516 Tachinidae. 



Male. Frons above not miich more than half as broad as the eye. 

 Orbits and cheeks silvery, the former darkened above, jowls more 

 grey; frontal stripe velvet black or brownish black. Orbits with 

 some few hairs; jowls black-haired. Occiput grey, all black-haired, 

 only below with few pale hairs. Antennæ black, second joint a little 

 reddish at apex; arista thickened in nearly basal half. Palpi black. 

 Thorax black, grey pruinose, with three black stripes, the median 

 broadest; in certain views the median stripe is grey with two narrow 

 dark stripes. Thorax black-haired. Abdomen black, sometimes more 

 or less reddish at the sides of third and fourth segment; it is grey 

 pruinose, shifting with dark brown irregular tessellations according 

 to view; a shifting middle line and narrow hind margins dark. Abdomen 

 black-haired; second segment with a pair of marginal bristles, the 

 other segments with two to three or more pairs of discai, and on 

 third a pair, on fourth a row of marginal bristles. Fifth sternite cleft 

 to base, and the incision more or less squarely widened at base. Legs 

 black, tibiæ reddish; legs with strong bristles, front tibiæ with a 

 number of posterior bristles; claws and pulvilli strongly elongated. 

 Wings yellowish or brownish tinged, yellow at base; veins brown 

 or dark brown. Squamulæ yellow, with the margin deep yellow, 

 Halteres yellow. 



Female. Similar; frons broader than the eye. 



Length 8 — 9 mm. 



P. tibialis is common in Denmark; Gentofte, Ordrup, Ermelund, 

 Dyrehaven, Ryget Skov, Ruderhegn, Grib Skov, Sorø, Alindelille, 

 and in Jutland at Sønderborg, Funder and Gam.melstrup near Viborg; 

 the dates are ^^/j — ^"/e, it is thus an early occurring species. It is 

 known as parasite especially on Vanessa and has been bred from 

 urticae, io, polychloros and antiopa^ further from Agrotis strigula^ 

 Mamestra oleracea, Sesia tipuliformis and the non Danish Thauma- 

 topoea pityocampa and Phlogophora scita; it is also recorded from 

 Saperda popiilnea. Nielsen has (Vidensk. Medd. fra Dansk naturh. 

 Foren. 67, 1916, 12) treated its biology; he bred it from V. io and 

 urticae; larvæ of io were taken in June, the parasite larva was then 

 nearly fullgrown; only one, rarely two larvæ were present in each 

 host; the fullgrown larva bored out and pupated in the ground where 

 they hibernated and developed next year in June (af ter Nielsen, 

 but the specimens in his collection came from '/g — ^o^^^ There is only 

 one yearly brood. Nielsen declares that the eggs are not deposited 

 on the host larva, but Baer 1. c. communicates that he has had 



