NEW RECORDS FOR THYREODON FROM SOUTH TEXAS 
(HYMENOPTERA, ICHNEUMONIDAE) 
By Charles C. Porter 
Department of Biological Sciences 
Fordham University 
Bronx, N.Y. 10458 
Since 1973, I have been surveying the Hymenoptera of the 
lower Rio Grande Valley of south Texas 1 and have established 
the presence there of Thyreodon niger, heretofore reported only 
from Mexico and Guatemala (Townes, 1966, p. 190). Concurrent- 
ly, Dr. James E. Gillaspy of Texas A. & I. University at Kingsville 
has loaned me for identification a series of Texan ichneumonids, 
containing not only additional material of niger but also two 
specimens of T. laticinctus, another Neotropic Thyreodon pre- 
viously unrecorded north of Mexico (Townes, 1966, p. 189). 
The present contribution offers taxonomic and ecological 
notes on niger and laticinctus as well as brief discussion of the 
other U.S. Thyreodon. 
Genus Thyreodon Brulle 
The following combination of characters will separate this 
genus from all other New World ichneumonids: 
Large to very large species, length of fore wing 16-28 mm.; 
apex of clypeus broadly triangular and reflexed; maxilla and 
labium about 0.4 as long as height of head; first intercubitus joins 
cubital vein far distad of second recurrent; second brachial cell 
with a long spurious vein that borders all or most of its hind edge; 
nervellus broken near upper 0.3; propodeum strongly inflated 
basally, so that the spiracle is situated in a deep depression; spi- 
racle of first gastric tergite well behind middle; gaster strongly 
compressed. 
Thyreodon is an excusively New World genus of very large 
and conspicuous ichneumonids belonging to the Tribe Enico- 
1 Acknowledgements: My Texas fieldwork currently is supported by a U.S. 
National Science Foundation Grant (DEB 75-22426) and from 1973 to 1975 was 
made possible by grants from the Committee for Research and Exploration of 
the National Geographic Society. 
Manuscript received by the editor December 7, 1976. 
304 
