1922] Unique Method of Defense of Bremus fervidus Fahricius 183 



bumblebees never molest certain intruders, e. g. the larvae of 

 Brachycoma, even though the latter are very deadly to their 

 brood. 



At first there was some doubt as to the nature of the liquid 

 which Bremus fervidus uses in connection with this interesting- 

 behavior, but the writer finally decided that it is honey. This 

 conclusion is based on the following facts: (1) the liquid has a 

 sweet taste; (2) a young Psiihyrus ashtoni queen which was 

 being daubed (experiment 1), lapped up a drop of hquid which 

 accidentally adhered to some cotton; and (3) the fervidus 

 workers themselves lapped up the liquid from the wings of a 

 katydid (expirement 15) after the latter had been stung to death. 



This habit of daubing certain intruders with honey recalls 

 an interesting habit of the honeybee. AccorcHng to Phillips 

 (1921, p. 117), it sometimes happens that Hzards or small 

 snakes get into a hive. The honeybee workers seal up such 

 intruders in propolis, a sticky substance which they obtain from 

 trees and other sources. Because of the different nature of the 

 substances used, it seems rather improbable that the habit of the 

 honeybee and the habit of Bremus fervidus are related, yet it 

 would be interesting to know whether there is any similarity in 

 behavior while the substances are being applied. 



It would also be interesting to ascertain whether any other 

 species than Bremus fervidus resort to honey daubing. The writer 

 found no trace of such a habit in his affinis, himaculatus, impatiens, 

 and vagans colonies. Nor is such a habit mentioned by Goedart 

 (1700), Reaumur (1742), Huber (1802), Putnam (18G5), Hoffer 

 (1882-83), Kristof (1883), Coville (1890), Barter (1890), Beng- 

 tsson (1903), Lie-Petterson (1906), Wagner (1907), Gundermann 

 (1908), Sladen (1912), Armbruster (1914), Bachman (1916), 

 and Prison (1917, 1918), all of whom have paid more or less 

 attention to the behavior of bumblebee colonies. However when 

 we consider that Putnam (1865), who had colonies of Bremus 

 fervidus under observation, did not notice this habit, it may well 

 be that it was overlooked in other species. 



According to the classifications of Frankhn (1912-13) and 

 Sladen (1912), one based on structure and the other on habit, 



