324 CLASS viu. 



The larvae of these flies live parasitically in other insects, many species in 

 caterpillars, and, with the ichneumons, are the most serviceable in pre- 

 serving a balance in the economy of nature, by restraining the excessive 

 multiplication of noxious insects. Many are viviparous. Comp. C. TH. 

 VON SIEBOLD, Ueber die u-eiUiche Gescldecktsorgane der Tachinen, WIKG- 

 MANN'S Archiv f. Naturgcsch. 1838, s. 191 201. Some larvse leave the 

 insect in which they live before changing into pupae. 



Sp. Tachinafcra,Muscafera~L., PANZER Deutschl. Ins. Heft 20, Tab. 18, &c. 



Sub-genera : Echinomyia DUMER., LATR., MACQ., Micropalpus 

 MACQ., Thryptocera MACQ., Trixa MEIG., Nemorcea ROBIN., MACQ., 

 Senometopia MACQ., Eurig aster MACQ., Masicera MACQ., Metopia 

 (MEIG. previously) MACQ., Lydella ROBIN., MACQ., Tachina MACQ. 

 Chrysosoma MACQ., Clysia ROBIN., Myobia ROBIN., MACQ., (Hebia, 

 Melia, Myobia ROBIN.), Zophomyia MACQ., Cassidcemyia, MACQ., 

 Sericocera ROBIN., MACQ., Philocera ROBIN., Melanophora (MEIG. 

 previously) MACQ. 



Gonia MEIG. Antennae with third joint elongate, surpassing the 

 two preceding taken together. Seta of antennae triarticulate, geni- 

 culate. 



Miltogramma MEIG. Antennae with third joint elongate, sur- 

 passing the two preceding taken together. Seta of antennae biarti- 

 culate, straight. Abdomen oval or conical, in some not setose, 

 downy. 



To this genus the observations of C. TH. VON SIEBOLD refer (Observ. 

 quced. entomologicce de Oxybelo uniglume atque Miltogramma conica. 

 Erlangae, 1841, 4 to) ; the female of Oxybelus uniglumis, a species of 

 hymenopterum, digs for each of her eggs a hole in sandy ground, and 

 deposits near it some flies, her booty. In this work she is watched and 

 followed by Miltogramma conica, which lurks near the entrance of the hole 

 for an opportunity to slip in with her as she enters, and to fix some young 

 larvse on the booty, which afterwards penetrate from it into the larva of 

 Oxybelus; the reason why the Oxybelus does not drag this Miltogramma 

 itself into the hole as food for the larva of her egg, is readily explained by 

 this dipterum being viviparous, for then she would have drawn in the 

 Trojan horse ; and hence these Tachinarice are avoided. LEPELETIER DE 

 SAINT-FABGEAU has made similar observations as well on Oxybelus as on 

 Cerceris; Hist. Nat. des Hymen. 1841, n. pp. 567, 568, 573. 



B.} Conopsarice. Proboscis exsert, in most filiform, in some 

 cylindrical or conical. 



* Wings imperfect, very short, unfit for flying. 

 Carnus NITZSCH. 



