群居型和散居型东亚飞蝗雌成虫飞行肌的超微结构

应用电子显微镜对群居型和散居型东亚飞蝗Locusta migratoria manilensis（Meyen）雌成虫背纵肌进行了比较观察。结果表明：群居型和散居型成虫背纵肌具有类似的亚细胞结构,飞行肌的肌原纤维具有1∶3粗细丝比例,每根粗丝由6根细丝环绕排列成六角形结构。飞行肌的发育和线粒体的形成均是渐进的过程,在不同日龄成虫间存在差异。肌节长度为2.1～3.4 μm;7和10日龄时群居型成虫肌节长度小于散居型;7日龄群居型肌原纤维直径显著大于散居型。背纵肌内线粒体含量约占肌纤维的20%～43%,两型飞蝗之间存在着显著的差异,7日龄时群居型线粒体占肌原纤维的比例高达42.96%,而散居型的只有22.45%;10日龄群居型线粒体含量为41.32%,散居型线粒体29.98%。上述差异可能是东亚飞蝗群居型成虫飞行能力显著强于散居型成虫的重要原因之一。

Ultrastructure of the flight muscle of female adults in the gregarious phase and solitary phase of the oriental migratory locust,Locusta migratoria manilensis(Meyen)(Orthoptera:Acrididae)

The electron microscope examination of ultrastructure of flight muscle of female adults in both gregarious and solitary phases of the oriental migratory locust, Locusta migratoria manilensis (Meyen) was performed. The results show that 7 days after emergence, the adults of both phases have the similar structures of indirect flight muscle, where the thick and thin filaments form a hexagonal lattice with myosin and actin in the ratio of 1∶3. The development of flight muscle and formation of mitochondrion are gradually changeable process with differences between the different day-old adults. The sarcomere length (2.1-3.4 μm) of 7 or 10 day-old adults in the gregarious phase is shorter than that in the homologous solitary phase. The myofibril diameter of 7 day-old adults in the gregarious phase is thicker than that in the solitary phase. The mitochondrion displays some shapes in the early adult period and grows daily. The mitochondrion content in myofibril is 20%-43%, which are different between the phases: 42.96% in 7 day-old adults of the gregarious phase and 22.45% in those of the solitary phase;  41.32% in 10 day-old adults of the gregarious phase and 29.98% in those of the solitary phase. It is inferred that the above differences in sarcomere length, myofibril diameter and mitochondrion content in flight muscle may contribute to different flight abilities in the two phases of L. migratoria manilensis adults, of which those in the gregarious phase can migrate for longer distance.