86 THE EARLY STAGES OF TABANID^ 



"The larva [Plate 3, Fig. 46] is a large twelve-jointed cylindrical affair, taper- 

 ing at each end, of a transparent, highly polished, glassy, yellowish or greenish 

 appearance, shaded with bluish green and furnished above and below as in the 

 figure (figure given by Riley) with large roundish sponge-like tubercles which 

 are retracted or exserted at the will of the insect. Though the external integu- 

 ment is so transparent that the internal structure is readily visible, yet this 

 integument is firm and the larva most vigorous and active, burrowing with great 

 strength either backward or forward in the earth and between one's fingers when 

 it is being held. Placed in water it will swim vigorously by suddenly curhng 

 round and lashing out its tail, but it is apparently not as much at home in this 

 element as in the moist earth, for it is restless and remains near the surface with 

 the tip of its tail elevated into the air. When the water is foul it moves about 

 actively near the surface, but when it is fresh it remains more quietly at the 

 bottom." 



This specimen, which Riley succeeded in breeding, was sent to 

 him by Mr. Adolph Engelmann, of Shiloh, St. Clair County, 111. 

 It was found by Mr. William Cooper, of the same county, about ten 

 feet from a small but permanent body of water. Mr. Cooper at first 

 took it to be a leech, but when he attempted to catch it it immediately 

 commenced burrowing into the ground. 



The larva is declared by Riley to be semiaquatic, for it is at home 

 either in moist earth or water. This specimen was kept for over two 

 weeks in a large earthen jar of moist earth well supplied with earth- 

 worms. It manifested no desire to come to the surface. Riley 

 found several pale dead worms in this jar, though not able to say 

 positively whether they had been killed and sucked by this larva. 



Hart (1895) reports that he has taken the larva of Tabanus atratus 

 in every month of the season except June, at which time they had 

 mostly reached the pupa or imago stage. They seemed to prefer 

 the sandy shores, and were taken abundantly May 17 at Hart's 

 Survey Station C, by running through a coarse sieve the surface 

 layers of sand of the shore near the wave-washed margin. Station 

 C is characterized by Hart as being located near the outlet of Quiver 

 Lake, the shores being here near together and sheltered. The east 

 bank was sandy, with a muddy coating over the part which is exposed 

 at low water, while the west shore was of black mud grown over with 

 willow trees and overflowed in moderately high water. The water 

 was clear and on both sides thickly filled in summer with algae and 



