380 



BEDBUGS AND THEIR ALLIES 



naturally infected with Trypanosoma cruzi in South America. 

 On account of its domestic habits, Triatoma megista (Fig. 168) 

 is the most important species in the transmission of the disease 

 to man. This bug is a large, handsome, black and red insect, 

 locally known as the " barbeiro," which infests the dirty thatched 

 houses of the natives in the state of Minas Geraes in Brazil. 

 It is nocturnal in habit, coming forth from its hiding places in 

 the thatch of the roof or in the debris of the floor to feed upon 



its human victims after the man- 

 ner of bedbugs. The bugs are 

 so active and hide so rapidly 

 when a light is produced during 

 their foraging in the dark that 

 they can seldom be caught. The 

 details of the development of the 

 trypanosome of Chagas' disease 

 in this insect and the relation 

 of the insect to the disease are 

 described in Chapter VI, p. 110. 

 Torres believes the bugs almost 

 invariably become infected by 

 feeding on infected vertebrates, 

 since Triatoma does not devour 

 excrement of its own species, 

 as does the allied Rhodnius pro- 

 lixus, and cannibalism is rare 

 among these bugs, except in young 

 larvae which sometimes feed on 

 each other. 



The life history of the barbeiro is quite like that of other 

 members of the genus, except that the eggs are laid in or about 

 human habitations. The eggs hatch in from 20 to 40 days and 

 the young pass through five moults to reach maturity, the whole 

 life cycle occupying about a year. The females begin depositing 

 eggs about a month after the last moult. These insects suck 

 blood at intervals of from four days to several months. 



A number of other South and Central American species of 

 Triatoma have been found to harbor Trypanosoma cruzi or a 

 species indistinguishable from it. Triatoma geniculata, which 

 inhabits the burrows of the armadillo and various rodents, is 



Fig. 168. The "barbeiro," Tria- 

 toma megista. X if. (After Chagas.) 



