TWO EUROPEAN SPECIES OF CHELOSTOMA 
ESTABLISHED IN NEW YORK STATE 
(HYMENOPTERA: MEGACHILIDAE)* 
By George C. Eickwort 
Department of Entomology 
Cornell University 
Ithaca, New York 14853 
Introduction 
Chelostoma is a Holarctic genus of slender, black megachiline 
bees that is widespread in the Palearctic region and has eight species 
in western North America. The Nearctic species all occur in 
California, with the range of two extending northward to Washing¬ 
ton, one of which also occurs eastward to Utah and Idaho (Hurd 
and Michener, 1955). No native Chelostoma occur east of the 
Rocky Mountains. Chelostoma is replaced east of the Great Plains 
by the closely related genus Prochelostoma, which contains one 
species, P. philadelphi (Robertson). However, Chelostoma has 
recently become established in northeastern United States, where 
two European species, C. campanularum (Kirby) and C. fuligino- 
sum (Panzer), have been collected in several localities in central 
New York State (Fig. 1). 
Taxonomy 
Both European species key to Chelostoma in the keys to genera of 
Megachilini in Michener (1944) and Hurd and Michener (1955). 
Like the native Nearctic Chelostoma, the two European species 
possess a longitudinal carina along the inner ventral angle of each 
hind coxa and have the third segment of the labial palp flattened 
and connate with the second. These characters are often difficult to 
see in pinned specimens. This was of little practical consequence 
because they served in keys to separate Chelostoma from Prochelos¬ 
toma, and the native ranges of these genera do not overlap. 
Prochelostoma philadelphi, however, is common in New York 
where the European Chelostoma are now established. I suggest the 
* Manuscript received by the editor May 7, 1981. 
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