462 



Wirth and Stone: Diptera 



Subfamily ERISTALINAE 



Genus Tubifera Meigen 1800 



[=Eristalis Latreille 1804, Elophilus Meigen 1803] 



Johannsen (1935) has published descriptions of seven 

 North American species of ratrtailed maggots of this 

 genus. Excellent figures of the immature stages of 

 T. tenax (L.) and aeneus (F.) also have been pub- 

 lished by Metcalf (1913), and an exceptionally fine 

 account of the Australasian T. arvorum (F.) in Hawaii 

 was given by Williams (1939) (fig. 14:53c?-/, h, i). 



Key to Adults of the California Species of Tubifera 



1. Eyes bare, reddish brown, with more or less confluent 

 dark brown spots; scutellum concolorous with meso- 

 notum; California aenea (Scopoli) 1763 



— Eyes not spotted, hairy; scutellum more or less yellow- 

 ish 2 



2. Mesonotum with a transverse metallic fascia situated 

 between the scutellum and the suture; San Bernardino 

 County alhambra (Hull) 1925 



— Mesonotum without a prescutellar band 3 



3. Pile of eyes confined to a vertical stripe; large, honey- 

 beelike species, moderately pilose; widespread .... 



tenax (Linnaeus) 1758 



— Pile of eyes not confined to a vertical stripe 4 



4. Third abdominal segment of males with conspicuous, 

 lateral, yellow spots; moderately pilose species; 

 mesonotum with a pair of anterior, longitudinal sub- 

 lateral, pollinose bands; California 



occidentalis (Williston) 1882 



— Third abdominal segment of males dark except for 

 narrow basal and apical bands; thinly pilose species; 

 mesonotum without pollinose bands 5 



5. Arista with long pubescence on basal 1/2; California 

 hirta (Loew) 1865 



Arista entirely bare; widespread . .latifrons (Loew) 1865 



Genus Mallota Meigen 



Johannsen (1935) gives descriptions of the immature 

 stages of the common eastern species M. posticata 

 (Fabricius) and M. cimbiciformis (Fallen) which 

 breed in tree holes. Apparently they are not reported 

 from California. 



Genus Helophilus Meigen 



The larva of Helophilus latifrons Loew, which was 

 described and figured by Jones (1922), is similar to 

 that of Tubifera except that the two longitudinal 

 tracheal trunks are undulating (fig. 14:536). 

 California species: 



fasciatus Walker 1849. 

 latifrons Loew 1863. 



Widespread 

 Widespread 



REFERENCES 



BLOOMFIELD, E. N. 



1897. Habits of Sericomyia borealis Fin. Ent. Mon % Mag., 

 33:222-223. 



CURRAN, C. H. 



1934. Notes on the Syrphidae in the Slosson collection of 

 Diptera. Amer. Mus. N^vit. no. 724, 7 pp. 

 GREENE, C. T. 



1923. A contribution to the biology of N. A. Diptera. 

 Proc. Ent. Soc. Wash., 25:82-89, 2 pis. 

 HEISS, E. M. 



1938. A classification of the larvae and puparia of the 

 Syrphidae of Illinois exclusive of aquatic forms. 

 Illinois Biol. Monogr., 16:1-142, 17 pis. 



JOHANNSEN, O. A. 



1935. See Diptera references. 

 JONES, C. R. 



1922. A contribution to our knowledge of the Syrphidae 

 of Colorado. Colorado Agr. Coll. Agr. Exp. Sta. Bull. 

 269:1-72, 8 pis. 

 METCALF, C. L. 



1913. The Syrphidae of Ohio. Ohio Biol. Surv. Bull. 



1:1-123, 11 pis. 

 1916. Syrphidae of Maine. Maine Agr. E< p. Sta. Bull. 

 253:193-264, 9 pis. 

 SHANNON, R. C. 



1916. Notes on some genera of Syrphidae with descrip- 

 tions of new species. Proc. Ent. Soc. Washington, 

 18:101-113. 

 WILLIAMS, F. X. 



1939. Biological Studies in Hawaiian water-loving in- 

 sects. Part III. Diptera or flies. B. Asteiidae, Syrphidae 

 and Dolichopodidae. Proc. Hawaii. Ent. Soc, 10: 

 281-315. 8 pis. 



Fomily EPHYDRIDAE 



Shore Flies and 3rine Flies 



Ephydrid adults are small to minute in size, usually 

 dull in color with characteristic prominent face and 

 gaping mouth. They inhabit moist environments where 

 they are commonly seen walking about on the surface 

 of the mud or water, lapping up or scraping off the 

 minute particles of algae or diatoms which make up 

 much of their food. The ephydrids are especially 

 prominent around inland salt and alkaline ponds and 

 marshes and thermal and mineral springs. 



Most of the larvae are aquatic or semiaquatic, and 

 some of them live in or on the leaves and stems of 

 aquatic plants. The peculiar petroleum and saline 

 species have already been mentioned under the 

 general discussion of Diptera. The larvae of these 

 saline and alkaline pond inhabitants are occasionally 

 so multitudinous that they occur as large balls of lar- 

 vae floating through the water, or so densely packed 

 in shallow waters about pond and lake margins that 

 nothing else can be seen. 



Cresson (1942-1949) has admirably brought up to 

 date the adult taxonomy including keys and the known 

 distribution of the North American ephydrids with the 

 exception of the Ephydrinae and a part of the Pary- 

 drinae which have currently been revised by Sturtevant 

 and Wheeler (1954). Ilennig (1943) collected all the 

 information known about the immature stages. The 

 following keys are adapted from the preceding 

 references. 



