114 THE CANADIAN ENTOMOLOGIST 



The wasps are predatory, choosing as their victims spiders, 

 flies, ants, caterpillars, etc., according to the genus. The great 

 army of the bees has made an aihance with the flowers, cross- 

 polHnating them in return for feed of the richest and daintiest 

 kind — pollen for the nurture of their young, aromatically flavoured 

 nectars for their own delectation. There are many instances of 

 certain species of bees associating only with certain species of 

 plants. In the bees the body hairs are branched or plumose and 

 gather up the pollen dust from the flowers they frequent, and they 

 have beautifully adapted apparatus, becoming more intricate and 

 perfect in the more specialized families, on their hind legs— and in 

 one group (the leaf-cutter bees) on the underside of the abdomen — 

 for collecting this pollen. In the wasps the body hairs are un- 

 branched. 



No species of bee runs riot, multiplying by millions under 

 favourable conditions like certain insects in other orders, for the 

 interesting reason that from nearly every genus in which are found 

 species that by dint of special vigour or adaptability are inclined 

 to overproduction, there has sprung a non-industrious genus, the 

 speciesof which prey on the abundant industrious species, laying their 

 eggs in their nests. The parasite, when it hatches, usually consumes 

 both the host egg or larva and also its store of food, but in case 

 of the semi-social bumble-bees, the parent parasite lives in the nest, 

 producing young which the hcst workers tend and feed as they do 

 their own brothers and sisters. As parasitic genera in all stages of 

 separation from the host genus occur, we have here presented one 

 of the most attractive and promising fields of study for the evo- 

 lutionist that can be found. In some cases the parasite has drifted 

 from its original host and has taken up with another. In general, 

 the parasitic genera are less hairy than their hosts, and their 

 tegumental colours are brighter. The bumble-bee parasites closely 

 mimic their hosts and have so much structural similarity to 

 them that they must have developed their parasitism comparative- 

 ly recently. 



In Canada by far the richest regions in species of wasps and 

 bees are certain localities near and reaching to the southern borders. 

 Three very rich localities can be distinguished. One of these is in 

 Old Ontario, especially the region south of Toronto. Another, 



