BREEDING EXPERIMENTS WITH CONFINED 

 BREMUS (BOMBUS) QUEENS. 1 



O. E. PLATH, 

 COLLEGE OF LIBERAL ARTS, BOSTON UNIVERSITY. 



The biologist who attempts to give a complete account of the 

 life-history and habits of the bumblebees of any part of the 

 world, is generally confronted with the following difficulties: 

 (i) He rarely, if ever, has the opportunity to study the be- 

 ginning and early stages of a bumblebee colony, and (2) it is 

 usually impossible for him to ascertain the biology of the less 

 common species, because he is unable to secure their nests. The 

 first attempts to overcome these difficulties were made by the 

 Austrian zoologist Hoffer ('82). This eminent bumblebee student 

 confined a large number of Bremns queens in a museum at Graz, 

 and thus was able to observe how the queen of Bremus lapidarius 

 constructs her nest and the first egg-cell. However, none of these 

 breeding experiments of Hoffer ('82, p. 413) produced a colony. 



Better results along this line were obtained by the late F. W. L. 

 Sladen ('12), who succeeded in rearing several colonies of Bremus 

 terestris, a species which is very common in most parts of Europe. 

 About the same time, similar experiments were carried out by the 

 Danish biologist Lindhard ('12) with queens bf Bremus agrorum, 

 distinguendus, hortorum, lapidarius, subterraneus, sylvarum, and 

 terrestris. With the exception of Bremus hortorum and subter- 

 raneus, at least one queen of each of these species started a nest, 

 some of the resulting colonies later becoming self-supporting. 

 In this country, Mr. Theodore H. Frison ('18) was equally 

 successful in artificially rearing a colony of Bremus auricomus, a 

 species concerning whose biology little was known up to that 

 time. 



I became interested in this subject during the summer of 1921 

 and decided to try similar artificial breeding experiments with our 



1 Contribution from the Entomological Laboratory of the Bussey Institution, 

 Harvard University, No. 222. 



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