Trigonaspis crustalis. 8i 



[The kidney gall is found in September. This gall grows only in 

 the shade, and on the north side of trees of Quercus pedunciilaia, 

 Q. sessiliflora, and Q. pubescens. 



Inquilines. Syncrgtis varius, S. vulgaris, S. tibialis, S. ntficoryiis, 

 S. pallicornis, and 5. Thautnacera, in April of second year. 



Parasites. Callitnome fuscicrus, Mesopolobus fasciiventris, Ptero- 

 mains Saxesenii, Pleurotropis cyniphidium, Anthomyia gallarunt.'] 



18^. Trigonaspis crustalis. Htg. ^ 



Gall. These round, sappy, red and white galls vary 

 in size from that of a pea to a cherry. They are found 

 most frequently low down on the trunks of old oaks, 

 often crowded together, but they also occur on small 

 last-year shoots. The gall always grows out of a bud, 

 and it is therefore not a bark gall. On old oaks it is 

 often found quite hidden under moss, so that it certainly 

 appears then to grow directly out of the bark, but this is 

 not the case. If the base of the gall be examined, it will 

 be found invariably to originate in a bud. (Fig. i8^.) 



To rear the Fly, it is necessary that the galls, which 

 are very succulent, should be gathered at the end of May, 

 shortly before maturity. Most of the flies emerge from 

 the beginning to the middle of June. 



Fly. Size 4 mm. long ; head and thorax black ; 

 abdomen bright orange, blackish at the apex only, 

 shining, distinctly pedunculate, and of a rounded form ; 

 legs orange ; wings very long ; males and females 

 similar in colouring; antennae of the male 15-jointed, 

 of the female i4-jointed; labial palpi 3-jointed, maxillary 

 palpi 5-jointed. 



Experimental breeding. I had repeatedly watched 



P Cynips megaptcra, Pz. Trigonaspis crustalis, Htg. T. tnegaptera, 

 Mayr. Cynips crustalis, Thorns,] 



G 



