Search Results (16)

Stingless bees are crucial for pollination and support diverse ecological relationships, offering economic benefits and contributing to enhanced crop yields. Their tropical pollinator status makes them highly sensitive to environmental changes and disruptions, which could affect their survival, as well as to pathogens that threaten their health. The lack of comprehensive research and the scattering of reports make it difficult to identify pathogens and contaminants. This review aims to provide an overview of diseases in stingless bees, examine chemical contaminants in their products, and explore threatened sources. Using the PRISMA flowchart, a total of 30 articles from 2009 to 2024 concerning pathogens and contaminants in stingless bees were retrieved. A total of 15 pathogens and 26 pollutants affect life expectancy and survival rate of stingless bees (mainly the genera Melipona and Tetragonisca) were identified in five major areas of the Neotropics, including Brazil, Mexico, Costa Rica, Australia, and Asia. Studies indicated that the bacterial genera Pseudomonas, Melissococcus, and Lysinibacillus are affecting the survival of stingless bees, particularly their brood, and contributing to annual colony deaths. Heavy metals, polycyclic aromatic hydrocarbons (PAHs), and microplastics have been detected in by-products of stingless bees, especially honey. Epidemiological research is crucial, including studies on pathogens associated with diseases, the effects of contaminants on bees, and the development of quality guidelines for stingless-bee products. Full article

Stonebrood (Aspergillus sp.) is a rare, poorly described disease of the Western honey bee (Apis mellifera) that can affect adult bees and brood. This study describes the pathogenesis using artificially reared pathogen-free Apis mellifera larvae, experimentally infected (5 × 10² spores/larva) with Aspergillus flavus. Between days 1 and 5 p.i. (larval age 4 until 8 days), five uninfected control larvae, up to five infected living larvae, and up to five infected dead larvae were examined macroscopically. Subsequently, the larvae were photographed, fixed (4% formaldehyde), and processed for histological examination (hematoxylin–eosin stain, Grocott silvering). Sections were digitized, measured (area, thickness), and statistically analyzed. In total, 19 of the 43 collected infected larvae showed signs of infection (germinating spores/fungal mycelium): dead larvae (from day 2 p.i.) showed clear histological and macroscopic signs of infection, while larvae collected alive (from day 1 p.i.) were only locally affected. Infected larvae were significantly smaller (day 2 p.i.: p < 0.001, 4 p.i.: p < 0.01, 5 p.i.: p < 0.01) than uninfected larvae (control group). Our study shows that the pathogenesis of stonebrood is characterized by a short period between Aspergillus germination and the onset of disease (about one day), and a rapid larval death. Full article

Background: Lappula patula (L. patula) is a plant with known medicinal properties, and its extracts have shown promise as potential anti-cancer agents. This study aimed to evaluate the nematocidal effects of L. patula extracts and investigate their impact on germline development, DNA damage responses, and apoptosis in Caenorhabditis elegans (C. elegans), a model organism for studying these processes. Methods: C. elegans was exposed to L. patula extracts to assess survival, development, and incidence of male phenotype. Germline abnormalities were examined using microscopy at different developmental stages. The DNA damage response was evaluated through the expression of the atm-1, atl-1 and pCHK-1. Apoptosis was quantified by monitoring cell death during the pachytene stage. LC-MS was used to identify bioactive compounds within the extracts. Results: Exposure to L. patula extracts resulted in a dose-dependent reduction in worm survival and larval developmental progress, with no significant impact on the male incidence. Germline defects were observed, including increased nuclear spacing at premeiotic and pachytene stages, altered number of bivalents during diakinesis. These defects correlated with a significant decrease in brood size. Also, L. patula extracts activated the DNA damage response pathway, marked by increased expression of atm-1 and atl-1. Moreover, the extracts induced apoptosis in the germline in a pCHK-1-independent manner. LC-MS analysis revealed 31 potential anti-tumor compounds, supporting the extract’s cytotoxic properties. Conclusions: Lappula patula extracts exhibit potent nematocidal and cytotoxic properties, suggesting their potential for cancer therapy. The observed DNA damage and apoptosis in C. elegans emphasize the extract’s promising role in anti-cancer drug development. Further studies are needed to explore the therapeutic potential of these compounds in clinical settings. Full article

Many mathematical models using ordinary differential equations (ODEs) have been used to investigate what type of stressors cause honeybee colonies collapse. We propose a simple model of a delayed differential equation system (DDE) to describe the effect of insecticides over brood death rate and its influence over honeybee population dynamics. First, we remember some basic facts for the model with no delay. To analyze our model, we study the equilibria and perform stability and sensitivity analysis of the DDE system. Next, by using the delay time $\tau$ as a bifurcation parameter, we find that no Hopf bifurcation could arise as the time lag $\tau$ varies within biologically plausible ranges. Numerical simulations with real data are studied for the biological significance of the model. Full article

Chalkbrood is a mycological brood disease of the Western honey bee (Apis mellifera), caused by the fungus Ascosphaera apis. The aim of this study was the investigation of the pathology of artificially reared Apis mellifera larvae, experimentally infected with A. apis spores (1.0 × 10³ spores/larva). Non-infected larvae served as control. Five living larvae and every dead larva were collected daily (day 1–7 p.i.). All larvae were macroscopically measured, photographed, formalin-fixed, and histologically processed (hematoxylin-eosin stain, Grocott silvering). Histological sections were digitized, and the size of the larvae was measured (mouth-after length, area) and statistically analyzed. Twenty-six larvae from the collected larvae (n = 64; 23 dead, 3 alive) showed histological signs of infection from 3 d p.i. onwards. The dead larvae showed macroscopically white/brown deposits, indistinct segmentation, and a lack of body elongation. Infected larvae were significantly smaller than the controls on days 3 p.i. (p < 0.05), 4 p.i. (p < 0.001), and 6 p.i. (p < 0.05). The early time of death, the low number of transitional stages, and the strong penetration of the larval carcass with fungal mycelium indicate a rapid and fulminant infection process, which is probably relevant for spreading the disease within the colony. Full article

Geese have strong brooding abilities, which severely affect their egg-laying performance. Phosphorylation is widely involved in regulating reproductive activities, but its role in goose brooding behavior is unclear. In this study, we investigated differences in the phosphoprotein composition of ovarian tissue between laying and brooding geese. Brooding geese exhibited ovarian and follicular atrophy, as well as significant oxidative stress and granulosa cell apoptosis. We identified 578 highly phosphorylated proteins and 281 lowly phosphorylated proteins, and a KEGG pathway analysis showed that these differentially phosphorylated proteins were mainly involved in cell apoptosis, adhesion junctions, and other signaling pathways related to goose brooding behavior. The extracellular regulated protein kinase (ERK)–B-Cell Lymphoma 2(BCL₂) signaling pathway was identified as playing an important role in regulating cell apoptosis. The phosphorylation levels of ERK proteins were significantly lower in brooding geese than in laying geese, and the expression of mitogen-activated protein kinase kinase (MEK) was downregulated. Overexpression of MEK led to a significant increase in ERK phosphorylation and BCL2 transcription in H₂O₂-induced granulosa cells (p < 0.05), partially rescuing cell death. Conversely, granulosa cells receiving MEK siRNA exhibited the opposite trend. In conclusion, geese experience significant oxidative stress and granulosa cell apoptosis during brooding, with downregulated MEK expression, decreased phosphorylation of ERK protein, and inhibited expression of BCL2. Full article

The acute toxicity of the detergent Nittol^® 0.8, 1.0, 1.2, 1.4, 1.6, and 0.0 mg NTL/L of clean water on Heterobrunchus bidorsalis, 5.5 ± 0.3 g, 6.4 ± 0.5 cm were investigated, using semi-static bioassay, for 96 h in 50 L capacity plastic test bowls. The fingerlings of the same brood stock and age were collected from Onose Farms Limited, Ughelli, Delta State to the University Research Laboratory, Enugu Lat. 7.4 N; 8°7′5 and long 6°8′ E. 7°6′ W. The test fish were acclimatized for 14 days, and fed at 3% body weight once daily, on a 40% CP commercial diet. Feeding was suspended 24 h before and during the range finding and acute tests. The whole set-up was replicated three times, and no death was recorded during the acclimatization period and in the control. A total of 180 fingerlings were used, and 10 fingerlings were assigned to each replicate. The test set-up was monitored daily for water quality parameters, opercular ventilation, tail fin beat frequency, and mortality. Dose and time-dependent behavioural patterns exhibited by the test fish, during the exposure periods include rapid swimming, air gulping, loss of balance, and a period of convulsion before death. Significant elevation in pH and temperature, reduction of DO compared to the control (p < 0.05) in the water quality, and dose-dependent early elevation of the tail and fin movements declined towards the end of the experiment. The 96 h LC₅₀ was determined to be 1.41 mg/L, indicating that the detergent NTL is toxic to the test fish. The haematological parameters were significantly (p < 0.05) reduced in the treated ranges of RBC 5.20 ± 0.07–8.00 ± 0.02 × 10⁶ mm³, HB 7.53 ± 0.50–10.72 ± 0.14 g/dl, PCV 13.20 ± 0.8.50–18.00 ± 0.43 % below their elevated respective controls of 10.50 ± 0.01 × 10 ⁶ mm³, 11.00 ± 0.01 g/dl, and 23.48 ± 0.2.6 %. The white blood cells (WBC) recorded a significant (p < 0.05) increase in ranges of 23.72 ± 0.14–51.80 ± 1.9 × 10³ mm³ above the control value of 11.00 ± 0.01 × 10³ mm³ Therefore, values greater than the safe amount of 0.014 mg/L should not be allowed in the receiving culture waters for Heterobrunchus bidorsalis fingerlings. Full article

Paenibacillus larvae is a deadly pathogen for bee brood, which can lead to the death of entire colonies. The presence of specific volatile organic compounds (VOCs) in the hive may be related to the occurrence of this bacterium in brood. Compositions of those volatile fractions present in healthy brood from control colonies and the brood without symptoms of infection collected from the colonies infected by P. larvae were compared using gas chromatography coupled with mass spectrometry (GC-MS) and solid phase microextraction (SPME). Among the seven compounds detected and quantified, the relative concentrations of 3-carene and limonene significantly differentiated the brood from healthy and infected colonies. Based on the ratio analysis, the samples were differentiated in terms of the number of emitted VOCs. Full article

Tissue phenotypic plasticity facilitates rapid adaptation of organisms to biotic and/or abiotic pressure. The reproductive capacity of honey bee workers (Apis mellifera) is plastic and responsive to pheromones produced by broods and the queen. Egg laying workers (ELWs), which could reactivate their ovaries and lay haploid eggs upon queen lost, have been commonly discussed from many aspects. However, it remains unclear whether midgut homeostasis in ELWs is affected during plastic changes. Here, we found that the expression of nutrition- and autophagy-related genes was up-regulated in the midguts of ELWs, compared with that in nurse workers (NWs) by RNA-sequencing. Furthermore, the area and number of autophagosomes were increased, along with significantly increased cell death in the midguts of ELWs. Moreover, cell cycle progression in the midguts of ELWs was increased compared with that in NWs. Consistent with the up-regulation of nutrition-related genes, the body and midgut sizes, and the number of intestinal proliferation cells of larvae reared with royal jelly (RJ) obviously increased more than those reared without RJ in vitro. Finally, cell proliferation was dramatically suppressed in the midguts of ELWs when autophagy was inhibited. Altogether, our data suggested that autophagy was induced and required to sustain cell proliferation in ELWs’ midguts, thereby revealing the critical role of autophagy played in the intestines during phenotypic plasticity changes. Full article

Beekeeping is essential for the global food supply, yet honeybee health and hive numbers are increasingly threatened by habitat alteration, climate change, agrochemical overuse, pathogens, diseases, and insect pests. However, pests and diseases that have unknown spatial distribution and influences are blamed for diminishing honeybee colonies over the world. The greater wax moth (GWM), Galleria mellonella, is a pervasive pest of the honeybee, Apis mellifera. It has an international distribution that causes severe loss to the beekeeping industry. The GWM larvae burrow into the edge of unsealed cells that have pollen, bee brood, and honey through to the midrib of the wax comb. Burrowing larvae leave behind masses of webs that cause honey to leak out and entangle emerging bees, resulting in death by starvation, a phenomenon called galleriasis. In this study, the maximum entropy algorithm implemented in (Maxent) model was used to predict the global spatial distribution of GWM throughout the world. Two representative concentration pathways (RCPs) 2.6 and 8.5 of three global climate models (GCMs), were used to forecast the global distribution of GWM in 2050 and 2070. The Maxent models for GWM provided a high value of the Area Under Curve equal to 0.8 ± 0.001, which was a satisfactory result. Furthermore, True Skilled Statistics assured the perfection of the resultant models with a value equal to 0.7. These values indicated a significant correlation between the models and the ecology of the pest species. The models also showed a very high habitat suitability for the GWM in hot-spot honey exporting and importing countries. Furthermore, we extrapolated the economic impact of such pests in both feral and wild honeybee populations and consequently the global market of the honeybee industry. Full article

American foulbrood is a dangerous bee disease that attacks the sealed brood. It quickly leads to the death of bee colonies. Efficient diagnosis of this disease is essential. As specific odours are produced when larvae rot, it was investigated whether an electronic nose can distinguish between colonies affected by American foulbrood and healthy ones. The experiment was conducted in an apiary with 18 bee families, 9 of which showed symptoms of the disease confirmed by laboratory diagnostics. Three units of the Beesensor V.2 device based on an array of six semiconductor TGS gas sensors, manufactured by Figaro, were tested. Each copy of the device was tested in all bee colonies: sick and healthy. The measurement session per bee colony lasted 40 min and yielded results from four 10 min measurements. One 10-min measurement consisted of a 5 min regeneration phase and a 5 min object-measurement phase. For the experiments, we used both classical classification methods such as k-nearest neighbour, Naive Bayes, Support Vector Machine, discretized logistic regression, random forests, and committee of classifiers, that is, methods based on extracted representative data fragments. We also used methods based on the entire 600 s series, in this study of sequential neural networks. We considered, in this study, six options for data preparation as part of the transformation of data series into representative results. Among others, we used single stabilised sensor readings as well as average values from stable areas. For verifying the quality of the classical classifiers, we used the 25-fold train-and-test method. The effectiveness of the tested methods reached a threshold of 75 per cent, with results stable between 65 and 70 per cent. As an element to confirm the possibility of class separation using an artificial nose, we used applied visualisations of classes. It is clear from the experiments conducted that the artificial nose tested has practical potential. Our experiments show that the approach to the problem under study by sequential network learning on a sequence of data is comparable to the best classical methods based on discrete data samples. The results of the experiment showed that the Beesensor V.2 along with properly selected classification techniques can become a tool to facilitate rapid diagnosis of American foulbrood under field conditions. Full article

Calanoida have the highest number of species among Copepoda in marine plankton, but not in fresh water, where the greatest number are Cyclopoida. Freshwater Cyclopoida also live in more freshwater sites than Calanoida. This could be a consequence of an invasion of freshwater by marine Cyclopoida before Calanoida. Similar to Cyclopoida, but different from marine Calanoida, freshwater Calanoida females produce egg sacs and care for eggs. This strategy is common among all freshwater plankton, suggesting that the evolution of parental care is an obliged adaption to conquer fresh water. Calanoida, different from Cyclopoida, survive adverse conditions as resting eggs. This life-cycle constraint obliges eggs to survive their mother’s death and wait in the benthos for a certain period. The necessity of completing embryonic development and the hatching of eggs far from the mother’s protection may be responsible for the relatively lower evolutionary success of Calanoida in fresh water compared to Cyclopoida (which rest as juveniles, thus protecting eggs in any moment of their development). Therefore, the brooding of eggs appears to be the obliged solution for Calanoida’s final establishment in fresh water, but the dispersion of eggs on the bottom after the mother’s death and during the rest period is probably the weak point in Calanoida’s competition with Cyclopoida. Full article

G6PD is required for embryonic development in animals, as severe G6PD deficiency is lethal to mice, zebrafish and nematode. Lipid peroxidation is linked to membrane-associated embryonic defects in Caenorhabditis elegans (C. elegans). However, the direct link between lipid peroxidation and embryonic lethality has not been established. The aim of this study was to delineate the role of lipid peroxidation in gspd-1-knockdown (ortholog of g6pd) C. elegans during reproduction. tert-butyl hydroperoxide (tBHP) was used as an exogenous inducer. Short-term tBHP administration reduced brood size and enhanced germ cell death in C. elegans. The altered phenotypes caused by tBHP resembled GSPD-1 deficiency in C. elegans. Mechanistically, tBHP-induced malondialdehyde (MDA) production and stimulated calcium-independent phospholipase A₂ (iPLA) activity, leading to disturbed oogenesis and embryogenesis. The current study provides strong evidence to support the notion that enhanced lipid peroxidation in G6PD deficiency promotes death of germ cells and impairs embryogenesis in C. elegans. Full article

Collection of blood from pregnant mares for extraction of equine chorionic gonadotropin (eCG) is a critical but relatively unknown and poorly regulated practice in the countries in which it occurs. Equine chorionic gonadotropin is a hormone that is widely used to enhance reproductive performance and management of dairy and beef cattle, sheep, goats, and pigs kept under intensive housing systems. eCG is extracted from the blood of brood mares between days 40–120 of gestation. Although alternatives have been sought, there is currently no efficacious replacement, natural or synthetic, for eCG. Recently, several animal welfare organizations have voiced concerns over the condition and treatment of pregnant mares kept for eCG production in some countries. Animal welfare issues may arise if mares are bled too frequently or if too much blood is collected at any time. In addition, these mares tend to be managed extensively on pastures with minimal veterinary oversight and they may be poorly desensitized and habituated to handling and other practices. This can lead to serious injuries and even death when mares are brought in for bleeding. This paper reviews the process of blood collection for eCG extraction and provides recommendations for ensuring mare welfare. Full article

The objective was to evaluate the toxicity of zinc- and doxycycline-loaded polymeric nanoparticles (NPs) using Caenorhabditis elegans as a model organism. These NPs are composed of ethylene glycol dimethacrylate, 2-hydroxyethyl methacrylate and methacrylic acid. NPs were loaded with doxycycline (D-NPs) and zinc (Zn-NPs) by chemical adsorption, and loading efficacy was demonstrated. Worm death rate in a concentration-response curve basis was calculated for lethality. Metabolism was evaluated through pharyngeal pumping assay. Body length measurements, brood size and egg lays were used to gauge growth, reproduction and fertility respectively. Intracellular hydrogen peroxide levels were determined to assess the reactive oxygen species production. One-way ANOVA and Bonferroni were used for comparisons (p < 0.05). Tested NPs at the highest dosage did not affect lethality or worm metabolism, expressed in terms of death rate and pharyngeal pumping per minute, respectively. Zn-NPs slightly increased worm growth. The concentration of the intracellular hydrogen peroxide levels was the lowest in the D-NPs group. The distinct NPs and concentrations employed were shown to be non-toxic for in situ administration of zinc and doxycycline, reducing the harmful effects of these compounds. Full article