INSTINCTS AND HABITS OF THE SOLITARY 

 WASPS. 



rNTRODUGTION. 



For the purposes of tliis work wasps may be divided into two 

 classes, the social and the solitary. Of these, those of the latter 

 class are much the more numerous, there being over one thou- 

 sand species in the United States alone, while there are only 

 about fifty species of the social genera. That the social kinds are 

 better known is due to the fact that the great size to which 

 their communities often attain makes it comparatively easy to 

 study them. 



The social wasps most commonly met with in Wisconsin are 

 the hornets and yellow-jackets of the genus Yespa, and a species 

 of Polistes that builds open combs. For the sake of comparison 

 let us sum up briefly the cycle of their lives. In the autumn 

 the queens, having mated with the drones, creep away into 

 crevices and sheltered comers where they pass the winter. In 

 the spring they may be seen seeking for suitable nesting places, 

 and forming, from the fibres of weather- beaten wood, which are 

 scraped off and chewed up, the first layer of cells. So much 

 being accomplished the queen deposits her eggs, one in each cell, 

 and when these develop into grubs she feeds them until at the 

 end of a week or ten days they spin their cocoons and become 

 pupae. In from eight to ten days the perfect wasp is formed 

 and emerges from its cell ready to assume its share of responsi- 

 bility in the work of the nest. These first wasps are always 

 neuters, and hereafter all the duties which the queen has been 

 obliged to perforai, with the single exception of egg-laying, fall 



