HYMENOPTERA 147 



the commercial products, honey and beeswax, which they 

 furnish, but, to a much greater extent, because of the part 

 they play in the fertilization of flowers. Many of the 

 valuable cultivated plants do not set fruit or produce seed 

 properly where there are not enough bees to provide for 

 their fertilization. Many flowers have remarkable adap- 

 tations of structure to insure pollination by the bees. 

 Honey-bees are found wild in all the countries where the 

 domestic bees have been carried, as escaping swarms live 

 in hollow trees or caves. In South America there are 

 found honey-producing bees which do not sting. This 

 apparent advantage is minimized by the fact that they 

 defend themselves by biting. 



Bumble-bees or "Humble-bees" are larger and more 

 hairy than the honey-bees and differ somewhat in their 

 social organization. Only the queens live through the 

 winter. They start the new colonies in the spring and 

 do all the work of the colony until such time as the 

 workers develop. Their nests are usually built on the 

 ground or under stones and are concealed with grass and 

 weeds. Their honey is stored in smaU oval sacks and is 

 not used commercially. There are workers and males 

 and, at times, several queens in one nest. The queens are 

 the largest individuals in the nests and are much more 

 active than the honey-bee queens. The over-wintering 

 females are fertilized in the fall. 



Bumble-bees are able to cross-fertilize certain plants 

 whose flowers are too deep for the shorter tongues of the 

 honey-bees to reach. A common plant of this type is the 

 red clover. 



Some bees bore in solid wood and make their nests in 

 the galleries which they construct. These are solitary. 

 One borer (Fig. 108, 1), or Carpenter-bee , resembles the 



