378 INSECTA. 



Ortalis, Fall. — Scatophaga, Tephritis, Dictva, Fab. — 



Tephritis, Lat., 



Where the abdomen is not terminated in the females by an always 



external prolongation, in the form of a tail or stilet, serving as an 



ovipositor*. 



The body of several species is somewliat more elongated than in 

 the following subgenus, and these Diptera, in this respect, are inter- 

 mediate between the latter and the preceding ones. 



The palette of the attennae is sometimes long and linear as in the 

 O.paludum, Fall.; and sometimes short and wide, as in the O.vi- 

 brans — Musca vibrans, Lin. — De Geer, Insect., VI, 1, 19, 20, the 

 body of which is black, and the head red, with a white streak on the 

 inner margin of each eye; a black spot may be observed at the ex- 

 tremity of the wings, and the first exterior nervure of their base 

 becomes thcikened where it unites with the edge, presenting the ap- 

 pearance of a black stigma. 



To this subgenus "M. Fallen refers the 3Iusca cerasi, L.-, or the one 

 whose larva feeds more particularly on the red and white-heart 

 cherry ; when about to become a pupa, it leaves the fruit and enters 

 the ground where its metamorphosis is completed. The perfect In- 

 sect is very black and glossy, with four transverse blackish bands on 

 the wings, united by pairs in ojiposite directionsf. 



Tetanops, Meig., 

 AVhere the abdomen of the females terminates by an always pro- 

 jecting, tubular oviduct, resembling a tail ; the head seen from above 

 appears to be almost triangular, and as long as it is wide|. 



Thephritis, Lat., Fab., Fall. — Tkypeta, Meig. — Dacus, Fab., 

 Where the abdomen is similarly terminated; but the head, seen 

 from above, is rather transversal than longitudinal, and rounded. 



The species in which the palette is more elongated, form the genus 

 Dacus of Fabricius. Of this number is the one that usually attacks 

 the Olive, Avhich he however places among his Oscini. It is reddish, 

 with the top of the thorax, some streaks on the back and scutellum 

 excepted, blackish; the sides of the superior part of the abdomen are 

 also spotted with blackish. The scutellum is salient. Coquebert has 

 figured it in his lUust. Icon, des Insect. XXIV, 16. 



T. cardui; Musca car dui,h.; Reaum., Insect. Ill, xiv, 12 — 

 14. Black; head and legs fulvous-brown; a zigzag brown line 

 on the wings. The female perforates the stem of the Carduus 

 haemorrhoidalis, in order to deposit her eggs there, and a gall- 

 like excrescence soon forms, Avhich serves for food and shelter to 

 the larvae. 



The inhabitants of the Isle of France can scarcely obtain per- 



* According to Meigen the hypostoma is arched or rather carinated in the middle, 

 whilst it is plane in Trypeta. But this carina, although smaller, appears to me to 

 exist in several species of the last genus. 



t See Meigen. 



J Idem. A subgenus approximating to those of tlie Dolichocera in the pyramidal 

 form of the head, and to the Tephrites in their other chnrr.ctcrs, p.irticularly in the 

 abdomen, which is terminated in a truncated tuhe. 



