NEW LARVAL MITES 213

New Larval Mites (Acarina : Trombiculidae and Leeuwenhoekidae) By CHARLES D. RADFORD, F.Z.S. (British from African hosts.

Museum (Natural History).

[Received October 4, 1947.1

(With 24 figures in the text.)

INTRODUCTION. Our knowledge of the larval Trombiculidae from Africa is a t present limited

to some twenty-one species (Radford, 1942 and 1946). The present paper has been made possible mainly through the valuable co-operation of my friend Mr. G. H. E. Hopkins, O.B.E., recently Senior Entomologist (Medical) a t Kampala, Uganda, and the S. African Zoological Survey Committee, Pretoria, S. Africa ; from both sources much interesting material has been sent for identi- fication. Recently a Green Mamba (Dendraspis viridis (Hallowell)) died a t the Belle Vue Zoological Gardens, Manchester, and the snake was given to me by Mr. Gerald T. Ilea for examination. Under the dorsal scales of the snake I found specimens of the species which has, in this paper, been named after the donor.

It is with pleasure that I name the species in honour of my friends and colleagues in recognition of the work they have done in the furthering of Acarological studies. Dr. Marc And&, Museum d’Histoire Naturelle, Paris; Dr. Carl Willmann, Bremen; Dr. R. F. Lawrence, Natal Museum, Pietermaritzburg, S. Africa, and Dr. P. J. Du Toit, Zoological Survey Com- mittee, Pretoria, S. Africa.

Figure 1. Figure 2.

Trmbiculu cluviglia, sp. n. 1. Doreum of larva. 2. Venter of larva.

Genus TROMBICULA Berlese, 1905. TROMBICULA C L A V ~ L I A , sp. n. The dorsum of tde larva (fig. 1 ) shows the scutum to be pitted and almost

twice as wide as long. The anterior margin of the scutum has a median projection round the base of the antero-median seta, and the lateral margin has a slight concavity close to the postero-lateral angle ; the posterior margin is slightly convex and wider than the anterior margin. The antero-lateral setae are pectinate, shorter than the antero-median seta, and placed at the

214 0. D. RADFORD

angles of the scutum. The postero-lateral setae are pectinate, longer than the antero-median seta and are placed in the postero-lateral angles of the scutum. Postero-lateral angles of the scutum level with the middle of the eye-plates. The sensory setae are long, filiform and barbed on the distal half. The sensory setal bases are in the anterior half of the scutum ; placed wide apart. Paired eyes, the anterior eye larger than the posterior. The dorsum is furnished with about thirty-eight long, pectinate setae, arranged in transverse rows : 2, 6, 8, 6, 6, 4 ,4 , 2.

The venter of the larva (fig. 2) shows the coxae to be pitted, each cosa bearing a single, pectinate seta. Between the coxae are two pairs of pectinate setae. On the posterior half of the venter there are about thirty-eight pectinate setae, arranged as shown.

Tarsi with a pair of claws and an empodium (fig. 17 d). Chelicera with a single dorsal tooth and a weak ventral tooth (fig. 17 c). Palpal claw tridentate; palpal setae i and ii with lateral barbs, seta iii nude (fig. 17 a, a). Galeal set8 pectinate (fig. 17 e).

Mewurernents.-AW=72 p ; PW=W p ; SB=37 p ; ASB=28 p ; PSB=20 p ; A-P=33 p ; AM=40 p ; AL=50 p ; PL=70 p ; Sens=64 p ;

Host .-A squirrel (Qraphiurus (Claviglis) rnurinus ssp.). LocaZity.-Serere, Teso, Uganda. Material.-Lectotype specimen in the British Museum (Nat. Hist.).

Paratype slides in the U.S. National Museum, Washington, U.S.A. ; Dr. P. J. Du Toit, Zoological Survey Committee, Pretoria, S. Africa ; and the author's private collection.

DS =35-40 p ; SD =48 p.

October 3rd, 1945.

Genus PENTACIONELLA Sig Thor, 1906. PENTAGONELLA ILESI, sp. n. The dorsum of the larva (fig. 3) shows the pentagonal shape of the scu tm,

its anterior margin is concave ; the lateral margin is concave and the posterior margin extending to a blunt point ; the scutum is pitted. The antero-lateral and postero-lateral setae are placed at the angles of the scutum ; the mtero-

Figure 3. Figure 4.

Pentagonella ileai, sp. n. 3. Dorsum of lerve. 4. Venter of larve.

NEW LARVAL MITES 215

median seta is not placed a t the edge of the scutum. Scutal setae are pectinate. The sensory setae are long, filiform, with lateral barbs on the distal third. Bases of sensory tletae are placed close together and level with the postero- lateral setae. The dorsum is furnished with about forty-four setae arranged in rowfi: 3. 8, 8. 8, 8, 6, 4. The fir& pair asre almost twice as long as the others.

The venter of the larva (fig. 4) shows the posterior half of the body to be provided with about thirty short, pectinate setae. Tarsi with a pair of claws and an empodium (fig. 18 d) . Chelicera with a single dorsal tooth and three ventral teeth ; the shaft of the chelicera is curved (gouge-shaped) (fig. 18 c). Palpal claw tridentate ; palpal setae i and iii with lateral barbs ; seta ii nude (fig. 18 a, b ) .

ASB =23 p ; PSB=33 p ; A-P=80 p ; AM=27 p ; AL=30 p ; PL=50 p ; Sens=54 p ;

Galeal seta nude. Measurements.-AW =52 p ; PW =80 p ; SB =20 p ;

DS =33 p ; SD =56 p. Host.-A Green Mamba (Dendruspis viridis (Hallowell)). Locality.-Belle Vue Zoological Gardens, Manchester. April 16th, 1947.

Gerald T. Iles. Material.-Lectotype specimen in the British Museum (Nat. Hist.)

Paratype slides in the U.S. National Museum,. Washington, U.S.A. ; H. Womersley, Entomologist, Adelaide Museum, S. Australia ; Dr. Carl W i U m a ~ , Bremen, Germany ; Dr. Marc Andr6, Museum d’Histoire Naturelle. Paris, France ; Dr. P. J. Du Toit, Zoological Survey Committee, Pretoria, S. Africa ; and the author’s private collection.

Genus ACOUTACARUS Ewing, 1942. ACOMATACAEIJS LAWRENCEI, sp. n. The dorsum of the larva (fig. 5) shows the scutum to have a long antero-

median process ; the anterior margin of the suctum is concave ; lateral margin concave, and the posterior margin is convex. The paired antero-median setae are shorter than the antero-laterals ; the postero-lateral setae are longer

Figure 5. Figure 6.

. Acomatacarua lawrencei, ‘ip. n. 6. Dorsum of larva. 6. Venter of larva.

The sensory setae are long, W o r m and nude. than the antero-laterals. The bases of the sensory setae are wide apart and slightly above the level of the postero-lateral setae. Paired eyes borne on plates, level with the postero- lateral setae ; the anterior eye larger than the posterior eye. The dorsum is covered with about fifty-six pectinate setac arranged in irregular rows.

216 C. D. BADFORD

The venter of the larva (fig. 6) shows coxa i to possess two setae ; coxae ii and iii each with but a single seta. One pair of setae lies between coxae ii and iii. On the posterior half of the body there are about forty-eight pectinate setae, those near the posterior end of the body being the longest.

The tarsi are provided with a pair of claws and an empodium (fig. 19d). Chelicera with a single dorsal tooth and a row of ventral teeth (fig. 19c). Palpal claw tridentate ; palpal setae i and ii with lateral barbs, seta iii nude (fig. 19 a, b) .

MeasuremenLs.-AW=60 p ; PW=70 p ; SB=23 p ; ASB=30 p ; Galeal seta pectinate (fig. 19 e).

PSB=18 p ; A-P=33 p ; AM=30 p ; &=50 p ; PL=@ p ; Sen~=60 p ; DS=33-40 p ; SD =48 p.

Host.-Graham’s Rock Mouse (Thallomys namap.uensis grahami Roberts). Locality.-Glen Craig, Grahamstown, S. Africa. May 24th, 1939, Dr. G.

Theiler . Material.-Lectotype specimen in the British Museum (Nat. Hist.).

Paratype slides in the U.S. National Museum, Washington, U.S.A. ; H. Womersley, Entomologist, Adelaide Museum, S . Australia; Dr. Carl Willmann, Bremen, Germany ; Dr. Marc And&, Museum d’Histoire Naturelle, Paris, France ; Dr. P. J. Du Toit, Zoological Survey Committee, Pretoria, S. Africa ; and the author’s private collection.

Genus S~HONQASTIA Oudemans, 1910. SCHONOASTIA WILLMANNI, sp. n. The dorsum of the larva (fig. 7) shows the anterior margin of the scutum

to be concave on each side of the median projection ; the posterior margin wider than the anterior, convex ; surface of the scutum is pitted. The antero- median seta is not placed on the anterior margin ; the antero-lateral setae about twice as long as the antero-median. The postero-lateral setae are shorter

Figure 7. Figure 8.

Schiingwtia wiUwuanni, sp. n. 7. Dorsum of larva. 8. Venter of larva.

than the antero-laterals, their bases are level with the middle of the eye-plates. Sensory setae globose ; their bases close together, above the level of the postero- lateral setae, and level with the anterior eye. Posterior eye smaller than the anterior. The dorsum is furnished with about thirty-four pectinate setae arranged in rows : 2, 10, 6, 6,4,4, 2.

Venter of the larva (fig. 8) shows the pitted coxae. On the posterior half of the body there are about thirty pectinate setac. Tarsi with a pair of claws

NDW LABVAL BUTEt3 217

and an empodium (fig. 2 0 d ) . Chelicera with five dorsal teeth and a curved ventral tooth (fig. 20 c). Palpal claws tridentate ; palpal setae i, ii and iii nude (fig. 20 a, b).

Measurements.-AW =43 p ; PW =73 p ; ASB =23 p ; PSB=20 p, ; A-P=26 p ; AM=30 p, ; &=66 p ; PL=53 p ; Sens=30 p ; DS=33 p ; SD=43 p.

Host.-Uganda unstriped grass-rat (Arvimnthis abyssinicus rubescens Wroughton).

LocaZity.-K.atwe, Toro, Uganda. July 29th, 1946, G. E. H. Hopkins. Material-Lectotype specimen in the British Museum (Nat. Hist.).

Paratype slides in the U.S. National Museum, Washington, U.S.A. ; H. Womersley, Entomologist, Adelaide Museum, S. Australia ; Dr. Carl Willmann, Bremen, Germany ; Dr. Marc Andr6, Museum d’Histoire Naturelle, Paris, France ; Dr. P. J. Du Toit, Zoological Survey Committee, Pretoria, S. Africa ; and the author’s private collection.

Galeal seta nude. SB =20 p ;

SCEONaASTLI ANDREI, Sp. n. Dorsum of the larva (fig. 9) shows the scutum to be pitted ; its anterior

margin concave with a median projection ; lateral margins with a concavity close to the postero-lateral seta ; the posterior margin of the scutum is convex. The antero-lateral setae are about twice as long as the antero-median seta.

Figure 9. Figure 10.

Sch6;ngastia andrei, 8p. n.

9. Dorsum of lenre. 10. Venter of larva.

The antero-median seta is placed well back from the edge of the scutum. The postero-lateral setae are not as long as the antero-laterals, and are level with the anterior eye. The sensory setae are clavate, their bases close together and below the level of the postero-lateral setae. Eye-plates with paired eyes, the anterior eye larger than the posterior. The dorsum is provided with about twenty-eight pectinate setae arranged in rows : 2, 8, 6, 6, 4, 2.

The venter of the larva (fig. 10) shows the pitted coxae. On the posterior half of the body there are about thirty pectinate setae. Tarsi furnished with a pair of claws and an empodium (fig. 21 a). Chelicera with six dorsal teeth,

.

218 U. D. RADFORD

the distal three being the largest (fig. 20 c). Palpal claw tridentate, palpal seta i with lateral barbs, setae ii and iii nude (fig. 21 a).

Measurements.-AW=60 p ; PW=83 p ; SB=17 p ; ASB=23 p ; PSB=10 p ; A-P 26 p ; AM=33 p ; AL=65 p ; PL=60 p ; Sens=32 p ;

Host.-Harsh-furred mouse (Lophuromys sikapusi ansorgei de Winton). Locality.-Kazinga, Toro, Uganda. August 20th, 1946. G. H. E. Hopkins. Material.-Lectotype specimen in the British Museum (Nat. Hist.).

Galeal seta nude.

DS=50 p ; SD=23 p.

Genus ASCOSCH~NUASTIA Ewing, 1946.

ASCOSCH~NGASTIA DUTOITI, sp. n.

The dorsum of the larva (fig. 11) shows the scutum to be rectangular. The anterior margin of the scutum is concave with a slight median projection ; the lateral margins faintly concave ; the posterior margin longer than the anterior and concaved niedially. The anterior median seta is close to the edge of the scutum and is shorter than the antero-lateral setae. Postero- lateral setae longer than the antero-laterals. Sensory setae globose, their

Figure 11. Figure 12.

Ascovohongastia dutoiti, sp. n.

11. Dorsum of larva. 12. Venter of larva.

bases wide apart, placed about midway between anterior and posterior margin of scutum, level with the middle of the eye-plates. Anterior eye larger than the posterior. The dorsum is provided with numerous pectinate setae (about ninety) arranged in irregular rows the posterior setae being stouter than the others.

The venter of the larva (fig. 12) shows the posterior half of the body to be furnished with about seventy-six set- of which the posterior rows are of stouter setae than the anterior rows. Tarsi with a pair of claws and an empodium (fig. 22 d ) . Chelicera with one dorsal tooth and two curved ventral teeth (fig. 22 c ) . Palpal claw tridentate, palpal aetae i and ii with lateral barbs, seta iii nude (fig. 22 a, b) .

Measurements.-AW=56 p ; PW=80 p ; SB=46 y ; ASB=30 p ; PSB=17 p ; A-P=40 p ; AM=27 p ; AL=33 p ;. P:L--42 u : Sens=30 p ;

Host.-Peter’s Pouched mouse (Samostmus campestris mmpestris Peters).

Galeal seta nude.

DS =30 p ; SD =47 p.

NEW LARVAL WTES 219

Locality.-Palmer’s Dam, Albany, Cape Prov., S. Africa.

Material-Lectotype specimen in the British Museum (Nat. Hist.).

April 23rd, 1939. Dr. G. Theiler.

AYCOSCHONQASTIA LONCIYPINA, sp. n.

The dorsum of the larva (fig. 13) shows the unusually elongated setae of the scutum. The dorsal scutum is about twice as broad as long, its anterior margin is concave on each side of the median projection ; the lateral margin deeply concave ; the posterior margin convexed around the bases of the sensory setae and with a deep median concavity. The antero-lateral and postero- lateral setae are borne upon projecting angles of the scutum. The antero- median seta is placed some distance from the anterior edge of the scutum. Antero-lateral setae about twice the length of the antero-median seta ; the postero-lateral setae are even longer. The sensory setae are globose, on long peduncles. The bases of the sensory setae are about equi-distant between the postero-lateral setae. anterior eye the larger and level with line drawn through the postero-lateral setae and sensory

Eye-plates with paired eyes ;

Figure 13. Figure 14.

AswffihongautM long&qha, sp. n. 13. Dorsum of larva. 14. Venter of larva.

setae. The dorsum bears about thirty-six long, slender, pectinate setae arranged in rows : 2, 8, 6, 6, 6, 4, 2,2.

The venter of the larva (fig. 14) shows the posterior half of the body to have a few long setae (about twenty). Tarsi with a pair of claws and an empodium (fig. 23 d). Chelicera with no dorsal teeth, but with two curved, ventral teeth (fig. 23 c) . Palpal claw tridentate, palpal setae i and ii with lateral barbs, seta iii nude (fig. 23 a, b) .

Mmsurementa.-AW=72 p ; PW=83 p ; SB=33 p ; ASB=25 p ; PSB=20 p ; A-P=28 p ; AM=40 p ; &=82 p ; PL=lOO p ; Sens=33 p ; DS =60 p ; humerals =70 p ; SD=45 p.

Host.-Graham’s rock mouse ( T h a l h y s mmquensis graharni Roberts). h1ity.-Glen Craig, Grahamstown, S. Africa. May 24th, 1939.

Dr. G. Theiler. Material.-Lectotype specimen in the British Museum (Nat. Hist.).

Paratype slides in the U.S. National Museum, Washington, U.S.A. ;

Galeal seta nude.

220 C. D. RADFORD

H. Womersley, Entomologist, Adelaide Museum, S. Australia ; Dr. Carl Willmann, Bremen, Germany ; Dr. Marc Andre, Museum d’Histoire Naturelle, Paris, France ; Dr. P. J. Du Toit, Zoological Survey Committee, Pretoria, S. Africa ; and the author’s private collection.

ASCOSCH~NGASTIA AFRICANA, sp. n.

Dorsum of the larva (fig. 15) shows the scutum to be broader than long, its anterior margin concave on each side of the median projection ; the antero- lateral angles projecting forwards. Lateral margin concave ; posterior margin of the scutum with projections near the sensory setal bases and a medial

Figure 15. Figure 16.

Ascoschongastia africanu, ap. n. 16. Dorsum of larva. 16. Venter of h a .

concavity. The antero-lateral setae are longer than the antero-median ; postero-lateral setae are almost twice as long as the anteromedian seta. Sensory setae clavate, their bases wide apart and level with the postero-lateral setae ; level with the middle of the eye-plates. Paired about equal in size.

The dorsum is provided with about thirty-eix long, slender, pectinate setae in rows ; 2, 8, 6, 2, 6, 6, 4,2.

Venter of the larva (fig. 16) shows the posterior half of the body to be furnished with about thirty-six pectinate setae ; the setae posterior to the anus are longer than the others. Tarsi with a pair of claws and an empodiurn (fig. 24d). Chelicera with two dorsal teeth, one pointing anteriorly; one ventral tooth (fig. 2 4 ~ ) . Palpal claw tridentate, palpal setae i and ii with lateral barbs, seta iii nude (fig. 24 a, b) .

PSB=23p; A-P=33p; AM=37p; AL=50p; PL=67p; Sew=44p; DS 4 0 p ; humerals =65 p ; SD =66 p .

Host.-Vlei or Swamp rat (Otomys tugelensis pretoriae Roberts). Locality.-Onderstepoort, Pretoria, 8. Africa. May 26th, 1939. Zoological

Survey Committee. Material.-Lectotype specimen in the British Museum (Nat. a t . ) .

Yaratype slides in the U.S. National Museum, Washington, U.S.A. ; H. Womersley, Entomologist, Adelaide Museum, S. Australia ; Dr. Carl Willmann, Bremen, Germany ; Dr. Marc Andr6, Museum d’Historie Naturelle, Paris, France ; Dr. P. J. Du Toit, Zoological Survey Committee, Pretoria, S. Africa ; and the author’s private collection.

Antero-median seta not close to the edge of the scutum.

Galeal seta nude. M M J S U W ~ R ~ ~ ~ . - A W =70 p ; PW =83 p ; SB=43 p ; ASB=33 p ;

NEW LARVAL MITES 221

Figures 17-24.

17. Trombicula claviglia, sp. n. : (a) Left palp (dorsel). (b) Left palp (ventral). (c) Chela. (d) Tarsus i (lateral). (e) Galeal seta. 18. Pentugonella ileai, sp. n..: (a) Left palp (dorsal). (b) Left palp (ventral). ( c ) Chela. (d) Tarsus 1 (lateral). 19. Acomtucarw Zawencei, sp. n. : (a) Left palp (dorsal). (b) Left palp (ventral). (c ) Chela. (d) Tarsus i (lateral). 20. SchGngaetia willmanni, sp. n. : (a) Left palp (dorsal). (b) Left palp (ventral). (c) Chela. (d) Tarsus i (lateral). 21. Schongastia andrei, sp. n. : (a) Left palp (dorsal). (b) Left palp (ventral). ( c ) Chela. (d) Tarsus i (lateral). 22. Ascoachongastia dutoiti, sp. n. : (a) Left palp (dorsal). (b) F f t palp (ventral). (c) Chela. (d) Tarsus i (lateral). 23. AscoachBngaetia longwpinu, sp. n. : (a) Left palp (dorsal). (b) Left palp (ventral). (c) Chela. ( d ) Tarsm i (lateral). 24. AmoschGngmtiu africanu, sp. n. : (a) Left palp (dorsal). ( b ) Lnft palp (ventral). (c) Chela. (d) Tarsue i (lateral).

222 NEW LARVAL MITES

REFERENCES. EWINQ, H. E. (1942). Remarks on the taxonomy of some American chiggers

(Trombiculinae), including the descriptions of new genera and species. J . Parasit. 28, 485-93.

Notes on the taxonomy of three genera of Trombiculid mites (chigger mites), together with the description of a new genus. Proc. Bid.

OUDEXANS, A. C. ( 1010). Acarologische Aanteekeningen.-XXXIII. Ent. Ber. Nederl.

RADFORD, C. D. (1942). The larval Trombiculinae (Acarina : Trombidiidae), with

RADFORD, C. D. (1946). New larval mites (Acarina : Trombiculidae). Proc. 2001. SOC

EWINQ, H. E. (1946).

SOC. Wash. 59, 69-72.

Ver. 3, 83-90.

descriptions of 12 new species.

Lond. 116, 579-601.

Parasitology, 34, 66-81.