Achaemenothrombium dariusi Saboori, Wohltmann & Hakimitabar

Saboori, Alireza, Wohltmann, Andreas, Hakimitabar, Masoud & Shirvani, Asghar, 2013, A new species of the genus Achaemenothrombium (Acari: Achaemenothrombiidae) from Iran, Zootaxa 3694 (2), pp. 143-152 : 144-152

Achaemenothrombium dariusi Saboori, Wohltmann & Hakimitabar sp. nov.

( Figs. 1–11 )

Description. Larva. For morphometric data see Table 2.

Gnathosoma ( Fig. 2 ). Cheliceral claw curved, small, with a subterminal tooth. Hypostomal setae (cs) (34–40) distally barbed, oral setae (as) (8) spine-like. No supracoxal seta (elcp) visible. Palp formula (ƒPp): N-N-NNN-NNNNNζω;. Palp trochanter absent. Palp femur and genu each with 1 spine-like seta (8–15) dorsally. Palp tibia with two spines (3–4) dorsally near base of odontus plus one elongate, smooth seta (55) ventrally. Odontus bifurcate, divided half its length. Palp tarsus with two distinctly prolonged, smooth setae (60–74), one long seta (28–32) and two spine-like, nude setae (3–4), one eupathidium (ζ) and one solenidion (ω) of about same length (6– 8).

Idiosoma ( Fig. 1 ). Scutum pentagonal, oblong, rounded anteriorly, without lateral flaps, punctate, punctations more distinct medially between AL and PL bases. AL and PL setae with minute barbs; AM and sensilla smooth. Posterior to scutum an ovoid scutellum I formed by fused c1 plates, setae c1 barbed, arising at half length of sclerite. Posterior to scutellum I, a second, smaller scutellum II formed by fused d1 plates, setae d1 barbed, arising just anterior to half length of sclerite. Two pairs of eyes at level of posterior part of scutum, each pair situated on an oval sclerite (28–33×54–62) and slightly protruding above idiosomal surface. Anterior lens (26–28) slightly larger in diameter than posterior lens (18–20). Rest of dorsum with barbed, soft cuticle folded. Dorsal setae barbed, situated on platelets, arranged in rows C1–3, D1–3, E1–3, F1–5 and H1–4 (including setae on anterior and posterior scutellum). Platelets of setae f4-6 and h1 distinctly larger (25–30) than anterior platelets (10–12).

Ventral side of idiosoma with one pair of Claparède's organs laterally between coxae I and II ( Fig. 3 ). Coxa I with setae 1a (50–55) and 1b (60–65) smooth, a smooth supracoxala (elc I) (8) located dorsolaterally on coxa I. Coxa II with serrated setae 2a (60–65) and 2b (30–35). Coxa III with seta 3b (60–65) smooth. Setae 3a (55–58) intercoxal, located in soft cuticle. Posterior to coxae 30–34 barbed setae around anal opening. Anal pore without sclerite, 40–45 long.

Legs ( Figs. 6–10 ). Segmentation formula: 6-6-6, for leg chaetotaxy see Table 1 . All normal setae on legs I-III setulose. Solenidia on Ta II round-ended. Pretarsus of legs I-II with paired claws and claw-like empodium. Pretarsus of leg III with one claw plus empodium normal, inner claw curved outside, shorter and slightly thicker.

Postlarval instars: unknown

Type material. All specimens of Achaemenothrombium darusi were collected in Sirch [ ARS-20130205-1a , 1b & 1f-1l], 30°11’8”N 57°24’54”E, 2600 m a.s.l., parasitic on Euxoa fallax ( Lepidoptera : Noctuidae ) ( Fig. 11 ), 6 October 2006 and Cheshmeh Bondar [ARS-20130205-1c, 1d, 1e], 30°37’7.5”N 57°2’51.2”E, parasitic on Euxoa fallax ( Lepidoptera : Noctuidae ), 8 July 2006, 2300 m a.s.l., Kerman province, Iran. Holotype [ARS-20130205-1a] and four paratypes [ARS-20130205-1b, 1c, 1d, 1e] deposited in Acarological Collection, ‘ Jalal Afshar Zoological Museum’, Faculty of Agriculture , University of Tehran , Karaj , Iran, four paratypes [ARS-20130205- 1f, 1g, 1h, 1i] deposited in Acarological Collection , Acarological Society of Iran, Faculty of Agriculture , University of Tehran , Karaj , Iran and three paratypes [ARS-20130205-1j, 1k, 1l] deposited at ‘Biozentrum Grindel und Zoologisches Museum’ (formerly Zoologisches Institut und Zoologisches Museum der Universitaet Hamburg, Germany).

Distribution. Iran, Kerman province, Sirch and Cheshmeh Bondar.

Etymology. The species is named for the third king of the Persian Achaemenid Empire, Darius the Great or Darius I (550–486 BC) who ruled the empire at its peak, when it included much of West Asia, the Caucasus, Central Asia, parts of the Balkans (Bulgaria-Pannonia), portions of north and northeast Africa including Egypt (Mudrâya), eastern Libya, coastal Sudan, Eritrea, as well as most of Pakistan, the Aegean Islands and northern Greece /Thrace-Macedonia. Darius is also mentioned in the Biblical canon of 1 Esdras.

Remarks. The original definition of the family Achaemenothrombiidae was based on two species; however, these species were described for only a single (A. talebii) and two ( A. cyrusi ) specimens, respectively ( Saboori et al. 2010). No data on intraspecific variability could be presented. Moreover, it could not be excluded that the examined specimens display some aberrant character states as known for other Parasitengona to occur ( Mąkol & Łaydanowicz 2006; Wohltmann & Mąkol 2009).

Present data for A. dariusi Saboori, Wohltmann & Hakimitabar sp. nov. is based on the examination of more than ten specimens from different hosts and shows that intraspecific variability is evident in some characters, e.g. concerning the number of normal and specialized setae on legs ( Table 1 ). However, data from A. dariusi sp. nov. fit proposed autapomorphies for Achaemenothrombiidae [Ti I–III with 8 or more N, Ti I with> 4 solenidia, Ta I with> 4 solenidia ( Saboori et al. 2010)] and confirm the unique evolutionary fate of the three species. Moreover, analysis of A. dariusi sp. nov. provided no contradictions to the arguments listed in Saboori et al. (2010) not to include Achaemenothrombium in any of the established families of Trombidioidea, thus confirming the hypothesis of a new family Achaemenothrombiidae. With regard to the validity of species, A. dariusi sp. nov. is clearly separate to A. talebii and A. cyrusi (see below). However, taking into account the intraspecific variability found in A. dariusi sp. nov., doubts arise about the separate state of A. talebii and A. cyrusi . Of the differentiating characters listed in Saboori et al. (2010), only the number of solenidia on Ti I (8 vs. 4), on Ta I (8–9 vs. 5), on Ta II (3 vs. 2) and the presence of two-tipped microsetae on Ti I and Ge II of A. talebii can still be considered as good indications; their evaluation based on additional specimens of both species is needed.

Achaemenothrombium dariusi sp. nov. differs from A. cyrusi and A. talebii in the higher number of normal setae on Ti I (13–15 vs. 9–10), on Ta I (53–63 vs. 37–44), on Ti II (10–12 vs. 8), on Ti III (10–15 vs. 8–9); the lower number of normal setae on Ge II (2 vs. 3); and its generally larger size (e.g. length of scutum 250–287 vs. 185–210; of Ta II 160–193 vs. 134–148; of Ta III 184–205 vs. 124–162).

Figures

FIGURE 11. Euxoa fallax (Eversmann) (Lepidoptera: Noctuidae) parasitized by A. dariusi sp. nov. larvae (orange arrows indicate larvae).

FIGURES 1 – 3. Achaemenothrombium dariusi sp. nov. (larva). 1. Dorsal view of idiosoma, with detail of seta; 2. Gnathosoma; 3. Ventral view of idiosoma, with detail of seta.

FIGURES 4 – 6. Achaemenothrombium dariusi sp. nov. (larva). 4. Leg I, trochanter-genu; 5. Leg I, tibia & tarsus; 6. Tarsus I, specialized setae.

FIGURES 7 – 10. Achaemenothrombium dariusi sp. nov. (larva). 7. Leg II, trochanter-genu; 8. Leg II, tibia & tarsus; 9. Leg III, trochanter-genu; 10. Leg III, tibia & tarsus.

Tables

TABLE 1. Chaetotaxy of Achaemenothrombium dariusi sp. nov. (1 a, holotype; 1 b – e, paratypes).

Character	1a	1b	1c	1d	1e
Palp Fe	1n	1n	1n	1n	1n
Palp Ge	1n	1n	1n	1n	1n
Palp Ti	2n, 1N	2n, 1N	2n, 1N	2n, 1N	2n, 1N
Palp Ta	2n, 3N, 1ω, 1ζ	2n, 3N, 1ω, 1ζ	2n, 3N, 1ω, 1ζ	2n, 3N, 1ω, 1ζ	2n, 3N, 1ω, 1ζ
Cx I	2N + elc I	2N + elc I	2N + elc I	2N + elc I	2N + elc I
Tr I	1N	1N	1N	1N	1N