There are exceptions to the rule of male insects being smaller than the females, and some

of these exceptions are intelligible. Size and strength would be an advantage to the males which fight for the possession of the females, and in these cases, as with the stag-beetle (Lucanus), the males are larger than the females. There are, however, other beetles which are not known to fight together, of which the males exceed the females in size, and the meaning of this fact is not known, but in some of these cases, as with the huge Dynastes and Megasoma, we can at least see that there would be no necessity for the males to be smaller than the females, in order to be matured before them, for these beetles are not short-lived, and there would be ample time for the pairing of the sexes.

According to the author, ______.

A．male insects are always smaller than females

B．in a given species nature provides differences between sexes to insure successful reproduction

C．size and strength protect females from other females

D．longevity is characteristic of the Dynastes and Megasoma