Doloisia (Traubacarus) gigantea ( Schluger, Grochovskaja, Ngu, Hoe and Tung, 1961 )

Antonovskaia, Anastasia A. & Stekolnikov, Alexandr A., 2021, Redescriptions of ten chigger mite species (Acariformes: Trombiculidae) from Vietnam, Zootaxa 4969 (1), pp. 1-53 : 33-38

Doloisia (Traubacarus) gigantea ( Schluger, Grochovskaja, Ngu, Hoe and Tung, 1961)

( Figs. 23A, B , 24–27 )

Traubacarus giganteus Schluger, Grochovskaja, Ngu, Hoe and Tung, 1961: 452 , figs. 25–32.

Traubacarus giganteus: Kudryashova 2004: 39 .

Doloisia (Doloisia) gigantea: Vercammen-Grandjean 1968: 97 .

Doloisia gigantea: Wen 1984: 302 .

Doloisia (Doloisia) gigantens (sic): Chau et al. 2007: 146, fig. 70.

Doloisia outoensis Chen and Hsu, 1965: 286 , figs. 8–10.

Diagnosis. SIF = 4B-N-3-2110.0000; fsp = 7.7.7; fCx = 1.3.7(6); fSt = 2.2; fPp = B/B/NNN(b); fSc: PL> AM> AL; Ip = 938–972; fD = 4H-[6-2]-8-6-4-3; DS = 32–33; V = 37–38; NDV = 70. Eyes absent. Standard measurements of type series given in Table 8 .

Description (larva) [based on lectotype and 2 paralectotypes]. IDIOSOMA ( Figs. 23A, B , 24 ). Eyes absent; 32–33 dorsal idiosomal setae covered with few short barbs, including two pairs of humeral setae; 4 sternal setae; 37–38 ventral setae; NDV = 70.

GNATHOSOMA ( Fig. 25 ). Cheliceral blade with two large hooks; gnathobase with sparse puncta and 1 pair of branched setae; palpal femur, genu, and tibia with sparse puncta; galeala nude; palpal claw with 3 prongs, internal prong long and strongly curved; setae on palpal femur and genu branched; dorsal and lateral palpal tibial setae nude, ventral palpal tibial seta nude or branched; palpal tarsus with 4 branched setae and tarsala.

SCUTUM ( Fig. 23A ). Bell-shaped, longer than wide, with slightly concave posterior margin, densely covered with small puncta, with 1 AM covered with few inconspicuous cilia and 1 pair of nude ALs; 1 pair of PLs covered with few inconspicuous cilia and situated off scutum; AM anterior to level of ALs; PLs much longer AM, ALs shorter AM; sensilla bulbous, with few short barbs on its stalk and 6 long spikes terminally; sensillum bases situated much closer to ALs than to PLs.

LEGS ( Fig. 26 ). 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, microgenuala; tibia 8B, 2 tibialae, microtibiala; tarsus 22B, tarsala, microtarsala distal to tarsala, subterminala, parasubterminala, pretarsala. Leg II: coxa 3B; trochanter 1B; basifemur 2B; telofemur 4B; genu 3B, genuala; tibia 6B, 2 tibialae; tarsus 18B, tarsala, microtarsala near and proximal to tarsala, pretarsala. Leg III: coxa 7B or 6B; trochanter 1B; basifemur 2B; telofemur 3B; genu 3B, genuala; tibia 6B; tarsus 18B.

Hosts. Leopoldamys edwardsi [= Rattus grochovskii D. Tien (nomen nudum)] ( Schluger et al. 1961), Niviventer confucianus (Milne-Edwards, 1871) ( Rodentia : Muridae ), Berylmys bowersi (= Rattus bowersi latouchei ), Rattus rattus (Wen 1984) .

Distribution. China (Wen 1984), Vietnam.

Type material examined ( Fig. 27 ). Lectotype (here designated): larva ZMMU Tdt-3179 (specimen 1) ex L. edwardsi No 44 [labeled as “ Rattus sp. n. ( Rattus grochovskii )”], Vietnam, Quang Ninh Province, Ha Lam District, Ha Long (= Hon Gai), 6 February 1956, coll. I.M. Grochovskaja. Paralectotypes: two larvae, ZMMU Tdt-3176 (specimen 4), ZMMU Tdt-3178 (specimen 1), same collection data as for lectotype.

Remarks. Doloisia gigantea is similar to D. varmai ( Audy and Nadchatram, 1957) ( Schluger et al. 1961) , from which it differs by the shape of sensillum (with an expanded top bearing 6 long spikes vs. rounded top covered with multiple, but shorter setules), by the presence of 3 setae on coxa II, vs. 4, branched palpal genual seta, vs. nude, wider scutum (AW = 30–35 vs. 25–26 and SB = 29–34 vs. 23–25), and longer AM (39 vs. 26–29). This species is also similar to D. vercammeni ( Audy and Nadchatram, 1957) by the very large size and by the shape of sensilla, but differs in the presence of 3 setae on coxa II, vs. 4, branched palpal genual seta, vs. nude, shorter scutal and idiosomal setae (AL = 18–24, PL = 44–47, and H = 54, vs. 31–34, 66–72, and 83, respectively), and lower number of idiosomal setae (NDV = 69–70 vs. 82–107).

Doloisia outoensis was synonymized with D. gigantea by Wen (1984). According the original description of D. outoensis , it has 3–4 setae on coxa II and 6–8 setae on coxa III ( Chen & Hsu 1965); thus, variation of these characters in D. gigantea is obviously wider than in its type series.

Figures

FIGURE 23. Doloisia gigantea (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1961). A, scutum of lectotype; B, anterior part of idiosoma, ventral aspect, of paralectotype ZMMU Tdt-3176 (specimen 4). Schoutedenichia alongensis Schluger, Grochovskaja, Ngu, Hoe and Tung, 1960 [syn. of S. centralkwangtunga (Mo, Chen, Ho and Li, 1959)]. C, scutum of paralectotype ZMMU Tdt-3279 (specimen 4); D, dorsal aspect of idiosoma of lectotype; E, ventral aspect of idiosoma of lectotype. Scale bars: 50 μm (A, C), 100 μm (B, D, E).

FIGURE 24. Doloisia gigantea (Schluger, Grochovskaja, Ngu, Hoe andTung, 1961), paralectotype ZMMUTdt-3176 (specimen 4). A, arrangement of dorsal idiosomal setae; B, arrangement of ventral idiosomal setae; C, dorsal idiosomal seta of 1st row; D, anterior sternal seta. E, preanal seta. Scale bars: 100 μm (A, B), 20 μm (C–E).

FIGURE 25. Doloisia gigantea (Schluger, Grochovskaja,Ngu, Hoe andTung, 1961), lectotype. A, ventral aspect of gnathosoma; B, dorsal aspect of gnathosoma.

FIGURE 26. Doloisia gigantea (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1961), lectotype. A, leg I (trochanter–tarsus) (subterminala missing); B, leg II (trochanter–tarsus); C, leg III (trochanter–tarsus).

FIGURE 27. Type specimens of Doloisia gigantea (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1961) on slides.