386 Tachinidae. 



The larvæ of Malacosoma were taken in June, and the imago came 

 in August ; the Orgyia larvæ were taken in August and the fly devel- 

 oped in October. 



Geographical distribution: — Europe; towards the north in 

 southern Sweden, but going far towards north, occurring in Green- 

 land to 77° L. N. 



Remarks : Whether T. fasciata is really a separate species I 

 dåre not say with certainty, but I much doubt it. It seems to me 

 that the distinguishing characters, the height to which the vibrissæ 

 ascend, the pubescence of the eyes, the colour of orbits and the 

 breadth of the frons etc, are ve ry vague and in no way free from 

 variation. As seen, Nielsen has in his biological papers, besides larva- 

 rum, still impotens, macrocera and vidua, thus in all four species; of 

 the last two no imagines are found in his collection (of macrocera 

 no imagines from Denmark). He gives some larval characters in the 

 shape of the pharyngeal skeleton and the posterior spiracles, but I 

 think that these small characters will not in a sufficiently large ma- 

 terial prove constant. When Villeneuve (1. c. 1912) stated the species 

 {macrocera) to be different from larvarum, he, by a mistake, thought 

 it to be larviparous, while it is in reality oviparous as the other species 

 of Tachina. The larviparous species which Nielsen had mentioned 

 was Ernestia radicum (Entom. Medd. 2, IV, 1913, 372). 



3. T. rustica Fall. 



Fall. 1810. Vet. Acad. Handl. XXXI, 282 et 1820. Dipt. Suec. Muse. 5, 5. 

 — 1838. Meig. Syst. Besclir. VII, 193, 21. — 1862. Schin. F. A. I, 474. — 1889. 

 B. B. Denkschr. Akad. Wiss. Wien, LVI, 98, Tab. IV, Fig. 65. — 1896. Pand. 

 Eev. Entom. XV, 65, 24. — 1907. Kat. palåarkt. Dipt. III, 341. — 1921. Baer, 

 Zeitschr. f. angew. Ent. VII, 359. — 1924. Stein, Arch. f. Naturgesch. 90, 6, 

 114, 3. — T. larmrum 1844. Zett. Dipt. Scand. III, 1015, 3. 



Male. Frons as broad or about as broad as the eye, or somewhat 

 narrower. Orbits yellowish or deeper yellow, cheeks of the same 

 colour or paler to whitish, palest below; rarely orbits greyish white 

 and cheeks white; jowls grey. Frontal stripe much narrower than 

 orbits, velvet black. Frontal bristles descending to the middle of 

 cheeks, or more or less below. Vibrissæ only a little ascending, about 

 to one third of the height. Orbits with very fine and sparse hairs; 

 jowls black-haired. Occiput grey, with pale yellow hairs. Antennæ 

 black, third joint relatively short, at most one and a half times the 

 second; arista thickened in less than basal half, second joint a little 



