24 BULLETIN 143, UNITED STATES NATIONAL MUSEUM 



The closed hive had been opened again and 30 dead bees lay on the floor of 

 the hive ; the bee wolf was supposed to be present among these. Since the bees 

 lay singly, against and over one another, a quick glance convinced me that 

 the opposite was true ; it was further asserted, however, that the bee wolf must 

 be found under the fallen bees. At this moment a honeybee fell from the mass 

 of bees and tumbled around on the floor of the hive with the bee wolf riding 

 on it and firmly biting at the back of the neck. The window of the lower 

 story was quickly opened and the bee wolf was captured. In examining the 

 bees strangled by the bee wolf, the injury was always found at the back of 

 the neck between the head and the thorax, and was sucked out from this place, 

 vampirelike. 



4. Permit me to quote verbatim the case experienced by Fiissel in Rosenthal 

 at Ktoigstein (see D. Bienenfreund, Jahrgang 1877, p. 233) of the destruction 

 of the bee brood by the bee wolf and the consequent weakening of the colony. 



My neighbor, Herr Kaufmann R., had received a short time before a colony 

 of Italian bees and he had requested me to help him remove them from the 

 transportation box to the hive. On this occasion he showed me a small weak 

 colony in a straw hive which he thought was queenless ; the bees became fewer 

 every day, so that he at the best, since there was still much honey In the 

 hive, might introduce the newly arrived Italian bees. I therefore cut away 

 three combs and on the fourth I saw how this insect, the bee wolf, was procur- 

 ing its subsistence on the still present brood. I took it, and after I had 

 shown it to Herr Kaufmann R. and we had convinced ourselves of the manner 

 in which it worked on the brood, I killed it, cut away the empty combs com- 

 pletely, left the few bees which were still running around between the honey- 

 combs and introduced the Italian bees. Early on another day Herr Kaufmann 

 R. found a magnificent German queen bee under some dead Italian bees on 

 the fioorboard stung to death. The hive had not been queenless. The bee 

 wolf not only prevents the growth of the colony, but it is so injured that 

 little by little, slowly but surely, it goes toward its ruin. 



The above accounts do not agree regarding the details of how 

 Mutilla europaea attacks honeybees, but it is certain that the authors 

 were convinced that M. europaea was the cause of the trouble. I 

 have been able to find no other records of injury to honeybees by any 

 species of Mutillids but if these accounts are at all correct they must 

 at least be considered as potential enemies and capable of inflicting 

 more or less injury upon a hive of bees. 



While it appears from the above accounts that Mutillids are 

 perhaps potential enemies of honey bees, yet the paucity of reports 

 regarding injury by them indicates that their activities in this re- 

 spect are not at all general. 



The relationship of three species of Mutillids to the tsetse fly in 

 Africa has already been mentioned. This is a case where the Mutil- 

 lids are directly beneficial to man as destroyers of this fly. It is 

 probable that other species of tsetse flies are also parasitized by these 

 or other species of Mutillids. Lamborn (1920) has suggested that 

 the decrease in the number of tsetse flies over certain areas is prob- 

 ably due to the effectiveness of their parasites. When our knowl- 

 edge of these relationships becomes more complete we shall no doubt 



