Bak indonesiensis, Bochkov & Otto, 2010

Bochkov, Andre V. & Otto, Jurgen C., 2010, Five new species of predaceous cheyletid mites (Acari: Prostigmata: Cheyletidae), Zootaxa 2727, pp. 1-20 : 17

Bak indonesiensis sp. nov.

( Figs. 12, 13)

Description. FEMALE (holotype). Body, including gnathosoma, 435 long (420, 440 in 2 paratypes), 170 wide (160, 185). Gnathosoma 125 long (130, 140), 105 wide (100, 110). Palpal femur about 35 long and 50 wide. Palpal claws with 2 basal teeth each, about 60 long. All gnathosomal setae, excluding comb-like eupathidia acm and sul bearing numerous tines, smooth. Dorsal seta of palpal femur dF about 35 long. Peritremes M-shaped, with 11–12 pairs of segments. Rostral shield (tegmen) with pair of distinct lateral teeth. Idiosoma. Most dorsal setae slightly clavate. Propodonotal shield trapezoidal, with truncate posterior margin, 110 long (105, 115) and about 110 wide, bearing 3 pairs of setae (vi, si, and se), 25–30 long, setae ve about 15 long, situated off this shield. Setae c2 smooth filiform, about 100 long, situated ventrally. Most hysteronotal setae similar in size to propodonotal setae. Setae c1 situated directly posterior to propodonotal shield. Setae d1 and d2 inserted on same level. Opisthosoma with 3 small sclerotized plates (remnants of hysteronotal shield)—pair of lateral plates about 35 long and 15 wide, bearing setae e2, and unpaired median plate about 30 long and 15 wide without setae. Setae e 1 in same sizes and shape as hysteronotal setae situated above. Setae f1 and f2 smooth filiform, about 8 long, setae h1 serrate, about 25 long. Setae of aggenital and genital series short filiform, subequal to 4a. Legs. All leg setae smooth filiform, excluding narrowly lanceolate setae dF I–IV and apically serrate p’ and p” on all tarsi. Leg I–IV setation: tarsus 9 + solenidion ω 1 (ft, tc’, tc”, p’, p”, a”, u’, u”, vs)–7+ s olenidion ω 1 (tc’, tc”, p’, p”, u’, u”, vs)–7–7, tibia 4 + solenidion φ (d, l’, v’, v”)–4–4–4, genu 1 + solenidion σ (d)–1(d)–1(l’)–0, femur 2 (d, v)–2–1 (d)–1, trochanter 1 (v)–1–1–1, coxae 3 (1a, 1b, 1c)–1 (2b)–3 (3a, 3b, 3c)–2 (4a, 4b).

MALE. Unknown.

Type material. Female holotype and 2 female paratypes ( ANIC # 42–000005 ), Australian border interception (N121257) from timber ornaments imported from Indonesia; phoretic on undetermined beetle, 3 March 2008, coll. D. Morgan.

Etymology. This species’ name refers to the country, from where the goods this mite was found on were imported.

Remarks. The genus Bak includes 13 species along with this species described above; the generic keys are provided in papers by Corpuz-Raros (2000) and Fain & Bochkov (2001). This new species possesses clavate dorsal setae on the idiosoma. It differs from the other two species with clavate setae, Bak elongatus Patxot & Goff, 1985 and B. faini Corpuz-Raros, 2000 by the presence of seta (l’) on genu III, the only slightly clavate dorsal setae of the idiosoma, setae e1 being subequal in shape and sizes to their anterior hysteronotal setae, and by the presence of a pair of distinct lateral teeth on the rostral shield. In B. elongatus and B. faini , the dorsal setae of the idiosoma, at least on the hysteronotum, are distinctly clavate, setae e1 are much shorter and narrower than their anterior hysteronotal setae, and the lateral teeth on the rostral shield are absent. According to the figures in the paper by Corpuz- Raros and Sotto (1977: 148, figs. 4, 5 and p. 149, figs. 6, 7) two more species, Bak payatus Corpuz-Raros & Sotto, 1977 and B. truncatus Corpuz-Raros & Sotto, 1977 , actually have slightly uneven (clavate) dorso-idiosomal setae. Bak indonesiensis sp. nov. differs from B. payatus by the truncate posterior margin of the propodonotal shield and by the absence of the second seta (v) on femur III. In B. payatus , the posterior margin of the propodonotal shield is acutely rounded, femur III bear two setae (d and v). It differs from B. truncatus by the presence of the paired lateral teeth on the rostral shield and by the hysteronotum bearing eight pairs of setae (setae e1 subequal is shape and sizes to their anterior hysteronotal setae). In B. truncatus , the rostral shield is devoid of the lateral teeth, the hysteronotum bears nine pairs of setae (setae e1 much shorter and thinner than above situated hysteronotal setae, an additional pair of setae the same shape and size are situated near e1).