CH. XV.] SPECIES OF DIPTEROUS INSECTS. 227 



telescope. The wings are broad, and covered with 

 very fine hairs, but they are ahnost entirely desti- 

 tute of nerves ; the antennae are also very beautiful 

 microscopic objects, being composed of a number of 

 small knobs, each of which is surrounded by a whorl 

 of fine long hairs ; the legs are also very long and 

 slender. 



The history of this fly, which is the Cecidomyia 

 triticea, has occupied the attention of several ento- 

 mologists, and from their researches it appears, that 

 it is towards the end of June and throughout July 

 that the operation of depositing the eggs takes place. 

 The flies are said to repose during the day on the 

 lower parts of the stems, becoming active about 

 sunset, their activity depending in a considerable 

 degree upon the sun's being either near or below 

 the horizon ; and frequenting during the day the most 

 shaded parts of the crop. The insects prefer the 

 ears emerging from the vagina to those farther 

 advanced for the deposition of their eggs, and, from 

 one side only of the ear being exposed when the 

 plant is in this stage of growth, the other side gen- 

 erally remains uninjured. Sometimes as many as 

 thirty-five flies have been observed upon a single 

 ear, in the act of depositing their eggs, which are 

 generally found in clusters, varying in number from 

 two to ten upon the inner chaflT; they are also to be 

 observed in the interior parts of the flower, being 

 fixed by a glutinous secretion, with which they are 

 covered when deposited. It seems to be one of 

 the objects of the female fly to fasten the anthers, 

 by means of a similar glutinous matter, so as to 

 prevent the flowers from blooming ; this is done 

 to enable the larva the more easily to attack the 

 anthers, upon which it feeds ; and it often happens, 

 that so intent are the females when thus employed, 

 that they become entangled in the corolla, and fall a 

 sacrifice to their maternal affection, or rather to the 

 instinct which impels them to perform this act. 



