【摘要】 互花米草(Spartina alterniflora)入侵盐沼生态系统导致了土著广食性昆虫素毒蛾(Laelia coenosa)发生宿主转移。但是,目前对素毒蛾在互花米草和芦苇(Phragmites australis)上的生活史规律的比较尚未见报道,而此信息对评价素毒蛾能否持续利用互花米草具有重要的参考价值。为了明确素毒蛾在其原始宿主芦苇和外来新宿主互花米草上的生活史动态,我们在上海崇明长江口盐沼湿地中,对素毒蛾在芦苇和互花米草生境中的发生情况进行了系统调查。结果显示,虽然素毒蛾在芦苇和互花米草上均一年发生3代,并都以幼虫越冬,但在互花米草生境中,越冬代幼虫开始越冬的时间要比芦苇中晚20d左右,其他世代中的多个虫态在互花米草上持续出现的时间也比芦苇上延迟了约10 d。这些结果表明,互花米草入侵后素毒蛾在外来植物上出现的持续时间虽然发生了延长,但其年世代数未变化。我们推测素毒蛾在互花米草和芦苇上生长发育规律的差异可能受生境的资源可利用性及两种植物的营养与防御水平调控。更多还原

【Abstract】 The invasion of Spartina alterniflora into saltmarsh ecosystems has resulted in a host transfer of a native generalist insect, Laelia coenosa. Currently, the life history of L. coenosa on S. alterniflora is unclear,although this information is of great importance for evaluating if the native insect can permanently use S.alterniflora. To compare the differences in life history dynamics of L. coenosa between its native host plant Phragmites australis and the invasive host plant S. alterniflora, we investigated the insect occurrence on the two plant habitats in a saltmarsh of the Yangtze River estuary in Chongming, Shanghai. We found that the insect occurred in three generations and overwintered as larvae on both S. alterniflora and P. australis. The larvae started overwintering about 20 days later on the invasive plant than on the native plant, and emerging duration of the insect at most stages of other generations was also approximately 10 days later on the invasive than on native plant. These results suggest that following S. alterniflora invasion the duration of the moth’s appearance on the invasive plant is prolonged however the number of annual generations does not change.We speculate that the differences in growth and development of L. coenosa between S. alterniflora and P.australis may be related to resource availability between plant habitats and the nutritional and defensive levels between plant species.更多还原