394 



TRANSFORMATIONS OF INSECTS, 



The Cecidomyidcu are very small Diptcra which, like the Cynips, 

 produce galls on plants in which their larvae live. Nevertheless, 

 there are exceptions to this gall-making peculiarity, for the wheat 

 fly, Cccidomyia tritici, lays its eggs in the centre of the flower of 

 the wheat plant, and when its larvae are hatched they eat the 

 pollen, and thus prevent the formation of the corn. An American 

 species, which is known by the name of the Hessian Fly, attacks 

 the lower part of the stem of the wheat plant, and the larva 



Ceridcmyia with viviparous larv.«. 



nourishes itself with the sap, which it appears to take by suctiofi, 

 and causes the stem to wither and die. 



A very interesting discovery has been made by Nicholas 

 Wagner, a professor at Kazan, to the effect that the larvae of 

 some species of Cccidomyia which live underneath the bark of 

 trees have the power of producing creatures like unto themselves. 

 In the centre of the engraving there is a representation of the 

 adult insect, and on either side of it drawings of the nymph, and 

 below the larva is depicted, and it will be seen to contain at a a 



