A diverse supply of pollen is an important factor for honey bee health, but information about the pollen diversity available to colonies at the landscape scale is largely missing. In this COLOSS study, beekeeper citizen scientists sampled and analyzed the diversity of pollen collected by honey bee colonies. As a simple measure of diversity, beekeepers determined the number of colors found in pollen samples that were collected in a coordinated and standardized way. Altogether, 750 beekeepers from 28 different regions from 24 countries participated in the two-year study and collected and analyzed almost 18,000 pollen samples. Pollen samples contained approximately six different colors in total throughout the sampling period, of which four colors were abundant. We ran generalized linear mixed models to test for possible effects of diverse factors such as collection, i.e., whether a minimum amount of pollen was collected or not, and habitat type on the number of colors found in pollen samples. To identify habitat effects on pollen diversity, beekeepers’ descriptions of the surrounding landscape and CORINE land cover classes were investigated in two different models, which both showed that both the total number and the rare number of colors in pollen samples were positively affected by ‘urban’ habitats or ‘artificial surfaces’, respectively. This citizen science study underlines the importance of the habitat for pollen diversity for bees and suggests higher diversity in urban areas.

The subject of the paper refers to the research on beekeepers’ perceptions of environmental threats to beekeeping in the Western Balkan region. The following environmental threats were supposed to be the most pronounced: cutting of melliferous perennial plants and clearing of forests, urbanisation and environmental pollution, use of pesticides in agricultural production, pests and agents of bees’ diseases, climate changes. The aim of the research was to find out how beekeepers perceived these threats, to determine the presence of the threats and to define their intensity as well as their mutual relationship. For the purpose of this research, the authors created a structured questionnaire which was filled in by randomly selected beekeepers living in the Western Balkans. The research results show that most beekeepers in the studied area evaluated the assumed threats as strong to very strong, while the greatest percentage of beekeepers believes that climate change represents the greatest threat to beekeeping in the region. All assumed environmental threats show the same tendency, while they have the most serious effect on large apiaries with more than 150 bee colonies, located in lowland areas up to 200 meters above sea level with intensive farming. Findings of this research are important in order to adapt the current beekeeping practice in the region to more sustainable solutions, through improvement of the existing beekeeping legislation and advisory services.

Apis cerana and Apis mellifera are important honey bee species in Asia. A. cerana populations are distributed from a cold, sharply continental climate in the north to a hot, subtropical climate in the south. Due to the Sacbrood virus, almost all A. cerana populations in Asia have declined significantly in recent decades and have recovered over the past five years. This could lead to a shift in the gene pool of local A. cerana populations that could affect their sustainability and adaptation. It was assumed that adaptation of honey bees could be observed by comparative analysis of the sequences of genes involved in development, labor division, and caste differentiation, such as the gene Vitellogenin VG. The VG gene nucleotide sequences were used to assess the genetic structure and signatures of adaptation of local populations of A. cerana from Korea, Russia, Japan, Nepal, and China. A. mellifera samples from India and Poland were used as the outgroup. The signatures of adaptive selection were found in the local population of A. cerana using VG gene sequence analysis based on Jukes–Cantor genetic distances, cluster analysis, dN/dS ratio evaluation, and Tajima’s D neutrality test. Based on analysis of the VG gene sequences, Apis cerana koreana subspecies in the Korean Peninsula were subdivided into three groups in accordance with their geographic localization from north to south. The VG gene sequences are acceptable tools to study the sustainability and adaptation of A. cerana populations.

Apis cerana and Apis mellifera, are very important honey species for agriculture in Asian countries. In recent decades, A. cerana populations have sharply declined in all Asian countries as a result of Sacbrood Virus infection and have now recovered to their original size. It can change the genetic structure of local populations of A. cerana. We used the nuclear gene Vitellogenin VG to assess the genetic structure of local populations of A. cerana and the signature of adaptive selection. We performed a population genetic analysis of the honey bees A. cerana from South Korea in comparison with A. cerana samples from Russia, Japan, Nepal, and China. The sequences of the gene VG of a closely related honey bee species, A. mellifera, from India and Poland were used as outgroup samples. A comparative analysis of northern and southern A. cerana populations was performed. The signatures of positive adaptive selection were found in the local population of A. cerana. We performed the Tajima's neutrality D test for A. cerana populations from different local populations based on the gene VG exon sequences. All A. cerana populations showed signs of population size expansion following the possible recent decline in population sizes. The local populations of A. c. koreana were subdivided according to their geographical distribution into southern, northern, and central Korean clusters. The gene VG exon sequences can be used as informative markers for monitoring the changes in genetic structure and adaptation to the environment processes in A. cerana populations.

Although concentrate feeds supply most carbohydrates and proteins, the protein component represents the most expensive fraction. A substantial portion of concentrate protein can be replaced with more economical protein sources from forages, particularly from legumes such as pea (Pisum sativum ssp. arvense L.), combined with cereals like oat (Avena sativa L.). Mixtures of these annual legumes and cereals generate a synergistic effect, where oats contribute yield stability and energy, while peas enhance protein concentration and improve forage preservation quality. Assessing protein quality requires understanding the distribution of individual protein fractions classified according to the Cornell Net Carbohydrate and Protein System (CNCPS), which categorizes proteins from PA (non-protein nitrogen) to PC (undegradable proteins bound to lignin, tannins, or Maillard products). This study investigated the influence of pea–oat seed ratios—SR (80:20, 60:40, 40:60, and 20:80) and developmental stages—S (early flowering and pod filling) on the dynamics of protein fractions in green biomass. Results showed that soluble protein fractions (PA, PB₁) decreased during maturation due to nitrogen translocation to developing grains, while structural and undegradable fractions (PB₂, PB₃, PC) increased, particularly in mixtures with higher oat proportions. The 60:40 pea:oat ratio produced the most balanced protein profile, maximizing the proportion of moderately degradable proteins (PB₂), which are crucial for efficient microbial protein synthesis in the rumen. This ratio also optimized the synergy between legume nitrogen fixation and cereal energy supply, enhancing sustainable ruminant nutrition. Statistical analysis confirmed significant differences between growth stages and mixture compositions. Overall, pea–oat mixtures represent a key component of economically viable and ecologically sustainable forage production for ruminant livestock systems.