PSYCHE 
Vol. 90 
1983 
No. 3 
NEST BUILDING BEHAVIOR AND DEVELOPMENT 
OF THE SUNFLOWER LEAFCUTTER BEE: 
EUMEGACHILE (SAYAPIS) PUGNATA (SAY) 
(HYMENOPTERA: MEGACHILIDAE) 
By D. R. Frolich* and F. D. Parker 
Bee Biology & Systematics Laboratory 
Agricultural Research 
Science & Education Administration 
USDA 
Utah State University, UMC 53 
Logan, Utah 84322 
Introduction 
Eumegachile (Sayapis) pugnata (Say), formerly Megachile (Say- 
apis) pugnata Say (Mitchell 1981), is a large (13-18 mm) leafcutter 
bee that is widely distributed throughout the United States and 
southern Canada (Hurd 1979). Eumegachile pugnata nests in a wide 
variety of situations including man-made borings in wood and is 
easily trapped in the wild (Medler 1964, Krombein 1967, Parker & 
Frohlich in prep.). 
Since E. pugnata is oligolectic to flowers of the Compositae 
(Tepedino & Frohlich 1982), attention has recently been directed 
toward developing the bee as a pollinator of commercial sunflower. 
Parker and Frohlich (1983) described its use in hybrid sunflower 
pollination; Tepedino and Frohlich (1982) discussed mortality fac- 
tors, pollen utilization and sex ratio; and Frohlich (1982) described 
various aspects of its ecology. The purpose of this study was to 
■Current address; University of Idaho, SW Idaho Research and Extension Center, 
Parma, Idaho 83660. 
Manuscript received by the editor March 29, 1983. 
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