32 



DIPTERA OF MINNESOTA. 



face that consideration by a simple synopsis, 

 which we beheve will be easily understood 

 ^ by the beginning student, and may be of 

 some service in helping him to place in its 

 proper family any fly which he may have 

 captured in the state. The synopsis is taken 

 from Comstock's "Manual for the Study 

 of Insects." Since the family Muscidae has 

 been separated into several, we have called 

 the same division Muscidea (a term used 

 by Williston) where the family name occurs 

 in Comstock's key, placing in connection all 

 the families which are included therein. 

 The three last families, however, Hip- 

 pohoscidae, Nyctcrybiidac and Branlidae are left in the same posi- 

 tion assigned them by Comstock. We have also introduced, in its 

 proper place, the family Acanthomeridae . 



Fig. 15. Diagram to illustrate 

 motion of a fly's wing in flight. 

 After Lowne. 



SYNOPSIS OF THE DIPTERA. 



The Straight Seamed Flies. Flies in which the pupa escapes 

 from the larval skin through a T-shaped opening (Fig. i6), 

 which is formed by a lengthwise split on the back near the 

 head end and a crosswise split at the front end of this, or 

 rarely through a crosswise split between the seventh and 

 eighth abdominal segments; adults without a frontal lunule. 

 Sub-order Ortiiorrhapha. 

 The Long-Horned Ortiiorrhapha or Nematocera. Flies with four 

 or five-jointed pendulous palpi and with many-jointed 

 antennae, which are usually long. The segments of 

 the antennae, except the basal two, are similar in form, 

 and are more than six in number. They are often 

 fringed with hairs or bristles. 

 The True Nematocera. The antennae usually long, and frequently bearing 

 whorls of long hairs, especially in the males; legs long and slender; 

 abdomen usually long and slender. 

 The Moth-like Flies, Family PsvchodidaE, p. 35. 

 The Midge-like Flies. 



The Crane-flies, Family TipulidaE, p. 36. 



The Net-winged Midges, Family BlEpharoceridae, p. 38. 



The Dixa-midges, Family DixidaE, p. 39. 



The Mosquitoes, Family CuucidaE, p. 40. 



The Midges, Family GiiironomidaE, p. 52. 



The Fungus-gnats, Family MycetophilidaE, p. 54. 



The Gall-gnats, Family Cecidomyidae, p. 57. 



Fig. 16. 



(After 



Comstock.) 



