Eutrombicula cathari Stekolnikov, 2022

Stekolnikov, Alexandr A., Capek, Miroslav & Literák, Ivan, 2022, New species and records of chiggers (Acariformes: Trombiculidae) from birds of the Neotropics, Zootaxa 5141 (6), pp. 501-552 : 510-513

Eutrombicula cathari Stekolnikov sp. nov.

( Figs. 4–6 )

Diagnosis. SIF = 7BS-N-2-3111.1000; fsp = 7.7.7; fCx = 1.1.1; fSt = 2.2; fPp = B/B(N)/NNB; fSc: PL> AM> AL; Ip = 1085–1186; fD = 2H-6-6-4-2(2-4); DS = 20; V = 11–13; NDV = 31–33. Inner prong of palpal claw slightly shorter than outer prong; scutal and dorsal idiosomal setae moderately covered with short barbs; scutum nearly pentagonal, densely covered with small puncta, without transverse striae; sensilla (trichobothria) with ca. 10 branches in distal half; sensillary bases far anterior to level of PL (PSB—P-PL = 8–13 µm). Standard measurements of type series given in Table 3 .

Description (larva) (based on holotype and 7 paratypes). IDIOSOMA ( Figs. 4 , 5A–E ). Eyes 2 + 2; 20 dorsal idiosomal setae, including one pair of humeral setae, moderately covered with short barbs, by 6 setae in 1 st and 2 nd (D) posthumeral rows, 4 setae in 3 rd (E) row, 2 setae in 4 th (F) row, setae in rows E and F can be also counted as 2 and 4, respectively; 4 sternal setae; 11–13 ventral setae; NDV = 31–33.

GNATHOSOMA ( Fig. 5F, G ). Cheliceral blade with tricuspid cap; cheliceral base with small dense puncta basally and sparse large puncta in distal part; gnathobase with small dense puncta, transverse striae, and 1 pair of branched gnathocoxal (tritorostral) setae; galeal (deutorostral) seta nude; palpal claw with 2 prongs, inner prong slightly shorter than outer prong; palpal femur with dense small puncta and branched seta; palpal genu with sparse small puncta and branched (in holotype and five paratypes) or nude (in two paratypes) seta; palpal tibia with few small puncta, nude dorsal and lateral and branched ventral seta; palpal tarsus with 7 branched setae, nude subterminala (ζ) and basal tarsala (ω).

SCUTUM ( Figs. 4C , 5A ). Nearly pentagonal, densely covered with small puncta, without transverse striae, with anterolateral shoulders, anterior scutal margin sinuous, lateral margins concave, posterior margin rounded; AM at level of AL, sensillary (trichobothrial) bases far anterior to level of PL (PSB—P-PL = 8–13 µm); all scutal setae uniform with dorsal idiosomal setae; PL> AM> AL; flagelliform sensilla (trichobothria), with ca. 10 branches in distal half. Rudimentary additional AM present in one paratype ( Fig. 4B ).

LEGS ( Fig. 6 ). 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) distal 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) proximal to tarsala, pretarsala (ζ). Leg III: coxa 1B; trochanter 1B; basifemur 2B; telofemur 3B; genu 3B, genuala; tibia 6B, tibiala; tarsus 14B, mastitarsala.

Hosts . Catharus frantzii , Catharus gracilirostris .

Localization on hosts. Near vent ( C. frantzii Nos BV 206 and BV213, C. gracilirostris Nos BV 179, BV193, BV196, B218, BV255), in ear ( C. gracilirostris No BV 217).

Type material. Holotype larva ( ZIN 9167 ) ex C. gracilirostris No BV 196, COSTA RICA: Braulio Carillo National Park , Sector Barva, 5 August 2010 . Paratypes: 6 larvae ( ZIN 9168–9173 ) with same data ; 36 larvae (interval of numbers: ZIN 9151–9200 ) ex C. frantzii Nos BV 117, BV206, BV211, BV213 (15 larvae) and C. gracilirostris Nos BV 179, BV193, BV212, BV217, BV218, BV255 (21 larvae), Braulio Carillo National Park , Sector Barva, 2–7 August 2010 .

Etymology. The species epithet cathari is derived from the generic name of the type host.

Differential diagnosis. Eutrombicula cathari is similar to E. tinami and differs from it by the presence of relatively longer inner prong of palpal claw, which is only slightly shorter than the outer prong, vs. less than the two thirds as long as the outer prong in E. tinami ; by the greater scutum (AW = 85–96, PW = 98–115, and SD = 67–76 vs. 76–77, 92, and 64, respectively); by longer PL (68–79 vs. 62–63) and longer D max (61–70 vs. 56) ( Fuller 1952). The new species differs from the E. tinami form described by Bassini-Silva et al. (2019), in addition to the relatively longer inner prong of palpal claw, by the relatively wider scutum (SD = 67–76 vs. 74–85, while PW is similar: 98–115, mean 105 vs. 93–116, mean 104) without transverse striae (vs. with transverse striae), longer ventral idiosomal setae (V min = 45–52 vs 32–33 and V max = 58–67 vs. 39–45), longer legs (TaIIIL = 99–110 vs. 89–97; total lengths of legs are incomparable with our data, as noted above).

Figures

FIGURE 4. Eutrombicula cathari sp. nov. A—general view (paratype ZIN 9162), B—dorsal aspect of idiosoma (paratype ZIN 9162), C—scutum (holotype), D—ventral aspect of idiosoma (paratype ZIN 9162). Scale bars: 100 µm (A), 50 µm (B–D).

FIGURE 5. Eutrombicula cathari sp. nov. A—scutum and eyes (holotype), B—dorsal idiosomal seta (holotype), C—ventral idiosomal seta (holotype), D—dorsal aspect of idiosoma (paratype ZIN 9162), E—ventral aspect of idiosoma (paratype ZIN 9162), F—ventral aspect of gnathosoma (paratype ZIN 9162), G—dorsal aspect of gnathosoma (paratype ZIN 9162). Abbreviations as in Fig. 2. Scale bars: 50 µm (A), 20 µm (B, C, F, G), 100 µm (D, E).

FIGURE 6. Eutrombicula cathari sp. nov., paratype ZIN 9162. A—leg I (genu–tarsus), B—leg I (trochanter–telofemur), C— leg II (trochanter–tarsus), D—leg III (trochanter–telofemur), E—leg III (genu–tarsus). Abbreviations as in Fig. 3.