Biology subjects

Hatjina, F.

Publications and source records attributed to Hatjina, F..

3 recordsLinked to original sources

bioRxiv2025

Reducing Honey Bee Winter Mortality with Molybdenum Supplementation: Field Evidence Across Europe

Nutrition is key to improve honey bees resilience to environmental stress factors that threaten their health. Yet, little is known about the micronutritional needs of colonies, in particular about molybdenum, an essential trace element in biology. This study focuses on a coordination complex based on molybdenum Mo(+V) which was assessed for compatibility with standard beekeeping practices. It was found to be non-toxic for bees, stable and easy to use. Importantly, it does not leave any residues in honey produced. This study investigated how supplementation with few milligrams of this complex can improve hive performance at early spring and reduce winter mortality. Over a two-year field campaign, 283 beehives spread over 6 apiaries located in Spain, Greece and France were involved: 142 beehives supplemented with the molybdenum-based compound and 141 beehives as a control group. Supplementation resulted in a significant reduction in winter colony losses, averaging a 44% decrease, ranging between 27% and 75% in the different apiaries. The risk of death was twice lower in the Na-Mo2O4-EDTA group compared to the control group (risk ratio: 0.51). The impact on bee populations and honey production was also evaluated. A significant increase in honey reserves within the brood area of 107% was observed in the Greek apiary, whereas no comparable effect was detected in Spain, suggesting that local environmental conditions or management practices may influence this parameter. This study highlights the importance of molybdenum in the management of honey bees as an efficient tool to reduce the winter mortality of the colonies. HighlightsO_LIMolybdenum-based feed supplementation reduced honey bee winter mortality by 44% in average and up to 75% C_LIO_LIThere are no adverse effects on honey bee health or honey and wax composition. C_LIO_LISupplement showed variable effects on honey reserves and no effects on bee population. C_LIO_LIALP levels increased transiently, while the TAC was unaffected.Supplementation with Molybdenum-based compound represents a promising strategy to enhance colony overwintering success C_LI

zoology↗

bioRxiv2025

Food supplementation with molybdenum complexes improves honey bee health

In this study, we evaluated the impact of supplementing honey bee feed with molybdenum-based compounds. Among a dozen of dinuclear Mo(V) complexes, we first selected the most stable and non-toxic complexes, which were tested as food supplements in an extensive eight-year campaign involving more than 700 beehives across various environmental conditions in Moldova, France, Greece and USA. This unprecedented field campaign revealed that a few milligrams of compounds Na-Mo2O4-EDTA or Li-Mo2O4-EDTA provided in spring or autumn, increased queen fecundity, hygienic behavior, and honey production, while infestation rates of worker bees and brood by the mite Varroa destructor, and mortality rates in winter were dramatically reduced. Hive monitoring showed that the Mo-containing syrup can be consumed over 1.5 months and is well assimilated by larvae and workers within the hive. In particular, Mo levels increased significantly in the head of the bees. X-ray fluorescence measurements demonstrated that Na-Mo2O4-EDTA increases Mo levels in brain, neurolemma and hypopharyngeal glands. The metabolism of Mo complexes was addressed using X-Ray photoelectron spectroscopy (XPS) on bee faeces, which revealed that the complexes are oxidized into Mo(VI) species and thus suggesting that Mo complexes may function as antioxidant agents in bees. These findings offer promising solutions for the beekeeping industry, which is struggling with weakening honey bee colonies. Significance StatementHoney bees play a crucial role as pollinators. Unfortunately, colony losses have increased significantly over the past decades through the action of multiple environmental stressors. Currently, solutions are sought to strengthen bees health and resilience. This study shows that feeding bees with small amounts of trace elements like molybdenum can improve honey bee condition and increase the production of hive products. Through an unprecedented series of field and lab tests it notably demonstrates that molybdenum complexes are i) non-toxic, ii) consumed by bees over several generations, iii) assimilated particularly in the brain and hypopharyngeal glands, iv) acting as antioxidant. These results open new avenues for using trace elements to improve pollinator health.

zoology↗

bioRxiv2023

Semi-automated curation and manual addition of sequences to build reliable and extensive reference databases for ITS2 vascular plant DNA (meta-)barcoding

With the breakthrough of DNA (meta)-barcoding, it soon became clear that one of the most critical steps for accurate taxonomic identification is to have an accurate DNA reference database for the DNA barcode marker of choice. Therefore, developing such a database has been a long-term ambition, especially in the Viridiplantae kingdom. Typically, reference databases are constructed from marker sequences downloaded from general public databases, which can carry taxonomic and other relevant errors. Herein, we constructed a curated (i) global database, (ii) European crop database, and (iii) 27 databases for the EU countries for the ITS2 barcoding marker of vascular plants. To that end, we first developed a pipeline script that entails (i) an automated curation stage comprising five filters, (ii) manual taxonomic correction for misclassified taxa, and (iii) manual addition of newly sequenced species. The pipeline allows easy updating of the curated global database. With this approach, 13% of the sequences, corresponding to 7% of species, originally imported from GenBank were discarded. Further, 259 sequences were newly added to the curated global database, which now comprises 307,977 sequences of 111,382 plant species.

bioinformatics↗