NO. IO COCKROACHES—ROTH AND WILLIS 99 
either the bird eats this cockroach, or there is another unknown host 
for the eyeworm (Schwartz and Schwartz, 1949). 
Experimental intermediate hosts—Periplaneta americana, Antigua 
(Hutson, 1943): The eyeworms developed to the infective stage in 
P. americana when injected into the body cavity. However, these 
cockroaches could not be infected by eating fowl feces because the 
feces were toxic and killed all cockroaches tested within 2 weeks. The 
American cockroach undoubtedly is not a vector of the eyeworm in 
nature for this reason. 
Pycnoscelus surinamensis, U.S.A., Florida (Sanders, 1929): The 
cockroaches became infected with the eyeworm after having had ac- 
cess for 72 hours to the freshly voided feces of a chicken severely 
infested with the eyeworm. Australia (Fielding, 1927, 1928a). Hawaii 
(Schwabe, 1951). 
Development in intermediate host—Pycnoscelus becomes infected 
by eating bird feces containing embryonated eggs or first-stage larvae 
of the eyeworm. First-stage larvae migrate through the wall of the 
midgut into the hemocoele where they burrow into the fat body. 
Second-stage larvae encyst on the alimentary tract, particularly around 
the rectum and entangled in the malpighian tubules. The tracheated 
cyst wall is secreted by the cockroach ; the cyst is filled with fluid and 
the enclosed larva is able to move about in it. The encysted larva 
molts again between the forty-fifth and fiftieth days. During the 
period of ecdysis, most of the parasites free themselves from the cysts 
and wander in the body cavity of the host. The complete develop- 
mental period requires about 51 days, and the third-stage larvae are 
infective to birds. (Schwabe, 1951.) 
The eyeworm may remain alive for some time in dead cockroaches 
(Sanders, 1928), and may live up to 72 hours in cockroaches killed 
by insecticides (Schwabe, 1950b) ; Schwabe (1950) emphasized the 
importance of preventing birds from eating dead cockroaches. 
Effect of worm on intermediate host.—Sanders (1929) believed 
that penetration of the intestine by large numbers of migrating larvae 
at one time is sufficient to kill the insect in some cases. 
Natural definitive hosts—Chicken, turkey, peafowl (Pavo crista- 
tus), English sparrow (Passer domesticus), mynah bird (Acridotheris 
tristis), Chinese dove (Streptopelia chinensis), Japanese quail (Co- 
turnix coturnix japonica), pheasant (Phasianus torquatus torquatus 
and P. vesicolor vesicolor), Argus pheasant (Argusianus argus 
argus), and Siamese fireback pheasant (Diardigallus diardi) 
(Schwabe, 1951). Ducks (Fielding, 1926). 
Infected wild birds are not important reservoir hosts in dissemina- 
