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Abstract:

【Aim】 Invasion biology is an emerging discipline in the field of biosecurity. Understanding the development process and current status of invasion biology biology both in China and globally is of significant importance for comprehensively grasping the global situation and frontiers of this discipline, as well as evaluating the scientific capabilities and influences of countries in this field. 【Method】 This study used ten keywords ("biological invasion""invasion biology" "invasion ecology" "invasive alien species" "alien species" "exotic alien species" "exotic species" "non-indigenous species" "non-native species", and "invasiveness") to search the databases such as Web of Science and China National Knowledge Infrastructure (CNKI) to obtain the scientific outputs (including papers and monographs) related to invasion biology. A bibliometric analysis was conducted to summarize and categorize various attributes of the scientific outputs. 【Result】 The period from 1950 to 2024 witnessed the publishing of a total of 117 575 Chinese and English papers and 389 monographs, the proposal of 45 hypotheses related to biological invasions, and the completion of genome sequencing and assembly of 1 463 invasive alien species. Despite a late start in the research on invasion biology, China has made remarkable progress in the past two decades and is now at the forefront of the world in terms of paper output, publications in top journals, number of monographs, leading researchers, and cutting-edge technology. Nevertheless, gaps persist between China and global leaders in this field. For instance, China lacks specialized journals with international influence, and its outputs remain to be improved. The citations of top-journal articles, hypotheses generated, and internationally co-authored papers from China accounted for only 30.0%, 16.7%, and 29.9%, respectively, of those from leading countries. 【Conclusion】 Filling the gaps should be prioritized for future development. The findings of this study objectively reflect the current research status of invasion biology in China and its international position and influence, providing a theoretical basis for pinpointing the future research directions.

Abstract:

China is one of the countries most severely affected by invasive species. With the increasing number of invasive species, assessing, and classifying invasive species based on their potential damage and impact to strengthen focused management is necessary. In this review, we classified diverse assessment, ranking, classification, and grading methods for invasive species' damage to all species groups, worldwide, and evaluated the advantages and disadvantages of each method. According to the assessment contents and quatification and presentation of the assessment results, the main methods can be divided into four categories: expert qualitative grading and ranking, impact grading and ranking based on literature evidence, grading and classification considering impacts and other factors, and multi-index comprehensive evaluation based on analytic hierarchy process. Among them, two methods, the impact classification for alien taxa and the general impact scoring system, have high repeatability, stability, and scientific evidence and are widely used. We compared these methods in terms of application, assessment objective, content, and results, and method stability and found that the present index systems and Chinese multi-index comprehensive evaluation method used have certain shortcomings, including incomplete evaluation contents and low stability. Finally, we propose improvements for the multi-index comprehensive evaluation method, hoping to improve the Chinese risk assessment method and assessment systems for invasive species. Supporting related research and management work will be needed.

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Cassava (Manihot esculenta Crantz) is an important economic and food crop in Latin America, Africa and Southeast Asia. Because of its excellences in drought and barren tolerance, cassava is widely cultivated in tropical and subtropical regions of the world. Cassava mosaic virus (CMV) is one of the most widespread diseases that threaten cassava production. Since cassava is a vegetatively propagated crop, CMV is mainly transmitted by infected planting material (stakes). Nevertheless, CMV is also transmitted by various species of the Bemisia tabaci (Gennadius) whitefly complex (Hemiptera: Aleyrodidae). Previously, there have been no reports of CMV occurrence and damage in cassava producing areas in China and Southeast Asia. However, in recent years, Sri Lanka cassava mosaic virus (SLCMV) has been widely spread in Southeast Asia. Now, it has become the main disease of cassava production in this region, and also poses a major threat to cassava production in China. This paper will discuss the occurrence, transmission and prevention strategies of SLCMV in Asia. It may provide reference for the prevention and control of SLCMV in China.

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Sicyos angulatus is an annual grassy vine climber native to the northeast United States. It is widely planted because of its ornamental value. It has now spread to most places in Europe and Asia posing a serious threat to the growth of native plants and is considered one of the most problematic invasive plants worldwide. Its mass introduction into China has caused serious harm to agriculture, urban gardens and the environment. The invasion strategy of S. angulatus is poorly understood. This paper reviews the distribution and hazard, nutrition and reproductive growth strategies, competitive strategy, prevention, and application of S. angulatus, and summarized the research progress to provide a scientific basis for controlling S. angulatus. The key factor of S. angulatus invasion success is its diversified adaptation strategies and powerful ability to spread. The main reason for its damage to agriculture and the environment is climbing strangulation and occupying different ecological niches. The control methods of S. angulatus include manual removal and chemical and biological control. S. angulatus has been applied in agriculture, soil remediation, and medicine. Further studies on the adaptive mechanisms in the natural environment, application development, and control methods are needed.

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【Aim】 To investigate the occurrence and invasion source of Phenacoccus solenopsis in Huizhou, an important invasive pest that invaded China in recent years. 【Method】 In this study, we investigated the infestation of P. solenopsis in Huizhou on collected samples using morphological identification, DNA extraction, and PCR amplification to analyze its sequence homology, genetic structure, and phylogenetic relationship with bioinformatics software. 【Result】 There are 43 species of host plants in 15 families in Huizhou, which include potatoes, vegetables, and other economically important crops. Four haplotypes exist in the mitochondrial COⅠgene sequence, which were compared in the GenBank database. The sequence similarity reached 100%, and the genetic distance between populations was 0-0.029. The genetic distance between the Huizhou and American populations was large, whereas the genetic distance between the Huizhou and other populations was small. A phylogenetic tree showed that the Huizhou and Pakistani populations clustered together in one group. Based on the genetic distance and phylogenetic tree data, it was speculated that P. solenopsis in the Huizhou area may have originated from Pakistan. 【Conclusion】 The mitochondrial COⅠ gene could quickly and accurately identify the invasion source and phylogenetic relationship of this insect, providing a scientific basis for monitoring the occurrence and precise control of this insect in potato and vegetable areas in Huizhou.

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【Aim】 The aim of this study was to investigate the impact of pine wood nematode (Bursaphelenchus xylophilus) on the endophytic bacterial community of Pinus massoniana in latent infection stage, identifying signature endophytic bacteria in the latent infection stage of B. xylophilus and elucidating potential pathogenic mechanisms. This provides a foundation for identifying latent B. xylophilus infections and preventing pine wilt disease. 【Method】 The endophytic bacterial communities in P. massoniana were analyzed using 16S high-throughput sequencing technology. Differences in the endophytic bacterial communities of P. massoniana infested with B. xylophilus and those without were compared. The correlation between the population density of B. xylophilus and the endophytic bacteria was analyzed. 【Result】 The endophytic bacterial community of P. massoniana with latent infestation by B. xylophilus showed significant differences compared to healthy P. massoniana. Species richness increased significantly, whereas evenness and diversity showed no significant changes. Network analysis of the endophytic bacterial communities revealed a reduction in the number of species in the largest cluster, an increase in the number of clusters, and a decrease in the correlation coefficients, with a higher proportion of positive correlations. The genus with the highest abundance in P. massoniana latently infected with B. xylophilus was Burkholderia-Caballeronia-Paraburkholderia, which was significantly more abundant than in healthy P. massoniana. The core genus of the endophytic bacterial community was Altererythrobacter. The genus Mycobacterium showed a significant increase in abundance in P. massoniana latently infected with B. xylophilus and was significantly positively correlated with nematode content. It also held a core position in the endophytic bacterial community of P. massoniana latently infected with B. xylophilus. The genus with the highest abundance in healthy P. massoniana was unclassified_f__Alcaligenaceae. Its abundance decreased significantly in P. massoniana infected with B. xylophilus. The genus Exiguobacterium showed no significant difference between the two groups of samples but held a central position in the endophytic bacterial community of healthy P. massoniana and was significantly negatively correlated with the population density of B. xylophilus. 【Conclusion】 The pressure exerted by B. xylophilus in the latent stage of P. massoniana infected with B. xylophilus disrupted the stability of the endophytic bacterial community, increasing its complexity and species richness. Burkholderia-Caballeronia-Paraburkholderia and Altererythrobacter may play assisting roles in the defense process of pine trees to pine wilt disease in the altered endophytic bacterial community. Mycobacterium may be involved in assisting B. xylophilus in harming pine trees. Alcaligenaceae and Exiguobacterium were of significant importance for the health of P. massoniana.

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【Aim】 In order to further understand the effect of nitrogen deposition on the competitive relationship between invasive and indigenous species, and to elucidate how it changes species competitiveness and affects invasive plants. 【Method】 A de Wit replacement competitive experiment with the invasive plant Ageratum conyzoides and the native plant Acalypha australis was performed. The effects of different levels of nitrogen deposition on plant height, aboveground biomass and number of branches were simulated by watering different concentrations of NH₄Cl solutions. Relative neighbor effect (R_NE) and replacement diagrams were used to estimate interspecific competition. 【Result】 In monoculture, medium and high nitrogen treatments (6 and 12 g·m^-2·a^-1) significantly promoted the height growth and aboveground biomass of Ageratum conyzoides at harvest. whereas, the nitrogen treatment group significantly increased the height growth and aboveground biomass of Acalypha australis at harvest. When two species are mixed, regardless of the cultivation ratio, there was no significant difference in plant height between different nitrogen treatment groups during the harvest of Ageratum conyzoides. At harvest, the height of the Acalypha australis in the high nitrogen group was significantly higher than that in the control group. Medium and high nitrogen treatments significantly increased the number of branches of Ageratum conyzoides at medium and high cultivation ratios (0.50 and 0.75). Under high cultivation ratios, high nitrogen treatment significantly increased the number of branches of Acalypha australis. R_NE showed that at high cultivation ratios, the competitive effect of Acalypha australis on nitrogen treatment groups of Ageratum conyzoides was not significant. When the cultivation ratio of Acalypha australis was high, nitrogen treatment improved the competitiveness of Ageratum conyzoides, and it was most obvious under low nitrogen treatment (3 g·m^-2·a^-1). The replacement diagrams showed that the actual biomass of Acalypha australis was lower than expected under any mixed planting method. Under low nitrogen treatment, the aboveground biomass of Ageratum conyzoides and total biomass of two species were higher than expected under high cultivation ratios. 【Conclusion】 Nitrogen deposition significantly affects the growth of Ageratum conyzoides and Acalypha australis and their interspecific competition. Nitrogen deposition, especially low nitrogen deposition, increases the competitive advantage of Ageratum conyzoides.

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【Aim】 The aim of this study was to identify the species of sunfish that invaded the waters of central Shanxi Province. 【Method】 The captured sunfish were identified morphologically on a preliminary basis, and six of them were selected randomly for DNA extraction, amplification of mitochondrial cytochrome C oxidase I (COⅠ) and cytochrome b (Cytb) genes by polymerase chain reaction and sequencing. The genetic distance of the sample sequences was calculated according to the Kimura 2-parameter model, and the resulting sequences were used to construct a phylogenetic tree using the neighbor-joining (NJ), maximum likelihood (ML), and Bayesian inference (BI) methods for clustering analysis. 【Result】 The results showed that the fish were morphologically consistent with the green sunfish (Lepomis cyanellus). The average length of the COⅠ gene sequences was 642 bp, and the average content of A+T (51.37%) was slightly greater than that of G+C (48.61%). The average length of the Cytb gene sequences was 819 bp, and the average content of A+T (52.54%) was greater than that of G+C (47.46%). The differences between the average inter- and intra-specific genetic distances of Cytb and COⅠ gene were 11.58 and 9.94, respectively. The measured gene sequences had the most closely related genetic similarities and distances to known green sunfish genes. Phylogenetic analysis showed that the 12 sunfish formed an independent clade based on COⅠ and Cytb gene sequences. The sample gene sequences clustered with green sunfish and were significantly different from those of the other closely related species. 【Conclusion】 The fish that invaded the waters of central Shanxi Province were green sunfish. The use of COⅠ and Cytb genes could effectively identify morphologically similar invasive species. The results provide an early warning for aquatic biodiversity protection in Central Shanxi and a scientific basis for the prevention and control of invasive fish.

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【Aim】 The mealybug (Pseudococcidae) is a biological group with strong reproductive and dispersal capacities, posing significant threat to mangoes and litchis among fruits and cash crops. Therefore, strengthening the risk assessment of alien mealybug invasion is necessary. In this study, we used a self-organizing map (SOM), a comprehensive quantitative model, to assess the global establishment risk, particularly in China. We screened out potentially invasive mealybug species to reduce the number of species to a manageable level, providing a reliable theoretical basis for early warning, quarantine measures, comprehensive prevention, and mealybug control in China. 【Method】 We summarized and constructed a geographically absent/present matrix including 109 Pseudococcidae species in 176 countries globally. Next, we performed a national cluster analysis using the SOM algorithm, based on similarities in species assemblages. 【Result】 We clustered 176 countries into 49 categories, grouping countries with similar species assemblages and geographically adjacent countries together. We further screened and ranked the SOM indices of the Pseudococcidae species not yet established in China, determining a ranking list of the establishment risks. We evaluated the establishment risks of Paracoccus interceptus, Dysmicoccus lepelleyi, and Planococcus ficus in countries where they are not yet present, including China. Our results demonstrated that the risks of these three mealybugs ranked first, second, and sixth in China, respectively. 【Conclusion】 Our findings indicated that Paracoccus interceptus, D. lepelleyi, and Planococcus ficus, which can cause serious economic losses, display high establishment potential in China. Therefore, we recommend strengthening the original area, port quarantine inspections, and implementing integrated management strategies to prevent the introduction of these harmful mealybugs, ensuring the healthy development of fruit trade in China.

Abstract:

【Aim】 The predation of Plutella xylostella by Sycanus bifidus in different insect states was investigated to provide a theoretical basis for the biological control of P. xylostella. 【Method】 The predation functional response, search effect, and interference response of old nymphs and adults of S. bifidus to the 3rd and 4th instar larvae of P. xylostella were studied under laboratory conditions. 【Result】 The functional responses of the 3rd, 4th, and 5th instar nymphs and adults of S. bifidus towards the 3rd and 4th instar larvae of P. xylostella conformed to the Holling II type disk equation, indicating that, the degree of predation increased with the increase in prey density. The female adults and 5th instar nymphs of S. bifidus showed higher daily maximum predation rates towards the 4th instar larvae of P. xylostella, i.e., 93.63 and 58.34, respectively, compared with those towards the 3rd instar larvae of P. xylostella. Compared with nymphs, the predation efficiencies (a/T) of the female adults of S. bifidus towards the 3rd and 4th instar larvae of P. xylostella were better, i.e., 60.98 and 103.65, respectively. The degree of predation of S. bifidus was positively correlated with prey density, whereas the search effect was negatively correlated with prey density, with the highest search effect being observed in female adults. With an increase in the densities of S. bifidus and its prey, the intraspecific interference increased, and the predation rate decreased. 【Conclusion】 The results showed that S. bifidus had good potential for the prevention and control of P. xylostella and could be used for pest management practices targeting P. xylostella.

Abstract:

【Aim】 The main goal was to explore the strain resources of phyllospheric bacteria of Pinus massoniana and analyze its population diversity. Moreover, we aimed to screen strains with Bursaphelenchus xylophilus killing activity and clarify their classification status, as well as to provide strain resources for biological control of pine wilt disease. 【Method】 Using plate separation culture method, the phyllospheric bacteria of P. massoniana was isolated and cultivated from Gutian and Xiapu counties of Ningde and Youxi county of Sanming. Bacterial strains were classified based on colony morphological characteristics and 16S rDNA PCR-RFLP analysis. The killing activity of the phyllospheric bacteria against B. xylophilus was determined using a centrifuge tube culture. The classification status of the antagonistic strains was determined through physiological and biochemical characterization and 16S rDNA and gyrB gene sequence analysis. 【Result】 The 141 phyllospheric bacterial strains of P. massoniana were isolated from plants from Gutian and Xiapu counties of Ningde and Youxi county of Sanming. The 141 strains of phyllospheric bacteria of P. massoniana were classified into nine types based on colony morphology. The 16S rDNA obtained by amplification was digested with HaeIII and MspI, and there were nine and 11 map types, respectively. At 100% similar level, the 141 strains of phyllospheric bacteria had 19 map types after combining the two map types. Using NB medium or sterile water as the control and the 48 h corrected mortality rate of B. xylophilus as the indicator, 120 strains with varying degrees of nematicidal effects were screened, accounting for 85.11% of the total screened strains. Using NB medium as the control, 11 strains with a corrected mortality rate greater than 50% of B. xylophilus, accounted for 7.80% of the total screened strains. Among them, the strain with the best nematicidal effect was strain GT10, with a 48 h nematode killing rate of 92.56%. The strain was gram-positive (G⁺) with rod-shaped, peritrichous flagella. The strain was able to utilize mannitol and citrate and showed positive results in the nitrate reduction reaction and V-P determination. Phylogenetic tree analysis showed that the 16S rDNA sequence and gyrB gene sequence of the strain clustered with those of the B. cereus model strain ATCC14579. Therefore, the strain GT10 was identified as B. cereus. 【Conclusion】 There was rich diversity of phyllospheric bacteria of P. massoniana. The B. cereus strain GT10 had a high nematicidal effect against B. xylophilus and could potentially be used for the biological control of pine wilt disease.

Abstract:

【Aim】 The main goals were to investigate the types, distribution, and morphological characteristics of the sensilla on the head of Archips micaceana larvae, and to analyze the morphological characteristics and functions of each sensillum. 【Method】 Scanning electron microscopy was used to observe the ultrastructure of the mouthparts and antennae of the fifth instar larvae of the A. micaceana 【Result】 We observed a total of seven types of sensilla on the mouthparts of the larvae, sensilla chaetica, sensilla trichodea, sensilla basiconica, sensilla styloconica, sensillum digitiformium, sensilla placodea, and sensory peg. Among these, sensilla chaetica had the widest distribution and sensilla basiconica was the most abundant. Moreover, we observed four types of sensilla on the antennae: sensilla chaetica, sensilla trichodea, sensilla basiconica, and sensilla styloconica. 【Conclusion】 This study clarified that the head of the A. micaceana larvae contains seven types of sensilla, among which the distribution of sensillum digitiformium may play a key role in the leaf-rolling behavior of the larvae.