294 
Psyche 
[Vol. 89 
Adult Characters 
In a study of adult diphaglossines, Michener (1966) discussed the 
similarities of Crawfordapis to Ptiloglossa and Caupolicana. Four 
characters found in Crawfordapis were said to be more or less 
Caupolicana- like: (4) outer hind tibial spur of male normal, articu- 
lated at base like inner spur; (6) lateral extremities of terga of male 
without areas of short, dense, erect hair; (7) sixth tergum of male 
with posterior margin not thickened or sulcate; (9) eighth sternum 
of male with apical process rather heavily pigmented, not down- 
curved. The similarity based on character 4 is definitely symplesio- 
morphic as the fusion of the hind tibial spur and the tibia is found 
only in Ptiloglossa. The other three characters appear to be plesio- 
morphic as well in that they represent the absence of some rather 
unusual features. 
Similarities between adult Crawfordapis and Ptiloglossa appear 
to be apomorphic for diphaglossines: (1) clypeus strongly elevated 
above level of adjacent parts of face; (2) marginal cell prolonged 
basally as a narrow sinus to apex of stigma; (3) expanded second 
and third hind tarsal segments of female considerably expanded 
above. This evidence also supports the Crawfordapis- Ptiloglossa 
sister-group relationship indicated by larval characters, but must be 
considered tentative until a comprehensive cladistic analysis of adult 
colletids has been performed. 
Summary 
Crawfordapis luctuosa, a large colletid bee, was studied at two 
nest aggregations in the mountains of Costa Rica. The aggregations 
were in exposed sites formed by landslides or clearing. Female bees 
slowly abandoned the aggregations as they became overgrown with 
vegetation. Several nests are described. In contrast to the crepuscu- 
lar habits of the closely related genus Ptiloglossa, Crawfordapis was 
active primarily between 0930 and 1400 hrs. Some individually 
marked females showed a high degree of constancy in nest visita- 
tion, while others visited several nests in succession. The exact 
explanation of this behavior is not yet known. The previously 
unknown larvae of Crawfordapis luctuosa are described. Informa- 
tion from these larvae supports the placement of the genus in the 
