INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY
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2020
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IF 3.827
Xiang Zhou,Yi-Zhou Ye,Mari H. Ogihara,Mika Takeshima,Daiki Fujinaga,Cheng-Wen Liu,Zhen Zhu,Hiroshi Kataoka,Yan-Yuan Bao
Ecdysteroids , insect steroid hormones , play key roles in regulating insect development and reproduction. Hemipteran insects require ecdysteroids for egg production; however, ecdysteroid synthesis (ecdysteroidogenesis) details have not been elucidated. We identified all known genes encoding ecdysteroidogenic enzymes in Nilaparvata lugens and clarified their necessity during nymphal and ovarian development . We confirmed that N. lugens utilized 20-hydroxyecdysone as an active hormone. Assays using heterologous expression of enzymes in Drosophila S2 cells showed conserved functions of enzymes Neverland, CYP306A2, CYP314A1 and CYP315A1, but not CYP302A1. RNA interference and rescue analysis using 20-hydroxyecdysone demonstrated that most of the genes were necessary for nymphal development. The identified N. lugens enzymes showed conserved functions and pathways for ecdysteroidogenesis . Knockdown of ecdysteroidogenic enzyme genes in newly molted females caused failure of egg production: less vitellogenic and mature eggs in ovaries , fewer laid eggs and embryonic development deficiency of laid eggs. Considering the high expressions of ecdysteroidogenic enzyme genes in adults and ovaries, ecdysteroidogenesis in ovaries was critical for N. lugens ovarian development. Our study presents initial evidence that hemipteran insects require ecdysteroidogenesis for ovarian development.
研究领域:
昆虫学
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分子生物学
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生物化学
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DOI
PubMed
高影响因子
JOURNAL OF PEST SCIENCE
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2020
·Vol. 94
·期 2
·463-472
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IF 4.578
Xu Hao,Zhao Jiajia,Li Faqian,Yan Qi,Meng Ling,Li Baoping
Riptortus pedestris (Fab.) is an important pest on soybean plants in East Asia. Females lay eggs scattered not only on host plants, but also on non-host plants, probably for avoiding detection by natural enemies. Newly hatched nymphs can develop to the second instar without the need of food except water. Second instar nymphs, the first-feeding stage with a strong locomotion, need to find suitable feeding sites on host plants. The mechanism is still not well understood. Here, we found second instars were attracted by both male and female adults, but generally repelled by second and fifth instar nymphs, wherein their responses were little affected by food volatiles (soybean seeds or seedlings). Nymphs distinctly differed from adults in chemical composition of the whole-body extracts. 4-oxo-( E )-2-Hexenal was the major component in nymph’s extracts, but it was not found in adults, whereas some ester compounds, such as ( E )-2-hexenyl esters, were exclusively found in adults and accounted for the main part in their extracts. The three esters, ( E )-2-hexenyl ( Z )-3-hexenoate (E2-6:Z3Hx), ( E )-2-hexenyl ( E )-2-hexenoate (E2-6:E2Hx) and myristyl isobutyrate, were male specific and had been reported as an aggregation pheromone. Synthetic 4-oxo-( E )-2-hexenal strongly repelled second instars, while ( E )-2-hexenyl hexanoate emitted by both males and females attracted them. The main component of the aggregation pheromone, myristyl isobutyrate, also strongly attracted second instars. How the findings may improve the efficiency of chemical traps in fields was discussed.
研究领域:
昆虫学
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化学生态学
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害虫管理
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产品关联
DOI
高影响因子
Parasites & Vectors
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2021
·Vol. 14
·期 1
·1-11
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IF 3.876
Nwanade Chuks F.,Wang Min,Wang Tianhong,Zhang Xiaoyu,Wang Can,Yu Zhijun,Liu Jingze
Background The tick Haemaphysalis longicornis (Neumann) is a well-known vector of numerous pathogens of veterinary and medical importance. Various control strategies, including the use of synthetic pesticides, have been developed to control this tick species. However, demand for effective and safe alternative pesticides is increasing due to the adverse effects associated with the intensive and injudicious use of synthetic pesticides, which include undesirable effects on non-target species and environmental pollution. Hence, the acaricidal activity of the extract and the essential oil of Cinnamomum cassia (Chinese cinnamon) and their major components, and the underlying mechanisms of this activity, were evaluated against unfed larvae and nymphs of H . longicornis . Methods The components of the extract and essential oil of C. cassia were determined by gas chromatography-mass spectrometry, and their larvicidal and nymphicidal activity were evaluated using the larval and nymphal packet test. The underlying detoxification mechanism was elucidated by targeting in vivo esterase and monooxygenase activity, and the toxicological effect was assessed on non-target Tenebrio molitor and Harmonia axyridis by topical application in open Petri dishes. Results ( E )-cinnamaldehyde was the predominant component of the extract (50.79%) and essential oil (89.95%). The 50% lethal concentration (LC 50 ) for larvae and nymphs treated with the extract was 11.56 and 49.18 mg/mL, respectively. The essential oil, ( E )-cinnamaldehyde and fenvalerate exhibited acaricidal activity, with LC 50 values of 3.81, 3.15, and 0.14 mg/mL, respectively, against the larvae, and 21.31, 16.93, and 1.89 mg/mL, respectively, against the nymphs. ( E )-cinnamaldehyde significantly increased esterase and monooxygenase activity in both larvae and nymphs. Unlike fenvalerate, C . cassia essential oil and ( E )-cinnamaldehyde did not cause mortality of T . molitor or H . axyridis adults. Conclusions This study demonstrates that C . cassia essential oil and ( E )-cinnamaldehyde have the potential to be developed into botanical-based larvicidal and nymphicidal agents for tick control. Graphical abstract
研究领域:
植物学
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昆虫学
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农药科学
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兽医学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）