T. D. A. COCKERELL 25 



NEOTROPICAL BEES, PRINCIPALLY COLLECTED BY 

 PROFESSOR BRUNER IN ARGENTINA 



BY T. D. A. COCKERELL 



Many 3^ears ago Professor L. Briincr visited Argentina to 

 report on the injurj^ caused b}" locusts in that country, and while 

 tliere, took occasion to collect bees. ]VIost of his material came 

 from Carcarana, which is, as I learn from Professor Bruner 

 through Professor Swenk, twenty- or thirt}' miles west of Rosario, 

 on the main railroad line. It is, therefore, not in the western 

 part of the country, as I had supposed, but is over 400 miles east 

 of Mendoza, the locality made famous by the collections of 

 Jorgensen and others. 



At the time when Professor Bruner made his collection, prob- 

 al)iy not less then eighty or ninet}- per cent of the species were 

 new, but since that time many bees from Argentina and Paraguay 

 have been descril^ed, principally by Holm]:)erg, Friese, Jorgensen, 

 Schrottky, Brethes and Strand. It appears, however, that no 

 one has collected extensively', if at all, in the Carcarana district, 

 and consequently man}' new species are still to be found among 

 Professor Bruner's captures. These species are probably for the 

 most part very local, or confined to particular plants, just as we 

 find to be the case in our own southwestern country. Travelling 

 from New JNIexico through Arizona into California we meet with 

 several different bee-fauna?, with often representative but quite 

 distinct species. Some species, of coin-se, range over the whole 

 area. The same seems to be true in Argentina, and the Carcarana 

 fauna resembles (and differs from) that of Mendoza nuich as that 

 of New Mexico does that of Southern California. 



The species of bees may spread over large areas, and then 

 break u]) into races and eventually species as they become ad- 

 justed to local conditions, especially to particular plants.' A 

 wide-.spread species has better chances for survival, as a species, 

 than a local one, but it is of no advantage to an individual bee 

 to belong to a wide-spread species. Its problem is rather adjust- 

 ment to the immediate surroundings, and in this respect it may be 



TRANS. AM. ENT. SOC, XLIV. 



