Wax Moth Galleria Mellonella Research Articles

Synergistic effects of putative Ca2+-binding sites of calmodulin in fungal development, temperature stress and virulence of Aspergillus fumigatus

ABSTRACT In pathogenic fungi, calcium-calmodulin-dependent serine-threonine-specific phosphatase calcineurin is involved in morphogenesis and virulence. Therefore, calcineurin and its tightly related protein complexes are attractive antifungal drug targets. However, there is limited knowledge available on the relationship between in vivo Ca2+-binding sites of calmodulin (CaM) and its functions in regulating stress responses, morphogenesis, and pathogenesis. In the current study, we demonstrated that calmodulin is required for hyphal growth, conidiation, and virulence in the human fungal pathogen, Aspergillus fumigatus. Site-directed mutations of calmodulin revealed that a single Ca2+-binding site mutation had no significant effect on A. fumigatus hyphal development, but multiple Ca2+-binding site mutations exhibited synergistic effects, especially when cultured at 42 °C, indicating that calmodulin function in response to temperature stress depends on its Ca2+-binding sites. Western blotting implied that mutations in Ca2+-binding sites caused highly degraded calmodulin fragments, suggesting that the loss of Ca2+-binding sites results in reduced protein stability. Moreover, normal intracellular calcium homeostasis and the nuclear translocation of the transcriptional factor CrzA are dependent on Ca2+-binding sites of AfCaM, demonstrating that Ca2+-binding sites of calmodulin are required for calcium signalling and its major transcription factor CrzA. Importantly, in situ mutations for four Ca2+-binding sites of calmodulin resulted in an almost complete loss of virulence in the Galleria mellonella wax moth model. This study shed more light on the functional characterization of putative calcium-binding sites of calmodulin in the morphogenesis and virulence of A. fumigatus, which enhances our understanding of calmodulin biological functions in cells of opportunistic fungal pathogens.

Diseases and Pests Harmful to Honeybees (Apis spp.) and Their Management Tactics: A Review

Honeybees (Apis spp.) play a vital role in pollination and contribute significantly to global agriculture. However, the health and survival of honeybee colonies are threatened by a range of harmful insect pests and diseases. This review provides an overview of the major pests and diseases that impact honeybee colonies and explores the diverse management tactics employed to mitigate their effects. The primary focus is on key pests such as the Varroa mite (Varroa destructor), which inflicts considerable damage by parasitizing adult bees and their brood, facilitating the transmission of debilitating viruses. Management strategies for Varroa mites encompass chemical treatments, integrated pest management (IPM) approaches, and organic treatments to curtail mite populations and prevent colony collapse. Another significant threat discussed is the small hive beetle (Aethina tumida), a beetle species that disrupts hives by laying eggs in comb and consuming stored resources. Hive manipulation, traps, and chemical controls are among the tactics utilized to control small hive beetle populations and mitigate their impact. The review also addresses wax moths (Galleria mellonella and Achroia grisella), which target hive comb, potentially causing comb destruction and honey fermentation. Hive maintenance, freezing, and pheromone traps are outlined as effective strategies to combat wax moth infestations. Additionally, the review covers Nosema infections (Nosema apis and Nosema ceranae), and microsporidian parasites that compromise adult bee health by weakening immune systems and reducing foraging efficiency. Hive hygiene, medications, and genetic selection are explored as methods to manage Nosema infections and bolster colony resilience. To effectively manage these harmful pests and diseases, a holistic and integrated approach is recommended. Beekeepers are encouraged to remain informed about the latest research findings and implement appropriate measures, considering local conditions and sustainable beekeeping practices. By combining scientific knowledge with practical application, the resilience of honeybee colonies can be enhanced, ensuring the vital role they play in pollination and global food security.

Discovery of a new highly pathogenic toxin involved in insect sepsis.

Insect sepsis is a severe consequence that arises from the invasion of the hemocoel by symbionts of entomopathogenic nematodes and bacteria. In the present study, we unveiled the heightened virulence of the entomopathogenic nematode Steinernema feltiae and the entomopathogenic bacteria Xenorhabdus bovienii, which operate symbiotically, against the wax moth Galleria mellonella. Maximum mortality was observed at 25°C while the optimal infestation efficiency was 20 nematodes per host. After infestation, G. mellonella displayed rapid darkening and softening, accompanied by an escalated esterase activity at 9 h. The X. bovienii, released by S. feltiae, underwent substantial proliferation and discharged toxins that attacked hemocytes, thus triggering extensive hemolysis and sepsis. The host G. mellonella was usually killed within 24 h due to disseminated septicemia. Additionally, X. bovienii infestation led to the upregulation of metabolites like 3-hydroxyanthranilic acid. Strikingly, we identified the perilous actinomycin D, generated through kynurenine metabolites, representing a novel biomarker of insect sepsis. Furthermore, a comprehensive transcriptomic analysis unveiled a noteworthy upregulation of gene expression associated with actinomycin D. Overall, X. bovienii induced apoptosis and sepsis through actinomycin D production, indicating its pivotal role in infestation activity. These findings open up new avenues for studying the mechanism of sepsis and developing innovative biotic pesticides. IMPORTANCE As a current biocontrol resource, entomopathogenic nematodes and their symbiotic bacterium can produce many toxin factors to trigger insect sepsis, having the potential to promote sustainable pest management. In this study, we found Steinernema feltiae and Xenorhabdus bovienii were highly virulent against the insects. After infective juvenile injection, Galleria mellonella quickly turned black and softened with increasing esterase activity. Simultaneously, X. bovienii attacked hemocytes and released toxic components, resulting in extensive hemolysis and sepsis. Then, we applied high-resolution mass spectrometry-based metabolomics and found multiple substances were upregulated in the host hemolymph. We found extremely hazardous actinomycin D produced via 3-hydroxyanthranilic acid metabolites. Moreover, a combined transcriptomic analysis revealed that gene expression of proteins associated with actinomycin D was upregulated. Our research revealed actinomycin D might be responsible for the infestation activity of X. bovienii, indicating a new direction for exploring the sepsis mechanism and developing novel biotic pesticides.

Genomics, transcriptomics, and peptidomics of the greater wax moth Galleria mellonella neuropeptides and their expression in response to lead stress.

Neuropeptides are crucial in regulation of a rich variety of developmental, physiological, and behavioral functions throughout the life cycle of insects. Using an integrated approach of multiomics, we identified neuropeptide precursors in the greater wax moth Galleria mellonella, which is a harmful pest of honeybee hives with a worldwide distribution. Here, a total of 63 and 67 neuropeptide precursors were predicted and annotated in the G. mellonella genome and transcriptome, in which 40 neuropeptide precursors were confirmed in the G. mellonella peptidome. Interestingly, we identified 12 neuropeptide precursor genes present in G. mellonella but absent in honeybees, which may be potential novel pesticide target sites. Honeybee hives were contaminated with heavy metals such as lead, enabling its bioaccumulation in G. mellonella bodies through the food chain, we performed transcriptome sequencing to analyze the effects of Pb stress on the mRNA expression level of G. mellonella neuropeptide precursors. After treatment by Pb, the expression of neuropeptide F1 was found to be significantly downregulated, implying that this neuropeptide might be associated with responding to the heavy metal stress in G. mellonella. This study comprehensively identified neuropeptide precursors in G. mellonella, and discussed the effects of heavy metals on insect neuropeptides, with the example of G. mellonella. The results are valuable for future elucidation of how neuropeptides regulate physiological functions in G. mellonella and contribute to our understanding of the insect's environmental plasticity and identify potential new biomarkers to assess heavy metal toxicity in insects.

Coxiella co-opts the Glutathione Peroxidase 4 to protect the host cell from oxidative stress–induced cell death

The causative agent of human Q fever, Coxiella burnetii, is highly adapted to infect alveolar macrophages by inhibiting a range of host responses to infection. Despite the clinical and biological importance of this pathogen, the challenges related to genetic manipulation of both C. burnetii and macrophages have limited our knowledge of the mechanisms by which C. burnetii subverts macrophages functions. Here, we used the related bacterium Legionella pneumophila to perform a comprehensive screen of C. burnetii effectors that interfere with innate immune responses and host death using the greater wax moth Galleria mellonella and mouse bone marrow-derived macrophages. We identified MceF (Mitochondrial Coxiella effector protein F), a C. burnetii effector protein that localizes to mitochondria and contributes to host cell survival. MceF was shown to enhance mitochondrial function, delay membrane damage, and decrease mitochondrial ROS production induced by rotenone. Mechanistically, MceF recruits the host antioxidant protein Glutathione Peroxidase 4 (GPX4) to the mitochondria. The protective functions of MceF were absent in primary macrophages lacking GPX4, while overexpression of MceF in human cells protected against oxidative stress-induced cell death. C. burnetii lacking MceF was replication competent in mammalian cells but induced higher mortality in G. mellonella, indicating that MceF modulates the host response to infection. This study reveals an important C. burnetii strategy to subvert macrophage cell death and host immunity and demonstrates that modulation of the host antioxidant system is a viable strategy to promote the success of intracellular bacteria.

Morphological and biological characteristics of Galleria mellonella L. (Lepidoptera: Pyralidae) reared on different artificial diets

The greater wax moth (Galleria mellonella L.) is a common insect used as alternative host for mass rearing and research of natural enemies. Finding appropriate artificial diets can aid in increasing the efficiency of mass rearing. The study evaluated three different artificial diets by determining some biological and morphological characteristics of greater wax moths in laboratory of Plant Protection Department, Agronomy Faculty, Nong Lam University, Ho Chi Minh City, Vietnam. The experimental results showed that the artificial diet CT2 was the most effective one of the three treatments. Its larval stage was shortest, with an average of 27.6 ± 4.2 days. The greater wax moth larvae reared on CT2 grew fast and had large size. Over a period of 20 - 30 days of age, the length and width of greater wax moth larvae ranged from 11.9 ± 5.2 to 16.3 ± 6.2 mm and 2.7 ± 1.4 to 3.9 ± 1.8 mm, respectively. The female greater wax moths laid 819.0 ± 175.5 to 1,008.1 ± 354.6 eggs on average. When greater wax moths were reared on three different artificial diets, there was no difference in fecundity

Potential of entomopathogenic nematode-infected insect cadavers for the biocontrol of the red imported fire ant Solenopsis invicta.

Entomopathogenic nematodes (EPNs) in an aqueous suspension treatment showed potential in the biocontrol of the red imported fire ant Solenopsis invicta, whereas colony relocation following this inundative application had restricted overall effectiveness. As a novel strategy, EPN pre-infected insect cadavers carrying the next generation of nematode-infective juveniles (IJs) might be used to efficiently manage insect pests. However, this strategy has not been tested on S. invicta. This study evaluated EPNs emerging from wax moth Galleria mellonella cadavers to facilitate infection of S. invicta compared to those used in aqueous suspensions. Among seven EPN species, Steinernema riobrave and Heterorhabditis bacteriophora had the highest insecticidal efficiency in aqueous treatment. Cadavers of G. mellonella colonized by either one of two EPN species were not damaged by worker ants, ensuring that the IJs could develop within and emerge successfully from the cadavers. Likewise, compared to an aqueous suspension treatment with an equivalent number of IJs, treatment with an S. riobrave-infected cadaver increased the mortality of S. invicta by ≈10%, whereas infection by H. bacteriophora did not differ between treatments. However, the coexistence of S. riobrave- and H. bacteriophora-infected cadavers adversely affected the control of S. invicta, likely as a result of competition resulting from the increased dispersal of each emerging EPN species. Using EPN-infected G. mellonella cadavers as a strategy increased the mortality of S. invicta in the laboratory. This study provides positive evidence for the future applications of S. riobrave-infected cadavers in the biocontrol of red imported fire ants. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Dose–effects in behavioural responses of moths to light in a controlled lab experiment

Insects play a critical role in providing numerous ecosystem services. However, insect diversity and biomass have been declining dramatically, with artificial light being suggested as a contributing factor. Despite the importance of understanding the dose–effect responses of insects to light emissions, these responses have been rarely studied. We examined the dose–effect responses of the greater wax moth (Galleria mellonella L.) to different light intensities (14 treatments and a dark control) by observing their behavioural responses in a light-tight box equipped with a LED light source (4070 K) and infrared cameras. Our findings reveal dose–effect responses to light, as the frequency of walking on the light source increased with higher light intensity. Additionally, moths exhibited jumps in front of the light source and jump frequency increased with light intensity. No direct flight-to-light behaviour or activity suppression in response to light was observed. Based on our analysis of the dose–effect responses, we identified a threshold value of 60 cd/m2 for attraction (walking on the light source) and the frequency of jumps. The experimental design in this study offers a valuable tool for investigating dose–effect relationships and behavioural responses of various species to different light levels or specific light sources.

The effect of ethanolic extract of Stinging Nettle (Urtica dioica) on the larval stages of Greater Wax Moth (Galleria mellonella) Lepidoptera

The effect of ethanolic extract of Stinging Nettle (Urtica dioica) on the larval stages of Greater Wax Moth (Galleria mellonella) Lepidoptera

Increased Production of Pathogenic, Airborne Fungal Spores upon Exposure of a Soil Mycobiota to Chlorinated Aromatic Hydrocarbon Pollutants.

Organic pollutants are omnipresent and can penetrate all environmental niches. We evaluated the hypothesis that short-term (acute) exposure to aromatic hydrocarbon pollutants could increase the potential for fungal virulence. Specifically, we analyzed whether pentachlorophenol and triclosan pollution results in the production of airborne fungal spores with greater virulence than those derived from an unpolluted (Control) condition. Each pollutant altered the composition of the community of airborne spores compared to the control, favoring an increase in strains with in vivo infection capacity (the wax moth Galleria mellonella was used as an infection model). Fungi subsisting inside larvae at 72 h postinjection with airborne spore inocula collected in polluted and unpolluted conditions exhibited comparable diversity (mainly within Aspergillus fumigatus). Several virulent Aspergillus strains were isolated from larvae infected with the airborne spores produced in a polluted environment. Meanwhile, strains isolated from larvae injected with spores from the control, including one A. fumigatus strain, showed no virulence. Potential pathogenicity increased when two Aspergillus virulent strains were assembled, suggesting the existence of synergisms that impact pathogenicity. None of the observed taxonomic or functional traits could separate the virulent from the avirulent strains. Our study emphasizes pollution stress as a possible driver of phenotypic adaptations that increase Aspergillus pathogenicity, as well as the need to better understand the interplay between pollution and fungal virulence. IMPORTANCE Fungi colonizing soil and organic pollutants often meet. The consequences of this encounter constitute an outstanding question. We scrutinized the potential for virulence of airborne fungal spores produced under unpolluted and polluted scenarios. The airborne spores showed increased diversity of strains with higher infection capacity in Galleria mellonella whenever pollution is present. Inside the larvae injected with either airborne spore community, the surviving fungi demonstrated a similar diversity, mainly within Aspergillus fumigatus. However, the isolated Aspergillus strains greatly differ since virulence was only observed for those associated with a polluted environment. The interplay between pollution and fungal virulence still hides many unresolved questions, but the encounter is costly: pollution stress promotes phenotypic adaptations that may increase Aspergillus pathogenicity.

Physiological responses of Greater wax moth (Galleria mellonella) to inoculation with some strains of endophytic fungi

Physiological responses of Greater wax moth (Galleria mellonella) to inoculation with some strains of endophytic fungi

Efficiency of the Iraqi Isolates of Beauveria Bassiana & Metarhizium Anisopliae in Controlling the Greater Wax Moth Galleria Mellonella L.

The current study was conducted in the laboratories of the Plant Protection Department/College of Agriculture and Forestry/University of Mosul during the year 2019-2020. The aim of this study was to evaluate the efficiency of the Iraqi isolate of the biological control fungi Beauveria bassian and Metarhizium anisopliaeas chemical pesticides alternatives in controlling different stages of the greater wax moth Galleria mellonella. The results of the biological effect of the fungi Beauveria bassiana and Metarhizium anisopliae on the greater wax moth life stages showed that the cumulative mortality of eggs increased gradually with increasing concentration used. However, Beauveria bassiana was more efficient in achieving higher mortality rates than M. anisopliae in general. The highest cumulative mortality rate for eggs was at the highest concentration (7.5g/l) for both fungi. On the other hand, it was found that the highest mortality rate in wax moth larvae was inB. bassianacombined treatmentwhere spraying the larvae and the feed. The third and fourth larval instars were more sensitive than the sixth and seventh larval instars, which were not affected by the lower concentrations of the pesticide (2.5 and 5 g/L), regardless of pesticide type. The results also showed that the mortality rate in all phases increases with the increase in the post-treatment period. The results of the study indicated the superiority of B. bassiana in all treatments, concentrations and periods after treatment and led to the highest mortality rate compared with using M. anisopliae. The cumulative mortality rate in the greater wax moth was directly proportional to the increase in treatment methods and the increase in concentration and the time period after treatment.

Role of ionizing radiation in the management of the Greater Wax Moth (Galleria mellonella L.): a comparative analysis of different types of ionizing radiation

Galleria mellonella L., is an insect pest of the honey bee combs and causes huge economic losses worldwide. Its management heavily relies on the use of chemical pesticides. However, chemical pesticides have drawbacks, including the incidence of colony collapse disorder and the development of pesticide resistance. Ionizing radiation has the potential to treat infested bee combs without leaving chemical footprints, thereby increasing agricultural output in general and honey production in particular. In the current study, research on how the type, energy, and dose rate of ionizing radiation affect radiation-induced damage was done on the eggs and larvae of G. mellonella. It was observed that although larval mortality increases with electron beam energy, egg hatchability depends more on dose rate and less on the energy of gamma and x-ray radiation in the MeV range of energy. Additionally, a significant association between dose rate and larval mortality was seen. Doses of 179.40 Gy and 158.60 Gy, respectively, of 0.66 MeV gamma rays and 15 MeV electrons, were required to stop pupal development completely. Gamma radiation in the MeV range of energy was found to be the most suitable modality of all ionizing radiation.

Zebularin'in Antioksidan Enzimleri ve Galleria mellonella (Lepidoptera: Pyralidae) Lipit Peroksidasyonu Üzerindeki Etkisi

Cytosine methylation is a process that adds a methyl group to a cytosine residue of DNA to convert it to 5-methylcytosine. Zebularine (ZEB) reactivates hypermethylated genes in yeast and solid tumor cells, with DNA methyltransferases that show a preferential effect on cancer cells. We investigated the effects of various doses (0.25-32 mg/ml) of ZEB, on antioxidant enzyme activity and lipid peroxidation in wax moth Galleria mellonella last instars. Injection of ZEB in last instars G. mellonella resulted in increases in SOD, MDA, and GST levels, in order of magnitude, but not in CAT enzyme activity. Two possible reasons were predicted for these results. This effect could be a result of the inhibitory effect of ZEB on DNA methylation in G. mellonella, which leaded to reducing gene transcription in insects. Or it was likely that high oxidative stress might cause a decreasing activity of enzymes.

Debilitation of Galleria mellonella hemocytes using CytCo a cytolytic-like protein derived from the entomopathogen Conidiobolus obscurus

Cytolytic (Cyt)-like genes are present in both pathogenic bacteria and fungi. Bacterial Cyt proteins can destroy insect midgut epithelial cells after ingestion by hosts and some of them have been developed as biopesticides; however, few studies have investigated their functions in fungal pathogens. This study investigated the effects of a Cyt-like protein (CytCo) derived from Conidiobolus obscurus (Entomophthoromycotina) on the hemocytes of the greater wax moth Galleria mellonella larvae. The results showed a significant decline in hemocyte viability after treatment with CytCo in vivo or in vitro. The hemocyte density in the hemolymph was reduced by 65.2% and 50.2% after 12 h in vivo and 6 h in vitro treatments, respectively. Apoptosis/necrosis tests using fluorescence microscopy demonstrated that CytCo-treated hemocytes displayed apoptosis, and many of them also showed necrosis after 6 h in vitro treatment. Based on transcriptome analysis, several genes involved in the programmed cell death signaling pathway were upregulated in the CytCo-treated hemocytes. Meanwhile, the differentially expressed genes related to energy production, signal transduction, transcription regulation, and melanization were upregulated, demonstrating activated immune responses; those putatively related to hemocyte adhesion were downregulated, possibly in response to the reduction of hemocytes in hemolymph. In conclusion, CytCo as a virulence factor, could irreversibly incapacitate host hemocytes, playing an important role in debilitating insect immunity. This novel insecticidal protein holds a potential to develop biopesticide for controlling agroforestry pests.

The Synergistic Effect of Surfactants and Plant Oils on the Effectiveness of Levo to Control the Fourth Phase Larvae of the Great Wax Moth Galleria Mellonella L. (Lepidoptera: Pyralidae)

The laboratory study aimed to know effect three surfactants (Inex-A, Stickon, Wetfix) and plant oils Includes Bitter apple oil Citrullus colocynthis, and Rosemary oil Rosmarinus officinalis on effectiveness five concentrations ppm ((30,40,50,60,70) for commercial pesticide plant origin Levo2.4SL (Oxymatrine) on fourth phase larvae to Great Wax Moth G.mellonella. The results showed that were significant differences in mortality percentage to fourth phase larvae of Great Wax Moth worm by the effects Levo pesticide on larvae, as (Levo + rosemary oil) treatment excelled in achieving highest larval mortality percentage 84%, followed by (Levo + bitter apple oil) treatment, with an average mortality percentage was 72%. while mortality percentage in (Steckon + Levo) and (wetfix + Levo) treatments was 70, 67.33, respectively. Levo pesticide efficacy decreased in (Inex + Levo) treatment to 38% compared with mortality percentage in before addition treatment to Levo pesticide, which amounted to 63.33%.

Valuation The efficiency of Nanotechnology and biological activity of Nanoparticle for two plant extracts Ricinus communis and Neriun oleander against immature stages of Greater wax moth.Galleria mellonella (Lepidoptera: pyralidae)

The results of present study conducted on the Laboratory of advance entomology \ Department of biology \ Faculty of Education for Girls \ University of Kufa, during the years 2018-2019 for evaluating The efficiency of Nanotechnology and biological control and the effect of two plant extracts on the different immature stages of the greater wax moth Galleria mellonella (Lepidoptera: Pyrallidae). eggs, first and fourth larval instars. The cold aqueous extract of castor Ricinus communis and Nerium oleander leaves ,from which different concentrations ( 1,2,3 and 4) mg \ ml were prepared in the Laboratory. The experiments include the enhancement of these plant extracts of toxic nature with chemically prepared particles, silver nanoparticles, and conducting multiple experiments for the same instars of the insect, which was treated with aqueous plant extracts .The statistical results as well as the observation during different stages of the experiments were superior of these nanoextracts over plant extracts in the mortality of eggs and first and fourth latval instars. Experiments indicated that the mortality percentages when treated with aqueous leaves extract of castor were (76, 91, 96) % respectively while the same instars were treated with nano extract of castor was(83.3 ,92.3 ,98.6 )% respectivly . The leaves extract of N.oleander was (86.6%, 96.6%, 99.4%) compared with (93.3, 100, 100) % respectively of the nanoparticle of the eggs and larvae of the first and fourth phases at 4 mg / ml. It also proved that the first instar was the most sensitive to the extract of the fourth instar, where the highest mortality percentages was (96.6, 100) % compared with (86.6, 93.3)% respectively of the first and fourth larval instars when treated with and nano of N. oleander and R.communis respectively.

UV-induced mutagenesis of Beauveria bassiana (Hypocreales: Clavicipitaceae) yields two hypervirulent isolates with different transcriptomic profiles.

The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) can infest over 300 plant species and cause huge economic losses. Beauveria bassiana (Hypocreales: Clavicipitaceae) is one of the most widely used entomopathogenic fungi (EPF). Unfortunately, the efficacy of B. bassiana against S. frugiperda is quite low. Hypervirulent EPF isolates can be obtained by ultraviolet (UV)-irradiation. Here we report on the UV-induced mutagenesis and transcriptomic analysis of B. bassiana. The wild-type (WT) B. bassiana (ARSEF2860) was exposed to UV light to induce mutagenesis. Two mutants (named 6M and 8M) showed higher growth rates, conidial yields, and germination rates compared to the WT strain. The mutants showed higher levels of tolerance to osmotic, oxidative, and UV stresses. The mutants showed higher protease, chitinase, cellulose, and chitinase activities than WT. Both WT and mutants were compatible with the insecticides matrine, spinetoram, and chlorantraniliprole, but incompatible with emamectin benzoate. Insect bioassays showed that both mutants were more virulent against S. frugiperda and the greater wax moth Galleria mellonella. Transcriptomic profiles of the WT and mutants were determined by RNA-sequencing. The differentially expressed genes (DEGs) were identified. The gene set enrichment analysis (GSEA), protein-protein interaction (PPI) network, and hub gene analysis revealed virulence-related genes. Our data demonstrate that UV-irradiation is a very efficient and economical technique to improve the virulence and stress resistance of B. bassiana. Comparative transcriptomic profiles of the mutants provide insights into virulence genes. These results provide new ideas for improving the genetic engineering and field efficacy of EPF. © 2023 Society of Chemical Industry.

Low dose γ-radiation induced effects on wax moth (Galleria mellonella) larvae

Larvae of the greater wax moth Galleria mellonella are common pests of beehives and commercial apiaries, and in more applied settings, these insects act as alternative in vivo bioassays to rodents for studying microbial virulence, antibiotic development, and toxicology. In the current study, our aim was to assess the putative adverse effects of background gamma radiation levels on G. mellonella. To achieve this, we exposed larvae to low (0.014 mGy/h), medium (0.056 mGy/h), and high (1.33 mGy/h) doses of caesium-137 and measured larval pupation events, weight, faecal discharge, susceptibility to bacterial and fungal challenges, immune cell counts, activity, and viability (i.e., haemocyte encapsulation) and melanisation levels. The effects of low and medium levels of radiation were distinguishable from the highest dose rates used – the latter insects weighed the least and pupated earlier. In general, radiation exposure modulated cellular and humoral immunity over time, with larvae showing heightened encapsulation/melanisation levels at the higher dose rates but were more susceptible to bacterial (Photorhabdus luminescens) infection. There were few signs of radiation impacts after 7 days exposure, whereas marked changes were recorded between 14 and 28 days. Our data suggest that G. mellonella demonstrates plasticity at the whole organism and cellular levels when irradiated and offers insight into how such animals may cope in radiologically contaminated environments (e.g. Chornobyl Exclusion Zone).

The opportunities of using a natural adaptogen from the <i>Galleria mellonella</i> larvae in veterinary medicine

A comparative analysis of the adaptation effects of the Porsolt test of fractionated solutions obtained from the products of the larvae of the large wax moth (Galleria mellonella) on biological systems was performed. The method of X-ray photoelectron spectroscopy determined that in the obtained light fraction of the products of larval life there is a high-energy component of N1s spectra (~402.0 eV) and bond energy for carbon in the C-N bond (~286.0 eV), which indicates the presence of protonated amino groups in the samples. Absorption at 1700 cm-1 can be attributed to the presence of dicarboxylic amino acids (glutamic and aspartic) and other organic acids, which are much less in the heavy fraction. During oral administration of the studied extracts, their multidirectional effect on the intestines of laboratory mice was found. The negative effect of heavy fraction on the microbiocenosis of the intestine by the qualitative composition of the microflora was detected. When the light fraction is used, the intestinal microflora is close to the control. Analysis of the number of leukocytes of the small intestine when the fractions were injected reflected the local immune response of the body. The content of these cells on the mucosal plate of mice injected with the lung fraction was 67.2% higher than that of the control mice (p ≤ 0.05). The content of leukocytes on the own plate of the mucosa of mice injected with the heavy fraction was 2.7 times higher compared to the control, indicating an inflammatory reaction. The difference between the experimental groups is significant (p ≤ 0.001). The comparative effect of the fractions showed that their oral administration had a different effect on the swimming time compared to the control. After 20 days of the experiment, mice injected with the heavy fraction had significantly increased their swimming time compared to the first day (p ≤ 0.05). However, a negative adaptogenic effect compared to the control group is noticeable. A significant difference was found between the results on the 30th day between the experimental groups, which indicates a pronounced difference in the results obtained.