146 



American Midland Naturalist Monograph No. 3 



last two segments much stouter than the preceding segments. Antenna extend- 

 ing to the apex of the third palpal segment or only slightly beyond; the last 

 two antennal segments comprising less than half the length of the entire 

 antenna. TERMINALIA. The terminalia of this species is very similar to that 

 of Psorophora ferox (Fig. 73B) . 



LARVA. (Fig. 75). — Head much wider than long. Antenna variable in 

 length (may be shorter or slightly longer than head), spinose; antennal tufl 

 multiple, barbed, inserted near middle of shaft, not reaching tip or barely so. 

 Head hairs: Preantennal (A) multiple, barbed, not reaching insertion of 

 antennal tuft; lower (B) triple, sometimes double, barbed, short, not reaching 



Fig. 75. Larva of Psorophora horrida (Dyar and Knab). A, Terminal 

 segments. B, Pecten tooth. C, Comb scale. D, Head. 



