Ambrosia beetles of the Euwallacea fornicatus species complex are emerging tree pests with a broad host range including important agricultural crops. Native to Southeast Asia, these species were introduced into various countries, where they cause considerable damage to many tree species. Here we report several outbreaks of E. fornicatus s.l. in Europe. The first individuals were found in 2017 in a palm house of a botanical garden in Poznan (Poland) whereas in 2020 an outbreak was detected in a tropical greenhouse in Merano (Italy). In 2021, two additional outbreaks were detected in two greenhouses in Germany, in Erfurt and Berlin. For both cases in Germany it was possible to trace back the invasion to a distributor of exotic plants in the Netherlands where several infested plants were detected. Molecular analyses show that individuals from Poland and Italy are genetically identical but belong to a different mitochondrial clade than individuals in Germany which are identical to most individuals of two greenhouses in the Netherlands. Moreover, in the two greenhouses in the Netherlands we found beetles that belong to another haplotype of E. fornicatus and two haplotypes of E. perbrevis , a species in the E. fornicatus complex, which has not been previously intercepted in Europe. Our study provides novel insights into the invasion history of E. fornicatus and the eradication measures in Europe. Considering the potential of introduction and establishment of Euwallacea ambrosia beetles, particular attention should be paid to monitor the presence of these pests in tropical greenhouses across Europe.
Questions Are the vegetation structure and soil properties of fallows similar to adjacent species-rich Mediterranean steppe communities 35 years after abandonment? Is there a spontaneous redevelopment towards the original steppe vegetation after reintroduction of the traditional grazing system? Can differences in functional trait composition be identified according to different land-use types? Do traits of selected species affect the ability to recolonize fallow land? Location Mediterranean steppe of La Crau (Southeastern France). Methods We conducted 80 vegetation surveys and soil analyses in the steppe and adjacent fallow land in six locations in La Crau in 2015; for three locations, data from 2001 were included. To compare the functional composition of steppe vs fallow land, community-weighted means (CMW) of specific leaf area (SLA), leaf dry matter content (LDMC) and canopy height were calculated. To test whether trait variability is associated with the recolonization success of 12 selected target species, we measured SLA, LDMC, canopy height, plant width and aboveground biomass on eight replicate individuals per site and species. Results Fallow land was characterized by lower species richness and elevated phosphorus and potassium content in the soil. Comparing vegetation releves between 2001 and 2015 revealed that the fallows were developing towards steppe vegetation. CWMs of SLA were significantly lower and CWM of LDMC higher in steppe than in fallow land. There was no similarity in trait composition between steppe species that successfully recolonized the fallow-land community, and no evidence that intraspecific trait variability is associated with recolonization success of these species. Conclusions Even after decades of abandonment and reintroduction of the grazing system, the vegetation structure, soil properties and plant functional trait composition of fallows differ from those of adjacent steppe communities. These results illustrate the need for active restoration to accelerate the recovery of former arable land to the target steppe communities.
The consumption of β-glucan-rich barley can contribute to a healthy diet. Sensory properties may be improved by roasting whereby the nutritional value should be preserved. The aim of the present study was to investigate the impact of different roasting conditions (160-200 °C, 20 minutes) on sensory quality, health-related compounds and viscosity in β-glucan-rich barley kernels, thin and thick flakes. Sensory quality was improved by roasting. Acrylamide levels increased due to roasting to maximum values of 322 μg kg-1 (kernels), 586 μg kg-1 (thin flakes) and 804 μg kg-1 (thick flakes). No relevant impact of roasting on the contents of fat, protein, starch and β-glucan was observed, whereas dietary fibre fractions were marginally modulated. Roasting significantly decreased viscosity 1.9-fold (kernels), 2.4-fold (thin flakes) and 2.7-fold (thick flakes), on average. In conclusion, improved sensory quality along with a favourable healthy composition of barley products may be achieved by roasting over a low to medium temperature range.
Flower-visiting insects are important crop pollinators, but their populations in agricultural landscapes are declining. One reason is the decreasing quantity and quality of floral resources. Deterioration of the situation caused by an increasing production of energy crops like maize, a pollen-only resource, may be mitigated by alternative crops such as Silphium perfoliatum L., which produces pollen and nectar over a long-lasting flowering period (July–September). The aim of this study was to assess the floral resources of S. perfoliatum. We calculated pollen grains and nectar sugar mass per inflorescence as well as inflorescences per plant using experimental plots and commercial fields in Germany. In addition, we analyzed free and protein-bound amino acids in pollen as well as sugars and free amino acids in nectar. The amount of pollen and nectar sugar per inflorescence decreased with increasing stem branching. The production of pollen and nectar sugar, however, was greatest in the second half of August due to the high number of inflorescences per plant at that stage. About half of the farmers harvested S. perfoliatum before the end of flowering to gain higher methane yields. With an early harvest around the beginning of September about one sixth of total pollen and one fifth of total nectar sugar production were lost to pollinators. Pollen and nectar showed high amounts of certain essential amino acids, particularly histidine, but total amino acids were low in concentration. Hence, S. perfoliatum should be complemented with different bee fodder plants to ensure a well-balanced diet.
