?4 M MEHP (mono-2-ethylhexyl phthalate), the most produced phthalate, had no effect on basal or LH-stimulated production of testosterone, but it reduced the number of germ cells by increasing their apoptosis, without modifying their proliferation. This is the first experimental demonstration that phthalates alter the development of the foetal testis in humans. Using our organotypic culture system, it is interesting to compare these results obtained in humans with the response to MEHP in the mouse and the rat testes to analyse the relevance of toxicological tests based on rodent models.     

Valeur trophique des acides aminés dans les graines de légumineuses et développement larvaire de Callosobruchus maculatus

Interspecific variation of protein amino acids between peanut, horse bean, french bean, lentil, cowpea and chick-pea was undertaken in relation to larval development of C. maculatus. Twenty-one groups of amino acids were identified and quantified. In all seeds, free amino acids exist in low quantities; but they are more numerous than bound amino acids. Essential amino acids for man are sufficient in the six species, except for the sulphur amino acids in all seeds, and for lysine in peanut. Utilization of those pulses, after cooking, in human food complements cereals. Larval development possibilities of C. maculatus upon the used seeds shows up that: (a) with chick-pea and cowpea, the bruchid thrives normally. However, although amino acids are higher in cowpea than in chick-pea, the better performances were observed on the latter; (b) peanut, french bean, horse bean and lentil are unsuitable for larval development of the insect. Although they are rich in amino acids, all larvae die at first in star within these pulses. We conclude that larval development of C. maculatus does not depend only on the amounts of amino acids in the seeds but also on other trophic factors. These could consist of the balance between different nutritive compounds and the presence of allelochemical substances in the tested seeds which bruchid larvae are unable to utilize.     

Succession,diversité et amplitude de niche dans les påturages du centre de la péninsule ibérique

Some diversity and niche amplitude parameters were applied to rangeland pastures of the Central Iberian Peninsula and to their succession stages after the periodical ploughing typical of the traditional management of these areas. Four different slopes within a large area of undulating terrain were selected for the monitoring of succession as they contained the characteristical geomorphological pattern of the area (denudation, transport and accumulation sectors).If we consider the total entropy theorem, H (E.P.)=H(E)+H(P/E), the total entropy of the slope H(E.P) and the entropy of species H(E) increase as succession progresses. As the value of the entropy of the sampling plots conditioned by the species H(P/E) is affected by the number of plots utilized, we employed the expression A=H(P/E)/log₂ number of plots, similar to Pielou's index for niche amplitude, W=H(P/E)/H(P).This values decreases with succession, indicating that plant species tend to occupy more definite sectors along the slope. The number of low entropy species H(P/E) _i or specialist species, confined to narrow sectors also increases. When computed separately within the different sectors niche amplitude results in small values for the low slope regions (accumulation sector). This effect becomes more pronounced when succession advances.

Nous remercions le Conseil d'Administration de La Paranza, propriétaire du Castillo de Vañuelas, et particulièrement Mrs. C. Hernandez-Ros et J. A. Léon-Vrquijò, pour les faeilités qu'ils ont données à cette équipe durant la réalisation de ce travail.     

Considérations sur l'importance du facteur osmotioue et du facteur rapique dans le développement de la vie dans la mer noire

Sans résumé     

Techniques de détection du VIH dans les milieux biologiques: Application à la recherche du virus dans le sperme

Growing numbers of HIV seronegative women want to have children with HIV infected partners by artificial insemination. The most sensitive assays for showing the presence of the virus are the coculture method and the DNA-PCR that are able to detect proviral load. HIV is detected from non spermatozoal mononuclear cells, seminal fluid but it was not found in spermatozoa fraction. But we know, by in vitro studies, that HIV can bound to and enter spermatozoa. Thus artificial insemination between HIV seropositive man and seronegative woman lead to a risk of contamination even with purified spermatozoa. Today, any virological assay is able to affirm that specimen is not infectious.     

Stimulation du potentiel de dégradation dans les eaux marines profondes par les bactéries barotolérantes colonisant les fèces du plancton migrateur

At a depth of 1 150 m in the northwest Mediterranean, amino acid uptake and bacterial biomass production rates increased, in a 12-day time interval, 5- and 30-fold, respectively. Simultaneously, bacterial response to pressure changes evolved from barophilic to barotolerant. During the same period, scanning electron microscope observations and in situ observations using Underwater Video Profiler showed a 2-fold increase in particle concentrations, mainly due to faecal pellet production by zooplankton. This input, nutrient rich and largely colonized with bacteria unaffected by pressure variations since they originated from organisms that regularly migrate up and down through the water column, could produce such microbial activity peaking in the deep water masses.     

Susceptibilité des chenilles du bombyx disparate (Lymantria dispar L.) envers la polyédrie dans les diverses phases de gradation de leur développement dans la nature

Summary Experimental research was carried out to establish the polyhedral sensitivity of the caterpillars ofLymantria dispar L., in regard to their gradation phase in nature. Differences in polyheral deathrate after virus infection, were revealed, in relation to the culmination, the retrogradation, the latent phases as well as an undetermined phase they originated from. The possible reasons for this are being discussed.      

Croissance individuelle et dynamique de population de Daphnia Magna en culture dans les eaux usées traitées

Résumé Pour atteindre les buts visés par le recyclage biologique des eaux usées, il faut exploiter une population d'organismes filtreurs dont l'augmentation nette de biomasse est rapide et importante. L'augmentation nette de biomasse sera favorisée par une croissance individuelle, une reproduction et une survie excellentes dans l'eau usée traitée. L'étude de ces paramèters sur des cohortes de Daphnia magna soumises à différentes conditions expérimentales, indique qu'il s'agit d'un organisme prometteur pour le recyclage biologique. Dans nos conditions expérimentales, D. magna montre un bilan azoté positif durant toute sa vie. La production rapide de biomasse est favorisée par une température élevée (15 °C) et une nourriture abondante. L'eau traité montre les signes d'une certaine toxicité envers les juvéniles mais non envers les adultes. Nos données établissent que la production d'oeufs requiert une taille minimale de la femelle de 2,7 mm, information primordiale pour l'exploitation future de la population.

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To realize the objectives of the biological recycling of wastewaters, it is necessary to exploit a population of filtering organisms, the biomass of which shows a rapid and important net increase. The net increase of biomass is favored by excellent individual growth, reproduction and survival in treated wastewaters. The study of these parameters, with cohorts of Daphnia magna submitted to different treatments, indicated that it is a promising organism for biological recycling. Under our experimental conditions, D. magna exhibited a positive nitrogen balance for the whole of its life. The rapid production of biomass was favored by high temperature (15 °C) and abundant food. The treated wastewaters proved to be somewhat toxic to juveniles but not to adults. Our results demonstrated that the egg production requires a female minimal size of 2.7 mm; this information is most important in the future exploitation of the population.

     

Seuil thermique de développement de trois coccinelles prédatrices de la cochenille du manioc au congo

Résumé Le seuil thermique de développement de 3 prédateurs de la famille desCoccinellidae (un exotique et deux locaux) a été étudié. L'équation de la constante thermique a été utilisée pour le calcul du seuil thermique. Les données obtenues ont été comparées entre elles. L'espèce exotiqueHyperaspis raynevali a un seuil thermique de développement plus bas que celui des 2 espèces locales (Hyperaspis senegalensis hottentotta etExochomus flaviventris). Le seuil thermique suivant a été obtenu pour chaque espèce, à savoir: 11,81°C pourH. raynevali; 13,78°C pourH. s. hottentotta; 13,63°C pourE. flaviventris. Des différences de seuil thermique de développement et de mortalité ont été enregistrées entre le prédateur exotique et les espèces indigènes. Des hypothèses explicatives sont évoquées dans la discussion.      

Dosage du fer et de l'aluminium échangeable dans les minéraux argileux et dans les sols

Résumé Une méthode est proposée pour le dosage du fer et de l'aluminium échangeable dans les minéraux argileux et dans les sols. La méthode est basée sur l'extraction successive des oxinates de fer et d'aluminium en fonction du pH.Les conditions optimales et l'influence des divers facteurs déterminant l'extraction quantitative et sélective de ces deux éléments ont été préalablement étudiées.Publication du Centre de Chimie Biologique et Colloïdale du sol subsidié par I'I.R.S.I.A.     

Hétérochronies du développement sensu Gould chez les foraminifères planctoniques cénomaniens : exemple de néoténie dans le bassin du Western Interior américain

Development heterochronies sensu Gould in the Cenomanian planktonic foraminifera: case of neotony in the American Western Interior Basin. During the Cenomanian–Turonian boundary, the anoxic event OAE2 has involved the disappearance of Rotalipora, complex keeled planktonic foraminifera which had conquered deep oceanic water. In the Western Interior basin, the last rotalipores are associated with Anaticinella, morphotypes without keel. The heterochronical relationship between these morphotypes is investigated. The loss of the keel would be a selective advantage enabling them to remain in the surface water, less reached by oceanic anoxia. Thus, two endemic species, only known in the American seaway, are observed: A. multiloculata (Morrow) and A. planoconvexa (Longoria). These species would respectively result by neoteny from R. greenhornensis and R. cushmani. To cite this article: D. Desmares et al., C.R. Palevol 2 (2003).