Protaetia Brevitarsis Research Articles

Isolation and Evaluation of Indigenous Isolates of Beauveria bassiana and Synergistic Control of Spodoptera frugiperda with the Parasitoid Microplitis prodeniae

Entomopathogenic fungi (EPFs) are capable of infecting a variety of insect pests and are widely used as biopesticides worldwide. This study intended to isolate indigenous EPFs from cadavers of Protaetia brevitarsis and investigate their effects on the fall armyworm Spodoptera frugiperda (FAW), a globally widespread invasive pest. Morphological and molecular analyses confirmed four native EPF strains all belong to Beauveria bassiana. Pathogenicity tests showed they were virulent toward FAW 1st instar larvae. The application of EPFs either by dipping or spraying significantly increased the larval mortalities compared to the control group, with corrected mortalities ranging from 92% to 73% after dipping in a fungal suspension of 108 conidia/mL, and those ranging from 76% to 35% after spraying with a fungal suspension of 107 conidia/mL. Our findings revealed the infectivity of four strains to FAW larvae significantly changed in a dose- and time-dependent manner. In addition, the combination use of the local B. bassiana strain and parasitoid Microplitis prodeniae resulted in a significantly enhanced S. frugiperda 3rd instar larval mortality compared to a single inoculation with one of them, suggesting an apparent synergistic effect for the joint application of these two biological control agents. The mortality inflicted by B. bassiana was probably promoted by the release of parasitoids, since the parasitoids’ movements and attacks could strengthen the fungal distribution and infection processes. This study underscores the potential of the combination use of EPFs and parasitoids against S. frugiperda early-instar larvae, and provides insights into the consequences of integrating these EPFs into integrated pest management systems.

Pig manure characteristics and decomposition ability of Protaetia brevitarsis seulensis larval instar stages

AbstractMany types of livestock waste can be treated with insect larvae; however, in‐depth research on the decomposition ability of Protaetia brevitarsis seulensis (PBS) larvae and the characteristics of manure after treatment with PBS is extremely limited. Therefore, this study examined the decomposition ability and survival rates of different instars of PBS larvae and their effects on the characteristics and pathogen counts of pig manure. Two treatments were designed: 1 kg of second instar or third instar PBS larvae per 10 kg of pig manure. Pig manure did not affect the decomposing capacity and survival rates of the two PBS larval instar groups (P > 0.05). However, the decomposition abilities of the different PBS larval instar groups on days 2, 7 and 8 significantly differed (P < 0.05). Over time, the changes observed in pH, moisture, total nitrogen, acid detergent fiber (ADF), neutral detergent fiber (NDF) and hemicelluloses did not significantly differ (P > 0.05) between treatments using second or third instar PBS larvae. On day 15, both total nitrogen and NDF significantly differed (P < 0.05) between the two treatment groups. During the experimental period, no significant (P > 0.05) change in Escherichia coli or Salmonella counts was observed in pig manure treated with different PBS larval instars. Our findings suggest that the decomposition abilities and survival rates of larvae and pig manure characteristics and pathogen counts do not differ for different PBS larval instar stages.

Anti-Diabetic Activity of Cordyceps-Fermented Edible Insects by the Promotion of Glucose Absorption.

Insects are considered important food resources for future diet due to diverse nutrients and pharmacological effects. Fermentation is an important strategy of food processing with various beneficial effects such as increasing nutrients, promoting bioavailability, and reducing anti-nutrients. Cordyceps is a mushroom that grows on insects and produces various active ingredients. Therefore, we investigated the effect of Cordyceps-fermentation of insects on the nutritional composition and functional benefits of the insects. Six edible insects: Bombyx mori, Protaetia brevitarsis, Caelifera, Gryllus bimaculatus, Tenebrio molitor, and Allomyrina dichotoma were fermented with Cordyceps militaris to produce mycelia and fruiting bodies. Analysis of nutritional components showed that protein content was increased whereas carbohydrate content was decreased by the fermentation with Cordyceps. In addition, the fermented insects showed anti-diabetic efficacy by the promotion of glucose absorption as evaluated using differentiated L6-GLUT4myc cells. Quantitation using HPLC analysis suggested that cordycepin was produced in both mycelium and fruiting bodies in Cordyceps-fermented edible insects with different amounts depending on insect type and cultivation conditions. Therefore, the fermentation of insects with Cordyceps is expected to increase nutritional values and bioactive constituents and exert anti-diabetic effects.

Spontaneous Color Preferences and Associative Learning in Protaetia brevitarsis (Coleoptera: Scarabaeidae).

Color vision, which varies among species, plays an important role in foraging, mating, and habitat selection among insects. Protaetia brevitarsis (Coleoptera: Scarabaeidae, Lewis) is an omnivorous beetle that damages both crops and fruit. Here, to understand the effect of vision and olfaction in host selection, experiments were conducted on the spectral wavelength preference, color preference, and associative learning ability of adult P. brevitarsis using LED lights and grapes. In our experiments, adults showed the strongest spontaneous preference toward the red spectrum, particularly 730 nm. Non-preferred lights were used to train adults with a food reward (grapes). Green-trained adults had an increasing tendency to prefer green light, and blue-trained adults had a clear preference for blue light. Furthermore, adults significantly preferred red grapes in the absence of olfactory cues, but their selectivity for grapes differed in the presence of olfactory cues, indicating that vision was not the only factor in foraging decisions, but that olfactory cues also influenced their decision making. The results lay the groundwork for revealing their host localization mechanism and provide promising avenues for biological control in the field.

Warming, nitrogen deposition, and provenance shift above-belowground insect interactions and host compensatory growth.

Above-belowground insect herbivore interactions and plant compensatory growth are crucial for reshaping the fitness of invasive plants, and it is likely that climate warming, nitrogen (N) deposition, and plant provenance influence this interaction and growth in a complex way. We performed an experiment with Solidago canadensis from home and introduced ranges, leaf-chewing Spodoptera litura, and root-feeding Protaetia brevitarsis under climate warming and N deposition, and addressed how these abiotic stressors and plant provenance jointly shaped the reciprocal effects between S. litura and P. brevitarsis and the compensatory growth of S. canadensis after herbivory. Under ambient conditions, S. litura and P. brevitarsis inhibited each other on the basis of growth; warming, N addition or warming plus N addition shifted or even reversed this competition depending on provenance. While the survival-based above-belowground interactions differed from growth-based ones, warming or warming plus N addition also shifted or even reversed the neutralism or amensalism detected under ambient conditions depending on provenance. S. canadensis from its home range was more tolerant of herbivory than from its introduced range under ambient conditions; warming, N addition or warming plus N addition decreased the plant compensatory growth of native S. canadensis, but increased that of invasive S. canadensis relative to ambient conditions. These findings suggest that climate warming and N deposition could enhance positive above-belowground insect interactions, increasing insect pressures on S. canadensis, and that plant provenance might be important in mediating climate change effects on insect interactions and host compensatory growth under plant invasions.

Bionic Design of High-Performance Joints: Differences in Failure Mechanisms Caused by the Different Structures of Beetle Femur-Tibial Joints.

Beetle femur-tibial joints can bear large loads, and the joint structure plays a crucial role. Differences in living habits will lead to differences in femur-tibial joint structure, resulting in different mechanical properties. Here, we determined the structural characteristics of the femur-tibial joints of three species of beetles with different living habits. The tibia of Scarabaeidae Protaetia brevitarsis and Cetoniidae Torynorrhina fulvopilosa slide through cashew-shaped bumps on both sides of the femur in a guide rail consisting of a ring and a cone bump. The femur-tibial joint of Buprestidae Chrysodema radians is composed of a conical convex tibia and a circular concave femur. A bionic structure design was developed out based on the characteristics of the structure of the femur-tibial joints. Differences in the failure of different joint models were obtained through experiments and finite element analysis. The experimental results show that although the spherical connection model can bear low loads, it can maintain partial integrity of the structure and avoid complete failure. The cuboid connection model shows a higher load-bearing capacity, but its failure mode is irreversible deformation. As key parts of rotatable mechanisms, the bionic models have the potential for wide application in the high-load engineering field.

Seasonal host shifts based on midgut residues of Protaetia brevitarsis (Coleoptera: Scarabaeidae).

White-spotted flower chafer adult (Protaetia brevitarsis, Coleoptera: Scarabaeidae), a serious omnivorous pest in regions with multiple fruits and crops, was studied to gain a deeper understanding of its damage patterns. DNA molecular tracking technology was used to identify host plant residues in adult P. brevitarsis midgut, and plant species with the most availability were determined during their growing season. Combining the 2019 and 2021 results, it was found that adults in the multi-cropped area fed on 32 plant species from 23 families, with grape (Vitis vinifera, 40%), peach (Prunus perisica, 23%) and mulberry (Morus alba, 14%) making up the majority of their diet. Some adults fed on multiple plant hosts, with four species detected in one adult and two to three species detected in one-third of adults. Adults shifted among host species during the season, moving from mulberry or grape to peach and then back to grape. These results provide a scientific basis for in-depth research to develop green integrated control technologies against P. brevitarsis adults.

Application of enzyme preparations in the treatment of sawdust spent mushrooms substrate by Protaetia brevitarsis larvae

Application of enzyme preparations in the treatment of sawdust spent mushrooms substrate by Protaetia brevitarsis larvae

Comparison of plastic and glass cages on volatile compounds in protein extracted from Protaetia brevitarsis larvae

Edible insects, known for their high-protein production efficiency, are vital for enhancing food security. However, standardized breeding protocols are lacking, and research on the impact of cage materials on insect product composition is limited. This study investigated the volatile compounds and processing properties of protein from Protaetia brevitarsis larvae reared in plastic and glass cages. Protein extracts from larvae reared in plastic cages contained 14 types of hydrocarbons, 4 types of ketones, and 1 type of phenol. Those reared in glass cages contained two types of acids, seven types of alcohols, and five types of aldehydes. Notably, plastic-derived compounds, such as p-xylene (110.87 μg/mL) and o-xylene (37.98 μg/mL), were significantly higher in the extracts from plastic cages, indicating potential plastic exposure. Processing properties, including protein solubility, pH, color, foaming properties, and emulsion characteristics, showed no significant differences between the two rearing conditions (P > 0.05). Therefore, considering the detection and potential accumulation of plastic-derived volatile compounds, using glass cages may be more beneficial for rearing insects for protein production.

Protective effects of Tenebrio molitor and Protaetia brevitarsis seulensis extracts on aging: Regulation of blood–brain barrier, amyloid β plaques, and intestinal inflammation in D-galactose-induced aging mice

Insects are considered as a potentially eco-friendly, highly nutritious, and protein-rich food source. We evaluated the effects of Tenebrio molitor (Tm) and Protaetia brevitarsis seulensis (Pbs) extracts in a mouse model of D-galactose (D-Gal) aging, focusing on the impact of the insect extracts on neuronal viability, blood–brain barrier (BBB) integrity, and gut health. D-gal administration led to cognitive and behavioral deficits and increased anxiety levels. Tm and Pbs extracts increased glutathione, superoxide dismutase, and catalase levels; protected neurons in the brain, preventing BBB disruption and brain edema; and prevented the deposition of amyloid-β plaques in the prefrontal cortex and hippocampus. Furthermore, both extracts prevented disruption of gut epithelial integrity and mitigated intestinal inflammation. Our findings suggest a novel therapeutic potential of insect extracts against aging-related changes; they can be used as functional foods in the aging process by controlling the BBB and intestinal health.

Comparison of volatile compound profiles derived from various livestock protein alternatives including edible-insect, and plant-based proteins

In this study, the distinctive chemical fingerprints that contribute to the flavor characteristics of various protein materials, such as insects, plant-based protein, and livestock, were investigated. In edible-insects (Tenebrio molitor and Protaetia brevitarsis), aldehydes and cyclic volatile compounds were the predominant volatile components and had distinct flavor characteristics such as cheesy, sharp, green, floral, and sweet. In contrast, the relatively high levels of pyrazines and furans in plant-based protein materials, such as textured vegetable and pea protein. They included unique flavor properties characterized by sweet, fatty, grassy, creamy, and roasted. The primary volatile chemical group detected in livestock protein materials, such as a pork and a beef, was ketones. The pork sample showed specific flavors, such as alcoholic, green, and fruity, while a beef presented distinctive flavor, including creamy, fruity, and alcoholic. Based on the results, this research provided the understanding of the flavor aspects of diverse protein materials.

Eco-friendly pH-responsive iron-doped insect larval frass extract as a hexaconazole nano-delivery system for controlling fungal disease and promoting crop growth

Developing environmentally friendly pesticides and improving pesticide utilization efficiency are urgent needs for modern agriculture. Herein, a pH-responsive biodegradable dual pesticide-fertilizer was fabricated using extracts from naturally occurring Protaetia brevitarsis larval frass (PBLF) material. Iron ions (Fe3+) were integrated as metal nodes into PBLF, and hexaconazole (Hex), a triazole fungicide, was encapsulated in Fe-PBLF with a loading rate of 22.93 %. Hex@Fe-PBLF nanoparticles (NPs) presented a sphere-like construction with a hydrated size of 715.3 ± 5.0 nm and exhibited acid-responsive controlled release behavior, gradually self-degrading in acidic environments within 120 h. The NPs showed good foliar adhesion and were effectively absorbed and translocated by pathogenic fungal mycelium and the rice seedling. Compared with Hex Technical control (TC), the control effects of Hex@Fe-PBLF against Rhizoctonia solani (R. solani) and Botrytis cinerea (B. cinerea) increased by 9.9 % and 12.73 %, respectively, after 7 days. This naturally sourced nanocarrier not only promoted the growth of rice seedlings as a fertilizer but also enhanced their stress resistance. The low mobility of Hex@Fe-PBLF NPs in soil effectively reduced environmental risks. The excellent biosafety of the Fe-PBLF nanocarrier was further evaluated. Overall, this environmental-friendly multifunctional nano pesticide-fertilizer has promising application potential in agriculture.

Protaetia brevitarsis larvae extract ameliorated obesity in high fat diet-fed mice by modulating gut microbiota and lipid metabolism

<em>Protaetia brevitarsis</em> larvae extract ameliorated obesity in high fat diet-fed mice by modulating gut microbiota and lipid metabolism

Research on Deployable Wings for MAVs Bioinspired by the Hind Wings of the Beetle Protaetia brevitarsis.

Deployable hind wings of beetles led to a bio-inspired idea to design deployable micro aerial vehicles (MAVs) to meet the requirement of miniaturization. In this paper, a bionic deployable wing (BD-W) model is designed based on the folding mechanism and elliptical wing vein structure of the Protaetia brevitarsis hindwing, and its structural static and aerodynamic characteristics are analyzed by using ANSYS Workbench. Finally, the 3D-printed bionic deployable wing was tested in a wind tunnel and compared with simulation experiments to explore the effects of different incoming velocity, flapping frequency, and angle of attack on its aerodynamic characteristics, which resulted in the optimal combination of the tested parameters, among which, the incoming velocity is 3 m/s, the flapping frequency is 10 Hz, the angle of attack is 15°, and the lift-to-drag ratio of this parameter combination is 4.91. The results provide a theoretical basis and technical reference for the further development of bionic flapping wing for MAV applications.

Investigating the Nutritional and Functional Properties of Protaetia brevitarsis Larvae and Isolated Soy Protein Mixtures as Alternative Protein Sources.

The growing demand for sustainable and alternative protein sources has spurred interest in insect-based and plant-based proteins. Protaetia brevitarsis (PB) larvae and isolated soy protein (ISP) are notable in this regard, offering potential health benefits and nutritional enhancements. We assessed the feasibility of PB larvae and ISP mixtures as alternative food ingredients. Methods included the optimized purification and freeze-drying of PB larvae, extraction and refinement of legume proteins, physicochemical and antioxidant capacity evaluations, DPPH radical scavenging activity measurement, total phenolic and flavonoids content quantification, general component analysis, amino acid profiling using HPLC, fatty acid profiling through gas chromatography, and mineral content analysis using inductively coupled plasma spectrometry. The study found that certain PB:ISP ratios, particularly a 7:3 ratio, significantly improved the blend's antioxidant capacity, as evidenced by DPPH scavenging activity. This ratio also impacted the nutritional profile by altering the mixture's general components, with a notable increase in moisture, crude protein, and fiber and a decrease in crude fat and ash. Amino acid analysis revealed a balanced presence of essential and non-essential amino acids. The fatty acid profile was rich in unsaturated fatty acids, especially in certain ratios. Mineral analysis showed a complex interplay between PB larvae and ISP, with some minerals decreasing and others increasing in the blend. PB larvae and ISP mixtures have significant potential as alternative protein sources, offering a diversified nutritional profile and enhanced antioxidant properties. The 7:3 ratio of PB larvae to ISP has been shown to be particularly effective, suggesting that this ratio may offer an optimal balance for enhancing the overall nutritional quality of the mixture. This study sets the stage for future research to further explore and optimize the potential of these mixtures for human consumption while considering the challenges of consumer acceptance and long-term safety.

Characterization and evaluation of actinomycete from the Protaetia brevitarsis Larva Frass.

Protaetia brevitarsis larvae (PBL) are soil insects important for the soil organic carbon cycle, and PBL frass not only contains a large amount of humic acid but also affects the diversity, novelty, and potential functions of actinomycetes. Here, we characterized and assessed the actinomycete. The operational taxonomic unit (OTU) data showed that 90% of the actinomycetes cannot be annotated to species, and pure culture and genome analysis showed that 35% of the strains had the potential to be new species, indicating the novelty of PBL frass actinomycetes. Additionally, genome annotation showed that many gene clusters related to antifungal, antibacterial and insecticidal compound synthesis were identified, and confrontation culture confirmed the antifungal activities of the actinomycetes against soil-borne plant pathogenic fungi. The incubation experiment results showed that all isolates were able to thrive on media composed of straw powder and alkaline lignin. These results indicated that PBL hindgut-enriched actinomycetes could survive in soil by using the residual lignocellulose organic matter from plant residues, and the antibiotics produced not only give them a competitive advantage among soil microflora but also have a certain inhibitory effect on plant diseases and pests. This study suggests that the application of PBL frass can not only supplement soil humic acid but also potentially affect the soil microbiota of cultivated land, which is beneficial for the healthy growth of crops.

Variation of volatile compounds and sensory profile for Protaetia brevitarsis larvae fermented with lactic acid bacteria and yeast

This study aimed to investigate the correlation between the composition of volatile compounds, consumer acceptance, and drivers of (dis)liking of Protaetia brevitarsis larvae fermented using lactic acid bacteria and yeast. Volatile compounds were analyzed using HS-SPME-Arrow-GC–MS, and a sensory evaluation was conducted with 72 consumers. A total of 113 volatile compounds were detected, and principal component analysis indicated that the samples could be divided into three groups. The calculated relative odor activity values (ROAV) revealed the presence of 27 compounds (ROAV >1). Volatile compounds with high ROAV were predominantly found during yeast fermentation. The sensory evaluation results indicated a strong correlation between low levels of off-odor intensity and high odor liking, emphasizing that odor profile had a more direct association with consumer acceptance than odor intensity. These findings suggest that yeast fermentation using volatile compounds, which positively influences consumer acceptance, is appropriate for Protaetia brevitarsis larvae.

Protaetia brevitarsis larvae produce frass that can be used as an additive to immobilize Cd and improve fertility in alkaline soils

Bioconversion of agricultural waste by Protaetia brevitarsis larvae (PBL) holds significant promise for producing high-quality frass organic amendments. However, the effects and mechanisms of PBL frass on Cd immobilization in an alkaline environment remain poorly understood. In this study, three types of frass, namely maize straw frass (MF), rice straw frass (RF), and sawdust frass (SF), were produced by feeding PBL. The Cd immobilization efficiencies of three frass in alkaline solutions and soils were investigated through batch sorption and incubation experiments, and spectroscopic techniques were employed to elucidate the sorption mechanisms of Cd onto different frass at the molecular level. The results showed that MF proved to be an efficient sorbent for Cd in alkaline solutions (176.67–227.27 mg g−1). X-ray absorption near-edge structure (XANES) spectroscopy indicated that Cd immobilization in frass is primarily attributed to the association with organic matter (OM-Cd, 78–90%). And MF had more oxygen-containing functional groups than the other frass. In weakly alkaline soils, MF application (0.5–1.5%) significantly decreased Cd bioavailability (5.65–18.48%) and concurrently improved soil nutrients (2.21–56.79%). Redundancy analysis (RDA) unveiled that pH, CEC, and available P were important factors controlling Cd fractions. Path analysis demonstrated that MF application affected Cd bioavailability directly and indirectly by influencing soil chemical properties and nutrients. In summary, MF, the product of PBL-mediated conversion maize straw, demonstrated promise as an effective organic amendment for Cd immobilization and fertility improvement in alkaline soils.

Structural response and mechanical properties of the hind wing of the beetle Protaetia brevitarsis.

The folding/unfolding mechanism and collision recovery effect of the beetle's hind wings can provide biomimetic inspiration for the optimization of wing deplorability and the investigation of collision prevention recovery mechanism of new amphibious morphing vehicle. In this study, a method is described to investigate the structural response and mechanical properties of the hind wings of the beetle Protetia brevitarsis under natural conditions. The specially processed test samples were conducted to tensile testing, which facilitates the evaluation of the mechanical properties of specific areas of the hind wing. The micro geometric morphological characteristics of the cross-section of the specimen after tensile fracture were observed by scanning electron microscopy. The three-dimensional morphology of the ventral and dorsal sides of the hind wing was characterized using three-dimensional scanning and reverse modeling methods. The finite element model of the hind wing is developed to investigate the structural deformation and modal response characteristics of its flapping. The uniformly distributed load on the hind wing surface is derived from the lift characteristics obtained from the computational fluid dynamics simulation of flapping wing motion. RESEARCH HIGHLIGHTS: Scanning electron microscope is used to observe the cross-sectional characteristics of the veins and membranes. The material properties of the wing membranes and veins of the hind wings were measured using the tensile testing system. The three-dimensional morphology of the hind wing was characterized using 3D scanning and reverse modeling methods. The finite element model of the hind wing is developed to investigate the structural deformation and modal response characteristics of its flapping.

Comparative Analysis of Hindgut Microbiota Variation in Protaetia brevitarsis Larvae across Diverse Farms.

Protaetia brevitarsis larvae are farm-raised for food, are used in traditional East Asian medicine, and convert organic waste into biofertilizers. Here, the comparative analysis of the gut microbiota of third-instar larvae obtained from five different farms was investigated using 16S rRNA microbial profiling. Species richness, evenness, and diversity results using α-diversity analysis (observed species, Chao1, Shannon, Simpson) were similar between farms, except for those between the TO and KO farms. β-diversity was significantly different in distribution and relative abundance between farms (PERMANOVA, pseudo-F = 13.20, p = 0.001). At the phylum level, Bacillota, Bacteroidota, Actinomycetota, and Pseudomonadota were the most dominant, accounting for 73-88% of the hindgut microbial community. At the genus level, Tuberibacillus, Proteiniphilum, Desulfovibrio, Luoshenia, and Thermoactinomyces were the most abundant. Although oak sawdust was the main feed component, there were large variations in distribution and relative abundance across farms at the phylum and genus levels. Venn diagram and linear discriminant analysis effect size analyses revealed large variations in the hindgut microbial communities of P. brevitarsis larvae between farms. These results suggest environmental factors were more important than feed ingredients or genetic predisposition for the establishment of the intestinal microbiota of P. brevitarsis larvae. These findings serve as reference data to understand the intestinal microbiota of P. brevitarsis larvae.