Age and growth in a European flagship amphibian : equal performance at agricultural ponds and favourably managed aquatic sites

In human-modified landscapes, little is known about the influence of aquatic habitat types on the demographic structure of residing amphibian populations. In the present paper, we focus on a European flagship urodele species (the great crested newt Triturus cristatus) at the north-western range of its distribution, applying the method of skeletochronology to compare the ages of individuals retrieved from agricultural ponds with individuals retrieved from aquatic sites favourably managed for T. cristatus presence. Median ages ranged between 4.5 and 10.0 years depending on sex and population, and did not differ between the two site categories. Females were on average older than males at both agricultural ponds as well as favourably managed sites. Median ages at sexual maturity (3 years for females and 2 years for males) were 4 years below the most commonly observed age cohort in both sexes, suggesting that young adults regularly forgo reproduction. Mean body size did not differ between agricultural ponds and favourably managed sites. However, the former were characterised by a higher variance in body size, which is possibly linked to more unstable ecological conditions in agricultural settings. Taken together, our findings confirm that under suitable conditions agricultural ponds can harbour sustainable populations, an important finding for the broad-scale conservation management of T. cristatus which does not usually take population demographies into account. Keywords: Demography Great crested newt Skeletochronology Triturus cristatus Urodele

Skin swabs with FTA® cards as a dry storage source for amphibian DNA

Amphibians are the most endangered group of vertebrates, and conservation measures increasingly rely on information drawn from genetic markers. The present study explores skin swabs with Whatman FTA® cards as a method to retrieve PCR-amplifiable amphibian DNA. Swabs from ten adult great crested newts (Triturus cristatus) were used to compare FTA® card-based protocols with tissue sampling based on toe clips. PCR success rates were measured for seven microsatellite markers and one mtDNA marker (ND4) after 6 months of sample storage. We demonstrate that the merging of eight FTA® card punches from Qiagen-based DNA extraction always led to successful amplifications in at least one replicate, at an overall PCR success rate of 78%. The newly established protocol has the potential for wide application to future DNA-based amphibian studies

Biologische Kontrolle von Eulenraupen im Kohl mittels Baculoviren

Baculoviren sind als hoch selektive biologische Kontrollagenzien für Kohleulenraupen (Mamestra brassicae) seit längerem bekannt und ihre gute Wirksamkeit wurde schon in verschiedenen Gewächshaus- und Freilandversuchen nachgewiesen. Um die Kontrollsituation von Kohleulenraupen im ökologischen Gemüseanbau insbesondere bei niedrigen Temperaturen zu verbessern, wurden die eulenpathogenen Mamestra brassicae Nukelopolyhedrovirus (MbMNPV) und Mamestra configurata Nukleopolyhedrovirus (MacoNPV-A) als mögliche Kontrollagentien geprüft. Es konnte gezeigt werden, dass auch MacoNPV-A für M.brassicae pathogen ist. In vergleichenden Bioassays bei 24°C zeigten MbMNPV und MacoNPV-A keinen signifikanten Unterschied hinsichtlich ihrer biologischen Aktivität gegenüber M.brassicae. In weiteren Bioassays wurden die konzentrationsabhängige Mortalität von M.brassicae im 2. Larvenstadium sowie die gefressene Blattfläche bei 24, 20, 16 und 12°C bestimmt. Im Vergleich zu 24 und 20°C waren die mittleren Letalkonzentrationen bei 16 und 12°C 100 bzw. 1000fach höher. Für eine mittlere Reduktion der konsumierten Blattfläche waren hingegen bei Temperaturen unter 20°C 10 bis 100fach höhere Konzentrationen notwendig. Durch die Neuformulierung von MbMNPV (Probis GmbH, Wiernsheim) konnte eine Wirkungssteigerung im Vergleich zu der nicht formulierten Virussuspension im Bioassay erzielt werden. In einem Freilandtest mit künstlicher Infestation in Kohlrabi konnte eine weitere Steigerung des Wirkungsgrades durch die Kombination mit dem Bacillus thuringiensis Präparat XenTari® im Vergleich zur Einzelapplikation der beiden Präparate erreicht werden. Eine breite Freilandtestung der Baculoviren-Präparaten gegen Kohlraupen bei kühler Witterung als Einzelpräparat und in Kombination mit Bacillus thuringiensis Präparaten sowie neuester Applikationstechnik für Ober- und Unterblattbehandlung wird empfohlen

Genome sequence of a Spodoptera frugiperda multiple Nucleopolyhedrovirus isolated from fall armyworm (Spodoptera frugiperda) in Nigeria, west Africa

Open Access Article; Published online: 26 Aug 2021We report the entire genome sequence of an isolate of Spodoptera frugiperda multiple nucleopolyhedrovirus from Nigeria, West Africa. The genome is 132,710 bp long and contains 144 open reading frames. The GC content is 40.3% and, based on baculovirus species demarcation criteria, the isolate belongs to the species Spodoptera frugiperda multiple nucleopolyhedrovirus

Effekten av olika koncentrationer av Rotstop R och Rotstop S och ofullständig täckning av Rotstop S på sporinfektioner av rotticka på granstubbar

The effectiveness of treatment with two Phlebiopsis gigantea based preparations (Rotstop® and RotstopS) in different concentrations against the root and butt rot causing fungus Heterobasidion annosum s.l. on Norway spruce (Picea abies) thinning stumps in southern Sweden was compared. The trees were cut on three sites during the summer 2004 and 285 stumps were treated manually with 100% cover with two different amounts of spores in solution corresponding to approximately 5×106 spores/l and 10×106 spores/l. 31 stumps received mechanical part cover with the highest spore concentrations of Phlebiopsis gigantea, i.e. approximately 20×106 spores/l. Mechanical treatment was assessed for satisfactory treatment effect. Three months later, samples were collected and analyzed. There was a significant reduction in frequency and relative areas of Heterobasidion spp. infections on stumps with manual application of control agents compared to untreated stumps. On average 10 to 23% of stumps subjected to manual treatments were infected compared to 52% for the untreated stumps. However, none of the concentration solutions of Rotstop® and RotstopS differed from the others in reduction of Heterobasidion spp. infections. Mechanical treatment failed to control the Heterobasidion spp. infections, but there was a tendency for the 85.1-95.0% cover class to provide better result than the others. Thus, despite of the incomplete control of the pathogen, stump treatment with different concentrations of Phlebiopsis gigantea oidia in suspensions provided equal effects at the present spore loads of Heterobasidion spp.Effektiviteten av behandling med två pergamentsvampsbaserade (Phlebiopsis gigantea) lösningar (Rotstop® och RotstopS) i olika koncentrationer mot sporinfektioner av rotticka (Heterobasidion spp.) på gallringsstubbar av gran (Picea abies) i södra Sverige jämfördes. Träd avverkades på tre olika lokaler under sommaren 2004 och sammanlagt 285 stubbar behandlades manuellt med en hundraprocentig täckning i två olika koncentrationer motsvarande ungefär 5×106 sporer/l respektive 10×106 sporer/l lösning. 31 stubbar på en av lokalerna behandlades maskinellt med en ofullständig täckning men med den högsta koncentrationen av pergamentsvamp (RotstopS), ca 20×106 sporer/l lösning. Effekten av den mekaniska behandlingens partiella täckning jämfördes med den manuella fullständiga. Tre månader efter behandlingen samlades prover in för analys med avseende på förekomsten av rotticka. Alla manuella behandlingar gav en signifikant reducering av frekvensen av och relativa arean av rottickeinfektioner jämfört med obehandlade stubbar. I genomsnitt var 10 till 23 % av de manuellt behandlade stubbarna infekterade jämfört med 52 % av de obehandlade. Ingen av de manuella applikationerna skiljde sig dock från varandra. Den mekaniska behandlingen gav inte ett tillfredsställande resultat men det fanns en tendens till att täckningsgradsklass 85,1- 95,0 % fungerade bättre än de andra. Således, trots att ingen behandling gav en 100 % -ig minskning av antalet rottickeinfektioner, verkar olika koncentrationer av Rotstop® och RotstopS ge ett likvärdigt resultat under de förhållanden i sportryck som rådde vid behandlingen

Untersuchungen zur Populationsgenetik der Minderempfindlichkeit des Apfelwicklers gegenüber Cydia pomonella Granulovirus (CpGV)

The Codling moth granulovirus (Cydia pomonella granulovirus, CpGV, Baculoviridae) is one of the most important bio control agents of the codling moth in apple production. Since 2003, codling moth populations have been observed in Germany and France, which show an up to thousand fold decreased susceptibility to CpGV. A spread of this phenomenon is a severe threat to the efficient control of the codling moth, particularly in organic farming. In order to prevent this development, investigations on the popula-tion genetics of codling moth populations in Germany were initiated to assess the baseline susceptibilities of selected populations. Furthermore, the genetic and biologi-cal background of resistance of the codling moth to CpGV are being elucidated by crossing susceptible and low susceptible codling moth populations. These investiga-tions will help to develop new control strategies or to restore high susceptibility to-wards CpGV. Mapping of traits involved in resistance will be performed. Involved loci will be identi-fied with the help of amplified fragment length polymorphism (AFLP). Loci coupled with susceptibility can help to elucidate resistance mechanisms. Analysis of comple-mentary DNA amplified fragment length polymorphism (cDNA-AFLP) will be per-formed to display differences in expression rate of particular genes. If there are differ-ences between sensitive and non-sensitive strains, the genes will be isolated and sequenced. Putative sequence homologies give the direction of the functional sense of the mentioned gene and further conclusion of the mechanisms of the susceptibility of CpGV

A toy model of the five-dimensional universe with the cosmological constant

A value of the cosmological constant in a toy model of the five-dimensional universe is calculated in such a manner that it remains in agreement with both astronomical observations and the quantum field theory concerning the zero-point fluctuations of the vacuum. The (negative) cosmological constant is equal to the inverse of the Planck length squared, which means that in the toy model the vanishing of the observed value of the cosmological constant is a consequence of the existence of an energy cutoff exactly at the level of the Planck scale. In turn, a model for both a virtual and a real particle-antiparticle pair is proposed which describes properly some energetic properties of both the vacuum fluctuations and created particles, as well as it allows one to calculate the discrete "bare" values of an elementary-particle mass, electric charge and intrinsic angular momentum (spin) at the energy cutoff. The relationships between the discussed model and some phenomena such as the Zitterbewegung and the Unruh-Davies effect are briefly analyzed, too. The proposed model also allows one to derive the Lorentz transformation and the Maxwell equations while considering the properties of the vacuum filled with the sea of virtual particles and their antiparticles. Finally, the existence of a finite value of the vacuum-energy density resulting from the toy model leads us to the formulation of dimensionless Einstein field equations which can be derived from the Lagrangian with a dimensionless (naively renormalized) coupling constant.Comment: 52 pages, 1 figure; a post-final, rewritten version with a number of new remarks and conclusion

Genetic and migratory evidence for sympatric spawning of tropical pacific eels from Vanuatu

The spawning areas of tropical anguillid eels in the South Pacific are poorly known, and more information about their life histories is needed to facilitate conservation. We genetically characterized 83 out of 84 eels caught on Gaua Island (Vanuatu) and tagged 8 eels with pop-up satellite transmitters. Based on morphological evidence, 32 eels were identified as Anguilla marmorata, 45 as A. megastoma and 7 as A. obscura. Thirteen of these eels possessed a mitochondrial DNA sequence (control region, 527 bp) or nuclear haplotype (GTH2b, 268 bp) conflicting with their species designation. These individuals also had multi-locus genotypes (6 microsatellite loci) intermediate between the species, and 9 of these eels further possessed heterozygote genotypes at species-diagnostic nuclear single nucleotide polymorphisms (SNPs). We classified these individuals as possibly admixed between A. marmorata and A. megastoma. One A. marmorata and one A. megastoma migrated 634 and 874 km, respectively, towards the border between the South Equatorial Current and the South Equatorial Counter Current. Both species descended from around 200 m depth at night to 750 m during the day. Lunar cycle affected the upper limit of migration depths of both species. The tags remained attached for 3 and 5 mo and surfaced <300 km from the pop-up location of a previously tagged A. marmorata. A salinity maximum at the pop-up locations corresponding to the upper nighttime eel migration depths may serve as a seamark of the spawning area. The similar pop-up locations of both species and the evidence for admixture suggest that these tropical eels share a sympatric spawning area