大螟成虫性信息素生物合成和释放及求偶和交配行为的昼夜节律

【目的】探索大螟Sesamia inferens性信息素顺11-十六碳烯乙酸酯(Z11-16∶Ac)和顺11-十六碳烯醇(Z11-16∶OH)的合成和释放及求偶和交配行为的昼夜节律，及其与田间性信息素诱捕的关系。【方法】通过溶剂浸提和固相微萃取(solid phase microextraction, SPME)分析大螟雌蛾性信息素Z11-16∶Ac和Z11--16∶OH的滴度，结合行为观测和多地田间实时性信息素诱捕数据，调查大螟性信息素的生物合成、释放及求偶和交配行为的昼夜节律。【结果】大螟雌蛾腺体内性信息素Z11-16∶Ac和Z11-16∶OH含量可检测到的时间始于暗期前1 h，暗期后4 h快速增加，暗期8 h为第1次高峰，但光期1h又一次高峰，光期5 h还可以被显著检测到。分泌至腺体外的性信息素化合物可检测到的时间始于暗期后6 h，高峰期在暗期后10 h，光期后1 h性信息素Z11-16∶Ac滴度达到96.9±20.9 ng/雌。采用溶剂浸提法获得的Z11-16∶Ac和Z11-16∶OH的比例在暗期平均为2.8±1.9，在光期平均为2.5±0.9，统计上二者没有显著差异，而SPME法获得的Z11-16∶Ac和Z11-16∶OH的比例在暗期平均为8.5±1.2，在光期平均为5.7±0.6，统计上二者差异显著。产卵器伸出时间发生在暗期6-8 h，产卵器伸出持续时间平均为80.8±4.4 min。大螟的交配发生在暗期4-10 h，交配持续时间平均为83.4±5.0 min。广东、四川、浙江、江苏四省性诱自动计数的田间每日每小时实时计数数据显示，越冬代诱蛾比较集中，之后的世代则比较分散，田间雄蛾的性诱昼夜节律受地理环境、季节和世代等因子的影响。【结论】本研究发现大螟交配和性信息素释放的昼夜节律在时间上不一致，交配时间在暗期较早时段。雌蛾性信息素有效的释放时间范围比雄蛾对性信息素反应的要小。产卵器伸展与雌蛾性信息素化合物的释放速率加快和扩散 范围有关。

Circadian rhythms of the sex pheromone biosynthesis and release and the calling and matingbehaviors of adultSesamia inferens(Lepidoptera: Noctuidae)

【Aim】 To explore the circadian rhythms of the synthesis and release of sexheromones Z11-16∶Ac and Z11-16∶OH and the calling and mating behaviors of adultSesamia inferens, and their relationships with sex pheromone trapping in the field.【Methods】 The sex pheromone titers of Z11-16∶Ac and Z11-16∶OH of female moths of S.inferens were analyzed by solvent extraction and solid phase microextraction (SPME), andthe circadian rhythms of sex pheromone biosynthesis and release and the calling and matingbehaviours of moths were investigated by behavioral observation and real-time counting ofmoth catches by sex pheromone trapping in the field in multiple localities. 【Results】 Thedetectable time of sex pheromone Z11-16∶Ac and Z11-16∶OH in the pheromone glands offemale moths of S. inferens started at 1 h before scotophase, and increased rapidly at 4 hinto scotophase, reaching the first peak at 8 h into scotophase and the 2nd peak at 1 hinto photophase. The sex pheromone compounds were significantly detected at 5 h intophotophase. The detectable time for sex pheromone compounds emitted outside of the glandsstarted at 6 h into scotophase and peaked at 10 h into scotophase, and the sex pheromoneZ11-16∶Ac titer still remained 96.9±20.9 ng/female even at 1 h into photophase. Theratios of Z11-16∶Ac and Z11-16∶OH obtained by solvent extraction were not significantlydifferent in scotophase and photophase, with averages of 2.8±1.9 and 2.5±0.9,respectively, while the difference in the ratios of Z11-16∶Ac and Z11-16∶OH obtained bySPME was statistically significant in scotophase and photophase, with averages of 8.5±1.2and 5.7±0.6, respectively. The full extrusion of ovipositor occurred at 6-8 h afterscotophase, and lasted 80.8±4.4 min on average. The mating of S. inferens occurred at 4-10h into scotophase, and lasted 83.4±5.0 min on average. The real-time hourly and dailycounting of moth catches in the field by automatic counting of pheromone trapping in thefour provinces of Guangdong, Sichuan, Zhejiang and Jiangsu showed that the number of mothstrapped was relatively concentrated in time in the overwintering generation, but wasrelatively scattered in the following generations. The circadian rhythms of male mothtrapping in the field were affected by such factors as geographical environment, season andgeneration. 【Conclusion】 This study reveals that the circadian rhythms of mating and sexpheromone release of S. inferens are inconsistent and the mating time is in the earlierperiod after scotophase. The range of effective release time of sex pheromone of femalemoths is shorter than that of response time of male moths to sex pheromone. The extrusionof the ovipositor is associated with the elevated release rate and the disperse range ofthe sex pheromones released by female moths.