1985] 
Porter — Cosmiocryptus 
481 
Province of north Chile. The Violaceipennis group (Porter 1967: 
217-18 apparently has no close relatives elsewhere in South Amer- 
ica. It thus may have evolved in situ during the last half of the 
Tertiary, when a rain shadow created by the uplifting Andes allowed 
development in what is now the Coastal Desert of a thorn scrub 
vegetation (similar to the Argentine Chaco) and favorable for com- 
paratively dry-adapted ichneumonids, such as Cosmiocryptus and 
Trachysphyrus. 
The ancient progenitor of the Violaceipennis group might well 
have reached the Coastal Desert from the Argentine and Bolivian 
Chaco, while the Andes still were low enough to allow easy dispersal 
between the arid parts of south-central South America and similar 
communities then developing on the Pacific coast (Solbrig 
1976: 38). 
field notes. Most of my specimens of C. violaceipennis were 
taken while sweeping herbaceous vegetation along rivers or irriga- 
tion ditches. The species does not seem to visit Baccharis as often as 
its relatives. 
host. C. violaceipennis has been reared from “Megalopyge 
prob. amitina’\ a megalopygid moth. 
5. Cosmiocryptus diplatys (Porter), new combination 
(Fig. 8, 9, 10). 
Trachysphyrus diplatys Porter, 1967. Mem. Amer. Ent. Inst. 10 : 222-4. Holotype 
Peru, Matucana, 2400 m, 23-VI- 1 955, W. Weyrauch (Tucuman). 
C. diplatys was described from a unique female (Porter 1967: 
222-24). Subsequent collecting has added 14 females and 50 males 
to this number, but has not extended the species’ range beyond 
Matucana, Peru. Herewith I give a revised description of the 
female and characterize the male for the first time. 
female. Color: antenna black with a white annulus on flagello- 
meres 4 or 5 to 8, 9, or 10; mandible usually all black; gaster some- 
times with extensive but irregular black staining; often with some 
red on fore and mid trochantelli and on bases of their femora. 
Length of fore wings: 8.1-12.8 mm. Flagellum: long, slender, 
cylindric; 1st flagellomere 6. 2-7. 8 as long as deep at apex. Malar 
space: 0.70-0.90 as long as basal width of mandible. Temple: 0.6-0. 8 
as long as eye in dorsal view; rather strongly receding. Wing vena- 
tion: radial cell 3.7-4. 1 as long as wide; 2nd abscissa of radius 
