Schoengastia pseudocordyli 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 : 17-19

Schoengastia pseudocordyli Lawrence, 1949

( Figs. 8 , 9 )

Schoengastia pseudocordyli Lawrence, 1949: 429 , fig. 16; Wharton & Fuller 1952: 89; Vercammen-Grandjean 1958b: 659, pl. 9; Stekolnikov 2018: 85 .

Schoengastia (Schoengastia) pseudocordyli : Zumpt 1961: 158; Vercammen-Grandjean 1965b: 82.

Diagnosis. SIF = 7BS-N-3-3111.0000; fPp = B/N/NNB; PL ≥ AM> AL; fD = 2H-8-6-6-4+(6–9); DS = 32–35; V = 26; NDV = 58–61; scutum nearly rectangular, with evenly arquate posterior margin and anterolateral shoulders; sensillary bases far anterior to level of PLs; Ip = 688–774. Standard measurements are given in Table 5 .

Redescription (3 non-type specimens). IDIOSOMA ( Figs. 8A , 9A–F ). Eyes 2 + 2, in ocular plate; 32–35 dorsal idiosomal setae, including one pair of humeral setae, moderately barbed, 8 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 6–9 caudal setae; 4 sternal setae; 26 ventral setae; NDV = 58–61.

GNATHOSOMA ( Fig. 9G–I ). Cheliceral blade with tricuspid cap and row of five dorsal teeth; cheliceral base and palpal femur with sparse puncta, gnathobase with sparse puncta, transverse cuticular striations, and one pair of branched gnathocoxal (tritorostral) setae; galeal (deutorostral) seta nude; palpal claw with three prongs; seta on palpal femur short, with few branches; seta on palpal genu short, nude; dorsal and lateral setae on palpal tibia nude; ventral palpal tibial seta branched; palpal tarsus with 7 branched setae, subterminala (ζ) and tarsala (ω).

SCUTUM ( Figs. 8 , 9C ). Nearly rectangular, moderately covered with small puncta, with anterolateral shoulders, anterior and lateral scutal margins almost straight, posterior margin slightly projected, evenly arquate, with cuticular striations; AM at level of ALs; sensillary (trichobothrial) bases far anterior to level of PLs (PSB – P-PL = 7–9), with curved anterior ridges; ALs uniform with dorsal idiosomal setae, PLs and especially AM covered with much longer thin barbs; PL ≥ AM> AL; sensilla (trichobothria) globose, covered with small setules.

LEGS ( Fig. 9J–L ). 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) far distal to tarsala, subterminala (ζ), parasubterminala (z), pretarsala (ζ). Leg II: coxa 1B; trochanter 1B; basifemur 2B; 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 15B, mastisetae absent.

Distribution and hosts. This species was described from Champagne Castle, Drakensberg Mts., Natal(KwaZulu-Natal Prov.), South Africa, ex Pseudocordylus spinosus Fitzsimons ( Squamata: Cordylidae ) and Trachylepis striata (Peters) (syn. Mabuya striata ) ( Squamata: Scincidae ).

Material examined. Three larvae, NM 4939 (slides 1–3), ex M. striata , coll. Lawrence, place and date unknown, prepared by Vercammen-Grandjean ( Fig. 1 , 15 ).

Remarks. Schoengastia pseudocordyli is similar to S. moreli Taufflieb, 1960 , but differs in the absence of mastitarsala, presence of prominent anterolateral shoulders of the scutum, much longer AM (37–41 vs. 22), shorter AL (31–32 vs. 55), and in PL ≥ AM> AL vs. AL> PL >> AM.

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 8. Schoengastia pseudocordyli Lawrence, 1949, specimen NM 4939/3. A, dorsal aspect of idiosoma; B, scutum. Scale bars: 50 µm.

FIGURE 9. Schoengastia pseudocordyli Lawrence, 1949, specimen NM 4939/3. A, dorsal aspect of idiosoma; B, arrangement of ventral idiosomal setae; C, scutum and eyes; D, humeral seta; E, dorsal idiosomal seta; F, preanal idiosomal seta; G, galeal (deutorostral) seta; 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: S, sensillum; ζ, palpal subterminala (ζ); other abbreviations as in Figs. 3 and 4. Scale bars: 100 µm (A, B), 50 µm (C), 20 µm (D–F), 20 µm (G–I), 50 µm (J–L).

FIGURE 15. Schoengastia gerrhosauri Lawrence, 1949, paratype NHM 1957-8-12-36 (A), Schoengastia mabuyana Lawrence, 1949, paratype NM 26422 (B), Microtrombicula (Microtrombicula) zumpti Vercammen-Grandjean, 1965, specimen NM 5871/1 (C), Neotrombicula (Anamasticula) rhodesiana (Lawrence, 1949), holotype (D). Dorsal aspect of idiosoma (A, B), scutum (C, D). Scale bars: 50 µm.