Eutrombicula mistrali, Stekolnikov, Alexandr A. & González-Acuña, Daniel, 2015

Stekolnikov, Alexandr A. & González-Acuña, Daniel, 2015, A review of Chilean chiggers (Acari: Trombiculidae), with the description of a new genus and ten new species, Zootaxa 3964 (1), pp. 1-43 : 6-9

Eutrombicula mistrali sp. nov.

(Figs. 3, 4)

Diagnosis. SIF = 7BS-N-2-3111.1000; fsp = 7.7.7; fCx = 1.1.1; fSt = 2.2; fPp = B/N/NNB; fSc: PL> AM> AL; Ip = 947–1028; fD = 2H-[(9–13)-(8–11)]-(17–24)-(11–17)-…; DS = 65–86; VS = 45–50; NDV = 112–131. Standard measurements of holotype: AW 81, PW 92, SB 36, ASB 25, PSB 26, SD 51, P-PL 21, AP 24, AM 34, AL 32, PL 46, S 68, H 48, D min 28, D max 44, V min 27, V max 38, pa 324, pm 293, pp 329, Ip 947, DS 71, VS 46, NDV 117, TaIIIL 86, TaIIIW 16, m-t 0.375. Standard measurements of type series given in Table 1 .

FIGURE 3. Eutrombicula mistrali sp. nov. A, scutum and eyes (holotype); B, dorsal idiosomal seta of 1st row; C, preanal ventral idiosomal seta; D, arrangement of ventral idiosomal setae (holotype); E, arrangement of dorsal idiosomal setae (holotype). Scale bars: 50 Μm (A), 20 Μm (B, C), 100 Μm (D, E).

Description (larva). IDIOSOMA. Eyes 2 + 2, on ocular plate, anterior larger. One pair of humeral setae, 63– 84 moderately barbed dorsal idiosomal setae, 1st row of dorsal setae double, in holotype fD = 2H-[13-8]-[9-8]-13- 18; 4 sternal setae; 45–50 ventral setae; total number of idiosomal setae excluding coxal and sternal 112–131.

GNATHOSOMA. Cheliceral blade with tricuspid cap; cheliceral base with dense puncta in proximal part; gnathobase with transverse striations (sometimes poorly visible) and sparse puncta of varying size; palpal femur with few puncta; gnathobase with 1 pair of branched setae; galeala nude; palpal claw with 2 short subequal prongs separated from each other by shallow cleft; seta on palpal femur branched; seta on palpal genu nude; dorsal and lateral palpal tibial setae nude, ventral palpal tibial seta branched; palpal tarsus with 7 branched setae, nude subterminala, and tarsala.

SCUTUM. Nearly rectangular, with broadly rounded posterior margin, dense puncta of moderate size on whole surface and very small inconspicuous puncta in anterior and central part; AM base at level of ALs; SB anterior to level of PLs (PSB—P-PL = 4–6; mean value 4.8); PL> AM> AL; flagelliform sensilla with about 5–6 branches of moderate length in distal half.

LEGS. All 7-segmented, with 1 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, 3 genualae, microgenuala; tibia 8B, 2 tibialae, microtibiala; tarsus 22B, tarsala 16–17 long, microtarsala distal to tarsala, subterminala, parasubterminala, pretarsala. Leg II: coxa 1B; trochanter 1B; basifemur 2B; telofemur 4B; genu 3B, genuala; tibia 6B, 2 tibialae; tarsus 16B (17B in paratype No. 9610 used for Fig. 4 , B; 16B in paratypes Nos 9609 and 9614; counted on one side), tarsala thin, 16–19 long, microtarsala proximal to tarsala, pretarsala. Leg III: coxa 1B; trochanter 1B; basifemur 2B; telofemur 3B; genu 3B, genuala; tibia 6B, tibiala; tarsus 14B, nude mastitarsala.

Host. Microlophus quadrivittatus (Tschudi) ( Squamata : Tropiduridae ).

Type material. Holotype larva ( ZIN collection No. 9611, T-Tr.-67) ex Microlophus quadrivittatus No. 381, CHILE: Arica and Parinacota Region, Arica Province, Caleta Vitor, 18º 45′ S, 70º 20′ W, 2 June 2011, coll. D. González-Acuña & S. Muñoz-Leal; 6 larvae paratypes (9609, 9610, 9612–9615) with same data.

Etymology. The species named after a famous Chilean poet Gabriela Mistral, the Nobel laureate of 1945 for Literature.

Remarks. The new species is very close to Eutrombicula nerudai sp. nov. and differs from it in a greater number of idiosomal setae (DS, VS, NDV), less prominent posterior scutal margin (PSB) and shorter scutum (SD), somewhat shorter scutal and idiosomal setae (AM, AL, PL, H, D min, D max, V min), and in the shorter tarsus of leg III (TaIIIL) ( Table 1 ).

Figures

FIGURE 4. Eutrombicula mistrali sp. nov. A, tarsus, tibia, and genu of leg I; B, tarsus, tibia, and genu of leg II; C, tarsus, tibia, and genu of leg III; D, dorsal aspect of gnathosoma (tip of cheliceral blade is broken); E, cheliceral blade; F, ventral aspect of gnathosoma (tip of cheliceral blade is broken). Scale bars: 50 Μm (A – C), 20 Μm (D – F).