186 



PSYCHE. 



April iS 



guests were reared. The flies ap- 

 peared in abundance. 



Andricus si)igularis Bass. Galls 

 very common on ^. rubra leaves. In 

 shape and structure these galls resemble 

 the gall of A. inanis., but are much 

 smaller, large specimens seldom attain- 

 ing one-half inch in diameter. The 

 galls project on both sides of the leaves, 

 the larger portion always being below. 

 Galls taken June 18 gave flies June 20. 

 No guests were reared and the galls 

 were little parisitised. Parasites unde- 

 termined. 



Aiidric?is petiolicola Bass. Galls 

 found common on ^. alba.^ ^. macro- 

 carpa and ^. blcolor. The galls are 

 formed by the enlargement of a portion 

 of the petiole of the leaf, and after the 

 leaves have fallen the galls stand out 

 like little knotty projections. The galls 

 that I have taken vary from 5-16 to 

 10-16 of an inch in diameter. Galls 

 taken at Ames, July 3, gave flies July 5. 

 Ceroptres petiolicola is a very common 

 guest in this gall. 



Cynips diviorphus Ash. ms. Mr. 

 W. H. Ashmead, of the Florida Exp. 

 Station, iri forms me that he has had this 

 cynip and gall described in manuscript 

 under the above name. Galls, red and 

 globular, two to three mm. in diameter, 

 and arranged in clusters of from 10 to 

 30 or more on the under side of the 

 leaves of J^. prinus., J^. macrocarpa 

 and ^. bicolor in September and 

 October. Rather common. Galls 

 taken in the fall contained larval cynips 

 on the first of Jvdv following. 



Cynips strobilana O. S. The gall 



of this cynip I find quite rare. The 

 galls are easiest found after the leaves 

 have fallen. They have been taken from 

 ^. macrocarpa and J^. bicolor. The 

 individual galls are irregular, cone- 

 shaped bodies, from fifteen to thirty of 

 which constitute a cluster which always 

 arises from a terminal bud. My largest 

 cluster measures nearly two inches in 

 diameter. Specimens taken last Oc- 

 tober still contain larvae (Sep. 20). 



The guest, Synergus lignicola^ has 

 been reared from the galls in considerable 

 numbers and also a few parasites belong- 

 ing to the genus Eurytoma. 



Acraspis erinacei Walsh. ( C. pisum 

 Fitch.) Galls common in September 

 and October on the leaves of ^. alba., 

 usually on the under side. When grow- 

 ing they are of a beautiful rose or straw 

 color and are covered with short spines 

 or hairs. The gall is exceedingly hard 

 when dry and the surface is made up of 

 little seed-like projections, much re- 

 sembling the siu'foce of a strawberry. 

 The galls seldom contain less than two 

 or more than five larval cells. 



The mature insect emerges in Nov- 

 ember and is wingless, or, rather, with 

 only stubs of wings. 



A very common paiasite reared from 

 this gall is Decatoma Jiava. 



Biorhiza forticornis Walsh. ( Cynips 

 jicus Fitch.) Galls occurring near the 

 tips of the twigs of ^. alba^ almost in- 

 variably on young second growth shoots. 

 A hundred or more are often crowded 

 together about the shoots and appear 

 much like a great number of little com- 

 pressed sacks. When green they are 



