The postembryonic development of the indirect flight muscles in Cenocorixa bifida (Hung.) (Hemiptera: Corixidae)

Abstract

The postembryonic development of the mesothoracic indirect flight muscles of Cenocorixa bifida is described and compared with the corresponding development in a terrestrial hemipteran, Oncopeltus fasciatus. The early development in the first four larval instars in the two insects is very similar, since the dorsolongitudinal muscles of the first instar disappear, and are replaced in later instars by new muscles that function in the adult.C. bifida emerges as an adult with the indirect flight muscles in a juvenile condition, this being the result of a developmental arrest that takes place within a few hours of the adult molt. The non-flying form of this corixid is shown to have muscles with juvenile characteristics, and it is concluded that this form represents a permanent retention of the teneral adult muscle condition. The muscle structure of the non-flying morph is not the result of degeneration of the indirect flight musculature in the adult.By comparison with other developmental systems, it is suggested that the developmental arrest in C. bifida results from a lack of mRNA. It is suggested that the arrest is hormone regulated.The non-flying morph of C. bifida is compared with the non-flying forms of other aquatic Heteroptera, and reference is made to the tracheoparenchymatous organ that has been described in these species.