Search Results (179)

Successful conservation biological control programs require a good understanding the nutritional ecology of natural enemies to maximize their field efficacy. This study evaluated the effects of non-floral sugar sources on fitness parameters of Mastrus ridens, a specialized parasitoid of the codling moth. In the laboratory, we compared the longevity, parasitism, and reproduction of adult parasitoids exposed to different sugar sources, including Vicia faba extrafloral nectar, honeydew from several hemipteran species, diluted honey (positive control), and no-sugar controls. We also tested the effects of exposing parasitoids to honey for only 24 h. The results showed that sugar availability and source type significantly affected parasitoid performance. Extrafloral nectar was better than mealybug honeydew, with female offspring numbers similar to those exposed to honey, and increased the number of parasitized host larvae by up to 3.5-fold compared to no-sugar conditions. The effects of honeydew effects on male longevity were variable, possibly explained by its composition, and the mode of presentation. Parasitoids with a short exposure to high-quality sugar performed poorly. Our findings indicate that successful conservation and augmentative biological control programs using this species require field provision of high-quality, accessible sugar resources. Full article

Non-invasive Electrical Impedance Tomography (EIT) and Electrical Impedance Spectroscopy (EIS) are emerging as promising techniques for real-time monitoring and quality assessment in food processing and agri-food applications. This study reviews recent advances in impedance-based sensing for fruit characterization and investigates the experimental implementation of multi-electrode impedance measurements for tomographic imaging. Particular attention is devoted to electrode configurations, electrode polarization effects, and equivalent circuit modeling. Experimental measurements were performed on yellow honeydew melon samples using a four-electrode configuration and a impedance analyzer Keysight E4990 (Keysight Technologies, Santa Rosa, USA) over the frequency range from 20 Hz to 1 MHz. The impedance spectra were validated through Kramers–Kronig consistency tests and interpolated using several fractional-order equivalent circuit models, including single-Cole, double-Cole, and Hayden-based models. The results show that four-electrode measurements are less sensitive to electrode-sample interface artifacts than conventional two-electrode approaches, thereby providing a more reliable estimate of the sample impedance, particularly at low frequencies. Among the tested models, the double-Cole model provided the best interpolation accuracy, while the fractional Hayden models effectively described the temporal evolution of extracellular resistance and membrane-related parameters. Preliminary EIT reconstructions further demonstrate the feasibility of non-destructive tomographic imaging for fruit monitoring. These findings support the potential of EIS and EIT as low-cost, portable, and non-invasive tools for smart food quality assessment and precision agriculture applications. Full article

The white-backed planthopper, Sogatella furcifera, and the brown planthopper, Nilaparvata lugens, severely impact rice production, necessitating effective selection methods for resistant cultivars. S. furcifera poses a significant threat to rice cultivation, particularly in Asia. Through this study, we aimed to establish an effective approach to identifying resistant rice varieties based on feeding behavior, physiological and chemical responses, and genetic analysis. Three key activities were involved: (1) evaluation of planthopper feeding behavior utilizing the honeydew drop method, the electrical penetration graph technique, and growth rate analysis; (2) investigation into the physiological and chemical traits of rice; and (3) analysis of resistance-related gene expression. The results indicated larger honeydew drop areas, fewer and shorter probing events, and structural defenses such as increased trichome density in resistant rice genotypes, likely hindering insect attachment and feeding. We confirmed the suitability of the growth rate method for resistance screening. Gene expression analysis identified PR10a upregulation in resistant rice, suggesting a molecular basis for resistance. This study enables the selection of rice varieties resistant to planthoppers, supporting sustainable pest management and breeding programs. The findings support sustainable pest management by enabling the targeted selection of resistant varieties, ultimately aiding in the development of rice genotypes with enhanced resistance across growth stages. Full article

Ant–hemipteran mutualism is mediated by honeydew through long-term coevolution. To clarify the feeding preferences for the main honeydew components (sugars and amino acids) in the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), this study employed a self-developed feeding preference assay system to systematically determine the feeding and attraction preferences of workers for ten sugars, eleven amino acids, and their different concentrations and combinations in both laboratory and field experiments. Results showed that: (1) S. invicta workers exhibited a significant feeding preference for sucrose and leucine among all tested sugar and amino acid solutions; (2) Feeding preferences for both sucrose and leucine were concentration-dependent. Specifically, preferences for 20% sucrose and 0.5% leucine were significantly higher than for lower concentrations, while not significantly different from higher concentrations; (3) The feeding preference for 10% sucrose or 0.5% leucine alone was higher than that for multi-sugar mixtures or a mixture of all eleven amino acids. However, a mixture of sucrose and leucine solutions significantly enhanced field attraction compared to single solutions of sucrose or leucine. The self-developed feeding preference assay system provides a new tool for measuring feeding preferences in ant colonies under near-natural conditions. Overall, this study systematically clarifies the feeding preference for key nutrients in S. invicta workers and establishes a critical theoretical basis for understanding its foraging ecology and developing highly effective liquid baits. Full article

The valorization of waste cooking oils (WCOs) provides a strategy to reduce environmental impact while converting residues from the food industry into valuable products. This study developed and characterized antimicrobial soaps from purified WCOs (sunflower, palm, and pumpkin oils) enriched with natural bioactive ingredients. WCOs were purified by filtration, treatment with 10% NaCl, and bleaching with 3% H₂O₂, followed by cold saponification with NaOH. Twelve soap formulations were prepared, including six enriched with bee products (propolis, poly-floral honey, linden, acacia, honeydew, and sunflower) and six enriched with essential oils (EOs) (clove, rosemary, mace, nutmeg, white pepper, and juniper). The WCOs, natural bioactive ingredients, and soaps were characterized using physico-chemical methods (FTIR, GC-FID, phenols, flavonoids, etc.), while their antibacterial activity was determined against two microbial strains: Staphylococcus aureus and Escherichia coli. The antimicrobial activity of soaps is related to their alkaline pH, while the addition of honey, propolis, or EOs contributes to additional antimicrobial effects. Among honey- and propolis-enriched soaps, those with propolis produced the largest inhibition zones (up to 8.67 mm for S. aureus and 7.0 mm for E. coli). EO-based soaps exhibited higher activity, with rosemary EO-based soap showing the largest zones (up to 9.5 mm for S. aureus and 7.5 mm for E. coli). These data support the potential of enriched soaps containing honey, propolis, and EOs for antimicrobial applications, highlighting their value as a sustainable alternative in the valorization of WCOs. Full article

Honey authenticity is increasingly threatened by the addition of low-cost sugar syrups and substitutes, which reduce its nutritional value and market credibility. In this study, five types of Polish honeys (honeydew, forest, multifloral, nectar–honeydew, and rapeseed) were intentionally adulterated with beet syrup, beet molasses, invert syrup and artificial honey at levels of 10% and 50% (v/v). The impact of adulteration was evaluated using elemental profiling by ICP-OES combined with physicochemical analyses (water content, sugar content and electrical conductivity) and chemometric methods (PCA and HCA). Natural honeys were characterized by high K, Mg and Ca contents and low Na levels, whereas adulterants significantly altered mineral composition, leading to a marked decrease in key authenticity ratios, particularly K/Na (decreases exceeding 90% at the 50% adulteration level, with systematic shifts already observable at 10% addition). Beet molasses caused the strongest disturbances in macroelement balance, while invert syrup induced weaker effects. Adulteration also resulted in increased water content, reduced °Brix values and pronounced changes in electrical conductivity. Chemometric analysis enabled clear discrimination between natural, adulterated and sugar-based samples. The combined use of elemental ratios, physicochemical parameters and chemometrics provides a robust and sensitive approach for detecting honey adulteration and supporting authenticity control. Full article

Laodelphax striatellus is one of the most destructive rice pests. However, the functions of TARs in rice pests remain largely unknown. Here, we cloned LsTAR1 from L. striatellus. LsTAR1 shares considerable sequence identity with its orthologous receptors, and clusters closely with its corresponding receptor groups. LsTAR1 was most highly expressed in the egg stage and brain of L. striatellus. Knockdown of LsTAR1 by RNA interference (RNAi) prolonged the preoviposition and oviposition period, and reduced the fecundity. Furthermore, LsTAR1 knockdown significantly decreased the mRNA levels of vitellogenin (LsVg) in the fat body and ovary, and increased the transcript levels of Vg receptor (LsVgR) in the ovary, as well as altered the expression levels of genes related to juvenile hormone (JH) and 20-hydroxyecdysone (20E) pathway. Additionally, LsTAR1 knockdown markedly reduced the honeydew excretion of the adults and affected the expression of neuropeptide signaling genes involved in insect feeding. Notably, disruption of LsTAR1 signaling via RNAi or an antagonist reduced the survival rates of L. striatellus. This study uncovers the crucial roles of LsTAR1 in reproduction, feeding, and survival in L. striatellus, and highlights its potential as a promising target for developing novel pest management strategies. Full article

Urban green spaces host complex arthropod communities, in which natural insect antagonists play a key role in regulating pest populations. The jumping plant-louse Cacopsylla pulchella is a sap-sucking pest widespread across Europe that attacks Cercis siliquastrum L., which is commonly used as an ornamental tree. Heavy infestations may contribute to host tree decline and cause indirect damage in urban environments by reducing aesthetic value and by extensive deposition of honeydew secretions on surrounding surfaces. As with many phytophagous insects occurring in urban contexts, information on the natural enemies of this species remains limited, particularly in Italy, and requires further documentation. Here, we investigated the parasitoids associated with C. pulchella in central and southern Italy based on surveys conducted between 2022 and 2025. Specimens were obtained from infested plant material and identified using an integrative taxonomic approach combining detailed morphological examination with DNA barcoding. Prionomitus mitratus was confirmed as the primary parasitoid of C. pulchella, while two species, Pachyneuron muscarum and Pachyneuron aphidis, were identified as hyperparasitoids. In addition, a single specimen of Anastatus bifasciatus was also recorded emerging from the psyllid as a hyperparasitoid. Molecular analyses generated the first publicly available mitochondrial and nuclear sequences for P. mitratus. For Pachyneuron, molecular results showed variable correspondence with available reference sequences, reflecting the uneven representation of species-level data for Pteromalidae in public databases. By integrating morphological and molecular evidence, this study clarifies trophic relationships within the C. pulchella parasitoid complex. It provides vouchered molecular references to support future taxonomic and ecological research in urban ecosystems. Full article

Hydrothermal liquefaction (HTL) is a thermochemical process by which biomass feedstocks are converted into bio-oil and multiple by-products, including aqueous co-product (ACP), gaseous co-product (GCP), and biochar. Bio-oil produced from food waste feedstocks represents a potential candidate for use in commercial waste-to-energy conversions. The objective of this study is to further develop this technology by investigating the product distribution and quality from the HTL of food waste feedstocks. Four food waste feedstocks were selected for analysis: brewery grains, pear lees, coffee grounds, and honeydew skins. Solids analysis was conducted on each as-received feedstock, with the results determining dilution ratios for optimizing water content for HTL (≥80%). HTL conversions were conducted at 300 °C with a retention time of 30 min. Biochar was measured after product filtration, while ACP and bio-oil were measured via liquid–liquid phase separation. Coffee grounds produced the highest percentage of bio-oil (0.460%) and biochar (9.96%), while pear lees produced the highest percentage of ACP (89.5%). After quantification, ACP was characterized for nutrient concentrations. The quality of the ACP differed significantly from values in the literature, highlighting the influence of feedstock type and reaction conditions on HTL product characteristics (in addition to distribution) and underscoring the need for further research to optimize co-product utilization and process efficiency. Full article

Recent research has focused on yogurts supplemented with plant-derived and apiculture ingredients to enhance functional properties. This study evaluates the symbiotic potential of provitamin A carotenoids, dietary fiber, and oligosaccharides from carrots, mangoes, and honeydew honey in probiotic-enriched bioyogurt. Formulations were assessed during fermentation (45 °C ± 1 °C for 5 h) and refrigerated storage (4 °C ± 1 °C for 21 days). Probiotic and starter culture viability was determined using pour-plate counts on MRS agar. Physicochemical parameters including pH, titratable acidity, total soluble solids, water-holding capacity, and antioxidant metrics (total phenolics and carotenoids) were analyzed. After 21 days of storage, the probiotic culture (VEGE 092) reached 10.26 log CFU/mL and the starter culture (YOFLEX) achieved 8.66 log CFU/mL, maintaining therapeutic thresholds. Total carotenoid content increased significantly (p < 0.05) from 2.15 to 3.96 µg β-carotene/g, indicating synergistic interactions between lactic acid bacteria and plant-derived bioactive compounds. These findings demonstrate that combining plant-derived carotenoids, prebiotic fibers, and honeydew oligosaccharides effectively maintains probiotic viability and enhances antioxidant stability throughout fermentation and refrigerated storage, supporting the development of functional dairy products with improved nutritional profiles. Full article

The objective of this work was to determine and compare a comprehensive set of quality markers, including main physicochemical properties and element profiles, in samples of Bulgarian oak honeydew honey (OHH) and coniferous honeydew honey (CHH). This investigation utilized a total of seventeen honey samples from Bulgaria harvested in 2022. The sample set comprised ten oak honeydew honey samples, sourced from the Burgas region, and seven coniferous honeydew honey samples obtained from the Smolyan region. The parameters of OHH samples varied within the following ranges: color (80–134 mm Pfund), water content (15.20–18.40%), electrical conductivity (0.80–1.33 mS/cm), specific optical rotation (2.25–12.50 ${\left[\alpha \right]}_D^{20}$), pH (3.92–4.50), total acidity (29.80–36.80 meq/kg), diastase activity (18.36–27.58 Gothe units), invertase activity (56–196 U/kg), proline content (155–477 mg/kg), and hydroxymethylfurfural (3.28–8.94 mg/kg). The CHH samples gave the following results: color (40–87 mm Pfund), water content (16.40–19.00%), electrical conductivity (0.80–1.26 mS/cm), specific optical rotation (−17.50–(−11.50 ${\left[\alpha \right]}_D^{20}$)), pH (3.40–3.75), total acidity (25.80–39.40 meq/kg), diastase activity (23.15–26.05 Gothe units), invertase activity (69–138 U/kg), proline content (287–651 mg/kg), and hydroxymethylfurfural (1.50–3.96 mg/kg). The elements Ca, Cu, Fe, Mg, and Mn were determined by Flame Atomic Absorption Spectrometer (FAAS), while Flame Atomic Emission Spectrometry (FAES) was used for K and Na determination. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) analysis was used to assess six elements (Al, Ba, Co, P, Sr, Zn). The elements Cd, Ni, and Pb were determined by Electrothermal Atomic Absorption Spectrometry (ETAAS). Potassium is the most abundant macro element in all investigated samples ranging 2332–2370 µg/g in CHH and 1846–1878 µg/g in OHH. Other examined elements are in the following descending order, Mg > P > Na > Ca > Mn > Al > Fe > Zn > Cu > Ba > Sr, presenting in µg/g levels, while Pb > Ni > Co > Cd are present in µg/kg levels. This work constitutes the first report on the physicochemical parameters and chemical elements of coniferous honeydew honey from Bulgaria. Full article

Melon (Cucumis melo L.) is a significant horticultural crop valued for its aroma and health-promoting compounds. However, the genetic similarity among numerous varieties poses challenges for identification and breeding. ‘Dongfangmi No.4’ is an F₁ hybrid derived from a cross between two Hami melon inbred lines, ‘M06-1-3’ and ‘M15-3’. This study utilized resequencing data derived from the bi-parents of ‘Dongfangmi No.4’ to identify 557,878 insertion and deletion (InDel) variations across the entire genome. Thirty-nine highly polymorphic InDel markers were screened to conduct a genetic analysis of 40 representative cultivated varieties, with marker MS108 specifically distinguishing ‘Dongfangmi No.4’ from the other 39 cultivated varieties. Genetic analysis revealed a high level of genetic diversity within the population (average observed heterozygosity Ho = 0.313, Shannon index I = 0.528), and polymorphic information content (PIC) analysis indicated that 54% of the markers (21/39) were highly polymorphic. Principal component analysis (PCA) and clustering demonstrated significant genetic differentiation between cantaloupe and Hami melons, as well as between cantaloupe and honeydew. In contrast, the genetic boundaries between Hami melons and honeydew were obscured due to frequent germplasm exchange. Ultimately, seven core InDel markers were selected to construct the DNA fingerprinting map, successfully achieving complete differentiation of 40 varieties. This marker system provides an effective molecular tool for melon variety identification, intellectual property protection, and breeding. Full article

Organic acids shape the organoleptic properties of honey and are linked to its health-beneficial properties. Their composition is affected by botanical and geographical origin, and some acids have even been proposed as markers for authentication of varietal honeys. Organic-acid composition was determined using high-performance liquid chromatography with photodiode-array detection (HPLC-DAD) in 152 samples of monofloral (willow, acacia, rape, phacelia, linden, heather, buckwheat and goldenrod) and honeydew (deciduous and coniferous) honeys from Poland. The deciduous and coniferous honeydew honeys were distinguished by high content of L-(+)-lactic acid and the presence of succinic acid as well as high total content of acids. Buckwheat honey was the only variety for which the presence of D-(−)-tartaric acid was quantified. These three honey varieties were clearly separated from the others using principal component analysis (PCA). Samples from the other varieties formed one cluster. We conclude that while some promising results were obtained for distinguishing honeydew and buckwheat honeys from other varieties, further investigation is needed, including analysis of additional acids and possibly other physicochemical parameters. Full article

The woolly whitefly, Aleurothrixus floccosus, is likely a Neotropical origin species that has spread globally. Introduced to France in 1969, it became a pest in southern European citrus groves, first reported in Italy in 1974. Integrated management using biological control agents is crucial due to the low efficacy of chemical controls. Nymphs produce waxy filaments and honeydew, limiting insecticide contact. Natural enemies, especially from Neotropics, have been documented. The parasitoids Amitus spiniferus and Cales noacki were released in France in 1970 and later observed in Liguria, Italy. In the Campania region, C. noacki was first found on Aleurotuba jelineki in 1984 and this finding preceded the first report of A. floccosus in the same area. Subsequently, C. noacki was also introduced in other regions where it showed better adaptation throughout the Italian territory, reaching high parasitization levels on the woolly whitefly nymphs. After many years since the last field investigations, surveys in 2024–2025 in organic citrus groves in central and southern Italy identified additional parasitoids. Besides C. noacki and A. spiniferus, Eretmocerus paulistus and Signiphora xanthographa were found for the first time in Italy. Both species were originally described from the Neotropical ecozone. The aphelinid finding represents its first documented establishment in Italy, while the signiphorid one represents a new record for the European fauna. E. paulistus is a primary parasitoid, while S. xanthographa is a hyperparasitoid that can limit the effectiveness of other parasitoids. The interaction of these parasitoids resulted in high parasitism rates for A. floccosus nymphs. Preserving the current complexity of parasitoids in integrated pest management (IPM) programs could effectively control the woolly whitefly in central and southern Italy. Full article

The invasive sap-feeding pest Toumeyella parvicornis (pine tortoise scale) is rapidly spreading across Europe, threatening pine ecosystems, particularly in forest–urban areas of Italy. In this scenario, early detection and monitoring strategies are critical to prevent new outbreaks and mitigate impacts in infested regions. Current surveillance is challenged by the lack of rapid, sensitive tools for indirect detection of this cryptic, canopy-dwelling pest, despite advancements in molecular diagnostics and environmental DNA (eDNA). Here, we established a highly specific qPCR assay using LNA probe chemistry for detecting T. parvicornis DNA from both adult insects and their excreted honeydew. DNA was successfully isolated/quantified from all tested matrices. We recorded average Cq values of 20.9 for insect specimens and 30.3 for collected honeydew samples. Targeting the COI barcoding region, the assay demonstrated excellent specificity in both in silico and in vitro tests, showing no cross-reactivity to other pine-associated taxa. The limit of detection for DNA isolated from insect was 64 fg/µL. This is the first diagnostic protocol to use honeydew as a matrix for indirect detection of T. parvicornis. Optimized for routine application by Plant Health Services, this eDNA-based tool offers a valuable approach for future monitoring of sap-sucking hemipterans in multiple environments. Full article