114 



THK KN lOMOLOGIST, 



DESCRIPTIONS OF OAK-GALLS. 



Translated from Dr. (r. L. Mayr's ' Die Mitteleuropaischen Eicliengallen.' 



By Edward A. Fitch. 



(Continued fi-oTn p. 88.) 



V\'^. 8-2. — (Jails oi' A)ulricu!i amenti: natural 

 size and magnified. 



Fig. 83.— Galls of 

 A. occuUits!. 



82. Andricus amenti, Gir. — Tiie small, inconspicuous gall 

 may be found about the middle of May, attached to a male 

 (lower of Quercus sessilijlora or Q. ptibescens. Il is oviform, 

 sharply rounded at the base, somewhat elongate, and 

 bluiiily-poiuted at the unattached end. It is at the most 

 2 millimetres long and 1 millimetre thick. At first greenish, 

 then brownish in colour, and tolerably thickly covered with 

 bristly, simple and short, yellow hairs. It is not succulent, 

 thin-walled, and contains a large larval chamber without an 

 inner gall. Dr. Giraud's opinion, that this gall is developed 

 from a stamen, admits of no doubt, as we often find the 

 altered portions of the anther, sometimes peculiarly formed 

 (for instance, in the shape of two slight swellings divided by 

 a fiurow), on the side of the upper half of the gall; so that, 

 iherelbre, the stamen with ihe connective is changed into the 

 gall. 'J"he gall appears singly or in great nuu)bers on a 

 catkin with ihe male flowers: at the fall of the bloom these 

 calkins are generally fresh, and often somewhat thickened ; 

 the stalk is also not uncommonly bent at the spot where the 

 galls occur. The yellow gall-flies bile themselves out, 

 through the rind of the gall, during the latter half of May or 

 beginning of June ; while the galls themselves, often together 

 with the stalk, remain on the tree the whole summer. — 

 G. L M.^YK. 



