HABITS AND LIFE HISTORIES OF TABANID^. 



35 



the surface, where they can not be seen. At first these larva? are very 

 hard to see on account of their small size; conseijuently not much has 

 been learned of their habits under natural conditions; but when 

 nearly grown they are to be found in a variety of places. Walsh was 

 the first to make reference in writing to this species in the larval stage. 

 He found specimens in floating debris and rotten logs and on one occa- 

 sion under a log on dry land. I have taken them while digging in the 

 ground in the vicinity of ponds, from under stones on ditch banks, 

 from the water with dip nets, and occasionally in most unexpected 

 places. However, if one is looking for them he is likely to meet with 

 more or less disappointment, as the finding of one specimen does not 

 indicate necessarily that others maybe taken under the same conditions. 



Fig. 9. — Tabanus at rat us: Adult male at left, female at right. From a photograph; enlarged 



(original). 



The fact that specimens have been taken from floating logs and 

 debris suggests that the}^ may be transported for longer or shorter 

 distances in this wa^', and during high water stranded upon ground 

 which, when the flood subsides, is high and dry and far removed from 

 the bed of the stream. Since the species in all its hal)its is closely 

 associated with water and wet ground, this seems to be the onh" way 

 of explaining the appearance of larvre in dr}- soil and in places remote 

 fron) where the eggs are laid. 



Full-grown larva nearly 2 incfies in length. General color yellowish white, with 

 wide dark brown bands at the union of each two segments. Protlioracic segment on 

 each side with two lateral grooves, which do not quite reach the posterior border 

 of the segment, and a dorsal groove continued for the entire length. These grooves 

 ■ and a number of irregular dots on the posterior part are dark colored, while the 

 remainder of the segment is light. Mesothoracic segment, on each side, with four 

 longitudinal grooves, which reach nearly the entire length. The dark markings on 

 this segment include a narrow anterior border, the lateral grooves, and a number of 



