THE ICHNEUMON FLY: ENEMY OF THE SPIDER
(Crypturopsis sp.)
It would seem as though the spider ought to be able to protect itself from such a beautiful creature as this, but she is said to be one of the spider’s worst enemies. With the long ovipositors which may be seen in the photograph and might almost be mistaken for her sting, she lays her eggs inside those of the spider and the larvæ hatching from them eat up the spider’s eggs. It is, so to say, an insect cuckoo, or worse than that, for the bird cuckoo only crowds the real children out of the nest, whereas the ichneumon fly devours them.
From man’s point of view, however, many of the tribe to which this so-called fly belongs are his good friends, for they hold in check some of the pests which molest the plants he lives upon.