TAXONOMY OF TROMBICULIDS 167 
given and the author’s intention is not clear. On the same page he lists hakei which Womersley describes 
as a form of hirsti , not of wichmanni. T. pseudo akamushi (p. 12) is a synonym of T. wichmanni. 
T. obscura (p. 15) has since been identified with T. akamushi by Womersley. As noted by Traub & 
Audy (1953, this Study p. 74) a form which appears to be very close to obscura is the dominant form of 
akamushi in North Borneo, where it occurs together with deliensis. Nymphs have been bred and an 
opinion on this form awaits further study. T. keukenschrijveri (p. 17) can be confirmed as a Trombicula 
( Leptotrombidium ) in the akamushi- group. T. hastata (p. 18) is placed by the present writer in the subgenus 
Trombiculindus. On p. 21 line 20 deliensis is a lapsus calamae presumably for mediocris. Of the adults 
listed on pp. 21-22, T. signata is not a trombiculid but a Podothrombidium (vide Worn., 1952:312; it is 
also listed by Wharton & Fuller, 1952:70); tindalei and translucens are now placed in Guntherana (see p. 
157 above). T. chiroptera (p. 22) is a synonym of quadriense. Of species listed under Schongastia on p. 25, 
Womersley has identified both katonis and pusilla with schuffneri , while he omits all mention of jamesi 
( = rotunda , nom. nud.). 
In dealing (p. 26) with the confusion of Eu — , Neo — , Para — , and Ascoschongastia, the author 
states that he is taking the bull by the horns, but he is thrown in the wrong direction in his choice of 
Neoschongastia which is the best-defined group and is therefore least suited to serve as a taxonomic dustbin. 
Trisetica (p. 37) is noted as fairly obviously a synonym of Tecomatlana but the authors of Trisetica 
have carefully discussed this very point. In connexion with the discussion of leeuwenhoekiids on p. 38, 
the reader may be referred to Womersley, 1953 (this Study p. 108). The Walchiinae (Gahrliepiinae), 
p. 43-48, are in a fluid state and have already been discussed above. 
Acknowledgments 
The writer particularly wishes to acknowledge the competent help of his assistant, Mr. 
M. Nadchatram, for the routine identification and screening of the large collections from Malay- 
sia and India; and also Messrs. Lee Fatt-Hing and Johan bin Haji Adam for their efforts in 
collecting and mounting. Messrs. Nadchatram, Lee, Johan, Aman bin Mahmood and Harun 
bin Peral, and formerly the writer’s colleague, Mr. K. L. Cockings, have all contributed towards 
the breeding of post-larval stages. The writer also wishes to thank those colleagues who have 
sent him material for study and given information on various points, especially Dr. Brennan, 
Mr. E. Browning, Mr. Crossley, Dr. G. O. Evans, Dr. Gould, Lt.-Col. Kalra, Dr. Lawrence, 
Dr. Michener, Dr. Radford, Dr. Sasa, Lt.-Col. Traub, Dr. Wharton, Mr. Womersley, 
Mr. Varma, Mr. Vercammen-Grandjean, and Dr. Zumpt. 
Summary 
1. The results of a prehminary study of some 130 species of trombiculid larvae and 
70 species of nymphs from Malaysia are recorded. The conclusions are provisional but are 
made available to fellow-taxonomists because it will be many years before the available material 
can be fully studied and described. This paper is intended to be an appendix to the mono- 
graphs by Womersley (1952) and Wharton and Fuller (1952). 
2. The taxonomic importance is discussed of various characters, as listed in the Contents, 
and attention is drawn to certain characters which have been neglected. A possible course of 
evolution is given of similar species with different seasonal behaviour occurring together in the 
same country. The humeral, dorsal, caudal and ventral, and the various scutal, setae are 
believed to be influenced by different embryonic developmental fields, so that their differences 
are probably of more taxonomic importance than is usually supposed. 
3. The classification of the trombiculids, at present based largely on the larval stage, will 
ultimately be based on postlarval as well as larval characters. Womersley’s important study 
of the postlarval stages is a pioneer work; much still remains to be done. Our understanding 
of the taxonomic characters of the postlarval stages is considered to be still too undeveloped to 
allow stabilisation. 
4. In the light of the Malaysian material, revised diagnoses (many of which are provisional) 
are given of the genera and subgenera of Old World chiggers, together with lists of those 
species from Europe, Africa, and the Asiatic-Pacific area which have been described by early 
1953 - 
MALAYA , No. 26 , 1953 
