Microtrombicula fulgida ( Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963 )

Antonovskaia, Anastasia A. & Stekolnikov, Alexandr A., 2021, Redescriptions of ten chigger mite species (Acariformes: Trombiculidae) from Vietnam, Zootaxa 4969 (1), pp. 1-53 : 42-46

Microtrombicula fulgida ( Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963)

( Figs. 31A, B , 32–34 )

Trombicula fulgida Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963: 696 , figs. 23–29.

Microtrombicula fulgida: Kudryashova 2004: 19 .

Microtrombicula (Microtrombicula) fulgida: Chau et al. 2007: 95 , fig. 44.

Diagnosis. SIF = 6B-N-2-3111.1000; fsp = 7.7.7; fCx = 1.1.1; fSt = 2.2; fPp = B/B/BbB; fSc: PL> AM> AL; Ip = 547–565; fD = 2H-7-10-5-5-4-4; DS = 31–37; V = 31–42; NDV = 67–74. Sensilla, sternal and coxal setae branched. Standard measurements of type series given in Table 10 .

Description (larva) [based on lectotype and 3 paralectotypes]. IDIOSOMA ( Figs. 31A, B , 32 ). Eyes 2 + 2; 31–37 barbed dorsal idiosomal setae, including one pair of humeral setae; 4 sternal setae, each with 2 barbs; 31–42 ventral setae; NDV = 67–74.

GNATHOSOMA ( Fig. 33A, B ). Cheliceral blade with tricuspid cap; gnathobase with sparse puncta and 1 pair of branched setae; cheliceral base and palpal femur with sparse puncta; galeala nude; palpal claw with 2 prongs, internal prong longer; setae on palpal femur and genu branched; dorsal and ventral palpal tibial setae branched, lateral palpal tibial seta with 1 branch; palpal tarsus with 6 branched setae and tarsala.

SCUTUM ( Figs. 31A , 33C ). Pentagonal, wider than long, with anterolateral shoulders, with rounded posterior margin, moderately covered with small puncta, with 1 AM, 1 pair of ALs and 1 pair of PLs; AM anterior to level of ALs; all scutal setae uniformly covered with small barbs; PLs longest and ALs shortest scutal setae; sensilla flagelliform, with 8 long branches in distal half; sensillum bases situated close to each other and far anterior to level of PLs (PSB – P-PL = 7–10 µm).

LEGS ( Fig. 33D–F ). All 7-segmented, with 1 pair of claws and claw-like empodium. Leg I: coxa with 1 seta bearing 3 long branches (1B); trochanter 1B; basifemur 1B; telofemur 5B; genu 4B, 3 genualae, microgenuala; tibia 8B, 2 tibialae, microtibiala; tarsus 23B, tarsala, microtarsala distal to tarsala, subterminala, parasubterminala, pretarsala. Leg II: coxa 1B (with 2 short barbs); trochanter 1B; basifemur 2B; telofemur 4B; genu 3B, genuala; tibia 6B, 2 tibialae; tarsus 16B, tarsala, microtarsala at level of tarsala, pretarsala. Leg III: coxa 1B (with 3 long branches); trochanter 1B; basifemur 2B; telofemur 3B; genu 3B, genuala; tibia 6B, tibiala; tarsus 13B, mastitarsala.

Host. Rattus tanezumi Temminck [= Rattus flavipectus (Milne-Edwards) ]. The host was indicated as a “rat” on the slide labels but was identified as R. flavipectus in the thesis of Grochovskaja (unpublished typescript).

Distribution. Vietnam.

Type material examined ( Fig. 34 ). Lectotype (here designated): larva ZMMU Tdt-3232 (specimen 5) ex R. tanezumi (labeled as “rat”) No 543, Vietnam, Nghe An Province, Phu Quy , 8 September1956, coll. I.M. Grochovskaja. Paralectotypes: three larvae, ZMMU Tdt-3229 (specimen 1), ZMMU Tdt-3231 (specimen 3), ZMMU Tdt-3280 “ Trombicula vitosa ” (specimen 5), ex R. tanezumi (labeled as “rat”) Nos 571, 568, Vietnam, Nghe An Province, Phu Quy , 10 September 1956, coll. I.M. Grochovskaja.

Remarks. Microtrombicula fulgida is similar to M. munda (Gater, 1932) and differs from it in the greater number of idiosomal setae (fD = 2H-7-10-5-5-4-4, DS = 31–36, V = 32–42, and NDV = 67–74 vs. 2H-6-6-4-4-2-2, 26, 32, and 58, respectively), all coxal and sternal setae branched vs. nude (except coxal setae I), and by longer legs (Ip = 547–565 vs. 488) ( Vercammen-Grandjean 1965a).

This species is also close to M. nadchatrami Vercammen-Grandjean, 1965 and differs from it in a shorter scutum (ASB = 20–21, PSB = 19–21, SD = 39–43, and AP = 19–22, vs. 24, 25, 49, and 25, respectively), shorter setae (AM = 24–25, AL = 20–22, PL = 29–33, D min = 18–24, D max = 25–26, V min = 9–16, V max = 22–24, vs. 31, 28, 38, 27, 32, 21, and 28, respectively), shorter legs (Ip = 547–565 vs. 644), and less branched sternal and coxal setae (sternal setae with 2 vs. about 6 barbs; coxal setae I and III with 3 vs. about 6 long branches; coxal setae II with 2 vs. multiple short barbs) ( Vercammen-Grandjean 1965a).

Figures

FIGURE 31. Microtrombicula fulgida (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963), lectotype. A, anterior part of idiosoma, dorsal aspect; B, anterior part of idiosoma, ventral aspect. Microtrombicula vitosa (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963), paralectotype ZMMU Tdt-3281 (specimen 1). C, anterior part of idiosoma, dorsal aspect; D, anterior part of idiosoma, ventral aspect. Scale bars: 100 μm.

FIGURE 32. Microtrombicula fulgida (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963). A, arrangement of dorsal idiosomal setae of paralectotype ZMMU Tdt-3231, specimen 3; B, arrangement of ventral idiosomal setae of paralectotype ZMMU Tdt- 3231, specimen 3; C, dorsal idiosomal seta of 1st row of lectotype; D, coxal seta I of lectotype; E, coxal seta II of lectotype; F, anterior sternal seta of lectotype; G, posterior sternal seta of lectotype; H, preanal seta of lectotype. Scale bars: 100 μm (A, B), 20 μm (C–H).

FIGURE 33. Microtrombicula fulgida (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963). A, ventral aspect of gnathosoma of lectotype; B, dorsal aspect of gnathosoma of lectotype; C, scutum and eyes of lectotype (one sensillum missing); D, leg I (trochanter–tarsus) of paralectotype ZMMU Tdt-3231 (specimen 3); E, leg II (trochanter–tarsus) of paralectotype ZMMU Tdt- 3231 (specimen 3); F, leg III (trochanter–tarsus) of paralectotype ZMMU Tdt-3231 (specimen 3) (mastitarsala broken). Scale bars: 20 μm (A, B), 50 μm (C–F).

FIGURE 34. Type specimens of Microtrombicula fulgida (Schluger, Grochovskaja, Ngu, Hoe and Tung, 1963) on slides.

Tables

TABLE 10. Standard measurements (µm) and numbers of setae of Microtrombicula fulgida (n = 4).

	Range	Mean	Lectotype
AW	42–44	43	42
PW	52–56	54	52
SB	15–18	16	16
ASB	20–21	20	20
PSB	19–21	21	19
SD	39–43	41	39
P-PL	11–14	12	11
AP	19–22	21	22
AM	24–25	25	25
AL	20–22	21	22
PL	29–33	31	32
H	33–39	36	39
D min	18–24	21	24
D max	25–26	25	26
V min	9–16	14	14
V max	22–24	23	24
pa	192–198	195	198
pm	161–176	167	162
pp	189–194	191	189
Ip	547–565	553	549
DS	31–37	33	31
V	31–42	36	36
NDV	67–74	70	67