【Aim】 This study aims to explore the crucial genes and metabolic pathways involved in obligatory summer diapause in Galeruca daurica, a new pest with great outbreak in the Inner Mongolia grasslands, northern China. 【Methods】 Using RNA-Seq, we performed sequencing, transcriptional profiling and functional prediction for G. daurica adults at different summer diapause stages, i.e. pre-diapause (PD), diapause (D) and post-iapause (TD), and screened differentially expressed genes (DEGs) at different summer diapause stages based on the RNA-Seq data. The expression levels of ten DEGs screened based on the RNA-Seq data were verified by qPCR. 【Results】 A total of 202 770 198 clean reads from nine libraries were filtered, and 12 078 060 transcripts were assembled into 82 292 unigenes with an average length of 783.59 bp and a N50 of 1 545 bp. The 2 395 (2 119 up-regulated and 277 down-regulated) and 62 (59 up-regulated and 3 down-regulated) DEGs were identified in the D vs PD and TD vs D omparison groups, respectively. The KEGG analysis revealed that the glycolysis/gluconeogenesis and fatty acid biosynthesis pathways were significantly enriched in the D vs PD and TD vs D comparison groups, respectively. Additionally, many DEGs related to the Ca²⁺ signaling were differentially expressed during diapause. Finally, the expressional analysis result by qPCR for ten DEGs showed a high consistency between qPCR and RNA-Seq results. 【Conclusion】 The glycolysis/gluconeogenesis, fatty acid biosynthesis, and Ca²⁺signaling pathways may play an important role in diapause regulation of G. daurica. This study establishes a foundation for future studies on the molecular mechanism underlying obligatory summer diapause in G. daurica.

【Aim】 To enrich the knowledge of the anticancer mechanism of antimicrobial peptide HI-3 extracted from Hermetia illucens by studying the effects of HI-3 on the amino acid metabolism of human colon carcinoma HCT-8 cells. 【Methods】 CCK-8 assay was used to determine the inhibition rates of different concentrations (80, 160, and 320 μg/mL) of antimicrobial peptide HI-3 on HCT-8 cells. The metabolites in HCT-8 cells were determined by GS-MS, and then the metabolic pathway with the most significant difference in amino acid contents and the target enzyme in this pathway were screened by pathway analysis based on R software. After the HCT-8 cells were treated with 320 μg/mL HI-3, the activity of the selected target enzyme glutaminase (GLS) was assayed by enzyme activity kit, its mRNA and protein expression levels were detected by RT-qPCR and Western blot, respectively, and the changes in the contents of important metabolites including glutamine (Gln), glutamic acid (Glu), glutathione (GSH), α-ketoglutaric acid (α-KG) and ATP involved in the glutamine and glutamic acid metabolic pathway in HCT-8 cells were detected by biochemical kits and ELISA kit. 【Results】 The inhibition rates of HCT-8 cells treated by HI-3 at the concentrations of 80, 160, and 320 μg/mL were 33.85%  ±3.50%, 46.26%±0.90%, and 55.53%±1.70%, respectively, and the inhibition rates increased with the increase of the HI-3 concentration. HI-3 at the concentration of 320 μg/mL showed the greatest effects on the glutamine and glutamic acid pathway with the contents of amino acid metabolites in this pathway most significantly different from those in the negative control group (0 μg/mL HI-3). The activity of GLS (the target enzyme in this pathway) and the mRNA and protein expression levels of its gene GLS in the 320 μg/mL HI-3 treatment group were extremely significantly lower than those in the negative control group. Moreover, the contents of important metabolites in this pathway, including Gln, Glu, GSH, α-KG and ATP, in the 320 μg/mL HI-3 treatment group were also significantly reduced as compared with those in the negative control group. 【Conclusion】 Antimicrobial peptide HI-3 from H. illucens at the concentration of 320 μg/mL has the most significant effect on the glutamine and glutamic acid metabolic pathway in HCT-8 cells, and can significantly inhibit the proliferation of HCT-8 cells by blocking this pathway.

【Aim】 The objective of this study is to assess the diversity of bacteria in the venom glands of the red imported fire ant, Solenopsis invicta, and to compare the bacterial communities in the venom glands with those of other two stinging ants, Solenopsis geminata and Diacamma rugosum. 【Methods】 16S rRNA V3-V4 regions of bacterial community of venom glands in S. invicta workers, alates and queens, S. geminata workers and D. ugosum workers were sequenced by using the Illumine Hiseq 2500 platform. Then, bioinformatic analysis was performed based on sequencing data. 【Results】 Proteobacteria were dominant in the venom glands of S. invicta workers, alates, and queens and S. geminata workers, while Firmicutes were abundant in the venom glands of D. rugosum workers. Tenericutes were more abundant in the venom glands of S. invicta queens than in the venom glands of workers and alates. The relative abundance of Pseudomonas in S. invicta queens was significantly higher than that in S. invicta alates and workers from Guangzhou. The relative abundance of Spiroplasma in the venom glands of S. geminata workers was significantly higher than that in D. rugosum workers. Microbial diversity analysis of venom glands of worker ants of Solenopsis species showed that the relative abundance of Bacillus and Lactococcus in S. invicta workers collected from Guangxi was significantly higher than that in S. invicta workers collected from Guangzhou. However, the relative abundance of Lactococcus in D. rugosum workers was significantly higher than that in workers of S. geminata from Guangxi. 【Conclusion】 The bacterial composition and diversity are different among the workers of three ant species, and among the three castes in red imported fire ant.

【Aim】 The citrus red mite, Panonychus citri, is an important pest of citrus in China where foliar fertilizers are commonly used in citrus orchards. The objective of this research is to assess the influence of two fertilizers, urea and compound amino acid, on the development and reproduction of this mite, and on the growth of citrus seedlings. 【Methods】 Two foliar fertilizers, urea (0.50%) and compound amino acid (0.17%), were applied separately to potted citrus (Citrus reticulata Blanco cv. Shatangju) seedlings in the laboratory, and the seedlings sprayed with water were used as the control. The life-table parameters ［the net reproductive rate (R₀), mean generation time (T), intrinsic rate of increase (r_m), finite rate of increase (λ) and population trend index (I)］ of P. citri, the growth parameters (leaf length, width and area; stem length; plant height; number and length of new shoot leaves) of citrus seedlings and the nutrient (N, P and K) contents in leaves of citrus seedlings were investigated under controlled environment conditions. 【Results】 The duration of immature stages of P. citri was not influenced by the fertilizers, but the survival rate of  deutonymphs on citrus seedlings applied with 0.50% urea (95.40%) was significantly higher than those on the control citrus seedlings (applied with water) (78.26%) and on citrus seedlings applied with 0.17% compound amino acid (75.61%). The fecundity of female mites reared on urea treated citrus seedlings (42.1/♀) was also significantly higher than that of females reared on the control citrus seedlings (33.1/♀). The longevity of females reared on compound amino acid treated citrus seedlings (19.5 d) was significantly longer than that of females reared on urea treated citrus seedlings (14.8 d) and the control citrus seedlings (14.5 d), and the longevity of males reared on compound amino acid treated citrus seedlings (17.6 d) was significantly longer than that of males reared on the control citrus seedlings (13.1 d). Overall, P. citri reared on urea treated citrus seedlings had the highest net reproduction rate (Ro) (17.88) and population trend index (I)(18.08), both significantly higher than that reared on the control citrus seedlings (10.08 and 11.17, respectively). Leaf growth (leaf length, width and area) of citrus seedlings was significantly promoted by both fertilizers. Both fertilizers also significantly increased N, P and K contents, and the ratio of N/K in leaves of citrus seedlings. 【Conclusion】 Urea and compound amino acid as foliar fertilizer both promote the growth of citrus seedlings. Compound amino acid should be recommended in preference to urea because spraying of urea increases P. citri populations in contrast to compound amino acid. However, P. citri population should be also monitored because that although compound amino acid does not facilitate population growth, it does increase the longevity of adult mites.