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



Literature. — For biology and immature stages see Edwards 

 and Keilin and Tate (68, pp. ^-51) ; for keys to the species of the 

 world, see Edwards (38) . 



SYLVICOLA FENESTRALIS (Scopoli) 



Synonyms. — Phryne fenestralis (Scopoli), Anisopus fenestralis (Scopoli), 

 Rhyphus fenestralis (Scopoli). 



Recognition Charactees. — Adult : The palpi are blackish ; the eyes are well 

 separated in both sexes. The wing (fig. 86) is distinctly mottled; its apex is 

 dark, the stigma well marked, and the spot between the stigma and the apical 

 region hyaline, not conspicuously whitish; the first basal cell has a dark spot 

 below the origin of the radial sector, but is clear below the fork of that vein. 

 The hind femur is darkened at its middle, the darkening, however, being often 

 obscure. Length 5-7 mm. Larva: The mature larva (fig. 87) is 12-15 mm. in 

 length; the integument is yellowish though because of its transparency the 

 internal organs show through and give the body a pinkish cast. Each thoracic 

 segment has characteristic patches of a deep brown color ; these are lacking on 

 the abdomen. The last segment is subdivided into several annuli ; the perianal 

 shield is confined to the ventral half of the segment. 



Geographical Distribution. — Nearctic Region : Nova Scotia, Quebec, Ontario, 

 Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, 

 New Jersey, Pennsylvania, Minnesota, Wisconsin, Idaho, Washington, California. 

 Palaearctic Region : Ireland, Scotland, England, Portugal, France, Netherlands, 

 Italy, Norway, Sweden, Finland, Czechoslovakia, Austria, Hungary, Azores. 



Biology and Pathogenesis. — Larvae have been found in various 

 situations involving fermenting organic matter, such as cow dung, 

 fermenting potatoes, decaying roots, fermenting sap in tree holes, and 

 home-made cider and wine. One remarkable case has been reported 

 of larvae breeding in liver that had been preserved in 10-percent 

 formalin for 10 years and at the time of infestation was partly sub- 

 merged in the formalin. The larvae move in a serpentine manner. 

 Pupation takes place in the medium in which they live. 



A case of enteritis in a child in England is recorded in which larvae 

 of this species were recovered at intervals over a period of 3 weeks. 



The Family STRATI OMYIDAE 



The Soldier Flies 



This family is readily recognized by the peculiar wing venation, 

 which is of the general type found in the Therevidae (fig. 3) , but with 

 the major veins crowded toward the costal margin (fig. 88). The 

 adults are variable in size and form. Many are brightly colored or 

 marked with bright patterns, but some are dark or drab. 



Larva. — The larvae, like the adults, are variable, but in general they 

 are strongly flattened, with the body finely shagreened; the head is 

 well developed ; the mandibles move vertically and when at rest assume 

 a vertical position; the posterior spiracles are closely approximated 

 and situated within a terminal or subterminal cleft or chamber, where 

 they are usually concealed. Many larvae are aquatic; the terrestrial 

 larvae are mostly scavengers, though some are predaceous. 



The Genus HERMETIA Latreille 



Members of this genus are rather easily recognized; they are of 

 medium to moderately large size ; the antennae are elongated, the last 

 segment being flattened and vanelike, and the segments (or annuli) 

 immediately preceding have a flattened or depressed longitudinal 



