19B0] 
Eickwort — Chelostoma 
319 
long, much larger than C. campanularum, and in general appear¬ 
ance more closely resembles some species of Hoplitis than it does C. 
campanularum and P. philadelphi. 
Additional characters to distinguish northeastern Hoplitis from 
the introduced Chelostoma include the clypeal apex of the female, 
which in Hoplitis is flattened and greatly overhangs the base of the 
labrum, 2 while in Chelostoma it is evenly convex and barely exceeds 
the base of the labrum. The apex of metasomal tergum VII of male 
Hoplitis is broadly rounded, truncate, or with a single median spine, 
unlike that of either species of Chelostoma (Figs. 5-6). 
Voucher specimens of C. campanularum and fuliginosum are 
deposited in the Cornell University insect collection, lot number 
995, and in the American Museum of Natural History, The U. S. 
National Museum of Natural History, the University of Kansas 
Snow Museum, and the Museum of Comparative Zoology at 
Harvard University. 
Biology 
The biology of both species of Chelostoma in Europe has been 
studied; the most thorough account is by Kapyla (1978) in Finland 
(in which C. fuliginosum is cited as C. rapunculi). Nests of C. 
fuliginosum (cited as C. nigricorne) in Italy have been briefly 
described by Bonelli (1967), and in France by Correia (1976), and 
nests of C. campanularum (as C. florisomne ) in Italy have been 
described by Grandi (1961). 
Both species are univoltine, mid-to-late-summer bees, with flight 
periods in Europe from May or June to August or September 
(Benoist, 1929; Stoeckhert, 1933; Correia, 1976; Kapyla, 1978). New 
York specimens of C. campanularum in the Cornell collection were 
captured from 1 July to 27 July, while specimens of C. fuliginosum 
were captured from 4 June to 26 July. 
Chelostoma campanularum and fuliginosum are both strictly 
oligolectic for pollen on bellflowers, Campanula (Campanulaceae), 
although other flowers are commonly visited for nectar (Kapyla, 
1978) . In contrast, the western Nearctic Chelostoma are all or 
mostly oligolectic on Hydrophyllaceae, especially Phacelia and 
Eriodictyon (Hurd and Michener, 1955). Prochelostoma philadel- 
2. Except in Hoplitis (H.) anthocopoides, which is a robust, Osmia-shaped species. 
