粘虫飞行对生殖及寿命的影响

该文报道了粘虫Mythimna separata（Walker）成虫飞行后产卵、交配及寿命的研究结果。1日龄成虫飞行6 h、12 h、18 h、24 h后的产卵前期均显著短于对照的，其中飞行6 h、12 h的比对照的短2天以上，产卵量均比对照的高。对1～5日龄成虫分别飞行23.5 h后的研究结果表明，1日龄飞行的产卵前期和上述结果相一致。2～4日龄飞行的与对照的没有显著差异，但产卵量则随飞行日龄的延迟而逐渐减少。5日龄飞行的产卵前期显著延长，产卵量已不到对照的一半。所有经过飞行的成虫产卵高峰日比对照的早1天。不同日龄成虫飞行时间、距离与成虫产卵量的关系为：1～3日龄飞行时间、距离长的个体产卵量也高；但4～5日龄的成虫飞行时间与距离越长，其产卵量越少，表现出明显的卵子发生飞行拮抗症(oogenesis-flight syndrome)。除了5日龄飞行的成虫交配率有所下降以外，所有经过飞行的成虫产卵历期、交配率及寿命与对照的没有显著差异。最后，根据这些结果，对粘虫迁飞的起飞时期，迁飞在粘虫生殖、种群动态及成灾规律中的作用进行了讨论。

INFLUENCES OF FLIGHT ON REPRODUCTION AND LONGEVITY OF THE ORIENTAL ARMYWORM, MYTHIMNA SEPARATA(WALKER)

The preoviposition period (POP), fecundity, copulation and longevity of the migratory oriental armyworm moth, Mythimna separata (Walker), as influenced by tethered flight were investigated in the laboratory. The moths flown for 6, 12, 18 and 24 hours at day-1 after emergence began oviposition 1-2 days earlier than the unflown ones, and the difference was significant. Life time fecundity of the moths flown at this age for various periods was also greater than that of the control indicating that flight can enhances the reproduction capacity of the moths. The reproductive parameters, however, differed greatly in the moth following 23-5 hours tethered flight at different ages after emergence. POP of the moths flown at day-1 was not only significantly shorter than that of the control, but also than that of the moths starting to fly from day-2 to day-5. POP of the moths flown at day-5, however was significantly longer than that of the control. Life time fecundity of the moth showed close relation to the age of the moths starting to fly. The earlier the moths started to fly after emergence, the greater the fecundity they had. When the moths flown at day-5 after emergence, for example, their life time fecundity was only half of that in the control and half less than that in the moths flown at day-1, exhibiting an oogenesis-flight syndrome. Relationship between flight distance and the total fecundity of the moth differed greatly as the age of the moth starting to fly varied. Fecundity in the moth flown farther or longer was greater than those flown shorter when the moth was tested at day-1 to day-3. The situation, however, got reverse when the moth was starting to fly at day-4 and day-5. Regardless of flight age of the moth, the oviposition peak of the flown moths occurred 1 day earlier than that of the moth without tethered flight. Longevity, mating percentage of the moths undergone flight were insignificantly different from that of the controls, except the mating percentage of the moth flown at day 5 was lower. The ascent period of the moth for migration, significance of flight or migration in the life history, population dynamics and outbreaks of the oriental armyworm are discussed on the results obtained together with the lights of published findings.