Trombiculindus griselda ( Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963 )

Stekolnikov, Alexandr A. & Antonovskaia, Anastasia A., 2021, Re-descriptions of eight chigger mite species (Acariformes: Trombiculidae) of the Leptotrombidium generic complex from Vietnam, Zootaxa 5057 (3), pp. 329-363 : 357-360

Trombiculindus griselda ( Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963)

( Figs. 20–22 )

Trombicula (Trombiculindus) griselda Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963: 699 , figs. 36–42.

Leptotrombidium (Trombiculindus) griseldae: Vercammen-Grandjean & Langston 1976: 641 , pl. 182.

Leptotrombidium (Trombiculindus) griselda: Chau et al. 2007: 63 , fig. 29.

Trombiculindus griseldae: Kudryashova 2004: 20 .

Trombiculindus griselda: Stekolnikov 2021: 145 .

Diagnosis. SIF = 7B-B-3-2111.0000; fsp = 7.7.7; fCx = 1.1.1; fSt = 2.2; fPp = N/N/BNN; fSc: AM ≥ PL> AL; Ip = 713–803; fD = 2H-8-6-6-2-4-2(4-2-2); DS = 24–30; V = 21–27; NDV = 45–56. Standard measurements of type series given in Table 8 .

Description (larva) (based on lectotype and 13 paralectotypes, fD recorded in one specimen). IDIOSOMA ( Figs. 20A , 21B–H ). Eyes 2 + 2; 24–30 dorsal idiosomal setae, including one pair of humeral setae, arranged 2H- 8-6-6-2-4-2 (posterior 3 rows can be also recorded as 4-2-2); 4 sternal setae; 21–27 ventral setae; NDV = 45–56. Humeral and dorsal idiosomal setae broadly foliate, ovate, with pointed end, irregularly covered with thick scalelike setules; caudal and postanal setae less expanded, lanceolate, sparsely covered with small scalelike setules; preanal setae setiform, covered with long thin barbs.

GNATHOSOMA ( Fig. 22A, B ). Cheliceral blade with tricuspid cap; gnathobase covered with puncta and bears 1 pair of branched gnathocoxal (tritorostral) setae; cheliceral base and palpal femur covered with puncta; galeal (deutorostral) seta branched; palpal claw with 3 prongs; setae on palpal femur and genu nude, dorsal palpal tibial setae branched, lateral and ventral palpal tibial setae nude; palpal tarsus with 7 branched setae and tarsala (ω).

SCUTUM ( Figs. 20 , 21A ). Nearly hexagonal, sparsely covered with small puncta, greatly projected posterior to PL, bases of AL and PL situated close to each other, posterior margin slightly concave in middle part; AM far posterior to level of AL, sensillary (trichobothrial) bases far posterior to level of PL (P-PL – PSB = 10–14 µm); AM and AL slightly expanded, covered with large barbs, PL broadly foliate, ovate, with pointed end, irregularly covered with thick scalelike setules; AM ≥ PL> AL; flagelliform sensilla (trichobothria) nude or having few branches in distal part.

LEGS ( Fig. 22C–E ).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, 2 genualae (σ), microgenuala (κ); tibia 8B, 2 tibialae (φ), microtibiala (κ); tarsus 22B, tarsala (ω), microtarsala (ε) proximal to tarsala, subterminala (ζ), parasubterminala (z), pretarsala (ζ). Leg II: coxa 1B; trochanter 1B; basifemur 2B; telofemur 4B; genu 3B, genuala; tibia 6B, 2 tibialae (φ); tarsus 16B, tarsala (ω), microtarsala (ε) not observed, pretarsala (ζ). Leg III: coxa 1B; trochanter 1B; basifemur 2B; telofemur 3B; genu 3B, genuala; tibia 6B, tibiala; tarsus 15B.

Distribution and hosts. This species was described from North Vietnam, Quang Ninh Province, ex Rattus rattus (= R. rattus alexandrinus ) and Leopoldamys edwardsi (Thomas) [= R. grochovskiae (nomen nudum)] ( Schluger et al. 1963).

Type material examined. Lectotype larva ( ZMMU Tdt-3151, specimen 1, designated here) ex L. edwardsi [labeled as R. grochovskii (nomen nudum)] No 44, VIETNAM: Quang Ninh Province, Ha Lam District, Ha Long (= Hon Gai), 6 February 1956, coll. I.M. Grochovskaja. Seven paralectotypes larvae ( ZMMU Tdt-3147, specimen 1; ZMMU Tdt-3148, specimens 2, 3, 4; ZMMU Tdt-3263, specimens 1, 2, 3) ex L. edwardsi [labeled as R. grochovskii (nomen nudum)] No 35, 2 February 1956, other data same as for lectotype; five paralectotypes larvae ( ZMMU Tdt- 3149, specimens 1, 2, 3, 4, 6) ex L. edwardsi [labeled as R. grochovskii (nomen nudum)] No 37, other data same as for lectotype; one paralectotype larva ( ZMMU Tdt-3150, specimen 1) ex L. edwardsi [labeled as R. grochovskii (nomen nudum)] No 39, 3 February 1956, other data same as for lectotype.

Remarks. Trombiculindus includes 59 species distributed in Southeast, East, South, and Central Asia ( Vercammen-Grandjean & Langston 1976, Li et al. 1997, Stekolnikov 2021). Trombiculindus griselda shares the most part of characters with T. cuneatum Traub and Evans, 1951 . The setation of palps and legs, number and arrangement of idiosomal setae, shape and measurements of scutum are almost identical in these species. Both species have slightly expanded AM and AL, but broadly foliate PL, H, and other dorsal idiosomal setae. Trombiculindus griselda differs from T. cuneatum in having foliate setae shorter and, therefore, relatively wider (PL 47–54, H 48–58, D max 53–64 vs. 60–70, 58–68, and 61–70, respectively) and irregularly covered with thick scalelike setules (vs. foliate setae with 8–9 longitudinal rows of setules); shorter AM (51–56 vs. 63–64) and AM> PL vs. PL> AM; and sensilla nude or with a few branches in distal half (vs. sensilla covered with small cilia in proximal part and up to 29–32 branches in distal two thirds).

Figures

FIGURE 20. Trombiculindus griselda (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963). A, dorsal aspect of idiosoma in paralectotype ZMMU Tdt-3149, specimen 1 (AL and sensilla lost); B, scutum of lectotype (right sensillum and right AL lost). Scale bars: 50 μm.

FIGURE 21. Trombiculindus griselda (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963). A, scutum of lectotype (right sensillum and rightAL lost, setules of right PL not figured); B, humeral seta (C antero-marginal) of lectotype; C, dorsal idiosomal seta of lectotype from anterior rows; D, caudal dorsal idiosomal seta of lectotype; E, preanal seta of lectotype, lateral view; F, preanal seta of lectotype, ventral view; G, arrangement of dorsal idiosomal setae in paralectotype ZMMU Tdt-3148, specimen 4; H, ventral aspect of idiosoma in paralectotype ZMMU Tdt-3148, specimen 4. Abbreviations as in Fig. 2. Scale bars: 50 μm (A–F), 100 μm (G, H).

FIGURE 22. Trombiculindus griselda (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963). A, dorsal aspect of gnathosoma of lectotype; B, ventral aspect of gnathosoma of lectotype; C, leg I (trochanter–tarsus) of paralectotype ZMMU Tdt-3263, specimen 2; D, leg II (trochanter–tarsus) of paralectotype ZMMU Tdt-3263, specimen 2; E, leg III (trochanter–tarsus) of paralectotype ZMMU Tdt-3263, specimen 2 (one claw lost). Abbreviations as in Fig. 2. Scale bars: 50 μm (A, B), 50 μm (C–E).