Aphilotrix autmnnalis. 57 



were placed upon an oak sapling, and on June 11 ten 

 buds were pricked by them. These active little flies 

 always choose the most tender axillary buds. Care 

 must be taken therefore in experimental breeding to 

 select only those oaks which have buds of a soft and 

 tender consistence. It was long before any change could 

 be seen in the pricked buds, and it was not till 

 September 3 that two of them showed the beginning of 

 gall formation. On October 2 a third gall appeared, 

 and all three galls were those described above as 

 Aphilotrix Malpighii. In April, 1879, I got two flies out 

 of these three galls. I made in 1878 a second experi- 

 ment in breeding with Andricus nudus, and from the 

 collected galls I obtained the first flies on May 30. On 

 June I I put them on a small oak. I observed that 

 several of them began at once to prick, and eighteen 

 buds were marked in all. In the beginning of Sep- 

 tember three galls grew out of these buds, and four 

 more at the end of the month ; consequently the con- 

 nexion between Aphilotrix Malpighii and Andricus 

 nudus appeared to me sufficiently proved. 



[The bald seed gall is found on Qtiercus sessiliflora in May. 



Fly. Length i-2 to i-6 mm. black, abdomen paler, testaceous on 

 ventral surface, thorax slightly shining, legs uniformly yellow ; 

 antennae of same colour except the fourth and fifth joints which are 

 darker. Males have the femora and tibiae dark, as also the antennae, 

 except the second and third joints which are bright yellow, meso- 

 notum finely shagreened and shining.] 



13. Aphilotrix autumnalis. Htg.^ 

 GaU. This gall, like the Aphilotrix globuli galls, 



[' Cymps autumnalis, Hartig. Andricus auiunwalis, Mayr. An- 

 dricus ramuli, agamous form, Cameron.] 



