Frey of the Yellow Dung-Fly. 121 



British localities." The victims, all of which were Diptera, 

 were as follows : — Dilophus febrilis, L. (Fam. Bibionidse) ; 

 Macronychia viatica, Mg. = 3f. griseola, Fin. (Tachiiiidse); 

 Stomoxys calcitrans, L. (Muscidse) ; Sciara carhonaria, Mg. 

 (Sciaridse) ; Fannia canicularis, L. (Anthom) idee) ; a small 

 " daddy-longlegs/' probably Erioptera sp. (Limnobiidse) ; 

 and Syrpkus pundulatus, Verr. (Syrphidse). Prof. Poulton * 

 also recorded three instances of other common British 

 Scatophagids, belonging to as many species {Scatophaga 

 suilla, F. ; S. lutaria, F. ; and S. merdaria, ¥.), being taken 

 with prey in their grasp, the names of the victims being 

 respectively Dicranomyia lutea, Mg. (Limnobiidte), Mydaa 

 urbana, Mg. (Anthomyidse), and Taxonus glabratus, Fin. (a 

 Hymenopterus insect, belonging to the Family Tenthre- 

 dinidse, or Saw-flies). It will be observed that in no single 

 one of these ten cases, whether the captor was S. stercoraria 

 or one of its congeners, was the victim a Calliphora ; and it 

 may be added that in almost every instance the insect 

 preyed upon belonged to a species markedly smaller and less 

 robust than the Dung-fly. Doubtless the latter, when in 

 need of a meal, will seize any fly that it is able to over- 

 power, and it is true that Blow-flies much under the normal 

 size are not uncommon. Neverthless, the average Blow-fly 

 or Bluebottle, whose well-known buzz is familiar to everyone 

 as the insect cannons up and down the window-pane, so 

 greatly exceeds the average S. stercoraria in bulk that its 

 very size, apart from the jerky, impulsive movements char- 

 acteristic of the species, must serve as a safeguard. 



Without in any way pretending to have devoted special at- 

 tention to the habits of the Yellow Dung-fly, the writer can at 

 least claim to have observed the species for upwards of thirty 

 years, and to have first made its acquaintance long before 

 he became aware of its scientific appellation. In the course 

 of this lengthy acquaintanceship, maintained and periodically 

 renewed in several English counties, chiefly in the Midlands 

 and South Midlands, Dipterous victims have frequently 

 been seen in the clutches of S. stercoraria, while the female 

 has often been found enjoying a meal of this kind when the 

 sexes were in coitu. In the majority of cases noticed the 

 victim was a small Anthomyid or Bibionid fly, and in no 

 single instance was it a Calliphora erythrocephala, ISIg., or 

 C. vomitoria, L. Now a fly such as Dilophus fehrilis or a 

 small Bibio does not occupy much space, especially when 

 sucked partially dry, and such an insect in the grasp of a 

 well-developed S. stercoraria might easily escape observation; 

 * Loc. cit. p. 391. 



