TAXONOMY OF TROMBICULIDS 
M 3 
Provisional Diagnosis (expanded). — Trombiculids whose larvae are similar to those of the Trombicula 
(. Leptotrombidium ) pallida subgroup (see above), but have at least the PL scutal setae and the anterior 
dorsal setae modified by replication or expansion (foliate). Nymphs & Adults (known only for 2 species 
here included for the first time in this subgenus) differing from those of Leptotrombidium in having no 
precoxal plates and in having the tectum (seen in one species only) convex instead of flat or concave distally. 
Remarks. — Foliate setae have been developed in a number of unrelated groups so that a 
Trombicula might be found with foliate setae but not closely related to the type T. squamosus. 
To the writer, the important character is not leaf-like expansion of the setae, but simply their 
modification. The exact form of modification may vary considerably (contrast the setae of 
cuneatus with those of squamosus and foliatus). He would therefore include such species 
as T. hastata (Gater) (slightly foliate setae), as well as T. fordi Worn., T. traubi Worn., and 
T. plumosa Rad., in which the setae are otherwise modified. Shorn of their ornamental setae, 
all larvae appear to be indistinguishable from those of the pallida-subgroup. The nymphs of 
hastata and fordi have been described. It will be interesting to see what the nymphs of the 
fully foliated species are like. 
World species (Asia & Pacific). — cuneatus, foliaceus, fordi N, hastata N, plumosa, squamifera , squamosus, 
n. sp. from Thailand (being described). Also kansai Jam. & Sasa, 1953. 
Subgenus Neotrombicula, Hirst 1915 
Type. — Acarus autumnalis Shaw, 1970, in Shaw & Nodder, Vivarium Naturae, or, The Naturalist's 
Miscellany, London ; vol. 2, next to plate 42. 
Provisional Diagnosis (sensu stricto, quoted from Wharton & Fuller 1952:56). — “ Trombicula 
in which the larvae have a pentagonal scutum, at least one mastitarsala III, normal scutal setae, and either 
nude whip-like or elongated feathered setae on some of the segments of leg III other than the tarsus. 
Adults elongated and without eyes.” 
Remarks. — The type species T. (TV.) autumnalis belongs to a distinct group with roughly 
pentagonal scuta and long setae which are nude, ciliated, or lightly plumose on the legs, 
especially on the more proximal segments. All the North American species have more than 
one mastitarsala III. It is difficult at present to separate this larval group from the larvae of 
Blankaartia (= Tragardhula ). Brennan & Wharton (1950:44) in dealing with larvae of 
Neotrombicula in North America separate the two as follows : 
Larvae with subequal plumose setae on the proximal segments leg III; usually parasitic on 
water birds; adults with eyes. 
T ragardhula = Blankaartia 
Larvae with whiplike or long plumose setae on the proximal segments of leg III; usually parasitic 
on terrestrial animals, especially small mammals; adults without eyes. 
Neotrombicula 
Womersley has however described this subgenus on the characters of nymphs and adults, 
which produces a much larger assemblage, the larvae of which are very heterogeneous. There 
are some very perplexing anomalies in this broad subgenus, suggesting that our ideas of what is 
or is not taxonomically important in post-larval characters may need drastic revision. The 
following species are included in this subgenus by Womersley: 
(a) Species known from Larvae & Nymph/Adult: autumnalis , consueta , fordi , goldii , 
harrisoni , hastata , inopinatum , jayewickremei , parmifera , rara , sarcina , scincoides , 
spicea , (also n. sp. near rara , in MS). 
(b) Species known only from Nymph/Adult, larvae unknown; Camilla , canestrinii , 
cavernarum , clavicata , coarcata, formicarum , manriquei , moesica , ?russica , 
(Vitzthum 1932, not Oudemans 1902; larva apparently unknown). 
(c) Species of larvae tentatively included by close resemblance to members in group {a) : 
kohlsi (cf. scincoides ), munda (cf. spicea ), tovelli (cf. scincoides ), traubi (cf. fordi). 
MALAYA, No. 26, 1953 
