HORSE FLIES AND RELATIVES. 



Aquatic larvae (such as those of Stratiomyia, Plate LXV, 

 and Odontomyia, Plate LXVI) have a circlet of bristles 

 on their tails which opens out flat when the larva is at the 

 surface taking atmospheric air into its tracheal system 

 through its tail-spiracles, but which folds together when the 

 larva wishes to free itself from the surface film. Many, or 

 most, of these aquatic larvae pupate in the mud at the 

 water's edge. Larvae also occur in cow dung (Myiochrysa), 

 in privies (Hermetia), under stones, in tree sap (Geosargus), 

 in decaying wood (P achy gas ter), in moss, in catsup, and on 

 vegetables, such as potato tubers and growing lettuce. 

 Some are carnivorous; others are vegetarians. Pupation 

 occurs in the larval skin. 



TABANID^: 



These (Plates LXV and LXVI) are surely of popular 

 interest ; they are the Horse Flies, Green-headed Monsters, 

 Gad Flies, Breeze Flies, Ear Flies or Deer Flies. Only the 

 females bite; the males content themselves with sipping 

 sweets from flowers. The predaceous larvae live in water 

 or in moist earth, apparently hibernating as mature larvae 

 and pupating, free from the larval skin, the following 

 spring. The somewhat flattened larvae have a circle of 

 fleshy protuberances around each segment, which aid 

 them in locomotion. There are many species, about 

 forty of Tabanus and thirty-five of Chrysops having been 

 recorded, for example, from New Jersey. The eyes of the 

 males touch each other above; those of the females are 

 somewhat separated ; but those of both sexes, especially of 

 Chrysops, are beautifully marked with brilliant colors 

 in life. These colors may often be temporarily restored 

 in dried specimens by moistening with water or glycerine. 



1. Hind tibiae with spurs at the tip 2. 



Hind tibiae without spurs at tip ; ocelli absent 3. 



2. Third joint of antennae composed of 5 superficially 

 separated rings, the first of which is much longer than the 

 following ones; ocelli present. Chrysops is the common 

 genus. The wings very often have broad, black crossbands. 

 The western SiLius is distinguished from it by having 

 the second antennal joint only half as long as the first. 



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