92 BULLETIN 190, UNITED STATES NATIONAL MUSEUM 



(C. Heinrich) ; 3 females, Cleveland, Ohio, from galls of Andricus 

 coniigerus. May 6, 1931 (F. DeGant) ; 3 females, Chickamauga, Tenn., 

 from gall of A. cornigerus; 1 male, Iowa (C. P. Gillette) ; 1 male, Hope, 

 Ark., July, caught in light trap; 1 male from galls of Andricus seminator, 

 June 10, 1893 (Zabriskie). 



Like the typical form, deciplens decipiens, the race rubristigma is a 

 borer in oak, attacking the bark but by preference living in cynipid galls, 

 which must be hard and woody in substance, not soft or spongy. Such 

 galls are occupied only after they have grown to near or full maturity but 

 still retain sufficient' living tissue to support the borers through their 1-year 

 cycle of life. Rearing from galls, collected during spring and early in 

 summer, is the easiest method of obtaining the adults. In the eastern 

 and midwestern States the favorite gall is Andricus cornigerus on black 

 oak. This gall is inhabited also by the far more common smaller species, 

 Thamnosphecia sciUila, and as emergence proceeds there is usually a great 

 preponderance of scitula and only an occasional specimen of decipiens. 

 This ratio is reversed along the coastal regions of the Southern States and 

 in the type habitat of decipiens in Colorado, where different species of 

 woody galls on different kinds of oaks are occupied. Cynipid galls on live 

 oak and on scrub oak at Pensacola, Fla., and Mobile, Ala., produced ex- 

 amples of decipiens only. There are no records of scitula from Colorado. 



The recognition of rubristigma as a race of decipiens stands on color 

 differences alone. Intergradations along the range of the species interfere 

 with a clear-cut geographical division. In general the race rubristigma 

 represents the eastern and northern part of the range, differing from 

 typical decipiens by the nearly complete transparency of the forewings in 

 the male and by the only narrowly suffused tips of the forewings in the 

 female. Westward and southward there is a gradual intensification of the 

 scaling on the forewings, this reaching its greatest development along the 

 coastal regions of northern Florida and Alabama, where transparent areas 

 become nearly obscured. A narrow belt across Florida from Jacksonville 

 to the northern State line remains untouched by field investigations. 

 Within this belt lies the meeting place of decipiens and florid ensis. The 

 question is, Do these two forms remain apart or do they blend? We are 

 inclined to suspect a blending. 



SYNANTHEDON SAXIFRAGAE (Hy. Edwards) 



Aegeria saxifragae Hy. Edwards, Papilio, vol. 1, p. 190, 1881.— Beutenmuller, Bull. 



Amer. Mus. Nat. Hist., vol. 6, p. 91, 1894. 

 Aegeria henshawii Hy. Edwards, Papilio, vol. 2, p. 56, 1882.— Beutenmuller, Bull. 



Amer. Mus. Nat. Hist., vol. 4, p. 173, 1892. 

 Sesia saxifragae Beutenmuller, Bull. Amer. Mus. Nat. Hist., vol. 8, p. 135, 1896. 

 Synanthedon saxifragae McDunnough, Check list of the Lepidoptera of Canada and 



the United States of America, pt. 2, No. 8719, 1939. 



