Summary• Stable isotope abundance analyses recently revealed that some European green orchids and pyroloids (Ericaceae) are partially myco-heterotrophic, exploiting mycorrhizal fungi for organic carbon and nitrogen. Here we investigate related species to assess their nutritional mode across various forest and climate types in Germany and California.• C-and N-isotope signatures of five green pyroloids, three green orchids and several obligate myco-heterotrophic species (including the putatively fully mycoheterotrophic Pyrola aphylla ) were analysed to quantify the green plants' nutrient gain from their fungal partners and to investigate the constancy of enrichment in 13 C and 15 N of fully myco-heterotrophic plants from diverse taxa and locations relative to neighbouring autotrophic plants.• All green pyroloid and one orchid species showed significant 15 N enrichment, confirming incorporation of fungi-derived N compounds while heterotrophic C gain was detected only under low irradiance in Orthilia secunda . Pyrola aphylla had an isotope signature equivalent to those of fully myco-heterotrophic plants.• It is demonstrated that primarily N gain from mycorrhizal fungi occurred in all taxonomic groups investigated across a wide range of geographical and ecological contexts. The 13 C and 15 N enrichment of obligate myco-heterotrophic plants relative to accompanying autotrophic plants turned out as a fairly constant parameter.

Summary• The leafless, circumboreal orchid Corallorhiza trifida is often assumed to be fully myco-heterotrophic despite contrary evidence concerning its ability to photosynthesize. Here, its level of myco-heterotrophy is assessed by analysing the natural abundance of the stable nitrogen and carbon isotopes 15 N and 13 C, respectively. • The mycorrhizal associates and chlorophyll contents of C. trifida were investigated and the C and N isotope signatures of nine C. trifida individuals from Central Europe were compared with those of neighbouring obligate autotrophic and mycoheterotrophic reference plants.• The results show that C. trifida only gains c. 52 ± 5% of its total nitrogen and 77 ± 10% of the carbon derived from fungi even though it has been shown to specialize on one specific complex of ectomycorrhizal fungi similar to fully mycoheterotrophic orchids. Concurrently, compared with other Corallorhiza species, C. trifida contains a remarkable amount of chlorophyll.• Since C. trifida is able to supply significant proportions of its nitrogen and carbon demands through the same processes as autotrophic plants, this species should be referred to as partially myco-heterotrophic.

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Genetic correlations between male and female traits can act as evolutionary constraints and, if involving reproductive traits, potentially influence sexual selection. Artificial selection on egg size in the tropical butterfly Bicyclus anynana has yielded highly divergent lines. Here we report evidence for correlated evolution in male traits. Males from the large-egg selected lines produced significantly heavier spermatophores independent of body size and tended to have more fertile sperm stored in their reproductive tracts than those from the small-egg selected lines. This may be due to an underlying genetic correlation in reproductive effort between the sexes. However, non-fertile sperm number and testis size remained unaffected by selection on egg size. Phenotypic correlations within an unselected population revealed that spermatophore mass and fertile sperm number, but not testis size and non-fertile sperm number, were positively related to male body size, and that larger spermatophores contained more fertile, but not non-fertile sperm. In addition, males provided larger females with bigger spermatophores and more fertile sperm, indicating males may be exercising mate choice during copulation.

Sciences (OTHR) established an English taught international cooperative bachelor program in the area of Engineering Physics/Optoelectronics. Students from China study their first four semesters at USST. They continue their studies in Germany for the last three semesters, including an internship and a bachelor thesis, graduating with a Chinese and a German bachelor degree. Students from Germany study their third and fourth semester at USST to gain international experience. While the first cohort of Chinese students is currently in Germany, the second cohort of German students is in Shanghai. Up to now the feedback regarding this study program is completely positive, thus it is planned to develop it further.