BEES. 



(Plate XCIII) includes metallic green, bluish, or purplish 

 bees with tarsal pads. They are called Mason-bees 

 because they construct small, earthen cells under stones, 

 in burrows excavated in twigs and decaying wood, in 

 deserted snail-shells, in plant-galls, and elsewhere. The 

 last to be mentioned but richest in species is Megachile 

 (Plate XCIII), moderately large bees without pads between 

 the tarsal claws; stigma short, not well developed; tip of 

 marginal cell obtuse and separated from the front wing- 

 margins. The species of Megachile are called Leaf-cutters 

 because the females snip more or less circular pieces out of 

 leaves, especially of roses, and of petals. These pieces 

 are fitted together and glued so skillfully that they form 

 tight, thimble-shaped cells, snugly filling some suitable, 

 ready-made space or burrows which the females make in 

 wood or earth. Putnam estimated that the thirty cells, 

 arranged in nine rows, under a board in his piazza, roof 

 contained at least a thousand pieces. Reed recorded 

 nests made by one of our common species, brevis, in curled 

 plum leaves. . 



CERATINID.E AND XYLOCOPID/E 



The Carpenter-bees make nests in wood or in stems of 

 plants. There are three submarginal cells; the first dis- 

 coidal cell is not as long as or scarcely longer than the 

 marginal cell; apex of sixth dorsal, abdominal segment of 

 females with a spine. Cemtina (Plate XCIII) in- 

 cludes small, dark blue-green bees with the first sub- 

 marginal cell longer than the second and about as long 

 as the third; stigma well developed, lanceolate. They 

 dig out the pith of elder, raspberry, etc., so that they may 

 have tunnels in which to nest. The large Carpenter-bees 

 which make galleries in rather solid wood, such as porch- 

 posts, are Xylocopa (virginica, Plate XCIV, is the only 

 Northern species). The stigma is short and not well 

 developed; first submarginal cell shorter than the second, 

 third almost as long as the first and second combined. 

 They are given to biting through the base of a flower 

 instead of getting at the nectar in a more legitimate way. 



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