GUESTS AND PARASITES OF HALICTUS. 



5 



other. The Rlutilla, too, is armed with a powerful sting, half the 

 length of her abdomen, but the sagacious Halictns grasps her 

 enemy about the waist and most successfully evades the sharp 

 thrusts. These combats continue for many minutes, concluded 

 either by the invulnerable Mutilla slipping from the bee's grasp, 

 for her body is hard and sleek, or by the death of the more 

 plucky Halictns. Each colony, where everything seemingly is 

 peace and content, is thus turned into a field of carnage, with the 

 bodies of one or more females ruthlessly tumbled to the bottom 

 of the hill. If the bee escapes unscathed, which happily is the 

 more usual outcome of these struggles, she spends a few moments 

 in preening her body, and then returns to her nest. But no 



"' ;: -\'"- ' '-i' 



. rr- v . . *',' . 



FIG. 3. Nest of Halictiu at Woods lioll, Mass. 



greeting awaits her after her loyal struggle. When she hurriedly 

 left the nest the male waiting his turn in the tunnel below quickly 

 took her place as guard at the door, and now he blocks the 

 entrance as obstinately as though it were a stranger begging 

 admittance. The taint of Mntilla is still to be recognized on the 

 body of the female and probably overpowers her family smell. 

 For quite a minute she must remain at the door parleying with 

 her mate before he is convinced of her identity. 



This observation is of interest when considering the organic 

 dependence of instinct. Fear of Mntilla has been cultivated 



