NO. 10 COCKROACHES—ROTH AND WILLIS 51 
YELLOW-FEVER VIRUS 
Disease —An infection of the hemapoietic system; mosquitoes are 
the only blood-sucking arthropods that have been shown to play a 
part in the epidemiology of yellow fever (Theiler in Rivers, 1948). 
Experimental vectors.—Blatta orientalis (Trop. Dis. Bull., 1942, 
p. 65, in Brumpt, 1949): According to Brumpt, the virus lasted less 
than 2 days in this insect. We have checked the reference given by 
Brumpt but found no mention of cockroaches and virus. 
Blattella germanica (Findlay and MacCallum, 1939): Yellow-fever 
virus injected into the insects’ abdomens retained its activity for at 
least 15 days. When yellow-fever virus was introduced into the stom- 
achs of Indian monkeys (Macaca mulatta) and African monkeys 
(Cercopithecus aethiops), the virus passed into the blood stream and 
caused fatal infections in the Indian monkeys. 
NEGATIVE FINDINGS 
The following cockroaches (U.S.A., Texas) were examined for 
viral invasions, with negative results, by Eads et al. (1954): Blatta 
orientalis, Blatiella germanica, Pertplaneta americana, and Supella 
supellectilium. 
NEWCASTLE DISEASE VIRUS 
California strain No. NC 194-5-6-7 
Disease-—Avian pneumoencephalitis. 
Experimental vector—Periplaneta americana, U.S.A. (Gallardo 
et al., 1957) : The virus could not be recovered in the feces after feed- 
ing to the cockroaches. 
