April 1SS9.] 



PSYCHE. 



187 



light yellow in color, but are brown 

 when dry. Common. 



A few undetermined parasites only 

 have been reared. 



Holcaspis globtdus Fitch. Galls 

 globular, from three to six eighths of an 

 Inch in diameter, composed of a corky 

 material with an egg-shaped central cell, 

 always occurring on the twigs of ^. alba. 

 The fly emerges late in October or early 

 in November. 



Decatoma variatis., an undetermined 

 species of the same genus, and a species 

 of Eurytoma. have been reared as para- 

 sites on this fly. Common. 



Holcaspis rugosa Bass. The gall 

 and the fly of this species resemble very 

 closely those of H. globjilus. I have 

 found the galls to be more highly colored 

 than those of the latter species, and 

 when matured they have a shriveled ^\\x- 

 face, while _o-/c<5?//?/5 is smooth. These 

 galls have been taken on ^. prinus only, 

 and ai"e scarce. One guest, Syneigus 

 Jicus.1 and the parasites, Decatoina var- 

 ians, Decatoma ^.'p.^ Etirytoma pimcti- 

 ventris and Syjitomaspis ?>\i.., have been 

 reared from the galls of this species. 



Holcaspis duHcori'a^a.^?,. (^H. viaiu- 

 ma Walsh.) This is probablv the gall- 

 fly referred to by Walsh in a foot-note 

 in the American entomologist., vol. i, 

 page 102, for which he suggests the spec- 

 ific name ma?nma. Mr. Bassett described 

 this insect and gave it the specific name 

 dtiricoria., a name that has been ac- 

 cepted by European entomologists. For 

 this reason, and for the farther reason 

 that Walsh's description is not suflficient 



to distinguish the species with any cer- 

 tainty, I have given Bassett's name the 

 preference. 



The galls are very common on the 

 twigs of ^tiercus bicolor and c^. niac- 

 rocarpa. They may appear singly but 

 are usually crowded together in clusters 

 about the twigs. The galls, unless much 

 crowded in the cluster, are sub-globu- 

 lar in outline with a small teat-like pro- 

 jection. The fly, which much resem- 

 bles H.globiilus^H. rugosa and^. Bas- 

 setti., began to appear in the breeding 

 cages Oct. 27. Fig. 3 is a full size rep- 

 resentation of a cluster of these galls. 



Two parasites, Decatoma varians 

 and Ormyrtis ventricosus were reared 

 from this species. 



Dryophanta papula Bass. These 

 galls have been taken on J^. rubra and 

 ^. cocciiiea. They consist of thick- 

 ened portions of the leaves that are 

 raised in many sharp points on the up- 

 per side. These thickened portions are 

 lighter in color than the surrounding 

 parts of the leaf and each little point 

 seems to mark the location of the larval 

 cell. Flies began to appear July 12. 

 Rare. 



The great majorit}' of insects reared 

 from these galls have been parasites of 

 the genus Tetrastichus. 



Netirotertis noxiosus Bass. The galls 

 are irregular swellings of the twigs of 

 ^. bicolor. Galls taken in January 

 gave the mature insects the last of March 

 following. Galls not at all common. 



The guests Synergus lignicola and 

 an undetermined species of the same 



