1986] 
Porter — Thyreodon from Costa Rica 
137 
specimens all the tibiae and tarsi are pale brown (legs wholly black 
in the 10th yellow-winged $), whereas both wings and legs are black 
in the 3 remaining $. Among the 10 $, 1 has yellow wings but dark 
legs, 1 black wings but pale legs, and 8 both black legs and wings. 
Relationships. Thyreodon santarosae belongs to the Atricolor 
group of Thyreodon (Porter 1984). This assemblage includes robust 
species with inflated temples, often weakly impressed notauli, and 
without a transverse or longitudinal crest at the anterior end of the 
notauli. It has several undescribed Sonoran, Middle American, 
Caribbean and South American species plus the Nearctic T. 
atricolor (Olivier), the Sonoran T. fernaldi Hooker, and T. orna- 
tipennis Cresson from the Mexican wet tropics. 
Thyreodon santarosae differs most trenchantly from its relatives 
in the extensively smooth and polished apical propodeal face (hind 
face of propodeum coarsely reticulo-rugose in T. atricolor and T. 
fernaldi, finely and densely puncto-reticulate in T. ornatipennis). 
Other diagnostic features are its laterally almost ecarinate scutel- 
lum; smooth speculum; and relatively sparse (mostly subadjacent or 
more distant) mandibular, clypeal, mesoscutal, and mesopleural 
punctures. 
Field Observations and Hosts. Santa Rosa National Park, 
the type locality, is in Tropical Deciduous Forest at 250-350 m on 
the Pacific Coast of Guanacaste Province, Costa Rica. Daniel H. 
Janzen reared the entire type series from “larvae of Saturniidae in 
the Subfamily Ceratocampinae. . .collected at 3-20 m above the 
ground” (personal communication). The parasites emerged during 
April to December 1984. No individuals of T. santarosae were 
obtained by hand nets or Malaise Traps. 
This species appears to be unique among Thyreodon for its 
apparent restriction to intermediate and higher strata of a Tropical 
Forest community and because it attacks ceratocampine caterpil- 
lars. Most other Thyreodon fly close to the ground or around 
understory shrubs at no more than 2 m altitude, and the only pre- 
vious rearing data for this genus involve sphingid Lepidoptera that 
pupate in the ground (Porter 1984). 
Specific Name. For Costa Rica’s Santa Rosa National Park, 
where Dan Janzen has found enthusiastic support for his ecological 
studies. 
