THE NESTING HABITS OF ANTHIDIUM. 1 



AXEL LEONARD MELANDER. 



The care and forethought which an insect shows in providing 

 for an offspring which in most cases she will never see have 

 always excited the interest of biologists. Among these insects 

 the solitary bees have especially attracted the attention of ob- 

 servers on account of their varied habits of nest construction. 

 Here, in a group of insects more or less homogeneous, we find 

 the style of architecture under such differing forms as the fence- 

 rail excavations of the carpenter-bees, the thimble-like nest of 

 the leaf-cutters, or the Andrena-burrows in wayside paths. 



The genus Anthidium affords no less interesting methods of 

 house construction. For many years the habits of a few species 

 of this genus have been well known, but they constitute but a 

 small contribution when the whole number of species is consid- 

 ered. In a recent monograph of the European species of An- 

 thidium Dr. Henry Friese estimates the .total number of species 

 of the world at between five and six hundred. Already some 

 two hundred and twenty have been described, but of these the 

 habits of the two hundred are yet to be made known. 



Anthidium is a genus of fixed morphology, that is the species 

 rather markedly resemble one another. All have the abdomen 

 destitute of hair above, and brightly ornate with yellowish mark- 

 ings. Notwithstanding this similarity in appearance the habits 

 of the species are quite different. Two distinct methods of nest- 

 building are presented, from one or the other of which the 

 species, at least so far as known, scarcely ever depart. The 

 French entomologist, Fabre, has tersely called these two catego- 

 ries, those of the " Cottonniers " and of the " Resiniers." 



The cotton-workers do not show much deviation from the 

 habits of other bees and might be considered to possess the 

 primitive nesting-habit of this genus. Among bees the female 

 either digs a hole in the ground or, more usually, occupies one 

 already dug. Apparently all that is sought is a convenient 



1 Contributions from the Zoological Laboratory of the Uninversity of Texas, No. 12. 



