52 INTRODUCTION TO ZOOLOGY. 



It is an advantage to the bumblebee to be thus col- 

 ored, for other animals, aware of its stinging power, 

 will let the bee alone if they know where it is. 



The drone bumblebee has no sting. In some 

 species, however, it is even more yellow and flaunts 

 a more conspicuous danger signal than the stinging 

 bumblebee. The conditions of mimicry are found in 

 the drone bumblebees. 



Wasps are of two kinds, the social and the solitary. 

 The social wasps have the same three kinds of indi- 

 viduals that are found among the bees. They build 

 nests like honeycomb, with six-sided cells, out of 

 paper. The true social wasps build these combs in 

 sheltered places, and put no covering over them. 

 The hornet builds the same kind of paper nest, 

 but surrounds the nest with a paper envelope. The 

 paper is made from disintegrated woody fiber, ob- 

 tained from weather-beaten boards or sticks of wood. 

 The young are reared in these cells. The wasps 

 themselves eat vegetable food, but they feed the 

 young upon the bodies of other insects. 



The solitary wasps. either dig holes in the ground 

 or build nests of mud which they place in some shel- 

 tered position. As soon as a cell is built, the wasp 

 provisions it with the bodies of other animals, such 

 as spiders, caterpillars, cicadas, etc. Each kind of 

 wasp selects a particular kind of animal with which 

 to provision its nest. The wasp, having found a 

 spider, for example, stings it in a ganglion of the 

 nervous system on the ventral side of the body. If 

 a caterpillar is the object of attention, the sting is 

 thrust into nine or ten of the ganglia. The slender 

 pedicel of the wasp, by which the abdomen is attached 

 to the thorax, enables it to reach around to the under 

 side of the spider or the caterpillar and sting it in the 

 proper place. The effect of this sting is to paralyze 

 the victim, not to kill it. It is then carried to the nest 



