1980] 
Eickwort — Chelostoma 
321 
Discussion 
At least eight exotic species of Megachilidae have accidentally 
become established in North America. Eickwort (1971) discussed 
five of these species: Megachile rotundata (Fabricius) ( =pacifica 
(Panzer)), Megachile concinna Smith, Megachile apicalis Spinola, 
Chalicodoma lanata (Fabricius), Anthidium manicatum (Finnaeus), 
and Hopliiis anthocopoides (Schenck). Roberts (1978) has recently 
recorded the establishment in New Jersey of Lithurge chrysurus 
Fonscolombe, a native of the Mediterranean region, and the present 
paper reports the establishment of two Palearctic species of Chelos¬ 
toma in New York. In addition, Osmia cornifrons (Radoszkowski) 
has been purposely introduced for fruit pollination into Utah and 
Maryland from Asia and appears to be established, at least in 
Maryland (Batra, 1979 and personal communication). 
Although many megachilid bees excavate nests in soil (Eickwort 
et al., 1981), all of these introduced species construct nests in 
cavities, bore into wood, or construct free-standing masonry nests. 
Human transport of substrates containing nests with diapausing 
bees probably was their mode of immigration. All of the introduced 
megachilids live in disturbed habitats and visit Old World garden 
flowers and weeds, either as generalists (Megachile spp., Chalico¬ 
doma lanata, Anthidium manicatum) or as specialists (Chelostoma 
fuliginosum and campanularum on Campanula, Hop litis anthoco¬ 
poides on Echium, and Lithurge chrysurus on Centaurea). The two 
species of Chelostoma compete for the same food resource but use 
different-diameter cavities for nests. 
Surprisingly, four of these eight species are known only from 
central New York State (H. anthocopoides 3 , A. manicatum, C. 
fuliginosum, and C. campanularum). Indeed, on a pleasant July day 
the latter three species plus M. rotundata forage simultaneously in 
one of Cornell University’s beautiful gardens. Ithaca, New York, is 
hardly a major port of entry, so I cannot explain this apidological 
touch of Europe that we enjoy. 
3. After this paper was accepted for publication, Hoplitis anthocopoides was cap- 
tured in Frederick Co., Virginia. 
