TAXONOMY OF TROMBICULIDS 
145 
picked out three groups, the autumnalis -, microti -, and bisignata- groups, characterised by the 
nude flagellate setae of leg III as follows (some species are ungrouped): 
Neotrombicula. Mastitarsala. Mastitibiala. Mastifemorala. 
autumnalis-group (Old World) 1 ... 0 ... o 
microti-group (New World) ... 2 ... 1 ... 1 
bisignata - group ... ... 3 ... 1 ... o 
Old World species of Neotrombicula sensu-stricto. — Europe: autumnalis , desaleri, fahrenholzi , muris 
(Ouds.), pomeranzevi , Asiatic-Pacific: fujigmo, japonica, mitamurai, nagayoi , tamiyai, TAT-group 
{kashmir ensis, kanzalwanensis, AX n. sp. Worn., & Audy in MS). 
Old World species which may or may not be related: possibly some of those known only as adults or 
nymphs; possibly the flag ellifera-tuhana group [see (vi) above]; possibly naultini , novae-hollandiae . 
Subgenus Blankaartia Oudemans, 1911 
=Tragardhula Berlese, 1912, Worn. 1948 
=Pentagonella Thor, 1936 
=Megatrombicula Michener, 1946 
Type. — Trombidium niloticum Tragardh 1904:78, Results Swedish Zool. Exped. to Egypt and the White 
Nile , 1901, 20, 1- 124. Adult only, from water-plants, Egypt. 
Diagnosis . — Species of Trombicula whose larvae have a pentagonal scutum, at least one mastitarsala 
III but, unlike the similar larvae of Neotrombicula, do not possess mastifemoralae and/or mastitibilae III 
or long lightly-feathered setae in the place of these; apparently swamp or water-frequenting, particularly 
parasitising water-birds*. Nymphs & Adults distinguished by having a pair of eyes lateral to and some 
distance from the crista (not near the sensillary bases as in Eutrombicula). 
Remarks . — It is necessary to regard Blankaartia as a subgenus until its relationships with 
Neotrombicula are satisfactorily clear. Blankaartia may for example have developed by its 
special habitat adaptations from a Neotrombicula stem. The correct usage of Blankaartia 
instead of Tragardhula (used by Womersley) has been discussed by Fuller & Wharton (1952) 
Of the 14 species listed by Womersley (who omits only the African T. ardeae ) five are known as 
larvae & nymphs adults, viz. acuscutellaris , alleei, attenuata , japonica , velascoi , and two 
( nilotica , peruviana) as adults only. The present writer agrees with Wharton and others in 
placing fugjimo , japonica , mitamurai , nagayoi , and tamiyai in Neotrombicula. The remainder 
( ( geckobia , gymnodactyla , pentagona ), all from reptiles, have 2-pronged palpal claws (undoubted 
Blankaartia species have 3) and no mastitarsala III — these form a distinct group (possibly 
including incurva & naultini) the relationship of which to the African lawrencei group (p. 147) 
should be investigated. 
Old World species. — U.S.S.R. : ?radfordi, Africa (Egypt): ardeae , nilotica A. Asia & Pacific: 
acuscutellaris NA. 
Subgenus Eutrombicula Ewing 1938 
Type. — {Trombicula flui van Thiel 1930, Ewing 1938:293. J. Wash. Acad. Sci., 28, 288-295; 
synonym) = Acarus batatas Linn. 1758:617. A common scrub itch mite: major hosts birds, Brazil 
to southern U.S.A. 
Diagnosis (largely after Fuller 1952:96; = most of subgenus Trombicula Worn. 1952:326). — Trombi- 
culids whose larvae have moderately large scuta, roughly rectangular, posterior border often slightly 
convex, usually distinctly punctate; leg III with a mastitarsala, possibly mastitibiala also; palpal claw 
2-pronged, with the accessory prong medial or ventromedial to the axial; galeal seta generally nude; 
generally parasitic on reptiles and birds but may be on mammals. Nymphs & Adults of Trombicula 
facies but typically with eyes present, close to and slightly behind the sensillary bases (insistence on this 
character might be a mistake, as discussed below). 
Remarks . — This has all the appearances of being a good larval genus on morphological 
as well as bionomic grounds, but its limits cannot yet be clearly defined. The writer suspects 
that the mastitarsala III and the general host-preference for reptiles and birds may be more 
important than details of the palpal claws. Putting aside Womersley’s interpretation of minor 
* In our collections, acuscutellaris appears to be associated with ricefields which are annually flooded. It is found on the 
ricefield-rat R. rattus argentiventer in suitable localities. 
MALAYA, No. 26 , 1953 
