30 
J. R. AUDY 
Table i. 
Distribution of species of hosts and mites collected in Selangor State, Malaya 
(cf. Table i, Audy & Harrison, 1951). 
Rodents and Insectivores. Trombiculid Mites. 
Number 
Number 
Number 
Number 
Number 
Source. 
trapped 
of 
of 
of 
of 
(to 1951). Species. 
Genera. 
Species. 
Genera. 
Forest 
5,524 
49 
30 
58 
6 
Deforested areas 
3,459 
15 
8 
16 
5 
Town (houses in Kuala Lumpur)... 
6,813 
5* 
3 
2(5t)* 
2 
* includes presumably introduced species. | the vectors T. deliensis and T. akamushi 
may be found exceptionally in the suburbs, so also may T. wichmanni , derived from poultry. 
An attempt is made below to summarise the main sources of trombiculids in the Asiatic- 
Pacific area. There were only six considerable collections made before the War : by Tanaka, 
Nagayo and others in Japan, by Mehta in India, by Walch in Sumatra, by Lewthwaite and 
Gater (Institute for Medical Research) in Malaya, by Gunther in New Guinea, and by Heaslip, 
Womersley and others in Australia. These together with casual collections yielded some 76 
species. Taking certain undescribed material into account, the total number of trombiculid 
mites (including leeuwenhoekiine or leeuwenhoekiid mites) now known from this same theatre 
alone probably exceeds 350. The number of new species from this region described in each 
decade has been as follows, the names of the principal investigators concerned being shown 
in brackets. It will be seen that in the three decades before 1950 these mites were described 
at a rate of 4 or 5 new species per annum, while since then the annual rate has been about 40. 
Before-1920 
14 spp. 
(Oudemans, Hirst). 
1920-1929 
20 spp. 
(Oudemans, Walch, Nagayo et al.). 
1930-1939 
42 spp. 
(Gater, Womersley). 
1940-1949 
75 spp. 
(20 before 1945, 4° after) (Womer- 
sley, Heaslip, Gunther, Radford, 
Kohls, Philip, Wharton). 
1950-1952 
over 120 
(Womersley, Wharton, Philip, Fuller 
Traub, Hardcastle, Radford, Audy) 
During the War ( a ) McCulloch 
in particular made many collections in Australasia and 
Borneo ; ( b ) Wharton and other members of U.S. Navy Medical Research Units (NAMRU 2) 
collected and studied extensively in the Pacific, while Wharton and Hardcastle made an impor- 
tant intensive study of bird-chiggers of the genus Neoschongastia ; (c) the U.S. Typhus Com- 
mission made very considerable collections in two theatres, viz. (i) in the Pacific area (New Gui- 
nea, Philippines) by Philip and Kohls in particular, who collaborated with Womersley over the 
taxonomic studies while they themselves were in the field, and (ii) in Assam, North Burma, and 
southwest China, by Fuller, Millspaugh, Sundermeyer, Melvin and Weber, who were based 
at Myitkyina, North Burma ; (d) Radford, followed by Jayewickreme, collected in Ceylon, 
while later, (e) Radford collected intensively in Addu Atoll (Maldives) and then for six months 
worked with (/) the Scrub Typhus Research Laboratory, a British War Office unit which made 
STUD. INST. MED. RES. 
