634 The American Naturalist. [July, 
Alternation of Generations in Cynips calicis.—A_ recent 
paper by Prof. M. W. Beijerinck in Archives néerlandaises d. sci. ex. e. 
nat. (tome XXX, livr. 5) brings to light a very interesting case of — 
alternation of generations in the genus Cynips as restricted by Mayr. 
Cynips calicis is a large agamic gall fly, produced from a rather large 
irregular gall on the acornsof Quercus pedunculata. This gall is rich 
in gallic acid and is of commercial importance in parts of southeastern 
Europe. In begins to develop in May, falls to the ground in autumn, 
and does not decay for several years. A portion of the flies come out 
at the end of the first winter and the remainder at the end of the second 
winter. The fly which emerges from this gall is incapable of produc- 
ing it. The eggs of Oynips calicis are not deposited on Quercus pedun- 
culata at all, but on another species of oak, Quercus cerris. Oynips 
calicis emerges in March and at this time the acorns of Q. pedunculata 
do not exist even in embryo, and are not in condition for eggs to be 
deposited in them until fully two months later. The eggs of Cynips 
calicis are deposited in the young anthers of Quercus cerris and from 
this oviposition results a conical tiny, hasty gall, very-easily overlooked. 
Out of these galls in about two months emerge tiny, smooth gall flies, 
male and female, which belong to the genus Andricus. These flies im- 
mediately pair and the females at once deposit their eggs on the now 
ready young acorns of Quercus pedunculata, and around these develop 
the large galls of the Cynips calicis. The author was led to these dis- 
coveries by the fact that Q. pedunculata bears no galls of Cynips calicis 
in the Netherlands except when an occasional tree of Q. cerris happens 
to have been planted in the vicinity of the other species. His observa- 
tions and experiments cover a period of several years, and there seems 
to be no doubt of his having proved his points. It is suggested that 
the galls of Cynips calicis might be made commercially important in 
the Netherlands by generally planting Q. cerris in the groves of Q. 
pedunculata. Of course, the thought lies very near that other species 
of Andricus simply represent the sexual stage of species of Cynips— 
Erwin F. Surra. 
General Notes.—Mr. F. H. Chittenden? has prepared a collection 
of articles on little known insects affecting stored vegetable products. 
Notes are given on a number of insects, some of which are previously 
unrecorded from America, and may prove decidedly injurious in the 
future. 
êU. S. Dept. of Agri., Div. of Entomology, Bull., No. 8—New Series. 
