58 MISC. PUBLICATION 631, U. S. DEPT. OF AGRICULTURE 



Larvaevoridae (Tachinidae). Townsend (153, pt. V, p. 122) uses 

 the name Calliphoridae in a more restricted sense to include only the 

 Calliphorini and the Chrysomyini ; this would exclude such genera as 

 Pollenia, Auchmeromyia, and Cordylobia, to which that author gives 

 a separate family status. 



The Calliphoridae include a large number of species of metallic blue, 

 green, or copper flies of medium size. Some species are otherwise 

 colored or nonmetallic, however, and some flies, such as the metallic 

 Muscini and certain larvaevorids, superficially resemble the blowflies. 



In the adult the arista is plumose, the hairs being usually long and 

 extending almost to its apex ; there is no postscutellum ( except in some 

 genera not treated here) ; hypopleural and pteropleural bristles are 

 present ; there are three sternopleurals, two in front and one behind ; 

 there are two notopleurals, rarely an adventitious third; vein m 1+2 

 bends strongly forward, greatly narrowing but usually not closing the 

 apical cell ; and the first abdominal sternite overlaps the lateral mar- 

 gins of the tergites. 



The larvae are for the most part scavengers feeding on decaying 

 animal matter; some, however, are accidental, facultative, or obliga- 

 tory parasites on vertebrates, and some may attack invertebrates. In 

 form they are, with rare exceptions, of the usual muscoid type; the 

 posterior end is truncated with usually three pairs of tubercles above 

 and three below, with an additional smaller pair above the three of 

 the lower series ; the posterior spiracles are not situated in a depres- 

 sion, as in the Sarcophagidae; the spiracular slits are elongated, 

 slender, and subparallel. 



The taxonomic literature is extensive. Hall (49) has monographed 

 the North American species ; his work, recently published, includes a 

 treatment of the larval as well as the adult stages, with much informa- 

 tion on the biology of the species. The second- and third-stage larvae 

 of the American species are described by Knipling (74). Among 

 the many European works that of Seguy (135) will be found useful. 

 The Oriental species are described by Senior- White, Aubertin, and 

 Smart (139) ; the South Pacific islands and Australia by Bezzi (16) ; 

 the larvae by Fuller (41, p. 78) ; and the New Zealand species by 

 Miller (90). 



KEY TO THE GENERA 



1. Base of the radius (before the humeral cross vein) ciliated posteriorly 



above (figs. 4 and 5) 2 



Base of the radius bare posteriorly above 6 



2. Hind coxae pilose posteriorly ; green to violet-green species, with 3 prom- 



inent black longitudinal vittae on the mesonotum 3 



Hind coxae bare posteriorly ; green to bluish-black species, sometimes 

 with transverse bands or 2 narrow longitudinal vittae or both on 

 the mesonotum, but never marked as above 4 



3. Palpus short and filiform, not nearly reaching the margin of the 



epistoma Callitroga Brauer 



Palpus elongated and clavate, almost reaching the margin of the 

 epistoma Paralucilia Brauer and Bergenstamm 



4. Lower squama pilose above Chrysomya Robineau-Desvoidy 



(including M icrocalliphora ) 

 Lower squama bare 5 



