^tje Caiinilinn J^iitomolujisi. 



Vol. XLIX. LONDON, APRIL, 1917 No. 4 



POPULAR AND PRACTICAL ENTOMOLOGY. 



Collecting Wasps and Bees.* 



by f. w. l. sladen, ottawa, ont. 



By general consent the Hymenoptera are considered to be the 

 highest order of insects, that is, the most specialized, adaptable 

 and highly organized in the adult state; and the stinging Hymenop- 

 tera, consisting of the ants, wasps and bees are the highest section. 

 Yet, although these insects are conspicuous, abundant and easily 

 preserved, this is one of the neglected orders. It is true there are 

 some "critical" groups, especially among the bees, but in many 

 genera the species can be separated easily. During the past four 

 years, the writer has been working at the wasps and bees of the 

 National Collection of Canada, during time that he could spare 

 from his apicultural duties; first, examining and separating into 

 species the material found in the collection and, second, losing no 

 opportunity to collect specimens, both in the Ottawa district and 

 during his annual tour of the provinces. Sufficient material has 

 now been accumulated, chiefly by collecting, to start making keys 

 to the species in hand, and several genera have already been thus 

 dealt with. 



Beginners often find it hard to separate the males from the 

 females. The best distinguishing character is to be found in the 

 antennae, which are thirteen-jointed in the males (only twelve- 

 jointed in some species of the wasp genus Crabro) and twelve- 

 jointed in the females; the first joint (scape) is very long, the 

 second joint is very short, and in the bee-genus Nomada scarcely 

 discernible. Further, in the males the abdomen normally has 

 seven segments exposed, but in the females only six. However, 

 in some genera one or two of the apical segments are covered in 

 both sexes. The chitinous genitalia of the male are replaced in the 

 female by the sting. 



*Part of this paper was read at a meeting of the Quebec Branch of the 

 Entomogical Society of Ontario, at Montreal on Nov. 16, 1916. 



