The insect cuticle plays critical roles in growth and development and provides protection against external injuries and environmental stresses. Aim This study aimed to clone cuticular protein (CP) family genes from the fall webworm, Hyphantria cunea, characterize their sequence features and spatiotemporal expression patterns, and investigate their transcriptional responses to Hyphantria cunea nucleopolyhedrovirus (HcNPV) infection. Methods The full-length cDNA sequences of HcCPs genes were cloned using RT-PCR, and their molecular and biological characteristics were analyzed using online bioinformatics tools and software. RT-qPCR was applied to detect the expression profiles of the HcCPs genes across different developmental stages (eggs, 1stu20137th instar larvae, pupae and adults), in different tissues (head, cuticle, Malpighian tubules, foregut, midgut, hindgut, silk gland, fat body, testis and ovary), and following exposure to different concentrations of HcNPV. Results The open reading frames (ORFs) of the seven H. cunea CP genes were 291, 492, 720, 426, 657, 408 and 742 bp in length, encoding proteins of 96, 163, 239, 141, 218, 135 and 313 amino acids, respectively. Their predicted molecular weights ranged from 10.8 to 32.2 kDa, and theoretical isoelectric points ranged from 5.00 to 9.44. Tertiary structure prediction revealed that HcCP proteins contained mainly of u03B1-helices, u03B2-sheets and random coils. Phylogenetic analysis demonstrated that the HcCPs were most closely related to homologous proteins from other lepidopteran insects. RT-qPCR analysis revealed relatively high expression levels of the HcCP genes in the head, cuticle, testis and during the 5th to 7th larval instars. Their expression levels were also higher in male adults than in female adults. Exposure of H. cunea larvae to different concentrations of HcNPV resulted in time-dependent changes in HcCP expression. Under both high-dose (2 u00D7 105 PIBs/mL) and low-dose (2 u00D7 103 PIBs/mL) treatments, transcriptional levels initially increased, subsequently decreased, and then increased again. Following exposure to 2 u00D7 103 PIBs/mL HcNPV, HcCP1, HcCP19, HcPCP36a and HcLCPA2B reached their highest expression levels at 120 h, ranging from 38.94u20134994.20-fold relative to the control. In contrast, HcPCP, HcL/PRCP66 and HcLCP30 peaked at 48 h, with expression levels 152.16-, 512.07- and 88.82-fold higher than those of the control, respectively. Following exposure to 2 u00D7 105 PIBs/mL HcNPV, HcCP1 achieved its highest expression level at 24 h (104.12-fold of control). The expression levels of HcCP19, HcPCP36a and HcLCPA2B peaked at 120 h and were 67.93-, 6824.97-and 12.66-fold higher than those of the control, respectively. Meanwhile, HcPCP, HcL/PRCP66 and HcLCP30 reached their highest expression levels at 48 h, at 85.91-, 218.66- and 29.16-fold those of controls, respectively. These findings indicate that HcCP genes are strongly involved in the response of H. cunea to HcNPV infection. Conclusion Collectively, these results demonstrate that HcCPs play vital roles in the defense of H. cunea against HcNPV infection and provide a foundation for further elucidating the mechanisms underlying HcNPV infection in this insect.
Aim To determine the effects of the physical characteristics and substances contained in the bark of different walnut tree varieties on the damage caused by Batocera horsfieldi, aiming to screen out varieties with strong insect resistance for promotion. Methods In this experiment, the main cultivated varieties, Xiluo No. 3, Xifu No. 2 and Xiangling, introduced into the same walnut orchard in Kang County, Gansu Province, were chosen as the research subjects, and the damage situation of B. horsfieldi on different walnut tree varieties was investigated, and the physical characteristics of the bark and the content of substances in the bark of different walnut tree varieties were measured and analyzed to explore their correlations with the damage of B. horsfieldi. Results The results indicated that the numbers of grooves and emergence holes of B. horsfieldi on different walnut tree varieties were in the order of: Xiluo No. 3 u0026gt; Xifu No. 2 u0026gt; Xiangling. The bark hardness, thickness, roughness and xylem thickness of Xiluo No. 3 were the greatest, followed by Xifu No. 2 and Xiangling were the smallest, among them, the difference in bark roughness was the most significant. The soluble sugar content of Xiluo No. 3 was the highest, at (7.25 u00B1 0.51) mg/g, which was significantly higher than that of Xiluo No. 2 and Xiangling; there was no significant difference in the soluble protein content among different walnut tree varieties; the tannin, total phenol, and water contents of Xiangling were significantly higher than those of Xiluo No. 3, and did not differ from those of Xifu No.2. Conclusion The degree of damage by B. horsfieldi was significantly positively correlated with the bark roughness, soluble sugar content and soluble protein content of different varieties of walnut trees, and significantly negatively correlated with tannin, total phenol content and water content. In summary, among the three introduced walnut varieties, Xiangling exhibited the strongest insect resistance.
[Aim]This study aimed to effectively control cassava pests from the source and promote the application of new cassava varieties in Wuming area.[Methods]We screened and evaluated insect-resistant cassava cultivars suitable for the Wuming area.The highly resistant cultivar C1115 and the highly susceptible cultivar SC205 were used as references.[Results]Field survey data from 2022 to 2024 showed that SC15,SC9,GR13 and GS1505 all exhibited resistance to both Tetranychus urticae and Paracoccus marginatus,with average damage indexes ranging from 27.29%to 33.36%,and 33.34%to 36.37%,respectively.These values were significantly higher than those for C1115(10.94%and 11.56%)but significantly lower than those of SC205(90.57%and 92.24%).Compared to SC205,the average damage indexes were reduced by 57.21%～63.28%and 55.87%～58.90%,respectively.SC12,GS1508,SC5,LIMIN,SC8002 and NZ199 showed moderate resistance to both T.urticae and P.marginatus with average damage indexes ranging from 41.34%to 55.61%and 45.83%to 56.24%,respectively.SC10,SC124,GR4 and GR891 exhibited moderate resistance to T.urticae but were susceptible to P.marginatus with average damage indexes ranging from 48.98%to 56.93%and 66.70%to 69.54%,respectively.SC6068 showed susceptibility to T.urticae but high susceptibility to P.marginatus with average damage indexes of 64.37%and 93.05%,respectively.GR10,KU50 and BREAD were highly susceptible to both T.urticae and P.marginatus with average damage indexes ranging from 93.22%to 95.95%and 95.01%to 95.61%,respectively.Further validation in the Liangjiang,Luoxu,Chengxiang,Taiping and Ningwu areas of Wuming confirmed the resistance performance of SC15,SC9,GR13 and GS1505 to T.urticae and P.marginatus.In these five areas,the average damage indexes ranged from 29.36%to 31.22%and 33.71%to 34.87%for SC15,31.18%to 33.48%and 34.48%to 35.87%for SC9,32.45%to 35.53%and 34.86%to 36.46%for GR13,and 34.33%to 35.76%and 35.13%to 36.65%for GS1505,respectively.[Conclusion]The results of this study indicate that SC15,SC9,GR13 and GS1505 exhibit excellent pest resistance to T.urticae and P.marginatus,making them suitable as regionally adapted ideal cultivars for large-scale application in the Wuming area.
Pest mites are a significant pest group on citrus,severely impacting the green development of the citrus industry.The use of phytoseiid mites for controlling citrus pest mites is an important biological control technology with tremendous application value.This article reviews the known phytoseiid mite natural enemies of Panonychus citri McGregor and Eotetranychus kankitus Ehara,including 35 species from 10 genera.It also summarizes the potential natural enemies of these two pest mites in citrus orchards in China,comprising 39 species from 13 genera of phytoseiid mites.Additionally,the paper analyzes the current application status of Neoseiulus barkeri Hughes,Euseius nicholsi Ehara&Lee and Neoseiulus cucumeris Oudemans in controlling P.citri and E.kankitus.Finally,we discuss future directions such as improving phytoseiid mite strains,enhancing mass-rearing technologies,and developing an integrated pest management system centered on phytoseiid mites.
[Aim]The corn leaf aphid,Rhopalosiphum maidis(Fitch),is a major piercing-sucking pest of maize,and its population dynamics are closely related to the level of host plant resistance.To screen for aphid-resistant maize germplasm,this study evaluated the resistance performance of 14 maize varieties and investigated the impact of maize with varying resistance levels on the population development of R.maidis.[Methods]Using the aphid density ratio method,the seedling-stage resistance of 14 maize varieties was evaluated under controlled laboratory conditions.Based on preliminary resistance ratings,representative varieties—a highly resistant variety(Longyan 588),a susceptible variety(Qiuqing 1),and a highly susceptible variety(Jinkai 10)—were selected to construct life tables for R.maidis.[Results]The results showed that resistant varieties significantly suppressed aphid population growth.Specifically,first-instar nymphs survived for only about one day on the resistant variety Longyan 588,compared to approximately 2 days on Qiuqing 1 and Jinkai 10.Furthermore,the differentiation rate of alate aphids decreased on resistant plants,whereas the opposite trend was observed on susceptible varieties.The resistance evaluation identified Longyan 588,Keyu 188,Huamu 3,Jinkai 7172,and Jinkai 3 as highly resistant;Nongda 108 as resistant;Yayu 26 as moderately resistant;Hongtai 66,Jinyuanzao 247,and Qiuqing 1 as susceptible;and Qiuqing 88,Yayu 8,Hongtai 826,and Jinkai 10 as highly susceptible.Life table analysis confirmed significant differences in the duration of each life stage and the total generation time among varieties.The highly resistant variety Longyan 588 significantly inhibited nymphal development,resulting in a total generation time of only one day on this variety,which was significantly shorter than the 8.57 days on the susceptible variety Qiuqing 1 and the 7.82 days on the highly susceptible variety Jinkai 10.[Conclusion]Longyan 588 exhibits significant resistance to R.maidis and can therefore serve as a valuable aphid-resistant germplasm resource for subsequent breeding programs and research into resistance mechanisms.
