Plovdiv University

This study introduces a novel synergistic approach to electrode modification that combines colloidal graphite (CG) and MXenes, presenting a promising material for enhancing voltammetric detection of rutin. This innovative strategy improves electrode performance by providing high conductivity, tunable surface chemistry, and ease of fabrication, while remaining cost‐effective. The CG–MXene‐modified electrode exhibited significant enhancements in charge transfer rates and electroactive surface area, facilitating efficient interaction with rutin. Its oxidation at the modified electrode was identified as a quasi‐reversible process controlled by diffusion. Under optimized conditions—specifically, a pH of 3.5 and a 5‐minute preconcentration time—rutin determination was achieved across a broad linear concentration range of 1–125 µmol L⁻¹, with a limit of detection of 0.2 µmol L⁻¹. The electrode demonstrated high reproducibility and selectivity in the presence of common excipients and vitamins. Recovery studies further validated the accuracy of the method, confirming its suitability for determining rutin in pharmaceutical products and food supplements.

Leguminous crops are usually sensitive to saline stress during germination and plant growth stages. The Salt Overly Sensitive (SOS) pathway is one of the key signaling pathways involved in salt translocation and tolerance in plants however, it is obscure in soybean. The current study describes the potential of calcium application on the mitigation of salinity stress and its impact on seed germination, morphological, physiological and biochemical attributes of soybean. The seeds from previously reported salt-tolerant and salt-susceptible soybean varieties were primed with water, calcium (10 and 20 mM), and stressed under 60, 80 and 100 mM NaCl and evaluated in various combinations. Results show that germination increased by 7% in calcium primed non-stressed seeds under non-stressing, whereas an improvement of 15%-25% was observed in germination under NaCl stress. Likewise, improvement in seedling length (3%-8%), plant height (9%-18%), number of nodes (3%-14%), SOD activity (20%) and Na⁺/K⁺ concentration (3%-5% reduction) in calcium primed plants, indicates alleviation of salinity-induced negative effects. In addition, this study also included in silico identification and confirmation of presence of Arabidopsis thaliana SOS genes orthologs in soybean. The research of amino acid sequences of SOS proteins from Arabidopsis thaliana (AtSOSs) within Glycine max genome displayed protein identity (60–80%) thus these identified homologs were called as GmSOS. Further phylogeny and in silico analyses showed that GmSOS orthologs contain similar gene structures, close evolutionary relationship, and same conserved motifs, reinforcing that GmSOSs belong to SOS family and they share many common features with orthologs from other species thus may perform similar functions. This is the first study that reports role of SOSs in salt-stress mitigation in soybean.

This study investigated the effects of dietary vitamin E (VE) and selenium (Se) supplementation on body weight changes, blood profile, and semen quality in Dexamethasone (DEX)-stressed Japanese quails. One hundred and five 10-week-old quail cocks were acclimated and divided into five treatment groups: negative control – G1, DEX-treated (20 mgL−1 of drinking water) – G2, DEX + VE (180 mg kg diet−1) – G3; DEX + Se (0.3 mg kg diet−1) – G4; and DEX + VE (180 mg kg diet−1) + Se (0.3 mg kg diet−1) – G5. The birds received their respective treatments over 21 days, and various performance, hematological, and semen quality parameters were measured. Results indicated that DEX treatment significantly reduced weight gain (WG) and feed intake (P < 0.05). Supplementation with VE and Se, individually and combined, ameliorated these effects, with groups G3, G4, and G5 showing similar WG to the control. Hematological analysis revealed significant increases (P < 0.05) in packed cell volume, hemoglobin, and white blood cell count in DEX-treated groups compared to G1. Treatment did not affect blood glucose and cholesterol levels (P ≥ 0.05). Plasma antioxidant assays showed elevated superoxide dismutase and catalase functions and reduced malondialdehyde levels in G3, G4, and G5 compared to G2, indicating reduced oxidative stress. No marked differences were seen in the plasma glutathione peroxidase activities across groups. Sperm motility was impaired in the DEX-only group but improved (P < 0.05) with antioxidant supplementation. In conclusion, dietary VE and Se effectively mitigated the negative impacts of DEX-induced stress on growth, antioxidant status, and spermatozoa motility in Japanese quail cocks. VE and Se supplementation could be beneficial in enhancing the welfare and productivity of poultry under stress.

The Thymus vulgaris and Origanum Vulgare essential oils (contained thymol and carvacrol in a range of 35-80%) are used in various products in the fields of medicine, cosmetics, and foods. Molecular hybridization between benzothiazole (BT) and phenolic monoterpenoids is a promising method for the development of biologically active compounds. New benzothiazole-monoterpenoid hybrids were synthesized through a regioselective α-amidoalkylation reaction of thymol and carvacrol with high yields (70-96%). This approach is both simple and cost-effective, employing easily accessible and inexpensive reagents to produce target molecules. The structure of the synthesized compounds was characterized spectrally using 1 H-, 13 C-NMR, FT-IR, and HRMS data. The newly obtained compounds are structural analogues of the UVB filter PBSA, which is used in cosmetics. The spectral properties of the aromatic products thymol hybrid (2-(4-hydroxy-5-isopropyl-2-methylphenyl)benzo[d]thiazole) and carvacrol hybrid (2-(4-hydroxy-2-isopropyl-5-methylphenyl)benzo[d]thiazole) were successfully examined, using a validated spectrophotometric method. SPF values varied from 31 to 36, compared to the PBSA (30), and were observed at concentrations of 1-0.25 mM. 2-Hydroxyphenylbenzothiazoles are known antimicrobial and antioxidant agents that have potential applications in the food industry and cosmetics as preservatives and antioxidants. In this context, antimicrobial activity of the hybrid compounds was evaluated using the agar diffusion method against E. coli, S. aureus, P. aeruginosa, and C. albicans. Compounds of methyl-2-(4-hydroxy-2-isopropyl-5-methylphenyl)benzo[d]thiazole-3(2H)-carboxylate containing carvacrol fragments showed high activity against Staphylococcus aureus ATCC 25923 (with 0.044 μmol content). The radical scavenging activity was determined using ABTS and DPPH assays, the highest activity was exhibited by the thymol hybrids ethyl-2-(4-hydroxy-5-isopropyl-2-methylphenyl)benzo[d]thiazole-3(2H)-carboxylate (IC50-133.70 ± 10 μM) and methyl-2-(4-hydroxy-5-isopropyl-2-methylphenyl)benzo[d]thiazole-3(2H)-carboxylate (IC50-157.50 ± 10 μM), defined by ABTS. The aromatic benzothiazole-monoterpenoid hybrids are classified using in silico analyses as non-mutagenic, with low toxicity, and they are non-irritating to the skin. These compounds were identified as new hit scaffolds for multifunctional molecules in cosmetics. Citation: Kirkova, D.; Stremski, Y.; Bachvarova, M.; Todorova, M.; Goranov, B.; Statkova-Abeghe, S.; Docheva, M. New Benzothiazole-Monoterpenoid Hybrids as Multifunctional Molecules with Potential Applications in Cosmetics. Molecules 2025, 30, 636. https://

The recent increase in mortality rates amongst honey bee colonies is a cause for concern. Assessing DNA damage in reproductive cells is crucial for species survival. This study aims to evaluate the potential of the sperm comet assay as a tool for in situ assessment of the genotoxic impact on honey bee populations with established high mortality rates. Previous studies have identified the presence of pesticide residues in bees and food stocks within the hives, indicating the existence of genotoxic agents in the localities under investigation. The values of comet assay parameters, namely Tail Intensity (TI%) and Olive Tail Moment (OTM, µm), scored in the sperm cells, increased following the mortality trend of the honey bee populations under study, providing evidence of significant DNA damage occurring during spermatogenesis. The alkaline comet assay in hemolymph confirmed the genotoxic effects observed in the sperm comet assay. The current study demonstrated for the first time that the sperm comet assay could serve as a reliable novel method for assessing genotoxicity in A. mellifera.

Background: New benzazacamalexin-related analogues are synthesized in an easily accessible one-pot approach. The method is based on the reaction of indoles with in situ formed electrophilic N-alkoxycarbonylbenzimidazolium reagents. For the first time, their application for N-alkylation of the indole nitrogen atom is announced toward novel tris-heterocyclic hybrids. The structure of newly obtained products was spectrally charac-terized by 1D and 2D-NMR, FTIR and HRMS spectral data. The current scientific re-search is based on the application of a convenient and efficient route for the preparation of various benzimidazoles. This approach is both straightforward and economical, utilizing readily accessible and affordable reagents leading to target compounds. Objective: The synthesis of novel benzimidazole-indole molecular hybrids as benzazacamalexin related analogues. Methods: A suitable in situ method has been successfully applied, using an α-amidoalkylation reaction of indoles with N,N-diacyliminium reagents derived from benzimidazoles and alkyl chloroformates. Results: The reactions led to the obtaining of ten novel compounds (5a-e, 6a-e), including bromine and iodine-containing benzo-analogues on a gram-scale scope and yields ranging from 82% to 99%. For the first time the synthesis of indole tris-heterocycles (7a, b) through the reaction of N-alkylation of the indole nitrogen atom is announced giving an-other potential synthetic application of the N,N-dialkoxycarbonyl-5,6-dimethylbenzimidazolium adducts. Conclusion: The structure of the newly synthesized products is spectrally analysed and proved.

The genus Amsonia, a member of the Apocynaceae family, comprises plants with notable medicinal benefits. In 2022 and 2023, Amsonia tabernaemontana Walt. seeds introduced to Bulgaria were collected and analyzed. Given the limited information available on the chemical composition of A. tabernaemontana, this study aimed to evaluate the phytochemical profile of the plant seeds collected over two consecutive years. Although members of the genus Amsonia are not conventional oilseed crops, the glyceride oil content was 7.8% and 11.1% in the respective samples. The chemical composition was meticulously analyzed, revealing carbohydrates in the largest amounts (60.4% and 61.3%), with crude fibers at 18.3% and 24.8%, and protein content at 19.5% and 13.0%. The amounts of ash and moisture content were also quantified. Additionally, the fatty acids, sterols, tocopherols, and phospholipids of the seed oil were examined. β-Sitosterol emerged as the main component in both harvests. The total tocopherol content was relatively low (52.7 mg/kg vs. 20.0 mg/kg), with α-tocopherol being predominant. Phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine were identified as the principal components of the phospholipid fraction. The fatty acid composition primarily included linoleic (61.0 and 61.2%) and oleic acids (28.7 and 28.6%).

Lipid peroxidation is a major process that determines the quality of various oil samples during their use and storage, in which the primary products are hydroperoxides (HP’S). HP’S are very stable compounds at ambient conditions and are harmful to human health. Therefore, the evaluation of the degree of oil oxidation is an excellent tool for ensuring food safety. The peroxide value (PV) is the main parameter used for quality control in oils. Herein, we propose an alternative electrochemical method to the classical iodometric titration method most widely used for determining the PV. Our approach is based on the electrochemical quantification of hydroperoxides/peroxides in an organic solvent medium (acetonitrile and organic ammonium salt) using a composite electrocatalyst–glassy carbon electrode modified with 2D-nanomaterial graphitic carbon nitride doped with Co3O4. Calibration was made by the method of standard addition using benzoyl peroxide (BPO) as a model peroxide compound, dissolved in chloroform and added to fresh Rivana-branded anti-cellulite oil, used as a model oil sample. Calibration plots showed a linear response and the very good reproducibility of the analytical result (R2 ˃ 0.99). Further, in terms of accuracy, the method showed good results, since the BPO quantitative analysis was close to the theoretical response. In addition, the accuracy of the electrochemical method was compared with that of the standard iodometric titration method for determining the PV of vegetable fats (according to a standard method). Finally, using the electrochemical method, the concentration of peroxides was determined in a real sample—an anti-cellulite oil of the trademark Rivana with an expired shelf life.

Lactobacillus is a key genus of probiotics commonly utilized for the treatment of oral infections The primary aim of our research was to investigate the probiotic potential of the newly isolated Levilactobacillus brevis DPL5 strain from human breast milk, focusing on its ability to combat biofilm-forming pathogens such as Staphylococcus aureus. Employing in vitro approaches, we demonstrate L. brevis DPL5′s ability to endure at pH 3 with survival rates above 30%, and withstand the osmotic stress often found during industrial processes like fermentation and freeze drying, retaining over 90% viability. The lyophilized cell-free supernatant of L. brevis DPL5 had a significant antagonistic effect against biofilm-producing nasal strains of Staphylococcus aureus, and it completely eradicated biofilms at subinhibitory concentrations of 20 mg·mL−1. Higher concentrations of 69 mg·mL−1 were found to have a 99% bactericidal effect, based on the conducted probability analysis, indicating the production of bactericidal bioactive extracellular compounds capable of disrupting the biofilm formation of pathogens like S. aureus. Furthermore, genome-wide sequencing and analysis of L. brevis DPL5 with cutting-edge Nanopore technology has uncovered over 50 genes linked to probiotic activity, supporting its ability to adapt and thrive in the harsh gut environment. The genome also contains multiple biosynthetic gene clusters such as lanthipeptide class IV, Type III polyketide synthase (T3PKS), and ribosomally synthesized, and post-translationally modified peptides (RiPP-like compounds), all of which are associated with antibacterial properties. Our study paves the way for the further exploration of DPL5, setting the stage for innovative, nature-inspired solutions to combat stubborn bacterial infections.

Environmental negotiations are complex, and conveying the interaction between science and policy in traditional teaching methods is challenging. To address this issue, innovative educational approaches like serious gaming and role-playing games have emerged. These methods allow students to actively explore the roles of different stakeholders in environmental decision-making and weigh for instance between sometimes conflicting UN Sustainable Development Goals or other dilemmas. In this work the phosphorus negotiation game (P-Game) is for the first time introduced. We present the initial quantitative and qualitative findings derived from engaging 788 students at various academic levels (Bachelor, Master, PhD, and Postdoc) across three continents and spanning 22 different countries. Quantitative results indicate that female participants and MSc students benefitted the most significantly from the P-Game, with their self-reported knowledge about phosphorus science and negotiation science/practice increasing by 71–93% (overall), 86–100% (females), and 73–106% (MSc students in general). Qualitative findings reveal that the P-Game can be smoothly conducted with students from diverse educational and cultural backgrounds. Moreover, students highly value their participation in the P-Game, which can be completed in just 2–3 h. This game not only encourages active engagement among participants but also provides valuable insights into the complex environmental issues associated with global phosphorus production. We strongly believe that the underlying methodology described here could also be used for other topics.

Herein, we report the synthesis of a series of new compounds by combining 2-aminobenzothiazole with various profens. The compounds were characterized using techniques such as 1H- and 13C-NMR, FT-IR spectrometry, and high-resolution mass spectrometry (HRMS), with detailed HRMS analysis conducted for each molecule. Their biological activities were tested in vitro, revealing significant anti-inflammatory and antioxidant effects, comparable to those of standard reference compounds. Lipophilicity was experimentally determined through partition coefficient (RM) measurements. To understand their binding affinity, molecular docking studies were perfsormed to analyze interactions with human serum albumin (HSA). The stability of these predicted complexes was further evaluated through molecular dynamics simulations. The results highlight the compounds’ promising biological activity and strong affinity for HSA. The new hybrid molecule between 2-ABT and ketoprofen 3b demonstrates significant promise based on the experimental data and is further supported by in silico calculations. Compound 3b exhibits the best hydrogen peroxide scavenging activity among the tested compounds, with an IC50 of 60.24 μg/mL. Furthermore, 3b also displays superior anti-inflammatory activity, with an IC50 of 54.64 μg/mL, making it more effective than the standard ibuprofen (76.05 μg/mL).

This article proposes a project aimed at introducing secondary school students to artificial intelligence and logic programming using the Prolog language. In commemoration of the 50th anniversary of Prolog’s development, the authors participate in the international initiative “Prolog Education and Thinking” through the “Digital Bulgaria in Prolog” activity, implemented in Bulgarian secondary schools. The article offers a concise overview of a STEM (Science, Technology, Engineering, and Mathematics) educational program and training for secondary school students in Bulgaria. STEM serves as a project-based learning approach, fostering students’ understanding of multiple disciplines and utilizing diverse technologies to enhance their skills. Additionally, the article showcases examples of student initiatives spanning natural sciences, informatics, humanities, culture, and art, illustrating the interdisciplinary nature of STEM education.

The Asteraceae family is a large plant family, with over 1600 genera and 25,000 species, most of which are generally herbaceous plants. This family’s members are widely used in the human diet and medicine. One of the most popular representatives is Centaurea benedicta L., known as ‘Blessed Thistle’. It is a famous plant in the herbal world with some medical benefits, such as strong antioxidant and antidepressant effects, with antibacterial and antiseptic properties, a stimulant of appetite, with a good effect on the liver and the secretion of bile juices, etc. Therefore, this work aimed to fully characterize the chemical composition of the seeds of C. benedicta introduced in Bulgaria, some of the physicochemical characteristics, as well as the biologically active compounds. The main nutrient in the chemical composition was carbohydrates (68.5%), and half of their quantity was occupied by fibers (32.2%). Total proteins accounted for 16.4%, and the glyceride oil content was rather low—about 11.0%. The main fatty acids identified in the seed oil were linoleic (72.1%) and oleic acids (18.1%), and the amount of the polyunsaturated ones predominated (73.0%). The main lipid-soluble bioactive components were sterols (0.9%), phospholipids (1.9%), and tocopherols (492 mg/kg). β-Sitosterol (59.5%) and stigmasterol (19.4%) were the main sterols, and α-tocopherol (472 mg/kg) predominated in the tocopherol fraction. The major phospholipids were phosphatidylethanolamine (45.4%), followed by phosphatidylinositol (37.1%) and phosphatidylcholine (6.1%).

This study explores the effects of varying exposure times of microelement fertilization on hydrochemical parameters, plant growth, and nutrient content in an aquaponic system cultivating Capsicum annuum L. (pepper) with Cyprinus carpio (Common carp L.). It also investigates the potential of visible-near-infrared (VIS-NIR) spectroscopy to differentiate between treated plants based on their spectral characteristics. The findings aim to enhance the understanding of microelement dynamics in aquaponics and optimize the use of VIS-NIR spectroscopy for nutrient and stress detection in crops. The effects of microelement exposure on the growth and health of Cyprinus carpio (Common carp L.) in an aquaponic system are investigated, demonstrating a 100% survival rate and optimal growth performance. The findings suggest that microelement treatments, when applied within safe limits, can enhance system productivity without compromising fish health. Concerning hydrochemical parameters, conductivity remained stable, with values ranging from 271.66 to 297.66 µS/cm, while pH and dissolved oxygen levels were within optimal ranges for aquaponic systems. Ammonia nitrogen levels decreased significantly in treated variants, suggesting improved water quality, while nitrate and orthophosphate reductions indicated an enhanced plant nutrient uptake. The findings underscore the importance of managing water chemistry to maintain a balanced and productive aquaponic system. The increase in root length observed in treatments 2 and 6 suggests that certain microelement exposure times may enhance root development, with treatment 6 showing the longest roots (58.33 cm). Despite this, treatment 2 had a lower biomass (61.2 g), indicating that root growth did not necessarily translate into increased plant weight, possibly due to energy being directed towards root development over fruit production. In contrast, treatment 6 showed both the greatest root length and the highest weight (133.4 g), suggesting a positive correlation between root development and fruit biomass. Yield data revealed that treatment 4 produced the highest yield (0.144 g), suggesting an optimal exposure time before nutrient imbalances negatively impact growth. These results highlight the complexity of microelement exposure in aquaponic systems, emphasizing the importance of fine-tuning exposure times to balance root growth, biomass, and yield for optimal plant development. The spectral characteristics of the visible-near-infrared region of pepper plants treated with microelements revealed subtle differences, particularly in the green (534-555 nm) and red edge (680-750 nm) regions. SIMCA models successfully classified control and treated plants with a misclassification rate of only 1.6%, Citation: Sirakov, I.; Stoyanova, S.; Velichkova, K.; Slavcheva-Sirakova, D.; Valkova, E.; Yorgov, D.; Veleva, P.; Atanassova, S. Exploring Microelement Fertilization and Visible-Near-Infrared Spectroscopy for Enhanced Productivity in Capsicum annuum and Cyprinus carpio Aquaponic Systems. Plants 2024, 13, 3566. https://doi.org/ 10.3390/plants13243566 Copyright: © 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/license s/by/4.0/). Plants 2024, 13, 3566 2 of 18 highlighting the effectiveness of the spectral data for plant differentiation. Key wavelengths for distinguishing plant classes were 468 nm, 537 nm, 687 nm, 728 nm, and 969 nm, which were closely related to plant pigment content and nutrient status. These findings suggest that spectral analysis can be a valuable tool for the non-destructive assessment of plant health and nutrient status.

This paper presents the utilization of a developed pilot wireless-based Air Quality Index (AQI) monitoring system, reporting live geo-grid resolved air quality data, for the purposes of healthy route generation and recommendation to users. The generated routes are visualized on a map and recommended to users through a specially developed web-based application, as part of the client tier of the supporting IoT platform EMULSION. A distributed computing architecture is utilized for the generation of healthy (more precisely, ‘least air pollution exposure’) routes, performed in near real-time using the dynamic Dijkstra algorithm, based on the interpolated AQI values. In addition, the fastest and shortest routes for each journey, requested by a user, are generated as well. The importance of the presented work lies within the practical applicability of the proposed method for healthy route generation, either as a stand-alone version of the software application developed for the purpose or integrated into the existing popular navigation systems and applications alike.

In this article, we present a unique system for identifying edible oils through the analysis of their thermophysical properties. The method is based on the use of active infrared thermography. The heating of the oils results from the optical absorption of laser radiation at a specified wavelength. This approach enables greater selectivity in differentiating between various types of edible oils, as the results depend not only on the thermal properties of the specific oils but also on their optical properties, which are uniquely characteristic of each oil. Additionally, the developed system provides a detailed visualization of spatial temperature gradients within the sample’s volume, as well as their changes over time. It overcomes the limitations of other methods that determine only the thermal conductivity coefficients of oils through resistive heating of the sample. In this article, four types of vegetable oils (extra virgin olive oil, sesame oil, sunflower oil, and rapeseed oil) have been studied. Fatty acid analysis, differential scanning calorimetry, and UV-VIS spectroscopy have been used to determine the authenticity, moisture content, and optical properties of the studied samples. The developed system allows for the visualization and determination of the emerging temperature gradients in the sample volume.

Oncolytic viral‐delivered chemotherapeutics have exciting potential for metastatic cancer therapies, including colorectal cancer, but require advanced screening systems for better patient prediction. We optimized primary metastatic colorectal tumor processing and 3D (3‐dimensional) bioprinted tumors to prove efficacy as long‐term screening systems. Normally, this time period would use animals, but we show it is possible to gain useful data in vitro before preclinical stages, to reduce animal modeling and give better clinical trial predictions. Liver tumors were collected from 12 colorectal cancer patients, evaluated for expansion, 3D bioprinted, and tested for ability to create long‐term organoid models with screening of oncolytic viral‐loaded FCU1 enzyme conversion of 5‐fluorocytosine (5‐FC) into the highly toxic 5‐fluorouracil (5‐FU). Donated tumor size was the limiting factor. 75% of patients could be used for screening of viral delivery. Response between patients was overall positive, with good secondary tumor development, outer active cellular content and inner necrotic core. Oncolytic challenge shows good screening potential and cellular targeting, demonstrating an added bystander effect, optimizing the low‐dose. Stable long‐term metastatic organoid models were made, lasting many months, with potential for retesting rather than one‐off analysis. Oncolytic virus‐delivered chemotherapy is promising and warrants further investigation for metastatic colorectal cancers.

Background Mesopolobus Westwood, 1833 consists of about 135 valid species worldwide. After the fundamental monograph of Graham (1969), 12 species have been described from continental Europe and three species have been described from the Canary Islands and Malta. Amongst them, one species, Mesopolobus blascoi Askew, 1994, has been synonymised under Mesopolobus maculipennis (Mercet, 1923). Only eight species have been reported from Bulgaria to date. New information Here we describe a new species, Mesopolobus askewi sp. nov. and present new data on the Bulgarian chalcidoid fauna obtained by sampling in foliage of the Norway spruce, P. abies. Mesopolobus askewi sp. nov. can be distinguished from the most morphologically similar species, M. longicollis Graham, by the following characters: clypeus with deeper emargination, fore wings with basal vein having complete row of setae, head blue to bluish-green, mesosoma bluish-green to green with coppery reflections, legs after coxae mostly fulvous, only distal one-fifth of meso- and metatibiae yellowish, protarsi with fifth segment yellowish, only tarsal claws fuscous, venation pale testaceous. Furthermore, we identified nine valid species of the family Pteromalidae belonging to four genera – Mesopolobus (three spp.), Pachyneuron (one sp.), Stenomalina (one sp.) and Trichomalus (four spp.) and one species of subfamily Asaphesinae (Chalcidoidea, incertae sedis), all represented in our samples by many specimens and none having previously been reported as associated with foliage of the Norway spruce. Three of the species are new records for the Bulgarian fauna.