The distribution and location of the symbiont Lagenophrys aselli on the freshwater isopod Asellus aquaticus

1. The distribution and location of the ciliated protozoan Lagenophrys aselli on the freshwater isopod Asellus aquaticus were studied in relation to water flow over the third pleopod surface. 2. At low densities L. aselli had a significant preference for the anterior centre of the pleopod; however, at the highest densities this preference was no longer significant. The distribution ranged from closer than random at low densities to further than random at the highest densities, and may have been a product of feeding and reproduction of L. aselli as well as the short intermoult period of the host. 3. An individual L. aselli has an effective area of both the lorica and the ciliated feeding disc. The ciliated feeding disc, when extended, may contribute to the presence of a small anterior–posterior gap being left between individuals.     

Lactobacilli-Host mutualism: "learning on the fly"

Metazoans establish with microorganisms complex interactions for their mutual benefits. Drosophila, which has already proven useful host model to study several aspects of innate immunity and host-bacteria pathogenic associations has become a powerful model to dissect the mechanisms behind mutualistic host-microbe interactions. Drosophila microbiota is composed of simple and aerotolerant bacterial communities mostly composed of Lactobacillaceae and Acetobactereaceae. Drosophila mono- or poly-associated with lactobacilli strains constitutes a powerful model to dissect the complex interplay between lactobacilli and host biologic traits. Thanks to the genetic tractability of both Drosophila and lactobacilli this association model offers a great opportunity to reveal the underlying molecular mechanisms. Here, we review our current knowledge about how the Drosophila model is helping our understanding of how lactobacilli shapes host biology.     

Effects of Bacillus thuringiensisδ-endotoxin-fed Helicoverpa armigera on the survival and development of the parasitoid Campoletis chlorideae

With the deployment of transgenic crops expressing δ‐endotoxins from Bacillus thuringiensis (Bt) for pest management, there is a need to generate information on the interaction of crop pests with their natural enemies that are important for regulation of pest populations. Therefore, we studied the effects of the Bt δ‐endotoxins Cry1Ab and Cry1Ac on the survival and development of the parasitoid Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) reared on Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) larvae fed on Bt toxin‐intoxicated artificial diet. The H. armigera larvae fed on artificial diet impregnated with Cry1Ab and Cry1Ac at LC₅₀ (effective concentration to kill 50% of the neonate H. armigera larvae) and ED₅₀ (effective concentration to cause a 50% reduction in larval weight) levels before and after parasitization resulted in a significant reduction in cocoon formation and adult emergence of C. chlorideae. Larval period of the parasitoid was prolonged by 2 days when fed on Bt‐intoxicated larvae. No adverse effects were observed on female fecundity. The observed effects appeared to be indirect in nature, because no Bt proteins were detected through enzyme‐linked immunosorbent assay in the C. chlorideae larvae, cocoons, or adults fed on Cry1Ab‐ or Cry1Ac‐treated H. armigera larvae. The effects of Bt toxin proteins on C. chlorideae were due to early mortality of H. armigera larvae, that is, before completion of parasitoid larval development.     

Predicting the impact of climatic warming on the carbon balance of the moss <Emphasis Type="Italic">Sanionia uncinata</Emphasis> on a maritime Antarctic island

The effects of climatic factors, especially those of temperature, on the carbon balance of the moss Sanionia uncinata were examined on King George Island in the maritime Antarctic. Net photosynthesis (P _n ) and dark respiration rates of two colonies (A and B) were measured with a portable infrared gas analyzer. Colony A showed small P _n compared with its dark respiration rates throughout the growing season. Colony B showed much higher net photosynthetic rates, but the dark respiration rates of the two colonies did not differ significantly. Net photosynthetic rate determined at light saturation was almost constant over a wide temperature range, from 5° to 15°C, while the dark respiration was strongly affected by temperature. To assess the impact of warming on the carbon balance of the moss, cumulative carbon gain of the moss was calculated using a simulation model for the main part of the growing season. The results suggest that climatic warming may cause a reduction of carbon gain in some relatively photosynthetically inactive moss colonies. Received: April 13, 2001 / Accepted: November 5, 2001     

Preliminary Report on the Distribution of <Emphasis Type="Italic">Callicebus oenanthe</Emphasis> on the Eastern Feet of the Andes

In 2007 we conducted a field study of almost 6 mo to determine the distribution of Callicebus oenanthe, formerly known as the Andean titi monkey. There previously has been no extensive study on the distribution and status by other fieldworkers. We visited a total of 96 localities within or around the presumed distribution of this rare primate species to determine the distribution of Callicebus oenanthe. We collected additional information on group size and threats to the species. Our expeditions revealed that the species is not endemic to the Alto Mayo Valley, as earlier authors suggested, but that its distribution extends into the Bajo Mayo and Huallaga Central. The study area is heavily deforested, and to date only one area was found where a viable population might live, although further research is needed to confirm this. The species lives in the southern part of its distribution in sympatry with another, undescribed species of Callicebus. We will continue the study to determine more precisely the distribution and conservation status of the Callicebus oenanthe, to determine if conservation measures are necessary for this species. This is the first activity of a long-term project for the conservation of Callicebus oenanthe initiated by La Vallée des Singes Primate park.     

Investigation on the chemiluminescence reaction of the phenylhydrazine‐luminol–peroxide system

We studied the chemiluminescence (CL) oxidation of phenyl hydrazine–luminol with various organic and inorganic peroxides. Maximum CL intensity for this system was obtained for t‐butylhydroperoxide. The enhancement in CL depended strongly on pH and was greatest at pH 12.5. The solvent drastically enhanced the CL intensity. DMSO was found to increase the CL intensity many‐fold as compared to acetonitrile and water. The effect of temperature on CL intensity has also been studied. The CL spectra revealed a broad peak at 425 nm, which suggests excited 3‐aminophthalate ion as the luminophor. A mechanism to explain the reactions is suggested. Copyright © 2012 John Wiley & Sons, Ltd.     

Observations on the Bionomics of the Freshwater Nematode Chromadorina bioculata

The biology and morphology of Chromadorina bioculata is presented. Tile nematode was abundant on the alga Cladophora of one lily pond, but absent from similar habitats in nearby ponds. The setae, caudal glands, high Iocomotory rates and positive photo response have been interpreted in relation to maintenance on, amongst and between algal filaments, suspended over large volumes of water.When placed in tap or distilled water, C. bioculata became inactive and died. The influence of pH buffers, tonicity, temperature and starvation on activity were investigated. C. bioculata survived longer in artificial sea water diluted 10 or 100 times with distilled water, or in NaCl isotonic with sea water diluted 100 or 1000 times, than in tap or distilled water. No evidence of wide osmotic toleration or osmoregulation was observed. Activity was influenced by temperature, with peak activities occurring at the seasonal normal temperature. These findings are discussed in terms of general hematology and habitat selection.     

Effect of the fungicide Prochloraz-Mn on the cell wall structure of <Emphasis Type="Italic">Verticillium fungicola</Emphasis>

The chemical structure of the cell wall of two isolates of Verticillium fungicola collected from diseased fruit bodies of the commercial mushroom Agaricus bisporus treated with the fungicide Prochloraz-Mn was analyzed. The isolates were obtained during different periods of time and grown in the absence and presence of the LD₅₀ values of the fungicide for V. fungicola. In addition, another V. fungicola isolate collected previous to the routine utilization of Prochloraz-Mn but grown under the same conditions was also analyzed. The overall chemical composition of the cell wall from the three isolates showed detectable differences in their basic components, with a significant decrease in the protein content in fungicide-treated cells. This inhibitory effect was partially compensated by an increase in neutral and/or aminated carbohydrates and was accompanied by appreciable modifications of polysaccharide structure, as deduced after methylation analysis and gas-liquid chromatography-mass spectrometry (GLC-MS). Moreover, differences in hyphal morphology caused by the fungicide were observed by transmission electron microscopy (TEM). Accepted 2 May 2002 Electronic Publication