PIONEERS OF COMMUNAL LIFE 



in it, when we are tempted to attribute to insects relations and 

 motives which exist only in the human community. 



As all things in Nature reveal the successive stages of a gradual 

 evolution, we shall not at once find the insect community in its 

 complete and perfect state. On the contrary, we shall find different 

 stages of social life, leading up from crude beginnings to the subtly 

 organized community of the Bees and Ants. The first condition 

 of a community is that the mother shall live to see the larvae hatch 

 from her eggs; the second, that the members of a species shall 

 build their brood-cells close together, so that the instinct of common 

 defence against danger is evolved. Thus, there are species of bees 

 which build their brood-cells for themselves alone, and care for 

 their larvae without assistance; but if anything disturbs even one 

 of these insects, their angry humming infects the others. From all 

 sides they fall upon the enemy, multiplying the efficacy of the 

 onslaught. 



The transition from the solitary to the social life is first seen 

 among the Wasps. We have made the acquaintance of the Hornets, 

 the Potter-wasps or Mud-wasps, and others; these are solitary as 

 regards their provision for their brood, but even among them there 

 are certain species whose activity does not cease with the preparation 

 and provisioning of the brood-cells, for they continue to visit the 

 cells when the larvae have emerged, and to bring them fresh supplies 

 of food. In those wasps which fold their fore-wing when at rest — 

 the Vespidae and the Eumenidae — these first steps are carried 

 a little further. Among them the 'Till- wasps" still live a solitary 

 life, but the true Wasps dwell in populous and well-organized 

 communities. 



In Brazil there are a great number of "Pill-wasps," with hand- 

 some black and yellow markings ; the family may be recognized by 

 the fact that the stalk by which the abdomen is attached is club- 

 shaped, being dilated at its hinder extremity. They are called 

 "Pill-wasps" because they make little spherical pots of clay, which 

 in the smaller European species look like pills. In Brazil we fre- 

 quently find such clay balls, prolonged at the top into short necks, 

 and sealed, on walls and on various plants. If we open such a sealed 

 jar we find inside paralysed insects, and the egg of the wasp, or 

 even its larva, which has begun to devour its victims. Other species 

 build larger pots, which may contain several cells in juxtaposition, 



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