Dryophanta longiventris. 6^ 



being at most i cm. in diameter. It is brilliantly 

 coloured, prettily striped with white and red, and the 

 outer rind is smooth or somewhat nodulated. (Fig. 15.) 



Rearing the fiy is simple if the galls are collected in 

 October when they mature. I have obtained the flies at 

 the end of November and in December. Although the 

 gall is not scarce, it is difficult to obtain any large number 

 of flies, as most of the galls are infested with parasites. 



Fly. 3-4 mm. long ; black ; the margin of the orbits, 

 sides of the thorax, two stripes on the meso-thorax, and 

 the scutellum are reddish brown ; abdomen black and 

 very shining ; legs reddish brown, trochanters and upper 

 halves of the femora black ; the pubescence is the same 

 as in Dryophanta scutel/aris, from which it cannot in 

 other respects be distinguished with certainty. 



Experimental breeding. On account of the small 

 number of these flies procurable, I had great difficulty 

 in getting any results from experiments. In November, 

 1877, I put several flies on a little oak and observed 

 that, like Dryophanta scuteUaris, they sought out the 

 younger adventitious buds and pierced them. It was 

 therefore probable that a similar bud-gall would be 

 formed, but the result was negative, for I obtained no 

 gall. My second experiment, made in 1878, was also 

 negative. For the third time, I tried to secure a gall 

 in November, 1879 ; several buds were pricked and I 

 succeeded in April, 1880, in obtaining two galls. They 

 were very like those of Spathegastcr TascJienbcrgi, but 

 with care it was not difficult to distinguish between 

 the two. This result was the more interesting because 

 it was now clear to me that I had hitherto mixed up 



F 



