[110] REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 



distinguislied from that of Sarcopliaga by the obsolescence (or in some species entire 

 absence) of the prothoracic spiracles so prominent in Sarcophaga, and the absence of 

 a cavity for the anal spiracles, both ends of the body being quite uniformly rounded. 



Barth^lemy has described the larva of Senomeiopia atropivora (Ann. Sc. Nat, 4« 86t., 

 vii, p. 115), while Laboulb^ne has described both larva and pupa of Tachina villica 

 (Ann. Soc. Ent. Fr., 1861, p. 231, pi. 7) ; but as these descriptions are not readily acces- 

 sible to the American reader, I reproduce from the Trans. Ac. So. St. Louis, vol. iii, p. 

 238-239 my description of the larva and pupa of Sarcophaga sarracenioe, and add for 

 comparison that of Belvoisia hifasciata (Fab.), one of our largest and most beautifuS 

 species, parasitic on CWieronia regalia and various species of Dryocampa. 



Sarcophaga sarraceni^. iarva.— 0.30-0.85 inch long. Body composed of but 11 

 visible joints exclusive of the head ; microscopically and transversely shagreened ^ 

 transversely wrinkled, the hind wrinkle on each joint more particularly prominent 

 laterally. Head extremely small, or one-fourth as large as joint 1, showing a division 

 into two maxillary lobes at the tip and a larger labial lobe beneath, with a small 

 bunch of setous fibres issuing from it; the black retractile jaws, of the ordinary form, 

 issuing between these lobes, and the antennae showing in two small rufous projections 

 above the maxillary lobes, sparsely armed anteriorly with minutei conical, sharp- 

 pointed spines decurved in front, directed backward beneath. Prothoracic spiracle 

 pale rufous, retractile, sponge-like, studded with numerous lobules, divided at the end 

 into a variable number of branches (6 being usually apparent, never more than 8), 

 which in their turn ramify into lobules. Anal stigmatic cavity quite deep ; the fleshy 

 prominences on the carina surrounding it, sub-obsolete ; the stigmata but slightly 

 excavated below, the border brown, inclosing three brown openings, the lower ends of 

 which reach to a circular clear space in the corneous and pale rufous peritreme. Anal 

 prologs quite small, with the longitudinal anal slit between, and a corneous plate in 

 front of them. 



Puparium. — 0.25-0.50 inch long ; neither smooth nor highly polished, and varying from 

 yellowish-brown to deep brown-black in color. Insections more or less distinctly 

 traceable. Head and prothoracic joint retracted ; the prothoracic spiracles protrud- 

 ing and forming two small ears about as long as joint 2 ; the mass of lobules hardened 

 and rufous. Joints 2 and 3 constricted and flattened ; 4 suddenly bulging. End of 

 body squarely docked by spiraeular cavity, the rim of which forms quite a ridge. 



Belvoisia bifasciata. Larva. — Length 15°»™. White, the skin" soft; body cylin- 

 drical, tapering on the anterior joints towards the head, the apex obliquely truncated. 

 Head small, furnished with two stout black hooks, situated under two crescentic ele- 

 vations at a moderate distance apart ; when viewed from in front the head obscurely 

 bilobed, near the center of each lobe two chitinous points, one situated above the other. 

 No prothoracic spiracles apparent, a distinct circular spiracle on the posterior border 

 of the fourth joint behind the head, and situated slightly above the median line. The 

 anterior border of each joint slightly prominent and, except on the dorsal side of the 

 apical joints, roughened with minute points, the posterior border of the apical joints 

 similarly roughened. Joints 4-11 with a distinct transverse median depression on the 

 ventral side, the depression deepest on the intermediate joints, the portion behind this 

 depression on the joint 11 forming a prominent transverse tubercle beneath the trunca- 

 tion, upon which the anal spiracles are situated. Anal spiracles black, each with the 

 slit-like openings, and a circular spot in a clear space beneath them. 



In Westwood's Introduction, vol. ii, fig. 131, is copied from Bouch^, a figure of the 

 larva of Tachina concinnala of similar form to that of Belvoisia; but the pecuLar " pro- 

 thoracic spiracle " figured in connection is not apparent in the larva before n.e. In 

 the normal form of theTachinid puparium the anterior pair of spiraeular cj>e/iiag8 are 

 even with the general surface of the puparium, so as to.be discoverable with difliculty. 

 The true spiracles are internal, and may be found opposite these perforations on the 

 membrane which lines the puparium after the fly has escaped. The puj arimn is red- 

 dish-brown, the anal spiracles and the anus black ; the joint of the body not difltinct; 



