8 Psyche [February 



Trigona flaveola mediorufa Cockerell. 



I found a colony of this beautiful fulvous bee at Eseuintla, 

 Guatemala, about four feet from the ground in the trunk of a large 

 tree. There was no cerumen spout to the nest entrance which was 

 a hole about f inch in diameter, guarded by a company of workers, 

 all with their shining yellow faces directed towards the outside. 

 On carelessly thrusting my tweezers into the opening I was given 

 a surprise for which my previous experiences with stingless bees 

 had not prepared me. They rushed at my face, neck and hands 

 in a compact swarm, emitting a scalding liquid which had the 

 rancid-butter odor of the ants of the genus Tapinoma. They bit 

 my ears and nearly blinded me by getting into my eyes, so that I 

 had to beat a hasty retreat. Only after I had moved about 30 

 feet from the nest did they all leave me and return to settle down 

 again in the nest entrance in the defensive attitude in which I had 

 first seen them. The action of the liquid on my skin was very 

 annoying, for all the spots on my cheeks, eyelids and hands which 

 the bees had moistened, remained sensitive and painful to the 

 touch for several days and in the course of the next two weeks lost 

 their epidermis as if violently sun-burned. 



T. flaveola mediorufa belongs to a group of Trigonas popularly 

 known in Brazil as "cagafogos" (literally '"fire-defecators") and 

 including T. tat air a Smith (cacafogo F. Miiller) and the typical 

 flaveola Friese. There seems to be considerable difference of 

 opinion as to the source of the scalding liquid with which these 

 insects so efficiently defend their nests. Von Ihering did not 

 observe the Brazilian species T. tataira, but assumes from the 

 statements of other observers "that the bee bites a small hole 

 in the skin with its mandibles and then injects the secretion of its 

 poison glands into this wound. In this manner arises a red spot 

 1 mm. in diameter, where the epidermis is lacking. It takes one 

 or two weeks for the little wound to heal completely." Silvestri 

 describes his experience with the typical T. flaveola Friese, which 

 he calls the "cagafoga" as follows: "I came upon a nest of this 

 species in a dead tree trunk near the River Cuyaba. On approach- 

 ing it I was assaulted by a few of the bees, which bit various parts 

 of my head. As these bites produced a slight burning sensation 

 and as I was not provided with protective apparatus. I deemed it 

 imprudent to expose myself to the attack of a greater number of 



