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J. R. AUDY 
Brennan (1949) and Wharton (1950) have made careful studies of the respiratory organs 
of chiggers and Wharton & Fuller (1952 : 28) have summarised information up to date. 
Salivary ducts with taenidia may easily be, and have been, confused with true tracheae in 
chiggers. A system of unbranched taenidia (opening on a pair of spiracles or stigmata between 
coxae I and the gnathobase) is apparently truly respiratory and is “characteristic of certain 
species of the genera Acomatacarus and Whartonia .” The salivary ducts with taenidia have 
been seen in various genera including Neoschongastia. 
Genus Acomatacarus Ewing, 1942 
Type. — Acomatacarus arizonensis Ewing, 1942:490, J. Parasite 28, 485-493. From reptiles, Mexico 
and U.S.A. 
Diagnosis (Wharton & Fuller, verbatim). — “ Leeuwenhoekiids whose larvae have an anterior, median 
scutal projection, paired submedian scutal setae, and a series of teeth on a relatively modified cheliceral 
blade ” Nymphs & Adults (known only for subgenus Acomatacarus ) not constricted. 
Remarks. — The following list includes the four subgenera represented in the Old World, 
viz. Acomatacarus Ew., Hyracarus Law., Austracarus Law., and Austrombicula Law., without 
repeating their diagnoses. The writer is grateful to Womersley for information about those 
species which have been bred to the nymph, and for details of unpublished species. 
Old World species. — Europe: paradoxus. Africa: A. (Acom.) gateri, geckobius, jaeger skioldii, lacertae , 
mabuyana , namaquensis , tenuitarsus, thallomyia, ?theileri. A. ( Austracarus ) procaviae, polydiscum. A. 
(. Austrombicula ) womersleyi. A. ( Hyr .) ty picus, lawrencei , longipilosus , natalensis. Asia and Pacific: A. 
(Acorn.) adelaidae , athertonensis , atollensis , attolus A., audyi, australiensis, ?barrinensis , dromus , echidnus , 
?gymnodactyli (Ew.), longipes , lygosomae, mccullochi, nova-guinea N, patrius A , retentus A , southcotti , and 
over 7 n. spp. (incl. 2 with nymphs) Worn, in MS. ; yosanoi F. & Ob., 1953. 
Genus Hannemania Oudemans, 19 11 
Type. — Heterothrombidium hylodeus Oudemans, 1910:88, Ent. Ber. } Amst ., 3, 83-90. From skin of 
an amphibian, Brazil. 
Diagnosis (from information provided by Wharton). — Leeuwenhoekiines whose larvae have an anterior 
medial scutal projection; without stigmata or tracheae, but with well-developed salivary ducts; well- 
developed teeth disrupting the blade-like conformation of the chelicera; apparently confined to amphibia, 
penetrating the skin. Nymphs & Adults distinguished by having constricted bodies (“ figure-8 ”). 
Mostly recorded from the New World. 
Remarks. — The nasus to the scutum has been missed in some species (e. g. H. hylodeus , 
rouxi — see Fuller 1952 : 239) and as a result this genus has accumulated some species properly 
belonging to Whartonia (q. v.). Ewing (1926) illustrated the constricted nymph of H. hylae and 
Wharton (letter dated April 1953) states that “at least four species of Hannemania have been 
reared and all have the 8-shaped nymphs and adults.” 
Old World species. — Europe (Sweden): Hannemania sp. Sellnick, 1949:129, Ent. Tidskr ., 70, 123-135. 
Pacific (New Caledonia) : rouxi. 
Genus Whartonia Ewing, 1944 
Type. — Hannemania nudosetosa Wharton, 1938:142, Cam. Inst. Wash. Publ. } 491, 137-152. From 
bats, Mexico. 
Diagnosis (after Wharton & Fuller, and Wharton in a letter of April, 1953). — Leeuwenhoekiines whose 
larvae are without an anteromedian projection (nasus) to the scutum; cheliceral blades modified as a series 
of recurved teeth; with spiracles (stigmata) and tracheae (cf. Acomatacarus): apparently confined to bats. 
Nymphs and Adults, according to Wharton in correspondence, known for “ Whartonia nudosetosa and 
two other species,” which have “ cordiform nymphs similar to Acomatacarus , whose larvae also have 
spiracles and tracheae.” 
Remarks. — Hannemania perplexa Bren, and the Hannemania n. sp. from Malaya noted 
by Audy (1952) both belong to Whartonia. Four species seen by the writer are very large 
chiggers. 
Old World species. — Africa: 2 n. spp. from bats in the Sudan sent by Dr. Thompson to Dr. Zumpt. 
Asia and Pacific: vellae; 1 n. sp. Worn, in MS from Malaya; 2 n. spp. from Borneo. 
STUD. INST. MED. RES. 
