Schoengastia monticola Lawrence, 1949

Stekolnikov, Alexandr A., 2024, Revision of South African chiggers (Acariformes: Trombiculidae) originated from the collection of R. F. Lawrence, with redescriptions of nine species, Zootaxa 5493 (1), pp. 1-35 : 23-26

Schoengastia monticola Lawrence, 1949

( Figs. 12–14 )

Schoengastia monticola Lawrence, 1949: 425 , fig. 12; Wharton & Fuller 1952: 88; Vercammen-Grandjean 1958b: 658, pl. 9; Stekolnikov 2018: 82 .

Schoengastia (Schoengastia) monticola : Zumpt 1961: 157; Vercammen-Grandjean 1965b: 82.

Diagnosis. SIF = 7BS-N-3-3111.1000; fPp = N/N/NNN; AL> PL >> AM; fD = 2H-8(9)-6-6-4+(4–8); DS = 29–35; V = 24–27; NDV = 56–62; scutum pentagonal, with greatly projected evenly arquate posterior margin; sensillary bases at level of PLs; Ip = 889–913. Standard measurements are given in Table 6 .

Redescription (holotype, 2 paratypes, and 3 non-type specimens). IDIOSOMA ( Figs. 12 , 13 , 14A–G ). Eyes 2 + 2, in ocular plate; 29–35 dorsal idiosomal setae, including one pair of humeral setae, moderately barbed, 8 (9 in one specimen) setae in 1 st posthumeral row (C excluding humeral setae), by 6 setae in next two rows (D and E), four setae in 4 th row (F) plus 4–8 caudal setae; 4 sternal setae; 24–27 ventral setae; NDV = 56–62.

GNATHOSOMA ( Fig. 14H, I ). Cheliceral blade with tricuspid cap and row of 4–5 dorsal teeth; cheliceral base with dense puncta in proximal part and sparse puncta in distal part; gnathobase with dense puncta, transverse cuticular striations, and one pair of branched gnathocoxal (tritorostral) setae; galeal (deutorostral) seta nude; palpal claw with three prongs; palpal femur and genu with sparse puncta and one short nude seta; palpal tibia with long nude dorsal seta and short nude lateral and ventral setae; palpal tarsus with 7 non-specialized setae, including 2 long branched dorsal and 5 short ventral bearing 1–2 branches or nude, subterminala (ζ) and tarsala (ω).

SCUTUM ( Figs. 12 , 13C , 14F, G ). Pentagonal, omorostigmal, densely covered with small puncta, anterior and lateral scutal margins almost straight, posterior margin greatly projected, evenly arquate; AM posterior to level of ALs; sensillary (trichobothrial) bases at level of PLs, slightly anterior or posterior (P-PL – PSB from –4 to 4), with curved anterior ridges; AM uniform with dorsal idiosomal setae, but much shorter, ALs and PLs covered with long thin barbs; AL> PL >> AM; sensilla (trichobothria) globose, covered with setules.

LEGS. All 7-segmented, with 1 pair of claws and claw-like empodium. Leg I: coxa with 1 branched seta (1B); trochanter 1B; basifemur 1B; telofemur 5B; genu 4B, 3 genualae (σ), microgenuala (κ); tibia 8B, 2 tibialae (φ), microtibiala (κ); tarsus 22B, tarsala (ω), microtarsala (ε) distal to tarsala, subterminala (ζ), parasubterminala (z), pretarsala (ζ). Leg II: coxa 1B; trochanter 1B; basifemur 1B; telofemur 4B; genu 3B, genuala (σ); tibia 6B, 2 tibialae (φ); tarsus 16B, tarsala (ω), microtarsala (ε) behind tarsala, pretarsala (ζ). Leg III: coxa 1B; trochanter 1B; basifemur 2B; telofemur 3B; genu 3B, genuala (σ); tibia 6B, tibiala (φ); tarsus 14B, mastitarsala.

Distribution and hosts. This species was described from South Africa (Drakensberg Mts, Champagne Castle, KwaZulu-Natal Prov.), ex Pseudocordylus subviridis . Here I report it from Dargle, KwaZulu-Natal Prov., ex Trachylepis striata (syn. Mabuya striata ) and from Zimbabwe (Vumba), ex T. varia (syn. M. varia ) for the first time.

Material examined. Holotype, larva NM 4827, Champagne Castle , Hostel, Natal, ex P. subviridis , collector and date unknown ( Fig. 1 , 20). One paratype, larva deposited in NHM (1957-8-12 -34), same data ( Fig. 1 , 21). One larva NM 4827, Vumba, S. Rhodesia (currently Zimbabwe), ex M. varia , February 1948, collector unknown ( Fig. 1 , 22). Three larvae NM 4810/1–3, Dargle, Natal, ex M. striata , coll. Lawrence, date unknown, prepared by Vercammen-Grandjean ( Fig. 1 , 23).

Remarks. I was unable to examine characters of gnathosoma and legs in the holotype and paratypes; therefore, these body parts were examined and drawn only in additional specimens NM 4810/1 and 3 ( Fig. 14 ). Schoengastia monticola differs from S. scincicola in the nude palpal femoral seta vs. bearing one branch; much shorter barbs of ALs and PLs; more weakly branched setae of legs; greater palps with puncta on femur and genu; greater scutum (PW 79–94 vs. 77–78, ASB 30–33 vs. 24–27, and P-PL 25–31 vs. 23–25); shorter AM (23–27 vs. 28–31), longer sensilla (S 29–33 vs. 24–29), H (40–47 vs. 32–40), and D max (38–44 vs. 34–38) ( Table 5 ).

Figures

FIGURE 1. Slide labels. 1, Microtrombicula homopholis, holotype; 2, Hypotrombidium subquadratum, holotype; 3, Willmannium natalense, lectotype; 4, W. natalense, paralectotype 1; 5, M. nivaria, paratype; 6, Herpetacarus (Abonnencia) alticolus, holotype; 7, H. (A.) alticolus, paratype; 8, H. (A.) alticolus, slide with topotypic specimens; 9, H. (A.) africanus, holotype; 10, H. (A.) africanus, topotypic specimen (ZIN label is on the opposite side); 11, H. (A.) longispinus, holotype; 12, H. (A.) longispinus, topotypic specimen (ZIN label is on the opposite side); 13, Ascoschoengastia rhabdomyia, slide NM 5387; 14, Riedlinia (Trombigastia) cadei, specimen NM 6544/3 (pencil inscription “/3” is mine; my identification label is on the opposite side); 15, Schoengastia pseudocordyli, slide NM 4939/1 (pencil inscriptions are mine; my identification label is on the opposite side); 16, S. scincicola, holotype; 17, S. scincicola, paratype NM 4870/2; 18, S. scincicola, paratype NHM 1957-8-12-35; 19, S. scincicola, non-type specimen (renounced paratype) NM 4870/3; 20, S. monticola, holotype; 21, S. monticola, paratype NHM 1957-8-12-34; 22, S. monticola, non-type specimen (renounced paratype) NM 4827; 23, S. monticola, specimen NM 4810/1 (pencil inscription “/1” is mine; my identification label is on the opposite side); 24, S. gerrhosauri, paratype NHM 1957-8- 12-36; 25, S. mabuyana, paratype NM 26422; 26, S. mabuyana, paratype NM 26423; 27, Microtrombicula (Microtrombicula) zumpti, specimen NM 5871/1 (pencil inscriptions are mine; my identification label is on the opposite side); 28, Neotrombicula (Anamasticula) rhodesiana, holotype.

FIGURE 12. Schoengastia monticola Lawrence, 1949, holotype. A, dorsal aspect of idiosoma; B, scutum. Scale bars: 50 µm.

FIGURE 13. Schoengastia monticola Lawrence, 1949, holotype. A, dorsal aspect of idiosoma; B, arrangement of ventral idiosomal setae; C, scutum and eyes; D, humeral seta; E, preanal seta; F, G, dorsal idiosomal setae. Abbreviations as in Fig. 2. Scale bars: 100 µm (A, B), 50 µm (C), 20 µm (D–G).

FIGURE 14. Schoengastia monticola Lawrence, 1949, specimens 4810/1 (A, B) and 4810/3 (C–L). A, dorsal aspect of idiosoma; B, arrangement of ventral idiosomal setae; C, humeral seta; D, preanal idiosomal seta; E, dorsal idiosomal seta; F, sensillum; G, scutum and eyes H, dorsal aspect of gnathosoma; I, ventral aspect of gnathosoma; J, leg I, trochanter–tarsus; K, leg II, trochanter–tarsus; L, leg III, trochanter–tarsus. Abbreviations as in Fig. 9. Scale bars: 100 µm (A, B), 20 µm (C–E), 50 µm (F, G), 20 µm (H, I), 50 µm (J–L).