22 



wings are without a fringe of hairs upon their borders and the hairs upon the 

 surface of the wings are not well developed, but appear in most cases as 

 minute specks. Described from thirteen reared specimens. 



Male. — Antennae 15-jointed, filiform, and longer than the body ; parapsi- 

 dal grooves more distinct than in the female ; wings with fringe of hairs and 

 hairs better developed on the surface of the wing. Length 1.4 mm.; other- 

 wise as female. 



Neuroterus vernus n. sp. Galls. — Almost identical with those 

 of Neuroterus mimita Bass. When occurring; upon the leaves they 

 are simply enlarged petioles, but the leaf usually becomes very much 

 dwarfed and deformed. The galls also occur in large numbers on 

 the stamen catkins, in which case the catkins become much enlarged 

 and irregularly sw^oUen, and remain green upon the tree until the 

 gall-flies within have completed their growth. The eggs are de- 

 posited in the buds of the bur-oak early in April, and the flies issue 

 early in June. Galls taken June 10, 1888, had lost most of their 

 flies. On April 9, 1889, the tree from which these galls were taken 

 was again visited, the day being warm and bright, and the females 

 found present in great numbers busily depositing their eggs. From 

 one to a half dozen or more of these flies were present upon every 

 bud, into w^iich their ovipositors were deeply inserted. The galls 

 resulting from eggs deposited at this time, began to give a second 

 brood of flies May i6th. The tree was also visited on a bright day 

 about the middle of April for the purpose of determining w^hether 

 or not the egg-laying had ceased. At this time no living flies could 

 be found, but many dead ones were seen that had not been able to 

 remove their ovipositors from the place where the last eggs were 

 laid. At this time the twigs of the tree were literally covered with 

 what would be termed ' ' honey-dew' ' which had oozed out from the 

 myriad punctures that the buds had sustained a week or ten days 

 before. This shiny, sticky material tasted very sweet, and one who 

 did not know what had happened to the tree a few days previous 

 might well wonder what could be the source of this sweet substance 

 if it did not gather as a dew. This is one of the most abundant of 

 the gall-flies in this vicinity where a bur-oak tree can hardly be 

 found, the foliage of which has not been seriously damaged by it. 



Gall-fly — Female. — Except joints of legs and tarsi, black; these 

 parts yellowish brown; antennae 12-jointed, the second joint most 

 robust; i — 1.3 mm. in length. 



Face smooth, shining black, or very finely rugose, and with very few 

 hairs. Mandibles black at tip, and black or brown-black at base ; palpi 

 brown ; antennae with first and second joints stout and subequal in length, 

 third joint longest and most slender, joints somewhat enlarging towards the 



