Search Results (72)

Trichogramma wasps are highly effective biological control agents, offering an environmentally sustainable solution for pest management through their parasitism of insect eggs. This study evaluates the parasitism performance of six Trichogramma species—T. dendrolimi, T. chilonis, T. leucaniae, T. ostriniae, T. japonicum, and T. pretiosum—on five treatments of Eri silkworm (ES) eggs, a potential alternative to the large eggs of Antheraea pernyi for mass rearing. The ES egg treatments included the following: manually extracted, unfertilized, and washed eggs (MUW); naturally laid, unfertilized, and washed eggs (NUW); naturally laid, unfertilized, and unwashed eggs (NUUW); naturally laid, fertilized, and washed eggs (NFW); and naturally laid, fertilized, and unwashed eggs (NFUW). The results demonstrate that all Trichogramma species, except T. japonicum, successfully parasitized ES eggs across all treatments. Notably, washed eggs consistently supported higher parasitism and emergence rates compared to unwashed eggs, while unfertilized eggs outperformed fertilized eggs in these metrics. Among the treatments, unfertilized and washed eggs (MUW and NUW) exhibited the shortest pre-emergence time and the highest number of emerged adults, with no significant differences in female progeny ratios across most species. A striking exception was T. dendrolimi, which showed a significantly higher female offspring ratio in the MUW treatment. These findings highlight that MUW eggs of ES are a highly suitable alternative host for the mass production of Trichogramma wasps. This study provides critical insights for optimizing host egg treatments to enhance the efficiency of Trichogramma-based biological control programs. Full article

Due to the biofactories’ concern for the quality of the parasitoid Cotesia flavipes (Hymenoptera: Braconidae), a common practice is to introduce a population collected from the field into the laboratory mass rearing, even without prior information about the introduced population’s quality or potential positive outcomes. Thus, the objective of this study was to determine whether populations of the C. flavipes parasitoid collected from the field exhibit better biological characteristics and flight activity, with the aim of incorporating them into laboratory mass rearing to enhance the quality of the parasitoids. To achieve this, a population of C. flavipes collected from the field (Pradópolis, SP, Brazil) was studied for twenty generations and compared with a population maintained in the laboratory for 42 years. The egg-to-pupa period in the field population was shorter across generations, particularly in the twentieth generation (11.0 days). Although the field population exhibited a lower number of adults that emerged per host in the fifth and tenth generations, by the twentieth generation, it showed higher offspring production per parasitized host (56.5 parasitoids/host). The results of the flight activity test revealed that both the laboratory-maintained population and the field-collected population exhibited higher percentages of insects classified as walkers compared to flyers (25.7% to 32.3% flying). The field-collected population stabilized in the laboratory by the tenth generation. Moreover, the results of the biological characteristics, longevity, and flight activity of the parasitoids indicate similar quality between the two populations studied after stabilization of the field-collected population. Full article

Amylostereum areolatum (Chaillet ex Fr.) Boidin (Russulales: Amylostereaceae) is a symbiotic fungus of Sirex noctilio Fabricius that has ecological significance. Terpenoids are key mediators in fungal–insect interactions, yet the biosynthetic mechanisms of terpenoids in this species remain unclear. Under nutritional conditions that mimic natural growth, A. areolatum was sampled during the lag phase (day 7), exponential phase (day 14), and stationary phase (day 21). Metabolome (solid-phase microextraction (SPME) combined with gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS)) and transcriptome (Illumina NovaSeq) profiles were integrated to investigate terpenoid–gene correlations. This analysis identified 103 terpenoids in A. areolatum, substantially expanding the known repertoire of terpenoid compounds in this species. Total terpenoid abundance progressively increased across three developmental stages, with triterpenoids and sesquiterpenoids demonstrating the highest diversity and abundance levels. Transcriptomic profiling (61.66 Gb clean data) revealed 26 terpenoid biosynthesis-associated genes, establishing a comprehensive transcriptional framework for fungal terpenoid metabolism. Among 11 differentially expressed genes (DEGs) (|log2Fold Change| ≥ 1, adjusted p < 0.05), HMGS1, HMGR2, and AaTPS1-3 emerged as key regulators potentially governing terpenoid biosynthesis. These findings provide foundational insights into the molecular mechanisms underlying terpenoid production in A. areolatum and related basidiomycetes. Full article

(1) Background: Larval diet composition significantly influences the developmental, physiological, and reproductive traits of Ae. albopictus and Ae. aegypti, major arbovirus vectors. Optimizing larval nutrition is essential for mass-rearing programs supporting the sterile insect technique and incompatible insect technique. This study evaluated the effects of three larval diets on key fitness traits, including pupation rate, male flight ability, adult longevity, female fecundity, pupal size, and wing length, which are critical for the success of SIT and IIT programs. (2) Methods: Ae. albopictus (GT strain) and Ae. aegypti (AEG strain) were reared on three diets with varying protein sources: diet 1 (≈1.23 dollars/kg; porcine liver/shrimp/yeast = 6:3:1), the IAEA-recommended diet; diet 2 (≈1.78 dollars/kg; bovine liver/shrimp/yeast = 6:3:1), a modified IAEA diet; and diet 3 (≈0.55 dollars/kg; tortoise food), a low-cost laboratory formulation. Life history traits were assessed using standardized protocols, and data were analyzed with ANOVA and Tukey’s post hoc test. (3) Results: Diet 3 consistently improved pupation rates, adult longevity, and male flight ability compared with diet 2. Mosquitoes reared on diets 1 and 3 exhibited significantly larger pupae and longer wings, while diet 2 performed sub-optimally. Adult eclosion rates (~100%) remained high across all diets. Male flight ability varied by species, with Ae. albopictus performing best on diet 1 and Ae. aegypti on diet 3. Female fecundity was diet-dependent, with diet 1 favoring Ae. albopictus and diet 3 benefitting Ae. aegypti. Longevity was highest in mosquitoes reared on diet 3, with a median survival of 19.5 days for GT males and 37.5 days for GT females. (4) Conclusions: Diet 3 emerged as the most cost-effective option, enhancing key fitness traits essential for SIT and IIT. Future studies should refine nutrient formulations and validate findings under field conditions to optimize mass-rearing efficiency in vector control. Full article

Plants require a flexible avoidance mechanism as they need to cope with external stimuli and challenges through complex specialized metabolites, among which volatile terpenoids make outstanding contributions, acting as key media signal substances in the cooperation between plants and surrounding organisms. In recent decades, the research on the identification and functional characterization of terpenoid synthase and factors regulating metabolic shunts has gained significant attention, leading to substantial progress and notable achievements. However, with the popularization of terpenoids in insect and disease prevention, medical care, cosmetics, and other fields, coupled with increasing resistance to artificially produced chemical products, the demand for natural terpenoids has outpaced supply, prompting the emergence and popularity of targeted engineering for the mass production of terpenoids using microorganisms and plants as platforms. In this paper, we provide a detailed overview of the key knowledge and research progress of volatile terpenoids with regard to multiple functions, complex synthetic pathways, key terpenoid synthase genes, related regulatory factors, and target engineering. Full article

In China, the Asian corn borer (ACB), Ostrinia furnacalis (Guenee) (Lepidoptera: Pyralidae), is the most significant economic insect pest of corn, causing losses ranging from six to nine million tons annually by feeding on all parts of maize, including damaging ears and leaves and making tunnels in stems. In China, since the 1970s, the Trichogramma species have extensively mass-reared from factitious hosts to control ACB and support integrated pest management programs. The Trichogramma dendrolimi Matsumura and T. ostriniae Pang and Chen are the most efficient biocontrol agents for controlling ACB among the available Trichogramma species. To evaluate the reproductive success of Trichogramma dendrolimi and T. ostriniae, we assessed the impact of varying parasitoid ratios (5:1, 3:1, 1:1, 1:3, and 1:5 representing T. dendrolimi and T. ostriniae, respectively) on adult offspring emergence and mortality from ACB eggs over multiple generations (from first (F₁) to third (F₃) generations). We discovered that both Trichogramma species’ offspring emergence was significantly influenced by the parasitoid generations, parasitoid ratios, and their interactions. The offspring mortality in both Trichogramma species was significantly affected by parasitoid generations but was not significantly influenced by parasitoid ratios or interaction between parasitoid generations and parasitoid ratios. Furthermore, at parasitoid ratios of 5:1, 3:1, and 1:1, the emergence rate of the F₁ generation of T. dendrolimi was significantly higher compared to the ratios of 1:3 and 1:5. However, in the F₂ generation, the emergence of T. dendrolimi decreased considerably, and no emergence was observed in the F₃ generation. A contrasting trend was observed in the emergence of T. ostriniae offspring. Overall, regardless of the parasitoid ratios, the offspring emergence of T. ostriniae in all three generations was significantly higher than that of T. dendrolimi. After assessing the offspring mortality in our research by dissecting the unhatched eggs, we found an inverse relationship between the T. dendrolimi generations and their mortality across different parasitoid ratios. Notably, mortality exhibited a significant decline with an increasing number of generations. A positive correlation was observed between the number of T. ostriniae generations and their mortality across different parasitoid ratios, indicating that mortality increased with successive generations. Overall, across all parasitoid ratios and generations, the offspring mortality of T. ostriniae was considerably greater than that of T. dendrolimi. These results suggest that mortality is a crucial empirical measure that validates T. ostriniae’s superiority over T. dendrolimi. These findings highlight the importance of selecting suitable parasitoid species when implementing Trichogramma for pest management. Full article

Western flower thrips (WFTs) are significant pests affecting various crops globally. Developing sustainable strategies for managing WFTs is essential for improving thrips management. Ethological control methods, particularly those employing volatile organic compounds (VOCs) emitted by plants to influence insect behavior, have emerged as a promising avenue for pest management. Natural hosts such as Alstroemeria provide an intriguing yet underexplored opportunity for developing attractants tailored to WFT management. This study examined the behavioral preferences of WFTs towards flowers of four commercial Alstroemeria cultivars, focusing on variations in VOC profiles. Using headspace solid-phase microextraction (HS-SPME), VOCs were captured in vivo from cultivars with contrasting levels of WFT infestation. Gas chromatography coupled with mass spectrometry (GC-MS) was employed to analyze the VOCs, with linear retention indices aiding compound identification. An untargeted volatile profiling-based comparative analysis revealed key VOCs that differed among cultivars, shedding light on their potential correlation with WFT behavior. Behavioral assays identified three specific VOCs—butyl butyrate, 1-methylnaphthalene, and citronellyl acetate—as influential in attracting WFTs. Attraction responses were concentration-dependent, with two tested concentrations eliciting significant behavioral effects. These findings highlight the potential of these active VOCs as components of novel attractants for WFT management. The results direct future research and the development of tools to integrate ethological strategies into sustainable pest management practices for crops. Full article

Asian corn borer (ACB), Ostrinia furnacalis Guenee (Lepidoptera: Crambidae) and the rice moth (RM), Corycyra cephalonica Stainton (Lepidoptera: Pyralidae) are economically significant insect pests that threaten the agricultural products worldwide. Trichogramma parasitoids are successfully mass-reared using artificial host eggs, RM, and are often managed by economically important lepidopterous pests, such as ACB in China. Trichogramma ostriniae Pang and Chen (To) and T. dendrolimi Matsumura (Td) (Hymenoptera: Trichogrammatidae) are two important parasitoids of ACB. To determine the influence of interspecific competition between To and Td on their offspring’s emergence. We determine the emergence of wasp progeny from two distinct hosts (ACB and RM eggs) of varying densities (10, 20, 30, and 100) by examining the effect of three distinct oviposition sequences (To-Td, Td-To, and To+Td) by two Trichogramma species. We discovered that the progeny emergence rate of To and Td from the host was substantially influenced by the parasitoid types, host types, oviposition sequences, and host densities, and their two-, three-, and four-factor interactions while investigating the ACB and RM eggs after oviposition. Additionally, the progeny of Td emerged from 10, 20, and 30 ACB host eggs under three oviposition sequences, which was significantly higher than that of ACB eggs of 100 densities. Nevertheless, the optimum emergence rate of Td progeny was also observed in ACB eggs with a density of 100 under all oviposition sequences. The most suitable oviposition sequences for both wasp species are To-Td and Td-To, as they have the highest rate of progeny emergence. The progeny emergence of both Trichogramma species from RM eggs of varying densities was observed to be significantly different. Nevertheless, the most influential density is 100 RM eggs, as a result of the maximal emergence rate of To and Td. Overall, it is concluded that host eggs with a density of 100 are adequate to meet the oviposition requirements of both wasps in all oviposition orders, thereby limiting their interspecific competition. These findings provide insights into optimizing host density and oviposition strategies for mass-rearing Trichogramma species, which can enhance their efficacy in biological control programs. Future research should explore field-level applications to validate these laboratory findings under natural conditions. Full article

There is a pressing need to expand the production and consumption of alternative protein sources from plants, fungi, insects, and algae from both nutritional and sustainability perspectives. It is well known that the postprandial rise in plasma amino acid concentrations and subsequent muscle anabolic response is greater after the ingestion of animal-derived protein sources, such as dairy, meat, and eggs, than plant-based proteins. However, emerging evidence shows that a similar muscle anabolic response is observed—despite a lower and slower postprandial aminoacidemia—after the ingestion of alternative protein sources compared with animal-derived protein sources. Therefore, a comprehensive analysis of plasma amino acid kinetics after the ingestion of alternative protein sources would play a significant role in recognizing and identifying the anabolic properties of these protein sources, allowing for the implementation of the best nutritional intervention strategies, contributing to more sustainable food production, and developing new medical nutritional products with optimal impacts on muscle mass, strength, and function, both in terms of health and disease. Therefore, this narrative review is focused on postprandial amino acid kinetics (the area under the curve, peak, and time to reach the peak concentration of amino acids) based on experimental randomized controlled trials performed in young and older adults following the ingestion of different novel, sustainable, and alternative protein sources. Full article

Cry toxins from Bacillus thuringiensis are effective biopesticides that kill lepidopteran pests, replacing chemical pesticides that indiscriminately attack both target and non-target organisms. However, resistance in susceptible pests is an emerging problem. B. thuringiensis also produces vegetative insecticidal protein (Vip3A), which can kill insect targets in the same group as Cry toxins but using different host receptors, making the combined application of Cry and Vip3A an exciting possibility. Vip3A toxicity requires the formation of a homotetramer. Hence, screening of Vip3A mutants for increased stability requires orthogonal biophysical assays that can test both tetrameric integrity and monomeric robustness. For this purpose, we have used herein for the first time a combination of analytical ultracentrifugation (AUC), mass photometry (MP), differential static light scattering (DSLS) and differential scanning fluorimetry (DSF) to test five mutants at domains I and II. Although all mutants appeared more stable than the wild type (WT) in DSLS, mutants that showed more dissociation into dimers in MP and AUC experiments also showed earlier thermal unfolding by DSF at domains IV–V. All of the mutants were less toxic than the WT, but toxicity was highest for domain II mutations N242C and F229Y. Activation of the protoxin was complete and resulted in a form with a lower sedimentation coefficient. Future high-resolution structural data may lead to a deeper understanding of the increased stability that will help with rational design while retaining native toxicity. Full article

Edible Insects (EIs) are an alternative source of bioactive compounds such as proteins or fatty acids and micronutrients as vitamins or minerals, thus showing potential to replace traditional foodstuffs in an economical and environmentally friendly way. Nonetheless, EIs can accumulate hazardous chemicals such as mycotoxins and heavy metals. The aim of the present study is to determine mycotoxins and heavy metal content in raw insect samples and those resulting products obtained after supercritical fluid extraction (SFE). Insect samples included Acheta domesticus (cricket) meal, Tenebrio molitor (mealworm) meal, Alphitobius diaperinus (buffalo worm), and Locusta migratoria (locust). For this purpose, a QuEChERS method followed by LC-MS/MS analysis was optimized with good results for the analysis of mycotoxins, principally Aflatoxins (AFs), Ochratoxin A (OTA), and Enniatins (ENNs). In contrast, heavy metals (As, Cd, Hg, Pb) were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The results obtained revealed that Locust was positive for AFG2 at a level of 115.5 μg/kg, and mealworm was only contaminated with OTA at 58.1 μg/kg. Emerging mycotoxins (ENNA, ENNA1, ENNB, and ENNB1) were detected at lower levels < 2.2 µg/Kg. Concerning heavy metals, limits exceeding regulation were detected for Cd in the insect species studied, with levels up to 219 μg/kg, and for Pb in crickets (100.3 μg/kg). Finally, the analysis of the post-extraction solids after SFE processing revealed that heavy metals remained in the resulting SFE cakes, while mycotoxins were detected at negligible levels (up to 1.3 µg/Kg). Full article

The occurrence of insect pests in crops directly affects the yield of plants and grains. This scenario led to the mass investigation of chemical products that overcome these adversities and provide control potential. Nonetheless, over the years, this strategy resulted in high production costs, generation of waste harmful to the environment, and resistance of target insects. The adoption of alternative practices, such as the formulation and production of products of microbial origin, emerges as an encouraging tool compared to control alternatives, indicating a sustainability bias, and allowing a reduction in the risks of human and animal contamination. The purpose of this study was to perform bioprospecting for microbial agents with potential insecticidal effects. The isolated microorganisms were submitted to submerged fermentation, at 28 °C and 120 rpm, for seven days. The fermented broth was filtered using a vacuum pump and centrifuged at 3200× g and 10 °C for 10 min. Initially, 163 microbial agents were collected. Subsequently, a pre-selection of the 50 most promising bioagents was conducted, based on the mortality rates (%) of the applied isolates to target pests. Furthermore, a global mathematical modeling design was created, indicating the best potential microorganisms. Moreover, to stipulate the difference between treatments, dilutions of the fermented broths of each microorganism were conducted (n × 10⁻⁵–n × 10⁻⁸). Mortality was maximum (100%) for Helicoverpa zea and Euschistus heros. Other encouraging results were indicated in the control of Anticarsia gemmatalis and Chrysodeixis includens (up to 87.5%) and Elasmopalpus lignosellus (up to approximately 83.5%). Fungal isolates were identified as Talaromyces piceae. Among the bacteria, based on sequencing of the 16S ribosomal gene, the isolates were identified as Lysinibacillus fusiformis, Paenibacillus ottowii, and Clostridium sphenoides. The results obtained are relevant to the scientific community and, especially, are interesting for companies that are operating in this field in the agricultural sector. Full article

Incorporating insect meals into poultry diets has emerged as a sustainable alternative to conventional feed sources, offering nutritional, welfare benefits, and environmental advantages. This study aims to monitor and compare volatile compounds emitted from raw poultry carcasses and subsequently from cooked chicken pieces from animals fed with different diets, including the utilization of insect-based feed ingredients. Alongside the use of traditional analytical techniques, like solid-phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS), to explore the changes in VOC emissions, we investigate the potential of S3+ technology. This small device, which uses an array of six metal oxide semiconductor gas sensors (MOXs), can differentiate poultry products based on their volatile profiles. By testing MOX sensors in this context, we can develop a portable, cheap, rapid, non-invasive, and non-destructive method for assessing food quality and safety. Indeed, understanding changes in volatile compounds is crucial to assessing control measures in poultry production along the entire supply chain, from the field to the fork. Linear discriminant analysis (LDA) was applied using MOX sensor readings as predictor variables and different gas classes as target variables, successfully discriminating the various samples based on their total volatile profiles. By optimizing feed composition and monitoring volatile compounds, poultry producers can enhance both the sustainability and safety of poultry production systems, contributing to a more efficient and environmentally friendly poultry industry. Full article

Feeding on mixed, alternating, or changing diets often favor insect development. With the aim to optimize mass rearing and use for the biological control of insect pests, we investigated the effects of various combinations of high-quality (the green peach aphid Myzus persicae) and low-quality (eggs of the grain moth Sitotroga cerealella) foods on the larval development of a predatory ladybird Cheilomenes propinqua. In the first experiment, eggs and aphids were mixed in different proportions; in the second experiment, larvae switched from feeding on aphids to feeding on eggs. Although the beneficial additive effect of mixed foods was detected in some treatments with limited diets, feeding on various combinations of eggs with aphids never resulted in higher survival, faster development, or a larger size of emerging adults than those observed for feeding on unlimited amounts of aphids. For the practice of biological control, we conclude that, if necessary (for example, in the case of temporary shortage or a lack of aphids in mass rearing facilities or in the case of preventing release of C. propinqua adults in greenhouses), C. propinqua larvae can be fed with grain moth eggs by replacing, mixing, or alternating with aphids, although this will inevitably result in a proportional decrease in pre-adult survival, rate of development, weight, and size of the emerging adults. On the other hand, even a minimal addition of aphids can have a substantial positive effect on larvae fed with grain moth eggs. Full article

Long-term storage is an important component of insect mass-rearing systems, prolonging the shelf life of biocontrol agents during a low-demand period or a temporary lack of suitable food. Macrolophus pygmaeus is a predatory heteropteran, mass-reared and widely used for the biological control of arthropod pests in greenhouses. With the aim to determine the optimal conditions and acceptable duration of cold storage, we evaluated the impact of different periods of storage of fed and starved third instar nymphs of M. pygmaeus at different temperatures on nymphal survival, adult emergence, and female fecundity. Four storage temperatures (3, 6, 9, and 12 °C) were tested. The longevity of starved nymphs decreased with an increase in the storage temperature, with a maximum of about 40 days at 3 °C, whereas the longest lifetime of nymphs fed on eggs of the grain moth Sitotroga cerealella (about 150 days) was observed at 9 °C. Further experiments demonstrated that the third instar nymphs of M. pygmaeus fed with eggs of the grain moth can be stored at 9 °C for 30 days, with a moderate (10–20%) decrease in survival and fecundity, whereas the survival of starved nymphs decreased by half after 10 days of storage at 3 °C. Full article