Scutellaria baicalensis Pith-decayed Root Inhibits Macrophage-related Inflammation Through the NF-κB/NLRP3 Pathway to Alleviate LPS-induced Acute Lung Injury.

Acute lung injury (ALI) is one of the representative "lung heat syndromes" in traditional Chinese medicine (TCM). Scutellaria baicalensis is an herbal medicine used in TCM for treating lung diseases, due to its remarkable anti-inflammatory and antiviral effects. When used in TCM, S. baicalensis root is divided into two categories: S. baicalensis pith-not-decayed root (SN) and S. baicalensis pith-decayed root (SD). Compared to SN, SD has a better effect on lung diseases. We constructed a lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model to study the pharmacodynamic mechanism of SD. The ethanolic extract of Scutellaria baicalensis pith-decayed root (EESD) significantly affected LPS-induced ALI by reducing alveolar interstitial thickening, pulmonary edema, and other pathological symptoms, decreasing the infiltration of inflammatory cells, especially macrophages, and inhibiting IL-1ß, TNF-α, and IL-6 transcription and translation. Furthermore, in the THP-1 macrophage model induced by LPS, EESD inhibited the expression of phosphorylated nuclear factor inhibitory protein alpha (p-IκBα), phosphorylated nuclear factor-κB P65 (p-p65), cleaved-caspase-1, cleaved-IL-1ß protein, and the release of inflammatory factors in the NF-κB/NLRP3 pathway, inhibiting macrophage function. In vivo experiments yielded similar results. Therefore, the present study clarified the potential of EESD in the treatment of ALI and revealed its potential pharmacodynamic mechanism by inhibiting the NF-κB/NLRP3 inflammasome pathway and suppressing the pro-inflammatory phenotype activation of lung tissue macrophages.

Rapid response of midgut bacteria in Bactrocera tau (Walker) (Diptera: Tephritidae) to lambda-cyhalothrin- and spinosad-induced stress.

In recent decades, the increasingly widespread application of chemical pesticides has exacerbated the emergence of insecticide resistance among insect pests. In this study, we examined the rapid response of bacteria in the midgut of the fruit fly Bactrocera tau (Walker) (Diptera: Tephritidae) to stress induced by the insecticides lambda-cyhalothrin and spinosad by analyzing the bacterial community structure and diversity in the midguts of 4-day-old B. tau. The results revealed that 4-day-old B. tau females were more resistant to lambda-cyhalothrin and spinosad than their 4-day-old male counterparts. Alpha- and beta-diversity analyses revealed no significant differences between male and female B. tau with respect to the diversity and richness of gut bacteria in response to the same treatments. In response to treatment with lambda-cyhalothrin and spinosad at lethal concentration 50 (LC50), we detected significant changes in the structure and diversity of the bacterial community in the midguts of both male and female B. tau. Particularly among the dominant bacterial genera, there were decreases in the relative abundances of Citrobacter, Enterobacter, Klebsiella, and Pectobacterium. Increases were observed in the relative abundances of Dysgonomonas, Erwinia, and Providencia. Our findings provide a theoretical basis for gaining a better understanding of the relationships between midgut bacteria and the insecticide resistance of B. tau.

HDAC1: An Essential and Conserved Member of the Diverse Zn2+-Dependent HDAC Family Driven by Divergent Selection Pressure.

Zn2+-dependent histone deacetylases (HDACs) are enzymes that regulate gene expression by removing acetyl groups from histone proteins. These enzymes are essential in all living systems, playing key roles in cancer treatment and as potential pesticide targets. Previous phylogenetic analyses of HDAC in certain species have been published. However, their classification and evolutionary origins across biological kingdoms remain unclear, which limits our understanding of them. In this study, we collected the HDAC sequences from 1451 organisms and performed analyses. The HDACs are found to diverge into three classes and seven subclasses under divergent selection pressure. Most subclasses show species specificity, indicating that HDACs have evolved with high plasticity and diversification to adapt to different environmental conditions in different species. In contrast, HDAC1 and HDAC3, belonging to the oldest class, are conserved and crucial in major kingdoms of life, especially HDAC1. These findings lay the groundwork for the future application of HDACs.

Atractylenolide III Ameliorates Bile Duct Ligation-Induced Liver Fibrosis by Inhibiting the PI3K/AKT Pathway and Regulating Glutamine Metabolism.

Liver fibrosis is one of the leading causes of hepatic sclerosis and hepatocellular carcinoma worldwide. However, the complex pathophysiological mechanisms of liver fibrosis are unknown, and no specific drugs are available to treat liver fibrosis. Atractylenolide III (ATL III) is a natural compound isolated from the plant Atractylodes lancea (Thunb.) DC. that possesses antioxidant properties and the ability to inhibit inflammatory responses. In this study, cholestatic hepatic fibrosis was induced in mice using a bile duct ligation (BDL) model and treated with 10 mg/kg and 50 mg/kg of ATL III via gavage for 14 days. ATL III significantly reduced the liver index, lowered serum ALT and AST levels, and reduced liver injury in bile-duct-ligated mice. In addition, ATL III significantly attenuated histopathological changes and reduced collagen deposition. ATL III reduced the expression of fibrosis-related genes α-smooth muscle actin (α-SMA), Collagen I (col1a1), Collagen IV (col4a2), and fibrosis-related proteins α-SMA and col1a1 in liver tissue. Using RNA sequencing (RNA-seq) to screen molecular targets and pathways, ATL III was found to affect the PI3K/AKT singling pathway by inhibiting the phosphorylation of PI3K and AKT, thereby ameliorating BDL-induced liver fibrosis. Gas chromatography-mass spectrometry (GC-MS) was used to evaluate the effect of ATL III on liver metabolites in BDL mice. ATL III further affected glutamine metabolism by down-regulating the activity of glutamine (GLS1) and glutamine metabolism. ATL III further affected glutamine metabolism by down-regulating the activity of glutaminase (GLS1), as well as glutamine metabolism. Therefore, we conclude that ATL III attenuates liver fibrosis by inhibiting the PI3K/AKT pathway and glutamine metabolism, suggesting that ATL III is a potential drug candidate for treating liver fibrosis.

Protective Effects of Atractylodis lancea Rhizoma on Lipopolysaccharide-Induced Acute Lung Injury via TLR4/NF-κB and Keap1/Nrf2 Signaling Pathways In Vitro and In Vivo.

Acute lung injury (ALI) is a syndrome caused by an excessive inflammatory response characterized by intractable hypoxemia both inside and outside the lung, for which effective therapeutic drugs are lacking. Atractylodis rhizoma, a traditional Chinese medicine, has excellent anti-inflammatory and antiviral properties in addition to protecting the integrity of the cellular barrier. However, few studies of Atractylodis rhizoma for the treatment of ALI have been published, and its mechanism of action remains unclear. In the present study, the chemical composition of the ethanolic extract of Atractylodis rhizoma (EEAR) was initially clarified by high performance liquid chromatography (HPLC), after which it was studied in vivo using a lipopolysaccharide (LPS)-induced ALI rat model. Treatment with EEAR significantly reduced the lung wet/dry (W/D) ratio, neutrophil infiltration, and malondialdehyde (MDA) and myeloperoxidase (MPO) formation, and enhanced superoxide dismutase (SOD) and glutathione (GSH) depletion in rats with ALI, thereby improving lung barrier function and effectively reducing lung injury. In addition, EEAR significantly reduced histopathological changes, decreased the expression of inflammatory factors (such as tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1ß), inducible nitric oxide synthase (INOS), and cyclooxygenase-2 (COX-2)), and inhibited the activation of the NF-κB signaling pathway, thus reducing inflammation. In addition, EEAR was found to also reduce oxidative stress in ALI by upregulating the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream proteins heme oxygenase-1 (HO-1) and NADPH quinone acceptor oxidoreductase 1 (NQO-1). EEAR also reduced LPS-induced inflammatory factor expression in THP-1 cells in vitro by inhibition of the NF-κB signaling pathway, and reduced damage from lipopolysaccharide (LPS)-induced oxidative stress in THP-1 cells by promoting the expression of Nrf2 and its downstream targets HO-1 and NQO-1, the molecular mechanism of which was consistent with in vivo observations. Therefore, we conclude that EEAR attenuates oxidative stress and inflammatory responses via TLR4/NF-κB and Keap1/Nrf2 signaling pathways to alleviate LPS-induced ALI, suggesting that Atractylodis rhizoma is a potential drug candidate for the treatment of ALI.

Larger males facilitate population expansion in Ophraella communa.

One of the most intriguing concepts in animal ecology is the reproductive advantages offered by larger body size, and the females prefer to mate with larger males to gain reproductive advantage. Currently, it is not clear how females recognize signs of male 'quality' and what mechanisms are involved in producing offspring with direct or indirect benefits. Our study aims to assess the preferences of females for males in Ophraella communa, determine the reproductive benefits and reveal the underlying mechanism behind this advantage. We demonstrate that male body size is an important determinant in the evolutionary process of O. communa, affecting female mate choice. Moreover, our study establishes that females prefer males with a larger body size, and this could further improve the developmental and reproductive fitness of their offspring. Finally, we focus on the seminal fluid proteins (SFPs) in O. communa, determine differentially expressed genes (i.e. OcACE, OcCBP and OcSFP) by analysing their proteomes and transcriptomes, and define the role of these SFPs-related genes through RNAi. Our study proved that the reproductive benefit of large males may be regulated by biased expression of crucial SFPs genes. The present study advances our understanding of the biological significance of preferential mating.

Olfactory co-receptor is involved in host recognition and oviposition in Ophraella communa (Coleoptera: Chrysomelidae).

Common ragweed (Ambrosia artemisiifolia) is a notorious invasive weed that has spread across most temperate regions of the world. The beetle (Ophraella communa) is considered to be an effective control agent against A. artemisiifolia. As an oligophagous insect, its olfactory system is extremely important for host seeking in the wild. To the best of our knowledge, there is no report on the molecular mechanisms underlying olfaction recognition in this beetle. Hence, in this study, we characterized the odorant receptor co-receptor of O. communa and named it as 'OcomORco'. Real-time quantitative PCR (qRT-PCR) showed that, compared to the control treatment, RNA interference (RNAi) strongly reduced the expression of OcomORco by 89% in male and 90% in female beetles. Electroantennogram assay showed that the antennal response of both male and female beetles to four volatiles of A. artemisiifolia was significantly reduced. The injected male or female beetles lost their preference for plant leaves as observed in the behavioural tests. In addition, disruption of the expression of OcomORco resulted in a reduction of oviposition, while there was no difference in larval hatching rate between control and knockdown females. We demonstrated that OcomORco plays a vital role in olfactory perception and host search in O. communa, and it is involved in oviposition in an indirect way.

Sox genes in Agasicles hygrophila (Coleoptera: Chrysomelidae) are involved in ovarian development and oogenesis.

The alligator weed flea beetle, Agasicles hygrophila is a monophagous natural enemy of the invasive alligator weed Alternanthera philoxeroides. Oogenesis plays a vital role in the process of individual development and population continuation of oviparous insects. Sox is an ancient and ubiquitous metazoan gene family that plays a key regulatory role in various physiological processes, including oogenesis, which is closely related to fecundity. In this study, two Sox genes AhDichaete and AhSox3 were cloned and characterized, and then the expression profiles of AhDichaete and AhSox3 were qualified by a quantitative reverse transcription-polymerase chain reaction. The result showed that these two Sox genes were expressed significantly higher in ovary, especially in the adult developmental stage. Furthermore, the functions of AhDichaete and AhSox3 in A. hygrophila females were studied using RNA interference (RNAi). Fewer offsprings were produced when AhDichaete and AhSox3 RNAi females mated with wild-type males. Moreover, dsAhSox3 injection reduced the hatching rate of eggs but injection with dsAhDichaete did not. Further study of the reproductive system of AhDichaete and AhSox3 RNAi females showed that yolk protein deposition reduction in the ovarioles, then the expression of vitellogenin gene AhVg2 in ovaries was decreased. These results indicate that AhDichaete and AhSox3 play an important regulatory role in the process of ovarian development and oogenesis by affecting yolk synthesis in the ovary of A. hygrophila.

Glucose Utilization in the Regulation of Chitin Synthesis in Brown Planthopper.

Glucose-6-phosphatase (G6Pase) and hexokinase (HK) are two key enzymes in the glycolysis and gluconeogenesis pathways, which catalyze the synthesis and degradation of glucose in insects, respectively. G6Pase and HK play an important role in insect growth by regulating the metabolism of glucose, leading to the efficient metabolism of other macromolecules. However, it is unclear whether these genes could be investigated for pest control through their actions on chitin metabolism. We studied the potential functions of G6Pase and HK genes in the regulation of chitin metabolism pathways by RNAi technology. Interference with G6Pase expression did not affect trehalose and chitin metabolism pathways in brown planthopper, Nilaparvata lugens (Stål). However, knockdown of the HK gene resulted in a significant decrease of expression of genes associated with the trehalose metabolic pathway but had no significant effect on trehalase activity, trehalose content, or glucogen content. Additionally, HK knockdown resulting in downregulation of the genes involved in chitin metabolism in the brown planthopper. These insects also showed wing deformities and difficulty in molting to varying degrees. We suggest that the silencing of HK expression directly inhibited the decomposition of glucose, leading to impaired chitin synthesis.

Deep-Fried Atractylodis Rhizoma Protects against Spleen Deficiency-Induced Diarrhea through Regulating Intestinal Inflammatory Response and Gut Microbiota.

According to the theories of traditional Chinese medicine, spleen deficiency often leads to diarrhea, and deep-fried Atractylodis Rhizoma (DAR) is commonly used for the treatment. However, the association between spleen deficiency and diarrhea remains unclear. The present study aimed to investigate the therapeutic effect of DAR for the treatment of diarrhea caused by spleen deficiency and analyze the related mechanisms. It was found that a high dose group of an ethanolic extract of deep-fried Atractylodis Rhizoma (EEDAR-H) significantly inhibited weight loss, diarrhea, and pathological changes in colon tissue induced by rhubarb. EEDAR-H was found to significantly reduce the level of intestinal inflammatory cytokines and increase the expression of gastrointestinal motility hormones. In addition, EEDAR-H significantly increased the expression of aquaporin 3 (AQP3) and aquaporin 8 (AQP8) and restored abnormal water metabolism; Shen-Ling-Bai-Zhu-San (SLBZS) induced the same effect as EEDAR-H. Additional tests on the mechanism found that EEDAR-H and SLBZS promoted the integrity of the intestinal barrier. Both significantly increased the expression of the tight junction protein ZO-1 and Occludin, inhibited the phosphorylation of p38MAPK and MLC, and significantly reduced the expression levels of PAR-2. Analysis of the gut microbiota indicated that overall changes in its structure were reversed after treatment with EEDAR-H or SLBZS, in addition to significant modulation of the abundance of different phyla. At the genus level, EEDAR-H or SLBZS significantly reduced the levels of potential pathogens and increased those of beneficial bacteria.

[Progress in the study of signal pathways for chronic inflammation-associated pancreatic carcinogenesis].

Pancreatic cancer is one of the most lethal and intractable human malignancies with poor prognosis. Chronic pancreatitis is the independent risk factor for pancreatic cancer. Smoking, obesity and family history are the risk factors for chronic inflammation-associated pancreatic carcinogenesis. Recent studies of signal pathways have made a significant progress in our understanding of chronic pancreatitis in pancreatic cancer. This review summarizes recent development in the important signal pathways involved in pancreatic carcinogenesis from chronic pancreatitis.

New sesquiterpenoids from Ambrosia artemisiifolia L.

A new pseudoguaianolide 1 and two new guaiane-type sesquiterpene glucosides 2 and 3, were isolated from the aerial parts of Ambrosia artemisiifolia L together with two known sesquiterpene dilactones 4 and 5. The new compounds were determined on the basis of spectroscopic and chemical methods to be 3ß-acetoxy-4ß-hydroxy-1α,7α, 10ß,11αH-pseudoguaia-12,8ß-olide (1), 1ß,7ß,9ß,10ß,13αH-guaia-4(5)-en-12,6ß-olide 9-O-ß-d-glucoside (2) and 4ß-hydroxy-1α,5α,7α,9αH-guaia-10(14),11(13)-dien-12-acid 9-O-ß-d-glucoside (3). The isolated compounds were evaluated for cytotoxicity against human promyelocytic leukemia HL-60 cell lines in vitro, but were all inactive.

Male-derived phospholipase A2 enhances WD46 expression and increases fertility in Ophraella communa.

Successful bisexual reproduction requires interactions between males and females. Male-derived seminal fluid proteins (SFPs) transferred to females during mating profoundly affect females from pre- to post-mating, and the subsequent shift in female physiology enhances their fertility. SFPs have important evolutionary implications for the fitness of many insects. However, little is known about how females respond to male SFPs. In this study, we identified a male-derived SFP-phospholipase A2 (PLA2) in Ophraella communa. PLA2 is a vital enzyme in eicosanoid biosynthesis; however, it has not been identified as an insect SFP. We found that OcPLA2 is specifically expressed in males, especially in the male accessory glands (MAGs); it is transferred to the female during mating and functions as an SFP to enhance fertility. The expression of a female-derived gene encoding the WD repeat-containing protein 46 (WD46) was upregulated when OcPLA2 entered the female reproductive tract, and this contributed to female egg production by increasing triacylglycerol lipase (TGL) gene expression and the triglyceride (TG) content. This is the first study to identify PLA2 as an SFP in insects. Our findings also shed light on the regulatory role of OcPLA2 in beetle reproduction; the expression of OcPLA2 is initially correlated with female WD46 expression and later with the decline in TGL gene expression and the TG content. This represents a unique mechanism of reproductive regulation by an SFP.

Polygala tenuifolia willd. Extract alleviates LPS-induced acute lung injury in rats via TLR4/NF-κB pathway and NLRP3 inflammasome suppression.

BACKGROUND: Acute lung injury (ALI) has received considerable attention in the field of critical care as it can lead to high mortality rates. Polygala tenuifolia, a traditional Chinese medicine with strong expectorant properties, can be used to treat pneumonia. Owing to the complexity of its composition, the main active ingredient is not yet known. Thus, there is a need to identify its constituent compounds and mechanism of action in the treatment of ALI using advanced technological means. PURPOSE: We investigated the anti-inflammatory mechanism and constituent compounds with regard to the effect of P. tenuifolia Willd. extract (EPT) in lipopolysaccharide (LPS)-induced ALI in vivo and in vitro. METHODS: The UHPLC-Q-Exactive Orbitrap MS technology was used to investigate the chemical profile of EPT. Network pharmacology was used to predict the targets and pathways of action of EPT in ALI, and molecular docking was used to validate the binding of polygalacic acid to Toll-like receptor (TLR) 4. The main compounds were determined using LC-MS. A rat model of LPS-induced ALI was established, and THP-1 cells were stimulated with LPS and adenosine triphosphate (ATP) to construct an in vitro model. Pathological changes were observed using hematoxylin and eosin staining, Wright-Giemsa staining, and immunohistochemistry. The expression of inflammatory factors (NE, MPO, Ly-6 G, TNF-α, IL-1ß, IL-6, and iNOS) was determined using enzyme-linked immunosorbent assay, real-time fluorescence quantitative polymerase chain reaction, and western blotting. The LPS + ATP-induced inflammation model in THP-1 cells was used to verify the in vivo experimental results. RESULTS: Ninety-nine compounds were identified or tentatively deduced from EPT. Using network pharmacology, we found that TLR4/NF-κB may be a relevant pathway for the prevention and treatment of ALI by EPT. Polygalacic acid in EPT may be a potential active ingredient. EPT could alleviate LPS-induced histopathological lung damage and reduce the wet/dry lung weight ratio in the rat model of ALI. Moreover, EPT decreased the white blood cell and neutrophil counts in the bronchoalveolar lavage fluid and decreased the expression of genes and proteins of relevant inflammatory factors (NE, MPO, Ly-6 G, TNF-α, IL-1ß, IL-6, and iNOS) in lung tissues. It also increased the expression of endothelial-type nitric oxide synthase expression. Western blotting confirmed that EPT may affect TLR4/NF-κB and NLRP3 signaling pathways in vivo. Similar results were obtained in THP-1 cells. CONCLUSION: EPT reduced the release of inflammatory factors by affecting TLR4/NF-κB and NLRP3 signaling pathways, thereby attenuating the inflammatory response of ALI. Polygalacic acid is the likely compounds responsible for these effects.

Chromosome-level genome assembly of an oligophagous leaf beetle Ophraella communa (Coleoptera: Chrysomelidae).

The leaf beetle Ophraella communa LeSage (Coleoptera: Chrysomelidae) is an effective biological control agent of the common ragweed. Here, we assembled a chromosome-level genome of the O. communa by combining Illumina, Nanopore, and Hi-C sequencing technologies. The genome size of the final genome assembly is 733.1 Mb, encompassing 17 chromosomes, with an improved contig N50 of 7.05 Mb compared to the original version. Genome annotation reveals 25,873 protein-coding genes, with functional annotations available for 22,084 genes (85.35%). Non-coding sequence annotation identified 204 rRNAs, 626 tRNAs, and 1791 small RNAs. Repetitive elements occupy 414.41 Mb, constituting 57.76% of the genome. This high-quality genome is fundamental for advancing biological control strategies employing O. communa.

Identification of candidate chemosensory genes in Bactrocera cucurbitae based on antennal transcriptome analysis.

The melon fly, Bactrocera cucurbitae (Coquillett) (Tephritidae: Diptera), is an invasive pest that poses a significant threat to agriculture in Africa and other regions. Flies are known to use their olfactory systems to recognise environmental chemical cues. However, the molecular components of the chemosensory system of B. cucurbitae are poorly characterised. To address this knowledge gap, we have used next-generation sequencing to analyse the antenna transcriptomes of sexually immature B. cucurbitae adults. The results have identified 160 potential chemosensory genes, including 35 odourant-binding proteins (OBPs), one chemosensory protein (CSP), three sensory neuron membrane proteins (SNMPs), 70 odourant receptors (ORs), 30 ionotropic receptors (IRs), and 21 gustatory receptors (GRs). Quantitative real-time polymerase chain reaction quantitative polymerase chain reaction was used to validate the results by assessing the expression profiles of 25 ORs and 15 OBPs. Notably, high expression levels for BcucOBP5/9/10/18/21/23/26 were observed in both the female and male antennae. Furthermore, BcucOROrco/6/7/9/13/15/25/27/28/42/62 exhibited biased expression in the male antennae, whereas BcucOR55 showed biased expression in the female antennae. This comprehensive investigation provides valuable insights into insect olfaction at the molecular level and will, thus, help to facilitate the development of enhanced pest management strategies in the future.

Construction of a Banker Plant System via the Host Switch Trait of a Natural Enemy Aenasius bambawalei.

Understanding the most effective host switch patterns in parasitic wasps, specifically Aenasius bambawalei (AB), is crucial for effectively controlling pests like Penacoccus solenopsis (PSS). This study aims to elucidate AB's ideal host switch pattern and assess its utility in maintaining synchronization between AB and PSS, thereby aiding in PSS control. We examined various host switch patterns and cycles to evaluate their impact on AB's offspring's parasitism rates and fitness in laboratory conditions. Concurrently, we assessed the fitness of both PSS and AB on tomato plants using different banker plant systems to maintain field synchronization. Results indicate that the three-repeat T1 host switch pattern of PSS-Penacoccus solani (PSI)-PSS was the most effective. Additionally, a specific banker plant system, "System B", which provided succulent plants hosting PSI, was optimal for synchronizing AB and PSS in a summer greenhouse setting. Our findings underscore the importance of employing specific host switch patterns and banker plant systems to effectively control PSS in the field. This research offers foundational data for incorporating a banker plant system into integrated pest management strategies for enhanced PSS control.

The carboxypeptidase B and carbonic anhydrase genes play a reproductive regulatory role during multiple matings in Ophraella communa.

Seminal fluid proteins (SFPs) are key factors in sexual reproduction and are transferred to females during mating with sperm. SFPs have a nutritional value because they protect and activate sperm storage and release to optimize fecundity. Multiple matings promote ovipositioning in several insect species. Therefore, insects may obtain more SFP through multiple matings to maximize reproduction, but this process has not yet been clearly confirmed. Here, the relationship between multiple matings and the SFPs in Ophraella communa (Coleoptera: Chrysomelidae), a biological control agent of the common ragweed Ambrosia artemisiifolia (Asterales: Asteraceae), was studied. Multiple matings significantly increased female fecundity and ovary egg deposition. Carboxypeptidase B (OcCpb) and carbonic anhydrase (OcCa) genes were identified as putative SFP genes in O. communa and they showed strong male-biased expression. Additionally, OcCpb and OcCa expression was upregulated in the bursa copulatrix of mating females compared to that in virgin females, but their expression gradually declined after copulation. Furthermore, OcCpb and OcCa knockdown in males led to a decrease in insect fecundity compared to that in the control. The reproductive tract of females mated with dsRNA-treated males was dissected and observed and, notably, the ovaries produced significantly fewer eggs. These data suggest that OcCpb and OcCa play regulatory roles during multiple matings in O. communa.

Host-Plant Selection Behavior of Ophraella communa, a Biocontrol Agent of the Invasive Common Ragweed Ambrosia artemisiifolia.

Understanding the host-selection behavior of herbivorous insects is important to clarify their efficacy and safety as biocontrol agents. To explore the host-plant selection of the beetle Ophraella communa, a natural enemy of the alien invasive common ragweed (Ambrosia artemisiifolia), we conducted a series of outdoor choice experiments in cages in 2010 and in open fields in 2010 and 2011 to determine the preference of O. communa for A. artemisiifolia and three non-target plant species: sunflower (Helianthus annuus), cocklebur (Xanthium sibiricum), and giant ragweed (Ambrosia trifida). In the outdoor cage experiment, no eggs were found on sunflowers, and O. communa adults rapidly moved from sunflowers to the other three plant species. Instead, adults preferred to lay eggs on A. artemisiifolia, followed by X. sibiricum and A. trifida, although very few eggs were observed on A. trifida. Observing the host-plant selection of O. communa in an open sunflower field, we found that O. communa adults always chose A. artemisiifolia for feeding and egg laying. Although several adults (<0.02 adults/plant) stayed on H. annuus, no feeding or oviposition were observed, and adults quickly transferred to A. artemisiifolia. In 2010 and 2011, 3 egg masses (96 eggs) were observed on sunflowers, but they failed to hatch or develop into adults. In addition, some O. communa adults crossed the barrier formed by H. annuus to feed and oviposit on A. artemisiifolia planted in the periphery, and persisted in patches of different densities. Additionally, only 10% of O. communa adults chose to feed and oviposit on the X. sibiricum barrier. These findings suggest that O. communa poses no threat to the biosafety of H. anunuus and A. trifida and exhibits a robust dispersal capacity to find and feed on A. artemisiifolia. However, X. sibiricum has the potential to be an alternative host plant for O. communa.

Feeding on rapid cold hardening Ambrosia artemisiifolia enhances cold tolerance of Ophraella communa.

Low temperatures greatly influence newly introduced species, and increased cold tolerance can facilitate their establishment in new environments. The invasive alien species Ambrosia artemisiifolia is distributed at high latitudes and altitudes, where it suffers more from cold stress than it would at low latitudes or altitudes. Whether cold stress influences the accumulation of cryoprotectants and cold tolerance in A. artemisiifolia, and further influences the cold tolerance of its biological control agent, Ophraella communa, through feeding remain unknown. We investigated the levels of cryoprotectants and metabolic changes in A. artemisiifolia. We found that the level of total sugar, trehalose, proline, and other cold responsible metabolites increased in A. artemisiifolia after rapid cold-hardening (RCH) treatment, when compared to normal plants. These indicated that RCH treatment could improve the cold-hardiness of A. artemisiifolia. We then investigated the levels of cryoprotectants and metabolic changes in O. communa. We found that O. communa fed on RCH-treated A. artemisiifolia had higher levels of total sugar, trehalose, proline, glycerol, lipid, lower water content, lower super-cooling point, and increased cold tolerance compared to O. communa fed on normal A. artemisiifolia. This suggested that O. communa fed on cold-hardened A. artemisiifolia could increase its cold tolerance. Results showed a trophic transmission in insect cold tolerance. Our study enriches the theoretical basis for the co-evolution of cold tolerance in invasive and herbivorous insects.