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Abstract Elucidating the intricate interactions between viral pathogens and host cellular machinery during infection is paramount for understanding pathogenic mechanisms and identifying potential therapeutic targets. The RNA modification N 6-methyladenosine (m6A) has emerged as a significant factor influencing the trajectory of viral infections. Hence, the precise and quantitative mapping of m6A modifications in both host and viral RNA is pivotal to understanding its role during viral infection. With the rapid advancement of sequencing technologies, scientists are able to detect m6A modifications with various quantitative, high-resolution, transcriptome approaches. These technological strides have reignited research interest in m6A, underscoring its significance and prompting a deeper investigation into its dynamics during viral infections. This review provides a comprehensive overview of the historical evolution of m6A epitranscriptome sequencing technologies, highlights the latest developments in transcriptome-wide m6A mapping, and emphasizes the innovative technologies for detecting m6A modification. We further discuss the implications of these technologies for future research into the role of m6A in viral infections. Graphical Abstract

Red imported fire ant (Solenopsis invicta Buren) is a severe and highly destructive invasive species. It has invaded mainland China since 2004. Understanding the foraging behavior patterns of workers in different habitats and conditions can help to develop scientific prevention and control measures. In this study, we used bait traps to measure the foraging activity of workers in newly established fire ant nests in various habitats and time periods. The results showed that the presence or absence of vegetation cover was an important factor affecting the foraging activity of fire ant workers. In bare land habitats, the foraging range and number of fire ant workers were significantly different from those in habitats with vegetation cover. The analysis of the daily average activity patterns of fire ants showed that the number of workers in sweet potato fields showed a bimodal pattern. In contrast, those in bare land and sugarcane fields showed an unimodal pattern, and those in pineapple fields showed a fluctuating pattern. It is worth noting that the bimodal and unimodal peaks in sweet potato, bare land, and sugarcane fields all occurred at 10:00 and 16:00. Therefore, in natural environments, vegetation cover, and temperature are important factors affecting the foraging activity of fire ants.

The red imported fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) is native to South America; however, its introduction to other countries has caused serious biodiversity, agricultural, and public health problems. As toxic bait is an effective method to control fire ant populations, the aim of this study was to determine the most effective concentration of sulfoxaflor, flupyradifurone, and triflumezopyrim as ingredients for baits against S. invicta under laboratory and field conditions. Sulfoxaflor, flupyradifurone, and triflumezopyrim had no effect on the feeding behavior of the fire ants. However, they significantly reduced the climbing, walking, and arrest abilities of the fire ant workers after 10 days of treatment, and insecticides were horizontally transferred from workers to alates or larvae. Specifically, sulfoxaflor and triflumezopyrim at 0.05% concentration were the most effective in exterminating fire ants. Sulfoxaflor and triflumezopyrim are nonrepellent and effective insecticides against S. invicta.

Bactrocera dorsalis is a highly invasive and destructive pest distributed worldwide. Chemical insecticides remain the primary measure for their control; however, this species has already developed resistance to several insecticides. In recent years, there have been several reports of monitoring B. dorsalis resistance in China, but continuous monitoring results are lacking and do not even span a decade. In this study, we monitored the dynamics of resistance to seven insecticides among 11 geographically distinct Chinese populations of B. dorsalis (2010–2013; follow-up in 2023). The 11 populations were found to adapt rapidly to antibiotic insecticides (spinosad, emamectin benzoate, and avermectin), reaching high levels of insecticide resistance in several areas. Overall, a decreasing trend in resistance to organophosphorus insecticides (chlorpyrifos and trichlorfon) was observed, whereas pyrethroid (beta-cypermethrin and cyhalothrin) resistance trends were observed to both increase and decrease. The monitoring of field resistance among different B. dorsalis populations over the duration of this study is important for improving the efficiency and sustainability of agricultural pest management, and the results provide a scientific basis for the development of more effective resistance management strategies.

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) is a global economic pest that poses a serious threat to the fruit industry. In the southwest of China, Yunnan Province sustains a severe infestation of B. dorsalis. An automated monitoring system designed for B. dorsalis was employed in this study to elucidate the annual population dynamics of B. dorsalis in four counties: Yuanjiang, Huaping, Guangnan, and Ludian in Yunnan. The system utilizes sex parapheromone and image recognition technology. The data uploaded by the device are used to analyze the annual population dynamics of B. dorsalis in different regions. The results showed that the populations of adult B. dorsalis in all four counties peaked twice annually, with Yuanjiang experiencing the earliest peak periods, followed by Huaping, Guangnan, and Ludian. Adult B. dorsalis occurred in Yuanjiang throughout the year, and Yuanjiang had the highest number of B. dorsalis monitored. In Huaping, adult B. dorsalis occurred in March–December and was highly active, with a high population density in 2019. Bactrocera dorsalis did not occur in December in Guangnan but only in May–October in Ludian. Bactrocera dorsalis abundance was correlated with temperature in all four areas. The outcomes of this experiment provide a practical foundation for developing control strategies targeting B. dorsalis in various orchards across each county.

Diptera and Lepidoptera species have the highest levels of insecticide resistance, and the mechanism of drug resistance has been studied in detoxification metabolism genes such as P450, GST, EST, and ABC. Since Bactrocera dorsalis are resistant to a variety of chemicals, the pattern and mechanism of resistance in Bactrocera dorsalis have been investigated from a variety of aspects such as detoxification metabolism genes, detoxification enzymes, intestinal symbiotic bacteria, and synergists in the world. In this study, 51 species and 149 detoxification metabolism genes were annotated in the Suppression Subtractive Hybridization (SSH) library, and 12 candidate genes related to beta-cypermethrin resistance were screened and quantitatively expressed in this library. Two genes were found to be upregulated in the egg stage, three genes in the larval stage, one gene in the pupal stage, and five genes in the adult stage, and four genes were found to be upregulated in the midgut and the malacca ducts in the midgut. The expression of cyp6g1, cyp6a22, GST-Epsilon9, and Trypsin-4 genes was upregulated in resistant strains, with the most obvious upregulation occurring in the midgut and the Malpighian tubules. These results provide new insights into the study of pesticide resistance in quarantine insects.

How alien pests invade new areas has always been a hot topic in invasion biology. The spread of the Bactrocera dorsalis from southern to northern China involved changes in food sources. In this paper, in controlled conditions, we take Bactrocera dorsalis as an example to study how plant host transformation affects gut bacteria by feeding it its favorite host oranges in the south, its favorite host peaches and apples in the north, and feeding it cucumbers as a non-favorite host plant, thereby further affecting their fitness during invasion. The result showed that, after three generations of feeding on cucumbers, Bactrocera dorsalis took longer to develop as a larva while its longevity and fecundity decreased and pre-adult mortality increased. Feeding it cucumbers significantly reduced the overall diversity of gut microbiota of Bactrocera dorsalis. The relative abundance of Enterobacter necessary for survival decreased, while the Empedobacter and Enterococcus increased, resulting in decreased carbohydrate transport and metabolism and increased lipid transport and metabolism. Feeding Bactrocera dorsalis Empedobacter brevis and Enterococcus faecalis resulted in a 26% increase in pre-adult mortality and a 2–3 d increase in adult preoviposition period (APOP). Additionally, Enterococcus faecalis decreased the longevity of female and male adults by 17 and 12 d, respectively, and decreased fecundity by 11%. We inferred that the shifted plant hosts played an important role in posing serious harm to Bactrocera dorsalis invading from the south to the north. Therefore, after an invasion of Bactrocera dorsalis into northern China, it is difficult to colonize cucumbers for a long time, but there is still a risk of short-term harm. The findings of this study have established that the interactions between an insect’s food source and gut bacteria may have an important effect on insect invasions.

Fruit flies cause substantial economic damage, and their management relies primarily on chemical insecticides. However, pesticide resistance has been reported in several fruit fly species, the mitigation of which is crucial to enhancing fruit fly control. Here, we assess the toxicity of a novel insecticide (fluralaner) and a common insecticide (dinotefuran) against three fruit fly species, Bactrocera dorsalis (Hendel), Bactrocera cucurbitae (Coquillett), and Bactrocera tau (Walker). Both pesticides exhibit robust lethal and sublethal effects against all three fruit fly species, with fluralaner being more potent. Fluralaner and dinotefuran suppress the reproductive capacities and survival rates of fruit flies. However, at the 50% lethal concentration, fluralaner stimulates the reproductive capacity of B. dorsalis and the survival rate of B. tau. Fluralaner also causes significant transgenerational effects, impacting the offspring hatching rate of B. cucurbitae and B. tau and reducing the proportion of female offspring. Thus, both pesticides exhibit high potential for controlling fruit flies. However, their application should be tailored according to species variations and the diverse effects they may induce. Collectively, the findings of this study outline the sublethal effects of two insecticides against fruit flies, helping to optimize their application to ensure the effective management of insecticide resistance.

Bactrocera dorsalis (Hendel) (B. dorsalis) is an important agricultural invasive pest that causes significant economic losses in tropical and subtropical fruit and vegetable crops. In this study, the proteins related to the sense of smell and taste of B. dorsalis, such as OBP, PBP, OR, IR, SNMP and CSP, were screened based on B. dorsalis transcriptome data. By integrating the compounds that were reported to be attractive to B. dorsalis, similar compounds of hydrocarbon compounds were obtained. Molecular docking was used to predict the binding between the similar compounds and the OBP, PBP, OR, IR, SNMP and CSP proteins. Network pharmacology was used to screen the potentially attractive compounds, and ecological experiments with B. dorsalis were finally conducted to verify the effect of these potentially attractive compounds on B. dorsalis. The results showed that the G protein-coupled receptor [BR: KO04030] and ion channel [BR: KO04040] pathways were closely related to the odor tropism of B. dorsalis. A total of 84 compounds, such as mitemcinal, exemestane and midecamycin, have potential binding effects on the B. dorsalis odor receptor proteins. The results of the ecological experiments showed that 1 mg/mL and 0.1 mg/mL 19-norandrostenedione, 1 mg/mL progesterone compounds was significantly attractive to B. dorsalis males, while 0.1 mg/mL exemestane was significantly attractive to B. dorsalis females. In this study, network pharmacology technology was used to discover the potential attractive compounds for B. dorsalis, which is important for the development and subsequent prevention and control of B. dorsalis. It can provide a reference in improving the success rates of clinical trials of new pest control products and in reducing the time and cost of drug development.

Insect gut microbial communities are recognized as important factors facilitating insect adaptation to host plant defenses. However, the impact of co-evolution with host plants on insects' reliance on their gut bacterial communities remains poorly understood. In this study, we first showed a decrease in fitness for Bactrocera dorsalis, Zeugodacus cucurbitae, Zeugodacus tau, and Bactrocera correcta after eliminating their gut microbes, but only when they were fed on nonpreferred hosts; no significant fitness changes were observed on preferred hosts. Furthermore, after a simulated adaptation period with bitter melon feeding, Z. cucurbitae larvae, whether axenic, symbiotic, or gnotobiotic, exhibited comparable fitness levels. In contrast, axenic larvae of B. dorsalis continued to display reduced fitness compared to their symbiotic and gnotobiotic counterparts. Our findings also revealed that bacterial removal altered gene expression patterns in B. dorsalis, indicating deficiencies in nutrient acquisition, assimilation, immunity, and detoxification processes, whereas these changes were less pronounced in Z. cucurbitae. Additionally, our experiments demonstrated that, unlike Z. cucurbitae, B. dorsalis relies on its intestinal flora to significantly detoxify bitter melon toxins. These results suggest that Z. cucurbitae may have developed microbe-independent strategies, such as genetically encoded detoxification or tolerance mechanisms, to cope with toxic host challenges. [ABSTRACT FROM AUTHOR]

Viral infections in insects often manifest in covert, nonlethal ways, presenting a significant challenge in understanding and quantifying their impact. These covert effects, while not immediately apparent, play a crucial role in the intricate web of virus-host interactions. Addressing this challenge, metabolomics has emerged as a key tool, revealing the unseen but critical aspects of these interactions. This review delves into the untapped potential of metabolomics-based approaches in studying insect virus infections, a field that has remained largely overlooked. We highlight how metabolomics has enabled researchers to detect and analyze dynamic changes in host metabolism triggered by viral infections. These insights have substantially enhanced our understanding of the complex dynamics of virus-host interactions in insects, highlighting the transformative power of metabolomics in this realm. We also discuss the challenges and future prospects in this field, including the integration of multi-omics approaches, the creation of insect-specific metabolite databases, and the emerging field of insect immunometabolism. Overall, this review underscores the paramount importance of metabolomics in unveiling the subtle yet significant effects of virus infections in insects, calling for greater exploration and recognition in this essential research domain. [ABSTRACT FROM AUTHOR]

Abstract Large-scale marine heatwaves in the Northeast Pacific (NEP), identified here and previously as ‘warm blobs’, have devastating impacts on regional ecosystems. An anomalous atmospheric ridge over the NEP is known to be crucial for maintaining these warm blobs, also causing abnormally cold temperatures over North America during the cold season. Previous studies linked this ridge to teleconnections from tropical sea surface temperature anomalies. However, it was unclear whether teleconnections from the extratropics could also contribute to the ridge. Here we show that planetary wave trains, triggered by increased rainfall and latent heat release over the Mediterranean Sea accompanied by decreased rainfall over the North Atlantic, can transport wave energy to the NEP, guided by the westerly jet, and induce a quasi-barotropic ridge there. Our findings provide insights into extratropical teleconnections sustaining the NEP ridge, offering a source of potential predictability for the warm blobs and temperature fluctuations over North America.