Leptotrombidium mondulkiri, Antonovskaia & Morand & Stekolnikov, 2024

Antonovskaia, Anastasia A., Morand, Serge & Stekolnikov, Alexandr A., 2024, New species and new records of chigger mites (Acariformes, Trombiculidae) from Cambodia, Zootaxa 5406 (2), pp. 343-358 : 344-346

Leptotrombidium mondulkiri sp. nov.

( Figs. 1A, B , 2 , 3 )

Diagnosis. SIF = 7B-B-3-2111.0000; fPp = N/N/BNB; fSc: AM> PL ≥ AL; SB-PL; fCx = 1.1.1; fSt = 2.2; Ip = 686–764; fD = (5–7)H-(16–21)-(12–16)-(9–18)-(2–10)-(2–9)-(2–7)-(1–5)-(0–3)-2(0); DS = 63–83; V = 48–71; NDV = 120–147. Standard measurements are in Table 1 .

Description (larva). IDIOSOMA ( Figs. 1A, B , 2B–G ). Eyes 2+2, on ocular plate; 63–83 heavily barbed dorsal idiosomal setae, including 5–7 humeral setae; separation of humeral and post-humeral setae sometimes unclear; 16–21 setae in 1 st post-humeral row (C excluding humeral setae), 12–16 setae in 2 nd row (D), 9–18 setae in 3 rd row (E); 4 sternal setae and 48–71 ventral setae; total number of idiosomal setae excluding coxal and sternal 120–147.

GNATHOSOMA ( Figs. 3A, B ). Cheliceral blade with tricuspid cap; gnathobase and palpal femur moderately covered with puncta; gnathobase with one pair of branched gnathocoxal (tritorostral) setae; galeal (deutorostral) seta heavily branched; palpal claw with three prongs; dorsal and ventral palpal tibial setae branched, other palpal setae nude; palpal tarsus with seven branched setae and basal tarsala (ω).

SCUTUM ( Figs. 1A , 2A ). Rectangular, moderately covered with puncta, with posterior margin straight or slightly concave in center; areas near bases of setae lack of puncta; AM base posterior to level of ALs; SB nearly at level of PLs (P-PL – PSB = –3–3, mean 0); AM> PL ≥ AL; scutal setae barbed similarly to dorsal idiosomal setae; flagelliform sensilla (trichobothria) with 8–10 branches in distal half.

LEGS ( Figs. 3C–E ). All 7-segmented, with a pair of claws and claw-like empodium. Leg I: coxa with 1 non-specialized 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) (18 long), microtarsala (famulus, ε) distal of 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) (14 long), microtarsala (famulus, 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.

Type material. Larval holotype ( ZIN 14237 , L-521) ex B. savilei No. C 0683, CAMBODIA, Mondulkiri Province, Keo Seima , 23 November 2009; nine larval paratypes ( ZIN 14196 , 14206 , 14215 , 14224 , 14242 , 14246– 14248 , 14250 ) with same data .

Etymology. The species name derived from the name of province, where the type locality is situated.

Differential diagnosis. The new species is similar to Leptotrombidium macacum (Womersley, 1952) , belonging to the binbium species group ( Vercammen-Grandjean & Langston 1976; Stekolnikov 2013), and differs from the latter in having 5–7 humeral setae vs. 2 (in L. macacum ), more numerous idiosomal setae (NDV = 120–147 vs. 94; 16–21 setae in 1 st post-humeral row vs. 10; 12–16 setae in 2 nd row vs. 10), relatively wider scutum (AW 64–70 vs. 60–64, PW 78–85 vs. 72–76, and SB 32–36 vs. 30–31), and slightly shorter setae (H 35–45 vs. 45–47, D min 31–35 vs. 33–43, D max 37–41 vs. 42–58, V min 18–24 vs. 22–31, and V max 32–38 vs. 38–49).

Figures

FIGURE 1. Leptotrombidium mondulkiri sp. nov., holotype. A—anterior part of idiosoma, dorsal aspect; B—sternal area, ventral aspect. Leptotrombidium pilosum cambodiensis subsp. nov., paratype ZIN 14251. C—anterior part of idiosoma, dorsal aspect; D—sternal area. Scale bars: 100 µm.

FIGURE 2. Leptotrombidium mondulkiri sp. nov., holotype (A–E), paratype ZIN 14250 (F, G). A—scutum; B—humeral seta; C—dorsal idiosomal seta; D—postanal seta; E—preanal seta; F—arrangement of ventral idiosomal setae; G—arrangement of dorsal idiosomal setae. Abbreviations: AM—anteromedian seta; AL—anterolateral seta; H—humeral setae; PL—posterolateral seta; S—sensillum (trichobothrium). Scale bars: 50 µm (A–E), 100 µm (F, G).

FIGURE 3. Leptotrombidium mondulkiri sp. nov., paratype ZIN 14246 (A, B), paratype ZIN 14244 (C–E). A—ventral aspect of gnathosoma; B—dorsal aspect of gnathosoma; C—leg I; D—leg II; E—leg III. Abbreviations: Cb—cheliceral base; Cs— cheliceral blade; Ga—galeal seta; ic—infracapitulum (gnathobase, gnathocoxa); PC—palpal claw; PG—palpal genu; PF— palpal femur; PTi—palpal tibia; PTa—palpal tarsus; S0—palpal tarsala (ω); f1—famulus I (ε), f2—famulus II (ε); ga—genuala I (σ); gm—genuala II (σ); gp—genuala III (σ); pST—parasubterminala (z); PT’—pretarsala I (ζ); PT”—pretarsala II (ζ); S1— leg I tarsala (ω); S2—leg II tarsala (ω); ST—subterminala (ζ); ta—tibiala I (φ); tm—tibiala II (φ); tp—tibiala III (φ); µga— microgenuala (κ); µta—microtibiala (κ). Scale bars: 20 µm (A, B), 100 µm (C–E).