No. 2368. AMERICAN SUBTERRANEAN GALLS ON OAK— WELD. 211 



indoors the next spring from February 20 to March 8. Old galls 

 were seen at Marianna, Florida, October 11, 1919. 



Agamic female. — The antennae of nebulosa are described as 16- 

 segmented, but these are really 15-segmented, the last over twice 

 as long as preceding and incompletely divided by a transverse groove 

 a little below the middle so that in certain positions it would be 

 counted as two. 



Note. — Found a similar old gall on Quercus lyrata Walter and 

 from it cut out a moldy fly belonging to the genus Odontocynips; 

 and it is probably the same species, as these two oaks have many 

 galls in common, but until reared it is better not to publish lyrata 

 as a host of nebulosa. 



At Cuero, Texas, October 23, and Austin, Texas, October 30, simi- 

 lar galls were found on roots of Quercus virginiana Miller, and a 

 fragment of an adult in an old gall showed it to be due to an Odonto- 

 cynips. Three stages of the galls were observed: 1, old galls with 

 numerous exit holes where flies had emerged the previous spring; 

 2, fresh galls containing pupae; 3, fresh galls not distinguishable from 

 the above but containing a thick transparent mass of nutrient ma- 

 terial with a barely visible larval cavity. This suggests that the 

 galls take two years to develop. Similar empty galls were seen at 

 Kerrville, Texas, July 21, 1918. Until adults can be reared it is 

 better not to publish virginiana as a host of nebulosa, however. 



Genus ANDRICUS Hartig. 



15. ANDRICUS RHIZOXENUS (Ashmead). 



Plate 32, fig. 14. 



Callirhytis rhizoxenus Ashmead, Proc. U. S. Nat. Mus., vol. 19, 1896, p. 132, No. 



35. — Cockerell, Ent. Student, vol. 1, 1900, p. 9. — Thompson, Cat Amer. Ins. 



Galls, 1918, pp. 5, 30.— Felt, Key to Amer. Ins. Galls, N. Y. St. Mus., Bull. 



200, 1918, p. 54. 

 Callirhytis rhizoxena Ashmead, Dalla Torre and Kieffer, in Wytsman Gen. 



Ins. Cynipidae, 1902, p. 67, No. 28; Das Tierreich, Lief. 24, 1910, p. 574. 



This species was described as Callirhytis rhizoxenus from a gall 

 "on the roots of a live oak at Fort Grant, Arizona." The type gall 

 in the United States National Museum is ellipsoidal, 36 by 22 by 

 25 mm., smooth on outside, very dark brown, hard and granular 

 inside instead of woody but contains no normal cells or exit holes. 

 The type flies have the tarsal claws with a tooth and run to Andricus. 

 They agree with adults the writer has reared from a rougher brownish 

 (not carbonaceous black) gall terminal on twigs of Quercus oblongi- 

 folia Torrey at Patagonia, Arizona. They were collected July 6, 

 1918, and contained pupae, the flics issuing by July 19. The types 

 agree also with flies from a similar gall on Quercus toumeyi Sargent 

 collected at same time and place and from which living adults were 

 cut out August 21. Similar galls occur also on Quercus arizonica 



