HABITS AND LIFE HISTORIES OF TABANID^. 



31 



August 2, of the same year, I took a large larva of this species in 

 Summit Count}', Ohio, from under a tiat stone along a brook that ran 

 from a spring. When taken this specimen measured over 40 mm. in 

 length and had every appearance of being mature, but it continued to 

 eat the angleworms given it until late in the 

 fall. It then ceased feeding until the fol- 

 lowing spring, when it took a small amount 

 of food and entered the pupal stage about 

 the middle of May, the adult, a male, issuing 

 June 14. 



From what I have learned of the life C3'cle 

 of the species it seems hardly possible that 

 it passes all its transformations in a single 

 year, for the larva? reared from eggs were 

 not over 8 mm. long when the specimen over 

 40 mm. long was collected; and as the latter 

 did not produce the adult until about the 

 normal time for adults to appear under natu- 

 ral conditions, it does not seem possible that 

 the first-mentioned larvie could have reached 

 maturity and i^roduced adults before the sec- 

 ond year. 



Larva, when first hatched, 4 mm. long; entirely light colored; form as in older 

 specimens. As growth continues size is the onh' noticeable change. 



The mature larva has been figured and described in detail by Hart 

 in his paper, "On The Entomology of the Illinois River and Adjacent 

 Waters. "« 



Pa/>a (fig. 7, a) 29 mm. long; color dark, approaching fuscous; prothoracic spiracle 

 strongly bent at the middle; rima oblique and straight for the outer half of its length, 

 remainder gradually curved, with a broad hook at the inner end. Teeth at the end 

 of the abdomen (fig. 7, b) six in number, nearly equidistant from one another, of 

 nearly the same size, with the extreme tips slightly turned inward. 



A, 



Fig. (!.— Adult female of Tahaniis 

 dyi/ius. From a photograph; 

 enlarged (original). 



Fig. l.— Tabanun stygius: A, pupa; b, terminal abdominal teeth of same. En- 

 larged (original 1. 



The pupa of stygius is much like that of .sulelfrons, but there is some 

 difi'erence in the prothoracic spiracles and in the abdominal teeth. 



«Bul. IlL State Lab. Nat. Hist., Vol. IV, Art. VI, pp. 239-240, PI. XI, figs. 47,48, 

 1895. 



