898 



THE NATURE BOOK 



of leaf, and may 

 tlius form some 

 idea of the amount 

 of labour com- 

 passed by the in- 

 sect ; but it should 

 be remembered 

 that to the labour 

 of leaf-cutting 

 must be added 

 that of tunnelling 

 and of gathering 

 provisions for each 

 cell as it is made. I 

 do not think that it is possible to estimate 

 the average nimiber of cells fonned by each 

 Bee in the course of the season, for the 

 reason that when one tunnel has been filled 

 the insect may, and sometimes un- 

 questionably does, make and fill another 

 tunnel. I am con\'inced, however, that 

 a score or more cells must often be made 

 by a single Bee. 



A photograph reproduced on this page 

 shows us part of a decayed beam (taken 

 from a greenhouse) from which one side 

 has been carefully removed, showing in 

 section two of the Bee's tunnels with leaf- 

 cells in situ. The egg in each cell hatches 

 in a few days after it is laid, and the young 

 grub begins at once to feed upon the 

 good things provided for it by the 

 instinctive labours of the mother Bee. 

 Another photograph shows us a leaf-cell 

 with part of its side removed, and the 



LEAF-CELL CUT OPEN TO SHOW HALF- 

 GROWN BEE-GRUB FEEDING UPON 

 HONEY WITHIN (MAGNIFIED). 



half - grown grub 

 within, literally 

 wallowing in syrup. 

 It is a remarkable 

 fact that the Bee 

 mother puts just 

 enough food into 

 each cell, and no 

 more ; so that 

 when the grub has 

 licked up the last 

 drop of S3'rup its 

 appetite is satis- 

 fied. Thereafter it 

 spins within its leaf-cell a cocoon of silk, 

 coarse without but very fine within, and 

 with a kind of cap at one end which — 

 when the grub ultimately becomes a 

 perfect Bee — is readily cut away. 



A curious detail connected with the 

 transformation of the Leaf-cutting Bee is 

 that the grub, when it has finished its 

 cocoon, does not at once become a 

 pupa. In fact, it remains what it is 

 throughout the whole winter, and only 

 becomes a pupa in the springtime, a few 

 weeks prior to its assumption of the imago 

 condition. 



Many solitary Bees pack their cells one 

 after another into a tunnel bored in the 

 ground or in rotten wood, and a moment's 

 thought will show the reader that, should 

 any of the insects at the end of this Indian 

 file come to maturity before those which 

 are nearer to the opening of the tunnel. 



^stfKfi^;:! 



tf.^-ir* 



SECTION THROUGH ROTTEN BEAM. SHOWING TWO TUNNELS PACKED 

 WITH LEAF-CELLS BY LEAF-CUTTING BEE. 



