Consequences of mixed species infestation on the searching behavior and parasitism success of a larval parasitoid

When two herbivore pest species are potential hosts of a single parasitoid species, two questions arise. Firstly, which host is preferable for mass rearing in terms of later parasitoid performance, and secondly, how do parasitoids perform in mixed herbivore situations after colony establishment? We tested Hyssopus pallidus, a gregarious parasitoid of two major pests of apple, Cydia (Grapholita) molesta and Cydia pomonella, before and after landing on apples infested by one of the two Cydia species. Pre-alighting host preference was tested in a Y-tube olfactometer setup, and parasitism success in a contact bioassay. To gain information on parasitoid performance throughout the growing season, different fruit growth stages were used. Irrespective of the host they had developed on, the parasitoids showed similar olfactory preferences when given a dual choice between infested and healthy fruits, and they did not discriminate between fruits infested by C.molesta and C.pomonella. Responsiveness was generally high, especially late in the season close to harvest. Both hosts are parasitized regardless of the host the parasitoid female had developed on, and no differences in parasitism rates or number of offspring were noted for the two hosts offered. Results were consistent for all apple growth stages tested. In conclusion, mass rearing of this parasitoid can be carried out on either host, without limiting the future efficacy of the bio-control agent. Similarly, established colonies are expected to develop further on both hosts without any bias in host preferenc

Comparison between volatile emissions from transgenic apples and from two representative classically bred apple cultivars

While most risk assessments contrast a transgenic resistant to its isogenic line, an additional comparison between the transgenic line and a classically bred cultivar with the same resistance gene would be highly desirable. Our approach was to compare headspace volatiles of transgenic scab resistant apple plants with two representative cultivars (the isogenic ‘Gala' and the scab resistance gene-containing ‘Florina'). As modifications in volatile profiles have been shown to alter plant relationships with non-target insects, we analysed headspace volatiles from apple plants subjected to different infection types by gas chromatography-mass spectrometry. Marked differences were found between healthy and leafminer (Phyllonorycter blancardella) infested genotypes, where emissions between the transgenic scab resistant line and the two cultivars differed quantitatively in four terpenes and an aromatic compound. However, these modified odour emissions were in the range of variability of the emissions recorded for the two standard cultivars that proved to be crucial reference

Up on the roof and down in the dirt:differences in substrate properties (SOM, potassium, phosphorus and pH) and their relationships to each other between sedum and wildflower green roofs

In urban areas green roofs provide important environmental advantages in regard to biodiversity, storm water runoff, pollution mitigation and the reduction of the urban heat island effect. There is a paucity of literature comparing different types of green roof substrates and their contributions to ecosystem services or their negative effects. This study investigated if there was a difference between sedum and wildflower green roof substrate properties (soil organic matter (SOM), potassium (K) and phosphorus (P) concentrations and pH values) of 12 green roofs in the city of Brighton & Hove. One hundred substrate samples were collected (50 from sedum roof substrates and 50 from wildflower roof substrates) and substrate properties were investigated using standard protocols. Comparisons were made between substrate characteristics on both types of roof substrate with a series of multiple linear regressions. Sedum roofs displayed significantly higher values of SOM, P and pH. There were significant positive relationships between SOM and K concentrations, SOM and P concentrations, pH and K concentrations and pH and P concentrations on sedum roofs. This study concluded that sedum roof substrates are more favourable for plant water use efficiency and also contained a significantly higher percentage of SOM than wildflower roofs. However, higher concentrations of P in sedum roof substrates may have implications in regard to leachates

Cold stored ectoparasitoid of Cydia fruit moths released under different temperature regimes

Cold storage of parasitoids to be used in biological control programs is desirable but risky for the performance of the stored parental generation as well as for its offspring. We studied the performance of cold stored and unstored parasitoids after release at different temperature regimes in the laboratory at the level of two subsequent generations in Hyssopus pallidus (Askew) (Hymenoptera: Eulophidae). This gregarious ectoparasitoid is a candidate biocontrol agent of Cydia pomonella L. (Lepidoptera: Tortricidae) and Cydia molesta (Busck) (Lepidoptera: Tortricidae) larvae, two fruit pests of high economic significance in apple cultivation. Cold storage for 14days at 4°C imposed to the pupal stage of the parasitoid did not reduce the parasitism capacity of the parental generation, nor did it alter the female biased sex ratio of the progeny. Remarkably, this short-term storage of the parental generation exhibited a significant and consistently positive effect on offspring weight throughout all ambient temperature regimes, resulting in an increased offspring weight. Furthermore, offspring number was only reduced after release at low ambient temperatures, but not at 25°C and 30°C. Irrespective of whether the parasitoids originated from the stored or unstored group, highest parasitism rate was achieved at temperatures above 20°C. In conclusion, this candidate biocontrol agent can be cold stored for short periods without any measurable quality loss after release at most except at low ambient temperatures. Our findings suggest that H. pallidus is a thermophilous parasitoid that will perform best when applied at warm ambient temperatures in fruit orchard

New insights in analysing parasitoid attracting synomones: early volatile emission and use of stir bar sorptive extraction

Summary.: It is well known that feeding by Pieris brassicae caterpillars on cabbage leaves triggers the release of volatiles that attract natural antagonists such as the parasitoid Cotesia glomerata. The temporal dynamics in the emissions of parasitoid attracting volatiles has never been elucidated in this system. In a time course experiment, caterpillar infested leaves attracted the parasitoid within one hour after infestation. At such an early stage of infestation, as much as fifty percent of the parasitoids flew towards the infested plant in a wind tunnel bioassay, while only five percent flew towards the non-infested control plant. Three hours after infestation and later, the response to the volatiles from the infested plant reached its maximum and then continued at a constantly high level for the remaining 14 hours of the experiment. Chemical analyses of volatiles collected from infested leaves at short time intervals during the first 24 hours identified a total of ten compounds, comprising green leaf volatiles, terpenoids, and a nitrile. Significant increase of emission within the first 5 hours following initial herbivory was detected for (Z)-3-hexen-1-ol, (Z)-3-hexen-1-yl acetate, cineole and benzylcyanide. Subsequently, a coupled bioassay-chemical analysis procedure was developed allowing for testing and analyzing the same sample for future identification of the bioactive compounds. This was achieved by using stir bar sorptive extraction for the analysis of solvent extracts of caterpillar-damaged leave

ペーター=ロット/アンヤ=フォン=デア=ロップ 「ヨーロッパにおける越境不作為請求訴訟の現状」

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Population genomic analysis of elongated skulls reveals extensive female-biased immigration in Early Medieval Bavaria

Modern European genetic structure demonstrates strong correlations with geography, while genetic analysis of prehistoric humans has indicated at least two major waves of immigration from outside the continent during periods of cultural change. However, population-level genome data that could shed light on the demographic processes occurring during the intervening periods have been absent. Therefore, we generated genomic data from 41 individuals dating mostly to the late 5th/early 6th century AD from present-day Bavaria in southern Germany, including 11 whole genomes (mean depth 5.56×). In addition we developed a capture array to sequence neutral regions spanning a total of 5 Mb and 486 functional polymorphic sites to high depth (mean 72×) in all individuals. Our data indicate that while men generally had ancestry that closely resembles modern northern and central Europeans, women exhibit a very high genetic heterogeneity; this includes signals of genetic ancestry ranging from western Europe to East Asia. Particularly striking are women with artificial skull deformations; the analysis of their collective genetic ancestry suggests an origin in southeastern Europe. In addition, functional variants indicate that they also differed in visible characteristics. This example of female-biased migration indicates that complex demographic processes during the Early Medieval period may have contributed in an unexpected way to shape the modern European genetic landscape. Examination of the panel of functional loci also revealed that many alleles associated with recent positive selection were already at modern-like frequencies in European populations ∼1,500 years ago

Ergänzung zur Stellungnahme des Zentrums für Lehrer*innenbildung der Universität Wien zum Lehrplan Digitale Grundbildung

Das neue Schulfach Digitale Grundbildung (DGB) wurde als Pflichtfach in der Sekundarstufe I mit überarbeitetem Lehrplan verankert – ein Grund zur Freude, dass der Digitalisierung auch innerhalb der schulische Bildung endlich die nötige Aufmerksamkeit gegeben wird. Das Fach stellt, besonders vor dem Hintergrund der Initiativen, die im Rahmen des 8-Punkte Plans der Bundesregierung gesetzt wurden, die notwendige Brücke zwischen Infrastruktur-Maßnahmen, Inhalten und der tatsächlichen Nutzung dieser Ressourcen dar. Das neue Schulfach Digitale Grundbildung – eine Projektionsfläche für mannigfaltige Bedürfnislagen. Aus Informatikperspektive und Sicht der Wirtschaft bietet es eine Gelegenheit, kompetenzorientierten Informatikunterricht schon in der Sekundarstufe I beginnen zu lassen. Aus medienpädagogischem Betrachtungswinkel ist das Fach ein lang gewünschtes Gefäß, um jungen Menschen ein besseres Verständnis von Medien und eine kompetente Mediennutzung nahezubringen. Aus der im Folgenden abgebildeten Perspektive des Zentrums für Lehrer*innenbildung der Universität Wien bietet das Schulfach den notwendigen Rahmen, um zumindest ansatzweise inklusive, diversitätsgerechte und interdisziplinäre Perspektiven auf die Digitalisierung und ihre sozialen, kulturellen, politschen und gesellschaftlichen Aus- und Wechselwirkungen zusammenzuführen