Isolation of microsatellite markers for Contarinia nasturtii,a European pest invading the New World

Microsatellite markers were developed for epidemiological studies on Contarinia nasturtii (Diptera, Cecidomyiidae), a native European pest that was introduced to the New World in 1996. Nine loci were found to be polymorphic and suitable for the analysis of 56 male individuals that were collected using pheromone traps. These markers all conform to Hardy–Weinberg expectations in at least one of the two tested populations, and carry an average number of 11 alleles among populations and observed levels of heterozygosity ranging from 0.32 to 0.86. Primers for all markers also successfully amplified fragments from Contarinia pisi and Contarinia tritici.     

Isolation and characterization of 15 microsatellite loci in the poplar rust fungus,Melampsora larici‐populina,and cross‐amplification in related species

We developed 15 microsatellite loci in the poplar rust fungus, Melampsora larici‐populina, using two enrichment protocols. Polymorphism of each locus was assessed on a panel of 30 isolates, comprising three subpanels (world, regional and local scales). Thirteen loci were polymorphic with three to eight alleles detected. The 15 loci were also tested on five related Melampsora species, M. allii‐populina, M. medusae f. sp. deltoidae, M. larici‐tremulae, M. rostrupii and M. pinitorqua, and partial or global cross‐amplification events were detected.     

Element localization in ultrathin cryosections of high-pressure frozen ectomycorrhizal spruce roots

We present, for the first time, elemental mapping of ultra-thin cryosections from high-pressure frozen ectomycorrhizal roots of Picea abies–Hebeloma crustuliniforme. The maps provide interpretable information on the relationship between elements and the structure of inhomogeneous objects. Cryoultramicrotomy together with energy dispersive X-ray microanalysis (EDX) offers the potential to study the subcellular localization of specific ions and ecologically important tracers (Cs and Sr) in ectomycorrhizal roots under conditions resembling the natural slate as closely as possible. Structural changes of the ectomycorrhizal roots, in particular the absence of a Hartig net at high NH₄⁺ levels in the nutrient solution, were accompanied by elemental modification of Ca in cortical cell walls, where markedly higher concentrations of Ca were found. Cs and Sr applied to the nutrient solution were localized in root and fungal cells of the Hartig net. Cs accumulated mainly in the vacuoles of the Hartig net hyphae and its distribution was very similar to the distribution of K. In contrast to Cs, Sr was found to occur mainly in electron-opaque and P-rich granules. From this study, (here is no indication that Ca is the only ion accompanying P in the P-rich granules. Several elements including Ca, K, Cl, S, Cs and Sr, with highest concentrations for S, can occur together with P in these granules. The occurrence of the P-rich electron-opaque deposits in fungal cells might be the first evidence of polyphosphate granules in the native state, since our specimen preparation technique did not include chemical fixation.     

Habitat‐specific population structure in native western flower thrips Frankliniella occidentalis (Insecta,Thysanoptera)

Invasions by pest organisms are among the main challenges for sustainable crop protection. They pose a serious threat to crop production by introducing a highly unpredictable element to existing crop protection strategies. The western flower thrips Frankliniella occidentalis (Insecta, Thysanoptera) managed to invade ornamental greenhouses worldwide within < 25 years. To shed light on possible genetic and/or ecological factors that may have been responsible for this invasion success, we studied the population genetic structure of western flower thrips in its native range in western North America. Analysis of nucleotide sequence variation and variation at microsatellite loci revealed the existence of two habitat‐specific phylogenetic lineages (ecotypes) with allopatric distribution. One lineage is associated with hot/dry climates, the second lineage is restricted to cool/moist climates. We speculate that the ecological niche segregation found in this study may be among the key factors determining the invasion potential of western flower thrips.     

Exclusion of ground predators improves Northern Lapwing Vanellus vanellus chick survival

Many farmland‐breeding wader species have declined across Europe, probably due to reductions in reproductive output caused by high nest losses as a result of agriculture or predation, or low chick survival between hatching and fledging. Most studies have focused on nest failures, and the factors affecting post‐hatching survival of chicks are poorly known. In an experimental approach, we fenced parts of the arable foraging areas of Northern Lapwing Vanellus vanellus families to quantify chick survival simultaneously in the presence and absence of ground predators. Lapwing chicks were radiotagged to estimate survival probabilities by daily locations, applying multistate capture–recapture models. During the night, chick survival was considerably lower outside fenced plots than within. During the day, chick survival was higher than at night and did not differ between protected and unprotected plots. This suggests that nocturnal ground predators such as Red Foxes Vulpes vulpes were responsible for a significant proportion of chick mortality. Cumulative survival probability from hatching to fledging was 0.24 in chicks within fenced plots, but virtually zero in chicks outside fenced plots. In farmland, temporary electric fences can be effective in minimizing the impact of ground predators and offer a promising short‐term method to increase fledging success of precocial birds.     

The occurrence and effect of a protozoan parasite, Ophryocystis elektroscirrha (Neogregarinida: Ophryocystidae) on overwintering monarch butterflies, Danaus plexippus (Lepidoptera: Danaidae) from two California winter sites

Abstract.

• 1 Monarch butterflies, Danaus plexippus, from two overwintering populations, were found to have Ophryocystis elektroscirrha spores on their scales at rates between 53% and 68%. The frequency of butterflies with O.elektroscirrha spores remained about the same between sites and throughout the winter.
• 2 The spores, recovered from all parts of the body of the butterfly, were most numerous on the abdomen, particularly near the posterior third.
• 3 Butterflies with spores survived as long as those without detectable spores at 10.1°C ±0.4 SE and 78.3% r.h. ±0.6SE. Insects with spores held at 19.4°C ±0.4SE and 44.9% r.h. ±1.5SE showed a significantly higher rate of moisture loss and survived a shorter period than monarch butterflies without detectable spores.

     

Common canonical variates

Canonical correlation analysis measures the linear relationshipbetween two random vectors X₁ and X₂ as the maximum correlationbetween linear combinations of X₁ and linear combinations ofX₂. Several generalisations of canonical correlation analysisto k2 random vectors X₁ ..., X_k have been proposed in the literature(Kettenring, 1971, 1985), based on the principle of maximisingsome generalised measure of correlation. In this paper we proposean alternative generalisation, called common canonical variates,based on the assumption that the canonical variates have thesame coefficients in all k sets of variables. This generalisationis applicable in situations where all X_i have the same dimension.We present normal theory maximum likelihood estimation of commoncanonical variates, and illustrate their use on a morphometricdata set.     

Characterization of microsatellite markers in the interspecific hybrid Phytophthora alni ssp. alni,and cross‐amplification with related taxa

Phytophthora alni ssp. alni is an interspecific hybrid oomycete causing a large‐scale decay of alders throughout Europe. In this study we developed a set of 10 microsatellite markers that shows promise for population studies and for studying hybridization events between the parental species of the hybrid. Moreover, the genotype and the ploidy of the different subspecies of P. alni might be inferred from the quantitative ratio of amplified genome‐specific alleles. Nine primer pairs cross amplified with the related species Phytophthora cambivora and Phytophthora fragariae and yielded distinct alleles.