ART. 9 



TWO- WINGED FLIES OF TEIBE MILTOGEAMMINI ALLEN 



the l)uccopharyngeal apparatus (pi. 5, fig. 34) is a])seiit or vestigial, 

 and the two divergent lateral hooks are strong and heavily chitinized; 

 two articulations, one between the hooks and the intermediate piece 

 and another between the intermediate piece and the basal piece, 

 are present; and above the intermediate region is a small rodlike 

 dorsal accessory piece. 



The puparium (pi. 4, fig. 21) is smooth and evenly rounded save 

 at the anterior end which sometimes shows distinct segmentary 

 folds, and the posterior end which is somewhat constricted and 

 truncate at the apex. At the anal end there is usually a deep pit 

 (pi. 5, fig. 27), in which the posterior spiracles are located. The 

 spiracle is pierced by three nearly straight, more or less converging 

 slits. 



The adults occur on barren sand, rocks, denuded soil, or less 

 frec[uently on herbaceous vegetation and low shrubby foliage. Some 



Fig. 2. Ventral VIEW OF abdomen to show variation in the development and position of the 



SECOND STEHNITE. A, TaCHINIDAE (FrONTINA ALETIAE RiLEY), B, MILTOGRAMMINAE (SeNOTAINIA 



trilineata Van der Wulp), C, Sarcophaginae (Sarcophaga, species), 2t tergite of first seg- 

 ment, S«, second sternite reduced and submerged beneath tergite in TaCHINIDAE, ENLARGED 

 AND OVERLAPPING TERGITE IN MiLTOGRAMMINAE AND SARCOHPAGINAE. 



are attracted to flowers, others to the flow of honey dew from aphids 

 or other Hemipterous insects. The females are viviparous, deposit- 

 ing active, motile maggots on or near their food. The maggots live 

 in the nests of fossorial Hymenoptera, feeding on the stores provided 

 for their young, which may be paralyzed insects or spiders, or masses 

 of pollen. The maggots are not known to be primary parasites of 

 the young of their Hymenopteron hosts, though their presence in 

 the nests frequently results in the death of the latter. So far as I 

 am aware, it has not yet been conclusively demonstrated that any 

 of these flies arc the primary parasites of phytophagous insects in 

 their native habitat. All the records investigated by the writer 

 indicate that while the flies do breed in the bodies of such hosts, they 

 display no interest in them imtil after they have become the prey 

 of some wasp. 



