Red imported fire ant nesting affects the structure of soil microbial community.

The red imported fire ants (RIFA, Solenopsis invicta) have become a well-known invasive species that poses significant ecological and economic threats globally. As of recent times, the geographic scope of its invasion in China is rapidly expanding, thereby aggravating the extent and severity of its detrimental effects. The importance of soil microorganisms for maintaining soil health and ecosystem function has been widely acknowledged. However, the negative impact of RIFAs on soil microbial communities and their functions has not yet been fully understood. In this study, we sequenced the V3-V4 variable region of the bacterial 16S rRNA gene in soil samples collected from three types of RIFA nests to investigate the impact of RIFA invasion on soil microbial diversity and composition. The results of alpha diversity analysis showed that the normal soil without nests of RIFAs exhibited the highest level of diversity, followed by the soil samples from RIFA-invaded nests and abandoned nests. Taxonomy and biological function annotation analyses revealed significant differences in microbial community structure and function among the different samples. Our findings demonstrate that RIFA invasion can significantly alter soil microbial community composition, which could ultimately affect ecosystem function. Therefore, effective management strategies are urgently needed to mitigate the negative impact of invasive species on native ecosystems.

Population Growth of Fall Armyworm, Spodoptera frugiperda Fed on Cereal and Pulse Host Plants Cultivated in Yunnan Province, China.

The fall armyworm, Spodoptera frugiperda is a major agricultural pest in China, and has migrated from its continuous breeding area to other parts of China. In our study, the biological behaviors of S. frugiperda fed on maize, wheat, barley, faba beans, and soya beans were evaluated in a growth chamber. Results indicated that maize-fed S. frugiperda larvae performed well, as evidenced by shorter larva-adult periods, adult pre-oviposition period (APOP), total pre-oviposition period (TPOP), and generation time (T), and a higher survival rate, intrinsic (r) and finite (λ) rate of increase, and net reproductive rate (Ro), However, S. frugiperda larvae performed weakly when fed barley and faba bean plants, as indicated by lower survival rates, r, and λ, and longer pre-adult period, TPOP, and T. A heavier pupal weight of both sexes was recorded on faba beans (0.202 g) and a lighter weight on barley (0.169 g). Fecundity was higher when fed faba beans and maize, and lower when fed wheat and barley. Thus, maize was the most optimal and barley was the least optimal host plant, followed by faba beans, for S. frugiperda larvae growth and development. This study enhances our knowledge of S. frugiperda in these host plants and can help in the design of management approaches.

IL-27 mediates anti-inflammatory effect in cigarette smoke induced emphysema by negatively regulating IFN-γ producing cytotoxic CD8+ T cells in mice.

Chronic airway inflammation mediated by CD8+ T lymphocytes contributes to the pathogenesis of Chronic obstructive pulmonary disease (COPD). Deciphering the fingerprint of the chronic inflammation orchestrated by CD8+ T cells may allow the development of novel approaches to COPD management. Here, the expression of IL-27 and IFN-γ+ CD8+ Tc1 cells were evaluated in patients with COPD and in cigarette smoke-exposed mice. The production of IL-27 by marrow-derived dendritic cells (mDCs) in response to cigarette smoke extract (CSE) was assessed. The role of IL-27 in IFN-γ+ CD8+ Tc1 cells was explored. We demonstrated that elevated IL-27 was accompanied by an exaggerated IFN-γ+ CD8+ Tc1 response in a smoking mouse model of emphysema. We noted that lung dendritic cells were one of the main sources of IL-27 during chronic cigarette smoke exposure. Moreover, CSE directly induced the production of IL-27 by mDCs in vitro. IL-27 negatively regulated the differentiation of IFN-γ+ CD8+ Tc1 cells isolated from cigarette smoke-exposed mice in a STAT1- and STAT3-independent manner. Systemic administration of recombinant IL-27 attenuated IFN-γ+ CD8+ Tc1 response in the late phase of cigarette smoke exposure. Our results uncovered that IL-27 negatively regulates IFN-γ+ CD8+ Tc1 response in the late stage of chronic cigarette smoke exposure, which may provide a new strategy for the anti-inflammatory treatment of smoking-related COPD/emphysema.

Effects of Aphidius gifuensis Release on Insect Communities and Diversity in Tobacco Fields of Yunnan Province, China.

BACKGROUND AND OBJECTIVES: The biocontrol agent Aphidius gifuensis has widely been released and applied since 1997 to control Myzus persicae in tobacco fields of Yunnan Province, southwestern China, but its ecological effects on the local insect community and diversity have not been described. Biological control agents may effect a diversity of organisms as well as the target for control but such trophic cascades have seldom been studied. This study aimed to explore the effects of A. gifuensis on the insect community and diversity in tobacco fields after long-term release and expansion of the biocontrol agent in Yunnan Province. MATERIALS AND METHODS: The effects of A. gifuensis on species composition, importance value, species richness, diversity indices and evenness index were studied for insect community samples obtained via field surveys and malaise trap collection in Yunnan Province. RESULTS: A total of 39 insect species and 1 spider, principally belonging to 40 families and 13 orders in tobacco fields of Yunnan Province were identified. Among these, there were 20 pests, 14 natural enemies and 6 others, constituting 50, 35 and 15% of total species sampled, respectively. Within insect communities, M. persicae, Empoasca flavescens and Drosophila melanogaster were the dominant species and Spodoptera litura, one unidentified species (Ichneumonidae), Sphex haemorrhoidalis, Vespa veutinaauraris, Aedes albopictus, A. gifuensis and Liriomyza huidobrensis were the subdominant species. From June to August, the relative density of A. gifuensis gradually increased and concomitantly the total relative density of other natural enemies exhibited a slight decline in July and marked increase in August. The relative density of M. persicae significantly increased in July and then declined precipitously in August. Moreover, the values of Simpson index, Shannon-Wiener index and Pielou index were greater than 0.50, 1.50 and 0.50, respectively, indicating high insect diversity. CONCLUSION: Beneficial insects, in addition to the biocontrol agent are relatively abundant in tobacco fields of Yunnan Province, marking improvement in the local insect community diversity after a long-term release of the biocontrol agent A. gifuensis, which, by land area, constitutes one of the largest natural enemy control programs in the world.

Ultrastructural and functional characterization of circulating hemocytes from Plutella xylostella larva: cell types and their role in phagocytosis.

The hemocytes of different types encountered in the diamondback moth Plutella xylostella larvae of each instar and the development of the differential hemocytes counts were herein presented. Hemocytes classes/populations characterized based on their affinity with fluorescent dye (acridine orange) and ultrastructural differences comprised the prohemcoytes (<10-16%), plasmatocytes (22-65%), granulocytes (25-72%), oenocytoids (<1-9%), and spherulocytes (<1%). Prohemcoytes were the smallest cells with a comparatively tremendous nucleus. Plasmatocytes and granulocytes occupied the main proportion of total cell numbers. Oenocytoids were in a most stable presence, i.e. rotund in a diameter of 10 µm and with a nucleus deviated from the central location; however, sometimes with two nuclei which were adjoining with each other. Spherulocytes were rare and only could be observed occasionally. Ultrastructural investigation revealed that hemocytes in the diamondback moth larvae were of the typical model as in the Lepidoptera insect larvae. It is interesting to find that the cell which could phagocytize bacteria in vitro was granulocyte, not the other types of hemocytes, although plasmatocyte was usually declared to participate in this reaction in various previous studies.

[Determination of trace elements in cardiocrinum giganteum by FAAS].

Conditions for simultaneous determination of multi-tract elements in Cardiocrinum giganteum by flame atomic absorption spectrometry were studied. Elements K, Ca, Na, Mg, Fe, Zn, Mn, Cu and Cr in different growth periods of Cardiocrinum giganteum were determined, the relative standard deviation of the method is between 0.20% and 2.1%, and the recovery is between 97.8% and 104.9%. Analytical results were satisfactory. The results showed that some elements essential to human such as Zn, K, Ca, Mg and Mn in Cardiocrinum giganteum are abundant, implying that the nutritive value of Cardiocrinum giganteum is high.