356 U. S. NATIONAL MUSEUM BULLETIN 216 



Island (Westerly); Utah (Logan Canyon at 5,000 ft., Mount Tim- 

 panogos, and Park City) ; Virginia (Arlington and Dayton) ; Washing- 

 ton (Ashford, Barnes State Park, Dartford, Garfield, Mount Rainier 

 at 2,700 ft., Pullman, Seattle, and Woodland) ; West Virginia (Bolivar) ; 

 and Wisconsin (Washburn Co.). 



Dates of collection are mostly from late spring to early fall, but a 

 few specimens were taken earlier or later. The earliest and latest 

 dates of capture are April 3 at Sharon, Mass.; April 8 and 12 at Rob- 

 son, B. C; April 28 at Forest Hills, Mass.; October 20 at Flatbush, 

 Long Island, N. Y.; October 26 at Holliston, Mass. and Mount Toby, 

 Mass.; November 7 at Arlington, Va.; and November 28 at Riverton, 

 N.J. 



There is some evidence that the species overwinters as an adult 

 female. This is as follows: 1. Two females were taken "under bark" 

 at Natick, Mass., on Apr. 23, 1944, by C. A. Frost. 2. We have seen 

 six females labeled "Quercus alba," Hummelstown, Pa., Jan. 1, 1917, 

 J. N. Knull. These presumably were collected in a log or stump of 

 this tree or under bark. 3. In spring of 1947 we were collecting in- 

 tensively in the Sierra Ancha of Arizona, at 5,000 to 6,000 ft. eleva- 

 tion. On May 1 and 2 females (only) of T. atalantae became sud- 

 denly abundant in two of the stream valleys we had been working and 

 remained abundant during the rest of our stay, but no males were 

 found. Prior to May 1 no specimens at all were seen in these two 

 places. This seems to be a case of emergence from hibernation as 

 adults. If it had been emergence from pupae, rather than as over- 

 wintering adults, males would have appeared with the females. 



In our own collecting we have found the species nearly always in 

 mesophytic or damp woods, usually in deciduous woods. 



This species has been reared many times as a parasite of medium- 

 sized or larger Lepidoptera, and sometimes as a secondary parasite of 

 ichneumonids. It is an important parasite of some of the pests of 

 forests. Its biology is rather well known. For a summary of the 

 published information see Townes, 1940 (Ann. Ent. Soc. America, vol. 

 33, pp. 286, 295-297). Host records on the pin labels of specimens we 

 have studied are: 2 rearings or reared lots from Choristoneura fumi- 

 ferana, 1 from Lambdina fiscellaria somniaria, 2 from Malacosoma 

 americanum, 1 from M. calijomicum, 3 from M. fragile, 4 from Mala- 

 cosoma sp., 2 from Neophobia menapia, 1 from Nepyiia phantasmaria, 

 1 from Nymphalis calif ornicus, 1 from Or eta rosea, 1 from Porthetria 

 dispar, 1 from cocoon in prune orchard, 1 from cocoon on Corylus 

 leaves, and 3 from tussock moth. The additional host records in 

 literature concern the same type of Lepidoptera, plus several ich- 

 neumonid hosts. 



