364 
PACIFIC SCIENCE, Vol. XXII, July 1968 
Ornithodoros denmarki Kohls, Sonenshine and 
Clifford 
This species is listed from Manana on the 
basis of two larvae recorded by Kohls et al. 
(1965) with the same data as the one larva 
listed for O. cap en sis. 
A new vims has been found recently in this 
species, giving it added importance as a poten- 
tial disease vector (Hughes et ah, 1964; Philip, 
1963). 
PROSTIGMATA 
CHEYLETIDAE 
Cheyletiella parasitivorax (Megnin) 
1 $ , ex Oryctolagus cuniculus, Feb. 29, 
1964 
C. parasitivorax is found on leporids through- 
out the world and has been reported from this 
host in the wild. According to some authorities 
this mite is a predator on Listrophoridae rather 
than a parasite of the rabbit. It was not known 
from Hawaii prior to its discovery on Manana. 
ASTIGMATA 
LISTROPHORIDAE 
Listrophorus gibbus Pagenstecher 
1 $ , 13 $ $ , 3 NN, ex Oryctolagus 
cuniculus, Feb. 29, 1964 
This species is a common parasite of both 
wild and domestic O. cuniculus and has been 
reported from many parts of the world. This is 
the first record of its occurrence in Hawaii. 
Listrophorus musculus Wilson and Lawrence 
3 $ S , 10 $ $ , 1 N, ex Mus musculus, 
Feb. 29-Mar. 1, 1964 
Hawaii is the only known locality for this 
fur mite. It is remarkable that an animal so 
common and widespread as the house mouse, 
and probably examined as frequently as any 
other rodent for ectoparasites, should be host 
to such a restricted and, until recently, un- 
described mite. It is very common on Mus in 
Hawaii and has been reported from Honolulu, 
Oahu and Honokaa and Kukuihaele, Hawaii 
(Joyce, 1959; Wilson and Lawrence, 1967). 
PSOROPTIDAE 
Myocoptes musculinus (Koch) 
4 £ £ , 14 $$, ex Mus musculus, Feb. 
29-Mar. 1, 1964 
M. musculinus is a common parasite of wild 
and laboratory mice throughout the world and 
has been reported from Hawaii by Joyce 
(1957). It is more abundant on mice on 
Manana than the few specimens indicate; how- 
ever, because of its small size and the condition 
of the hosts when examined it was difficult to 
estimate the degree of infestation. 
ENDOPARASITES 
While no endoparasites were identified spe- 
cifically from 2 rabbits examined in August 
1961, or from 13 in February 1964, it seems 
desirable to report the procedures used and 
findings made. Cursory examination of viscera 
revealed no nematodes, trematodes, or cestodes. 
Rectal pellets preserved in alcohol, and dry 
fecal pellets collected from the ground, proved 
unsatisfactory for the determination of coccidial 
oocysts or helminth ova. Distorted cyst-like ob- 
jects were present and additional effort should 
be made to identify them from new material. 
Rectal or freshly defecated pellets exposed to 
air for three days before fixation in dilute 
formalin (but kept damp to allow sporulation 
of coccidia), should provide suitable study 
samples. Sieving and microscopic search of 
intestinal contents, and similar critical examina- 
tion of the blood, gall bladder, liver, and other 
organs, is recommended for a complete ap- 
praisal of rabbit endoparasites. There are sev- 
eral definitive studies of the internal parasites 
of the European rabbit (Bull, 1958; I960; 
1964) which can be applied directly to the 
situation on Manana. 
The 6 mice likewise were negative for endo- 
parasites and further attention should be paid 
to this species. 
DISCUSSION 
It is of primary significance that the sea birds, 
rabbits, and vegetation of Manana have reached 
an obvious degree of mutual ecological adjust- 
ment. The unknown original vegetation un- 
doubtedly suffered greatly soon after it was 
exposed to rabbits, and events in its change 
to the present complex may have unfolded as 
follows. The large rabbit population present 
at the time of the brief early record of Manana 
(Anon., 1901) probably existed at most about 
