198 [July 



duces two generations each year. — the first (second?) appearing in July, from 

 the well-known wooly gall on the white oak, the last producing a somewhat 

 similar autumnal gall from which the insect emerges the following spring. 



I have not until this spring seen anything that favored this view. 



Early this spring I reared a species of gall-fly, in considerable abundance, 

 from galls gathered in the winter that are identical, I am quite sure, with the 

 C. q. batatus Fitch, (I think Dr. Fitch has described an inquilinae that I have 

 reared from the same gall in great abundance, and not the insect producing 

 the gall — I am not sure however,) and ten days ago a large number from green 

 galls on the same trees, evidently the same though then green and succulent. 

 I think the .June crop restock the galls with eggs that are developed the follow- 

 ing spring. 



Certain species of galls are usually abundant this season, in this section . 

 Those of C. q. operator 0. S.. can be gathered by the bushel. The flies have 

 now nearly all appeared and I have watched them carefully to learn if possible 

 whether the females deposited any eggs, and if so. whether they were deposited 

 in the young leaf-buds. 



I have reared thousands of the flies and have seen thousands more within a 

 few days on the leaves of the shrub-oak, but have not been able to find any in 

 the act of ovipositing until this afternoon. 



On visiting a shrub-oak ( Q. ilicifolia) thicket this afternoon I found hundreds 

 of C q. operator with the ovipositor, (nearly twice the length of the body.) in- 

 serted the full length into the cups of the young acorns. 



The acorn, as yet, projects scarcely at all above the cup and the fly alighting 

 on the edge of the cup inserts its ovipositor near the acorn but not touching it. 

 I cut out the ovipositor of twelve or fifteen and found that their points did not 

 touch, or at least penetrate the acorn, but seemed to curve around it so that 

 they were almost directly under it. I did not in any case find more than one 

 fly to a cup. 



Those who have studied this family and have felt how difficult it is to ac- 

 count for the appearance of some of the vernal species, will appreciate the 

 value of a discovery that will jjrobably solve the mystery and that may possi- 

 bly clear up the subjects of '" agamous species" and "dimorphism." 



I am inclined to think the larva now deposited will remain in the larva state 

 until next spring, but shall not be surprised to learn they produce an autum- 

 nal brood that depofit their eggs in the matured leaf-buds. I shall await, im- 

 patiently, further developments. Many interesting questions arise as to what 

 tnese developments maybe. Will the gallflies agree specifically \\\i\x the pa- 

 rent, — when will they appear, and how many of our species will be found to 

 produce two broods, and how many (jf our autumnal species are dimorphous 

 forms of vernal species ? 



I am sure all do not produce two broods. C. q. punctata (nobis), for instance, 

 which appeared in April, and whose galls apjieared a few weeks later and pro- 

 duced no flies till the next April. 



That you may see that I am not mistaken, I send you with this a few acorns 

 with the fly still attached. They were killed by immersing in boiling water. 



