THE LEAF-CUTTING BEE 



899 



they will be unable 

 to effect their escape 

 easily. The great 

 French entomologist 

 Fabre conducted ex- 

 periments with cer- 

 tain of these Bees, 

 in order to ascertain 

 how they behaved in 

 these circumstances. 

 He found that if the 

 imprisoned Bees could 

 not cut or force their 

 way between the ceUs 

 in front of them and the side of the 

 tunnel, they in no instance injured the 

 cells themselves. Rather, they waited 

 patiently until the way was cleared for 

 them by the maturing and escape of their 

 brothers and sisters in front. Whether 

 the Leaf -cutting Bee is similarly patient, 

 I am not yet able to state, though I 

 know of no reason for suspecting it to 

 be otherwise. 



The Leaf-cutting Bee has several 

 enemies, one of which is a near relative. 

 It is known as a " Cuckoo " Bee because 

 its habits remind one of those of the cuckoo 

 emiong birds. The mother Leaf-cutting 

 Bee forms her cell, provisions it, and lays 

 her egg. While she is away cutting the 

 leaf-fragments with which to cap the cell. 



COCOON OF LEAF-CUTTING BEE, SHOWING 

 NUMEROUS PUP/E OF THE CHRYSID 

 PARASITE WITHIN (MAGNIFIED:. 



the Cuckoo Bee steals 

 into the tunnel and 

 lays one of her eggs 

 side by side with that 

 of the riglitful owner. 

 The usual result is 

 that the Cuckoo grub 

 devours most of the 

 food, while the grub 

 of the Leaf-cutting 

 Bee pines and dies. 

 There are also cer- 

 tain minute Wasp- 

 hke insects, belonging 

 to the family Chalcididce, which contrive 

 to lay their eggs within the cocoon 

 spun by the Leaf-cutting Bee grub. 

 Exactly how they manage this I have not 

 discovered, but they are very tiny, and 

 so would be quite capable of forcing their 

 way between the leaf-cells and the sides 

 of the tunnel. Their egg-tubes, or ovi- 

 positors, would then enable them to pierce 

 the wall of the cocoon. The tiny grubs 

 of these Chalcid Wasps prey upon the big 

 sleeping Bee grub, and ultimately devour 

 it. Each is then transformed into a tiny 

 pupa. I give a photograph of a Bee's 

 cocoon with the side cut away. The 

 whole interior is packed with Chalcid 

 pupae, while not a vestige of the rightful 

 owner remains. 



• • • • 

 fflffiV 



FEMALE LEAF-CUTTING BEE. WITH THE ELEVEN PIECES OF LEAF WHICH 

 USUALLY GO TO THE MAKING UP OF A SINGLE CELL 



