Tachinidae. 49 



with prothoracal and posterior spiracles in the two last stages, meta- 

 pneiistic in the first stage {Ocyptera is metapneustic also in the second 

 stage and Ernestia rudis in all three stages). The body is more or less 

 armed with small or minute spinules. The pupa is a barrel-pupa of 

 a more or less cylindrical oval shape; sometimes there are no pro- 

 truding prothoracal spiracular tubes, at other times such are present ; 

 when present they protrude through the first abdominal segment 

 of the puparium. In opening the fore part of the puparium is detached 

 along a circular line lying anteriorly on first abdominal segment, 

 this part is divided in an upper and a lower piece by a horizontal 

 line; sometimes the lower piece is not detached. 



The Tachinids are for the most part parasitic in other insects; 

 the Sarcophaginae and Calliphorinae mainly saprophagous; some 

 of them are, however, parasitic f. inst. Sarcophaga-sipecies and Onesia 

 coerulea in snails, Pollenia rudis in earthworms. Species of Sarcophaga 

 are also often recorded as bred from Lepidoptera, and though they 

 certainly often attack sick Lepidopterous larvæ, they seem also to 

 be parasitic here. It really seems that many of these, which are 

 rather polyphagous, are developing from saprophagy to parasitism. 

 The Miltogrammini are food-parasites in the nests of Aculeata. The 

 true Tachinids are, as said, parasitic mostly on insects, above all on 

 Lepidopterous larvæ, then on Coleoptera, Hymenoptera {T enthredini- 

 dae), on some few Diptera^ on Rhynchota and Orthoptera (with Forfi- 

 cula). Besides a couple are known from Lithohius and Oniscus. The 

 species are partly oviparous, partly viviparous or ovoviviparous. 

 Pantel has (La Cellule, XXV, 1910) divided the species in ten groups 

 according mainly to the manner of depositing eggs or larvæ and the 

 way in which the parasite gets into the host (and also according to 

 other points connected with the propagation) ; from this I shall 

 detract the following: 



Group 1. Oviparous, with an oval egg flattened below; the egg 

 is deposited on the skin of the host. Here belong of Danish species 

 some Phasiins parasitic on Rhynchota: Clytiomyia, Gymnosoma, Cysto- 

 gaster, and perhaps Xysta; further some Tachininae parasitic on 

 Lepidopterous larvæ: Meigenia, Nemorilla floralis, Ptychomyia, 

 Parasetigena, Winthemia quadripustulata, Tachina, Tricholyga, and 

 probably Erycia and Phorocera. 



Group 2. Oviparous with very small, doubly coloured eggs, 

 which are laid on the piants and eaten by the host larva, thus getting 

 into the intestine. Here Monochaeta, Masicera sylvatica, Ceromasia, 



4 



