182 Psyche [August 



Workers of Bremus affinis, himaculafus, impatiens, and vagans. 

 Result: Same as in experiment l.^ 



Experiment 6. Introduced: Worker from another fervidus 

 colony. 



Result: Attacked with legs and mandibles. No attempt 

 at daubing.* 



Experiments 7, 8 and 9. Introduced (separately) : Worker 

 honeybee {Apis mellifica), male of Bremus impatiens, and male of 

 Polistes pallipes Lepeletier. 



Result: All stung to death and thrown out of the nest. No 

 attempts at daubing. 



Experiments 10, 11, 12, 13 and I4. Introduced (separately): 

 Blue bottle Uy (Calliphora vomitoria), drone fly {E^HstaUs tenax), 

 dragon fly {Sympetrum ruhicundulum) , small cricket {Nemohius 

 sp.), and gypsy moth {Porthetria dispar). 



Result: Same as in experiments 7, 8, and 9. 



Experiment 15. Introduced: Katydid {Conocephalus sp.). 

 Result: Stung to death, but also daubed. 



Experiments 16, 17, and 18. Introduced (separately): 

 Earth worm (Lumbricus sp.), young frog {Rana sp.), and mouse 

 {Mus musculus). 



Result: All stung to death. No attempts at daubing. 



From these experiments it will be seen that the workers of 

 a Bremus fervidus colony, at least when dealing with insects, 

 vary their method of attack with the nature of the intruder. 

 If stingless, or comparatively weak (e. g., the honeybee), the 

 intruder is seized immediately and stung to death, while daubing 

 is invariably resorted to if the intruder possesses superior fighting 

 abilit3\ What enables Bremus fervidus to make these distinctions, 

 it is difficult to say. In this connection it must be stated that 



31n connection with experiment 4 it may be stated that a worker of Bremus impatiens, 

 an cxceedinAly pugnacious species, sometimes attacks a jervidus worker, and may then be 

 stung to death by one or more workers of the latter species, though other members of the 

 colony, even during the struggle, continue to daub the intruder. 



''Similar results obtain if two feividwi colonies are combined. During the course of the 

 summer, the writer made four such combinations (one colony in each case being queenless), 

 but never noticed any daubing. 



