Effects of three modern insecticides, pyriproxyfen, spinosad and tebufenozide, on survival and reproduction of Chrysoperla carnea adults

Three novel insecticides, pyriproxyfen, spinosad and tebufenozide, were evaluated for their effect on survival and reproduction of Chrysoperla carnea adults using two methods of exposure: direct contact and ingestion. Pyriproxyfen and tebufenozide proved to be harmless to adult survival, whereas spinosad 72 h after treatment reduced the number of adults by 39.8% and 87.2% in topical and ingestion treatment at the maximum concentration recommended (800 mg a.i. litre^?1). Fecundity was not affected irrespective of the insecticide or time of application (before or after the onset of oviposition). Concerning fertility, only pyriproxyfen exerted a negative effect on hatching when the eggs were deposited by females treated by ingestion in the post‐oviposition period at the highest concentration tested (150 mg a.i. litre^?1).     

Population genetics of Mioscirtus wagneri,a grasshopper showing a highly fragmented distribution

The genetic consequences of population fragmentation and isolation are major issues in conservation biology. In this study we analyse the genetic variability and structure of the Iberian populations of Mioscirtus wagneri, a specialized grasshopper exclusively inhabiting highly fragmented hypersaline low grounds. For this purpose we have used seven species‐specific microsatellite markers to type 478 individuals from 24 localities and obtain accurate estimates of their genetic variability. Genetic diversity was relatively low and we detected genetic signatures suggesting that certain populations of M. wagneri have probably passed through severe demographic bottlenecks. We have found that the populations of this grasshopper show a strong genetic structure even at small geographical scales, indicating that they mostly behave as isolated populations with low levels of gene flow among them. Thus, several populations can be regarded as independent and genetically differentiated units which require adequate conservation strategies to avoid eventual extinctions that in highly isolated localities are not likely to be compensated for with the arrival of immigrants from neighbouring populations. Overall, our results show that these populations probably represent the ‘fragments’ of a formerly more widespread population and highlight the importance of protecting Iberian hypersaline environments due to the high number of rare and endangered species they sustain.     

Effects of Cold and Nocodazole Treatments on the Microtubular Systems of Paramecium in Interphase

The sensitivity of the microtubular systems to cold and nocodazole treatments as well as the cellular distribution of microtubules containing acetylated a-tubulin have been studied in Paramecium. Our results indicate that the microtubular systems of Paramecium show marked differences in stability. Cold and nocodazole treatments produce the depolymerization of the major part of the cytoplasmic microtubular network while the cortical structures remain stable under treatment. This differential stability of the microtubular systems is associated with the acetylation of the a-tubulin. The use of the antibody 6-11B-1, specific for acetylated α-tubulin, shows that the microtubular systems containing acetylated a-tubulin are the same as those that remain stable after depoly-merizing treatments. Finally, the images obtained during the repolymerization by heating suggest that the cortical dikinetids are able to nucleate the microtubules of the cytoplasmic network.     

A new Pyrenean hybrid Cirsium (Asteraceae) as revealed by morphological and molecular analyses

A new nothosubspecies Cirsium  ×  vivantii is described after a molecular and morphological characterization of eight individuals collected in two separate valleys of the French central Pyrenees. Both hypervariable Amplified Fragment Length Polymorphism (AFLP) markers and nuclear rDNA (ITS) and plastid ( trn L-F, TRNT-L) DNA sequences were analysed. The profiles of these hybrid samples were compared to those of 43 individuals belonging to their presumed parental taxa C. carniolicum ssp. rufescens and C. palustre . A total of 133 AFLP bands were scored from three primer-pair combinations. All 130 AFLP bands that amplified in the hybrid samples were present in either C. carniolicum ssp. rufescens , C. palustre or both taxa, supporting the participation of these plant genomes in the resulting hybrids. Several Additive Polymorphic Sites (APS) detected in the ITS sequences of the hybrid samples also confirmed their derived origins from ribotypes of the two parental taxa. The lack of exclusive AFLP markers and the nonconcerted evolution of rDNA polymorphisms towards either of the parental ribotypes indicated their recent origin. Plastid trn T-L sequences were used to identify C. palustre as the maternal parent of six of these hybrid individuals; either parent could have acted as the plastid genome donor for the other two individuals. The morphological study revealed that all hybrid individuals were morphologically intermediate between their parents showing largely lobed and less spiny basal leaves as in C. carniolicum ssp. rufescens and decurrent leaf bases and pinkish corollas as in C. palustre .  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 421–434.     

Advances in techniques for ecdysteroid analysis

Summary

Recent improvements in chromatographic methods for ecdysteroids are reviewed. Minor improvements in liquid chromatography have increased the separation and range of compounds which can be accomodated, some useful techniques have been introduced in thin layer chromatography, and with new radioactivity scanners and direct mass spectrometry from TLC, this technique retains an important place among the tools of the ecdysonist. Supercritical fluid chromatography has been suggested as a rapid and more sensitive alternative to liquid chromatography. In mass spectrometry, fast atom bombardment has proved most useful, though coupling HPLC through thermospray and ptasmaspray methods has been attempted, but as yet, these techniques lack sensitivity. New solid phase immunoassay methods using colorimetric rather than radioactivity measurements promise to give a better means of analysis of small amounts of ecdysteroids, capable of use in the presence of radiolabeled compounds. A solid phase separation of C-20, 22 diol ecdysteroids with immobilized phenylboronic acid has been reported.     

Conjugation in Stylonychia muscorum Kahl

SYNOPSIS. The process of conjugation in a strain of Stylonychia muscorum Kahl is described. It follows the general pattern reported earlier in other Oxytrichidae, but the following peculiarities can be noted: 1) mating never occurs between individuals possessing only two micronuclei, 2)exchange of small macronuclear lobes can be occasionally observed, and 3) the reorganization of the exconjugants involves the quick, successive passage of a series of reorganization bands.     

Ketoconazole Inhibits the Growth and Development of Ichthyophonus sp. (Mesomycetozoa) In Vitro

ABSTRACT. We determined the in vitro effect of the azol-derivative antifungal ketoconazole (KZ) on the morphology, growth, and development of teleost fish parasite Ichthyophonus sp. The KZ was delivered to culture medium using liposomes (L) or a lipid emulsion (E) at five different doses (i.e. 5, 50, 100, 200, and 400 μg/ml) for both L and E formulations. Controls consisted of Eagle's minimum essential medium (MEM) supplemented with 10% foetal bovine serum (MEM-10) alone (C-MEM) or containing amounts of L or E equivalent to those used in the KZ100 and KZ400 treatments (i.e. 100L, 400L, 100E, and 400E, respectively). Morphological alterations, such as a decrease in the number of dividing spores and nuclei, and condensation or even destruction of the cytoplasm, were observed using light and electron microscopy in the MEM-cultured organisms receiving KZ formulations, especially with KZ400L preparations, at both 7- and 14-d postinoculation. The KZ treatments also demonstrated a statistically significant inhibition of Ichthyophonus growth in MEM. These treatments also had an inhibitory effect on subsequent Ichthyophonus germination in Earle's fish saline agar (EFSA) medium, which was more evident for L formulations when the organism was treated for 7 d and for E formulations at 14 d. Our results endorse the potential use of KZ for the treatment for ichthyophonosis and provide support to proceed to in vivo assays.     

Differential Nuclear Coloration in Ciliates

SYNOPSIS. Application of the triple stain of Grosso (methyl green-pyronin-orange G) to the exconjugants of different species of ciliates produces a differential coloration of their nuclei. Both the old macronucleus or its remnants and the micronuclei bind methyl green whereas the newly developing macronucleus (macronuclear anlage) has a selective affinity for the orange G present in the mixture. This finding holds true not only for hypotrichous ciliates, whose macronuclear anlagen are involved in the formation of polytene chromosomes, but also for other ciliates not included in the order Hypotrichida. Such a reaction of the new macronuclei apparently results from the presence of non-histone (acidic) proteins associated with the nucleic acids.
The staining method is fully described to provide a more general application.