HYMENOPTERA— SAW-FLIE.S, ETC. 173 



Abdomen at least slightly metallic, somewhat shining, puncturation 

 finer and more remote, hairs on apical segments shorter . 2 



2. Abdomen rufescent beneath and often at the sides. (Attached to 



willow) ..... T. siLVATiCA, Lcach. 



Abdomen bronzy-black throughout .... 3 



3. Tibia", at least in $ , black or dark-brown. (Attached to hawthorn) 



T. TIBIALIS (Steph.) 

 Tibiae yellow. Apical segments of abdomen clothed with longer 

 hairs than the last species. (Attached to willow) 



T. LATREILLEI, Lcach." 



This synopsis is extremely interesting from a collector's or" nature- 

 student's point of view, but for practical purposes any species which 

 the local collector may find most abundantly may be taken as a type 

 of the other species. 



Trichiosoma tibialis (Steph.) 



This species is generally attached to hawthorn, and the pupal 

 cocoons may generally be found on the twigs of switched hedges, 

 more especially on twigs near 

 the base of the hedge. As 

 a rule, however, the cocoons 

 are opened by insectivorous 

 birds. The collector, there- 

 fore, should try as far as 

 possible to gather these 

 cocoons in the early autumn, 

 and place them in a jar for 

 hatching purposes. When „. ,,. „, , . , , . ,. 



o f I Fig. 160.- Tiichiosunia tibialis. 



this is done, the flies are 



very easily reared, and they hatch out from the middle of ]March to 

 the end of April. Fig. 160 is from a photograph of this species, and 

 fig. 161 is a representation of the pupa. 



It is best, in learing flies from the larval stage, to try and collect, as 

 far as possible, the fully developed larvae, as when the larvae are col- 

 lected at an early stage they do not feed readily in confinement, and 

 a great proportion of them die off". Fig. 162 is a representation of 

 the larvaj on a hawthorn leaf. 



