178 ANTS, BEES AND WASPS 



work and consume a very large proportion of the provisions, they 

 seriously affect the prosperity of the community. 



The genus Melipona includes some of the smallest species of 

 bees, some being so minute that they are commonly called " Mos- 

 quito Bees." These little bees inhabit most tropical countries 

 and sometimes form enormous colonies ; but it is not known 

 whether these colonies contain one or several queens. These 

 bees are also called " Stingless Bees " ; but although it is true they 

 do not sting, the term " stingless " is hardly correct, for, as a 

 matter of fact, they do possess all the essential elements of the 

 sting, though the lancet portion is undeveloped. The genus Meli- 

 pona now includes the Trigona or Tetragona, of which the little 

 Trigona carbonaria of Australia does not measure more than y^ 01 

 an inch in length. 



The Solitary Bees include a number of genera showing con- 

 siderable diversity in their habits : many bore holes in decayed 

 Wood, such as old tree-trunks or wooden posts ; others burrow 

 in the ground or take advantage of burrows already formed by 

 other creatures ; and while some bees select loose, sandy soil for 

 their excavations, others tunnel into stiff clayey soil, and the 

 situation chosen may be on the ground or in the face of a sloping 

 bank or cliff. Some species 'make their nests in the stems of plants 

 such as brambles and briers, from which they remove the pith ; 

 but whatever the situation and material chosen, the Solitary Bee 

 proceeds in much the same manner in the formation of her nest 

 i.e. the cell is first excavated, then provisioned with a cake of 

 honey and pollen, and an egg laid on the top of it ; the bee next 

 closes the cell and leaves it. The larva on hatching from the 

 egg consumes the provisions provided for it, and when fully fed 

 spins a cocoon and changes to a pupa within it. In this state, 

 if late in the season, it usually remains until the following year, 

 when it emerges as a perfect insect, seeks a mate, and provides 

 for the continuance of its species according to the custom of its 

 family. 



To the genera Andrena and Halictus belong the greater number 

 of species inhabiting Britain. The Halictus are very small bees, 

 and are particularly interesting in forming a link, as it were, 

 between the social and solitary orders. They form large colonies, 

 all the individuals combining to excavate a long, central gallery 





