Search Results (910)

The tolerance of the fall armyworm (Spodoptera frugiperda) to plant-derived secondary compounds gradually increases with instars. Therefore, even if plant-based additives are applied at early stages, such as the second or third instar, they may have a differential impact on the ecofriendly control of S. frugiperda. In this study, S. frugiperda larvae were exposed to vanillic acid or sinapic acid at the second and third instar, and physiological and growth parameters were measured. The results showed that the effects of vanillic acid treatment on S. frugiperda were similar at the different instars. They can significantly affect the larval carboxylesterase, glutathione S-transferase, and mixed-function oxidase activities. By reducing larval food intake, food conversion, and utilization efficiency while increasing the food consumption rate, it inhibits weight accumulation. This leads to a significant extension of the development of both the larval and pupal stages, and the adult longevity was reduced. Treatment with sinapic acid at the second instar extended the negative effects on the pupal duration of S. frugiperda when compared to treatment at the third instar, but did not affect adult longevity. Therefore, vanillic acid treatment at the second or third instar stage, can play an important role in the ecofriendly control process of S. frugiperda. The results of this study are of great significance for integrated pest management. Full article

Pardosa pseudoannulata plays an important role in the biological control of insect pests. The inclusion of yeast in the culture medium is very important for the growth, development, and reproduction of Drosophila melanogaster, but there have been few studies on the influence of nutrients in the culture medium on spider development. In order to explore the effects of different yeast treatments on the growth and development of D. melanogaster and as a predator, P.  pseudoannulata, three treatments (no yeast, active yeast added, and inactivated yeast added) were adopted to modify the conventional D. melanogaster culture medium. The addition of yeast to the medium shortened the development time from larva to pupation in D. melanogaster. The emergence and larval developmental times of D. melanogaster reared with activated yeast were shorter than those of the group without yeast addition, which promoted D. melanogaster emergence and increased body weight. The addition of yeast to the medium increased the fat, protein, and glucose content in D. melanogaster. The addition of activated yeast shortened the developmental time of P.  pseudoannulata at the second instar stage but had no effect on other instars. Different yeast treat-ments in the medium had no effect on the body length or body weight of P.  pseudoannulata. Adding yeast to D. melanogaster culture medium can increase the total fat content in P.  pseudoannulata, but it has no effect on glucose and total protein in P.  pseudoannulata. Our study shows the importance of yeast to the growth and development of fruit flies. Full article

Cadmium (Cd) is a highly toxic heavy metal that disrupts development and reproduction, primarily through oxidative stress. In this context, sulforaphane (SFN), an antioxidant compound, may serve as a promising agent to counteract Cd-induced oxidative damage and prevent developmental and reproductive abnormalities. This study aimed to evaluate the effect of SFN on reproductive toxicity induced by cadmium chloride (CdCl₂) in the nematode Caenorhabditis elegans (C. elegans). Five experimental groups were established: (I) Control: no treatment, (II) dimethyl sulfoxide (DMSO): 48 h with 0.01% DMSO, (III) CdCl₂: 24 h with 4600 µM CdCl₂, (IV) SFN + CdCl₂: 24 h with 100 µM SFN followed by 24 h with both SFN and CdCl₂, and (V) SFN: 48 h with 100 µM SFN. Co-exposure to SFN and CdCl₂ prevented the reduction in the percentage of adult nematodes and increased egg-laying. It also significantly improved hatching rates, allowing more embryos to reach the larval stage, and prevented reductions in body size. However, no effects were observed on glutathione S-transferase-4 (GST-4) levels in the transgenic CL2166 strain. In conclusion, SFN substantially prevents Cd-induced reproductive toxicity in C. elegans. Future studies should investigate the molecular mechanisms by which SFN enhances egg-laying and offspring viability in this model. Full article

Amphibians are the most threatened vertebrates, yet their resilience in relation to growth and locomotor performance with rising temperatures remains poorly understood. Here, we chose a critically endangered amphibian—the Chinhai spiny newt (Echinotriton chinhaiensis)—as the study species and set four water temperature gradients (20 °C, 24 °C, 28 °C, and 32 °C) to simulate climate changes. The thermal performance to climate warming was quantified by measuring morphometric parameters, basal metabolic rate (oxygen consumption rate), and the locomotor performance of Chinhai spiny newt larvae. We found that the optimal temperature range for Chinhai spiny newt larvae is 24–28 °C. Within the temperature range of 24–28 °C, the growth, oxygen consumption rate, and locomotor performance of the larvae were positively correlated with temperature. High temperatures inhibited larval growth, oxygen consumption rate, and locomotor performance, and the temperature threshold was 32 °C. In addition, Chinhai spiny newt larvae are more sensitive to acute temperature changes, meaning that climate-driven extreme events (e.g., heatwaves and droughts) pose significant threats to their larvae. The optimal temperature range obtained from this study could guide artificial breeding and early warming; future studies should integrate controlled temperature fluctuations in order to understand the thermal adaption of this threatened species. Full article

This study investigates the potential of entomopathogenic nematodes (EPNs) as biological control agents by exploring their occurrence and diversity in Amazcala, Querétaro. The aim was to characterise their distribution and evaluate their pathogenicity against insect pests. Soil samples were collected from various agricultural lands, followed by laboratory isolation and the molecular identification of EPN species. Morphological and genetic analyses confirmed the presence of several species with distinct pathogenic profiles. Pathogenicity assays using the larval stages of Galleria mellonella and Tenebrio molitor revealed that Heterorhabditis bacteriophora and Heterorhabditis atacamensis exhibited significant virulence, with Galleria mellonella being more susceptible. Among the 12 recovered EPN isolates, three strains—AMZX05 (Heterorhabditis atacamensis), AMZX10 (Heterorhabditis bacteriophora), and AMZX13 (Heterorhabditis atacamensis)—demonstrated particularly high pathogenic potential. These strains represent promising candidates for biological control and could contribute to sustainable integrated pest management (IPM) strategies. Further research is recommended to optimise their application across diverse agroecosystems. Full article

Recent advances in microbiome studies have deepened our understanding of endosymbionts and gut-associated microbiota in host biology. Of those, lepidopteran systems in particular harbor a complex and diverse microbiome with various microbial taxa that are stable and transmitted between larval and adult stages, and others that are transient and context-dependent. We highlight key microorganisms—including Bacillus, Lactobacillus, Escherichia coli, Pseudomonas, Rhizobium, Fusarium, Aspergillus, Saccharomyces, Bifidobacterium, and Wolbachia—that play critical roles in microbial ecology, biotechnology, and microbiome studies. The fitness implications of these microbial communities can be variable; some microbes improve host performance, while others neither positively nor negatively impact host fitness, or their impact is undetectable. This review examines the central position played by the gut microbiota in interactions of insects with plants, highlighting the functions of the microbiota in the manipulation of the behavior of herbivorous pests, modulating plant physiology, and regulating higher trophic levels in natural food webs. It also bridges microbiome ecology and applied pest management, emphasizing S. frugiperda as a model for symbiont-based intervention. As gut microbiota are central to the life history of herbivorous pests, we consider how these interactions can be exploited to drive the development of new, environmentally sound biocontrol strategies. Novel biotechnological strategies, including symbiont-based RNA interference (RNAi) and paratransgenesis, represent promising but still immature technologies with major obstacles to overcome in their practical application. However, microbiota-mediated pest control is an attractive strategy to move towards sustainable agriculture. Significantly, the gut microbiota of S. frugiperda is essential for S. frugiperda to adapt to a wide spectrum of host plants and different ecological niches. Studies have revealed that the microbiome of S. frugiperda has a close positive relationship with the fitness and susceptibility to entomopathogenic fungi; therefore, targeting the S. frugiperda microbiome may have good potential for innovative biocontrol strategies in the future. Full article

Insect metamorphosis is a complex developmental process regulated by hormonal signaling and gene transcription. To elucidate its transcriptional regulatory mechanisms, we examined chromatin accessibility dynamics during metamorphosis in two holometabolous insects, Harmonia axyridis and Drosophila melanogaster, using ATAC-seq. Our analysis revealed distinct stage-specific chromatin accessibility patterns, with peak accessibility during the prepupal stage in H. axyridis and the wandering larval to prepupal transition in D. melanogaster. Through analysis of differential accessibility regions (DARs), we identified enrichment of metamorphosis-related processes including cell morphogenesis, tissue remodeling, and hormone signaling pathways via Gene Ontology and KEGG pathway analyses. Integration of chromatin accessibility with gene expression data revealed 608 conserved genes exhibiting coordinated accessibility and expression changes across both species. Additionally, we constructed a regulatory network centered around four key transcription factors (dsx, E93, REPTOR, and Sox14) that form core regulatory modules controlling metamorphosis. This study provides novel insights into the epigenetic landscape of insect metamorphosis and establishes a foundation for understanding the transcriptional regulatory mechanisms governing this critical developmental process. Full article

Carbon nanotubes are promising in agriculture for improving crop resilience and delivering agrochemicals. However, their effects on insect pests, especially chewing pests such as the fall armyworm (Spodoptera frugiperda), remain underexplored. In this study, we investigated how two types of functionalized multi-walled carbon nanotubes—hydroxylated (MWCNTs-OH) and carboxylated (MWCNTs-COOH), both obtained from Jiangsu Xianfeng Nano (Nanjing, China)—affect the pest’s development and reproduction. Using an age-stage two-sex life table approach, we fed larvae diets containing 0.04, 0.4, or 4 mg/g of these nanomaterials. Both types of MWCNTs exhibited concentration-dependent inhibitory effects. At the highest dose (4 mg/g), larval development was significantly prolonged, adult pre-oviposition periods increased, and fecundity (egg production) sharply declined, especially with MWCNTs-OH. Population growth parameters were also suppressed: net reproductive rate (R₀), intrinsic rate of increase (r), and finite rate of increase (λ) were reduced at 4 mg/g, particularly with MWCNTs-OH, while mean generation time (T) was extended with MWCNTs-COOH. Overall, MWCNTs-OH demonstrated a greater inhibitory impact compared to MWCNTs-COOH. These findings suggest that functionalized MWCNTs could serve as potential novel pest control agents against S. frugiperda by impeding its development and reproduction. Full article

Rhipicephalus microplus is an important biological vector as it transmits several pathogens, including Babesia bovis, the causative agent of bovine babesiosis. The available strategies for controlling B. bovis are limited, resulting in substantial challenges for both animal health and livestock management. Infection of the tick midgut is the essential first step for the transmission cycle of B. bovis, yet this process remains largely unexamined. To better understand the first step of tick infection, this study employed a proteomic approach to identify a midgut protein that responds to B. bovis infection. We then used RNA interference for gene silencing to determine if the protein is essential for R. microplus infection. The protein we identified, Rm24, is twofold upregulated in the tick midgut during B. bovis infection. We silenced the gene encoding Rm24 and examined the effect of reduced expression on both tick fitness and B. bovis infection. Our results indicated that silencing the Rm24 gene impacted the survivability of adult female ticks, which exhibited a significant reduction in viability as compared to the control and non-injected groups. Importantly, we found that suppressing the gene encoding Rm24 led to a significant decrease in the number of engorged female ticks infected, with only 15% of female ticks testing positive for B. bovis kinetes as compared to over 50% in the control groups. We also detected a significant reduction in vertical transmission of B. bovis to larval progenies. These findings suggest that the Rm24 protein is critical for infection by B. bovis and could serve as a promising target for future transmission-blocking strategies. Full article

Entomopathogenic fungi (EPF) are substantial biocontrol agents reducing the populations of economically important pests in numerous crops. Recent findings indicate that their role in agroecosystems is more complex and extends to affecting plant physiology and growth. This study examined the effects of Beauveria bassiana and Isaria fumosorosea, as well as Salicylic acid (SA), on physiological parameters of grapevine (Vitis vinifera cv. Sauvignon Blanc). Additionally, the impact of SA on spore germination and pathogenicity of EPF against larvae of the European grapevine moth (Lobesia botrana) was tested. Foliar application of EPF was found to increase the electron transport rate (ETR) from PSII to PSI, indicating higher photosynthetic activity compared to control plants. EPF also elevated the transpiration rate (E) and stomatal conductance (gs). In contrast, SA treatments decreased E and gs, while the high dose (10 mM) exhibited reduced Fv/Fm value, accompanied by phytotoxic spots on leaves. Spore germination of both fungi was significantly reduced only by the SA concentration of 2 mM, while 0.5 and 1 mM did not affect germination. Combination EPF and SA treatments presented the highest larval mortality of L. botrana (87.5% at 28 °C and 77.5% at 24 °C for B. bassiana and I. fumosorosea, respectively). However, SA reduced larval mycosis in most cases. Overall, the results suggest that EPF and SA can be co-applied and included in vineyard integrated strategies to support grapevine health. Full article

The efficacy of two selected Metarhizium rileyi Mexican isolates (T9-21 and L8-22) against Spodoptera frugiperda was evaluated under greenhouse conditions. To this end, a suspension (1 × 10⁸ conidia/mL) of these isolates was sprayed on maize plants previously infested with six second-instar larvae. No significant differences were observed between the survival curves of the T9-21 and L8-22 isolates. Cadaver sporulation was significantly higher, and the lethal time was significantly lower with the T9-21 isolate compared with those of the L8-22 isolate (97% and 8 days vs. 70% and 10 days, respectively). Based on these results, a small-scale field trial on maize was performed to evaluate the degree of pest control achieved by the T9-21 isolate and compare it with the insecticide spinetoram, applied at a rate of 1 × 10¹³ conidia/ha and 75 mL/ha, respectively. No significant differences were observed in the proportion of larval mortality between the T9-21 isolate (0.49) and spinetoram (0.72). However, spinetoram significantly reduced natural enemies and phytophagous insect populations compared with the fungus and the control. In conclusion, M. rileyi T9-21 isolate could be a promising alternative for the control of S. frugiperda larvae. Full article

Sclerodermus sichuanensis, a parasitic wasp, plays a significant role in wood-boring forest pest control in China. Research has shown that the photoperiod significantly affects the development and reproduction of parasitic wasps. However, the effects of the photoperiod on S. sichuanensis have not yet been reported. This study investigates the impact of different photoperiods on the developmental duration and reproduction of S. sichuanensis. The wasps were reared under four photoperiod conditions: 0L:24D, 8L:16D, 16L:8D, and 24L:0D. The results show that increased light duration shortened the egg, larval, and pupal stages, with the total developmental period decreasing by up to 17 days. The number of offspring was highest in the 8L:16D and 16L:8D treatments, while constant light (24L:0D) led to a significant decrease in offspring numbers. The parasitism rate and pre-oviposition period were also affected by light exposure, with the longest pre-oviposition period observed in complete darkness. These findings indicate that the photoperiod plays a crucial role in regulating the development and reproductive efficiency of S. sichuanensis, suggesting that appropriate light conditions could enhance the efficiency of its use in pest control. Full article

Microplastics are pervasive in marine ecosystems and have been shown to affect a range of marine organisms, including corals. These particles can develop biofilms, facilitating the transport of pollutants and pathogenic microorganisms. Although the effects of primary microplastics on adult corals have been extensively studied, little is known about the impacts of secondary microplastics on early life stages. This study investigated (1) the effects of different abundances of secondary microplastics on the early development of Orbicella faveolata; (2) the influence of fibers and fragments on the larval settlement of Acropora palmata; and (3) the effects of the microplastic size, abundance, and biofilm presence on the settlement of Favia fragum. For O. faveolata, fertilization, embryogenesis, and settlement were all impaired by fragments, with embryonic development showing a 25.9% reduction in viability. Larval development was unaffected, but post-settlement survival declined by 35.8% with exposure to fibers and fragments. For A. palmata, settlement was reduced by fragments, while for F. fragum, only 2–4 mm fragments significantly decreased settlement rates. This study contributes to the knowledge of the effect of microplastics on the early development of corals, providing valuable information to improve strategies to control microplastic pollution. Full article

Current feeding protocols used in commercial hatcheries of Mediterranean fish species are, for a species-dependent period after hatching, based on live feeds which have often raised issues of biosecurity, stability, availability, price and nutrients content. Instead, dry feeds can offer stability in nutritional value, price and supply. The aim of the present study was to evaluate an alternative feeding protocol by co-feeding live and dry feed at first feeding red seabream larvae (on 3 days post-hatching—3 dph, DF3) and to compare it to a standard feeding protocol (i.e., dry feed introduced on 22 dph, DF22). Larvae productivity and functional development of the digestive system were evaluated under actual production conditions in a commercial hatchery. Additionally, post-larvae efficiency during pre-growing was evaluated under controlled laboratory conditions. The results obtained showed that the experimental protocol (DF3) promoted larval growth without affecting larval survival and the efficiency of the digestion processes. After pre-growing, DF3-produced juveniles showed a decreased incidence of spinal cord malformations, while the initially gained growth advantage was maintained. The present study shows the feasibility of an alternative feeding protocol for red seabream intensive larviculture and points out the critical role that larval rearing may have for later production stages. Full article

Background: Parasitic worm infections remain among the most prevalent and neglected health issues worldwide, affecting both humans and animals. Toxocariasis, caused by Toxocara spp., is a widespread zoonosis with significant public health and economic implications. Current anthelmintic treatments show limited efficacy, particularly against tissue-migrating larvae, underscoring the urgent need for new therapeutic options. This study aimed to evaluate the anthelmintic potential of H₁ antihistamines as repurposed drug candidates against Toxocara canis. Methods: Twenty-two H₁ antihistamines were screened for larvicidal activity against infective third-stage (L3) larvae of T. canis. Larval motility and morphology were assessed, and compounds with the highest efficacy were further investigated using density functional theory (DFT) to explore their electronic properties. Molecular docking simulations were also performed to predict interactions with T. canis β-tubulin. Results: Promethazine and rupatadine exhibited significant larvicidal effects, surpassing albendazole in reducing larval motility and inducing a distinct contorted morphology not observed in control or albendazole-treated larvae. DFT analyses suggested a strong electron-acceptor capacity, indicating a potential redox-based mechanism of action. Docking studies revealed favorable binding to the colchicine site of T. canis β-tubulin. Conclusions: This is the first report of larvicidal activity of antihistamines against T. canis, supporting their potential as repurposed therapeutic agents for the treatment of zoonotic helminthiases, particularly those caused by tissue-migrating nematodes. Full article