Macrocheles riparius Dwibadra and Takaku, 2014

Dwibadra, Dhian, Takaku, Gen, Ôhara, Masahiro & Ueda, Akira, 2014, Mites of the Family Macrochelidae (Acari: Gamasida) from Sungai Wain, East Kalimantan, Indonesia, Species Diversity 19 (1), pp. 43-57 : 50

Macrocheles riparius Dwibadra and Takaku sp. nov. ( Fig. 2 )

Type series. Holotype ( MZB. Acar. 7566): female, Hutan Lindung Sungai Wain, Balikpapan , East Kalimantan, 20 December 2006, ex residue in vial, A. Ueda and D. Dwibadra leg. Paratypes: SWPF: 5 females, 17 December 2006, ex Onthophagus semicupreus , O . waterstradti, and residue in vials; 2 females, 20 December 2006, ex residue in vial; 1 female, 12 December 2008, ex residue in vial, other data same as holotype . Km 24: 2 females, Balikpapan , East Kalimantan, 21 December 2006, ex O . schwaneri, residue in vial.

Description. Female. Length of dorsal shield 731.5 (680–770), width at level of coxae II 467.5 (410–510) (n =10). Specimens yellowish brown in color.

Dorsum ( Fig. 2A ). Dorsal shield with distinct punctations and reticulation; lateral margin of shield smooth; shield bearing 28 pairs of dorsal setae and 22 pairs of pores; seta j1 and Z5 pilose distally; J5 entirely pilose, r2 simple but sometimes slightly pilose; other setae simple.

Venter ( Fig. 2B ). Sternal shield wider than long; length 144 (130–150), width at level of coxae II 154.5 (150–160) (n =10); shield with 3 pairs of simple setae and 2 pairs of pores; l. ang. with punctation, disjunct from l. arc.; l. o. a. punctate; two l. arc. present as irregular punctate lines; l. m. t. punctate; l. o. p. present as paired transverse lines, with punctations, not connected to l. m. t.; two a. p. l. present. Metasternal shields oval and free; each shield with 1 simple seta and an anterior pore.

Width of epigynial shield 184.5 (160–200) (n =10); shield ornamented with punctuations and pair of simple setae.

Ventrianal shield longer than wide; length 260 (235–280), width 221 (195–245) (n =10); shield ornamented with reticulation and punctations; 3 pairs of preanal setae, 1 pair of paranal setae, and 1 postanal seta present; postanal seta pilose, other setae simple; cribrum located posterior to postanal seta.

Gnathosoma ( Fig. 2C ). Well developed and sclerotized, differing from that of Macrocheles dayaci only in median process of epistome ( Fig. 2E ) bearing many small spicules. Chelicera ( Fig. 2D ) same as in M. dayaci ; length of fixed digit 217.5 (210–220) and movable digit 69.8 (67.5–72.5) (n =10).

Legs. Most leg segments with simple and pilose setae except for coxae I–IV, trochanters I–III and tarsus I with only simple setae. Leg chaetotaxy typical for this genus. Genu IV with 6 pilose setae. Leg length (excluding ambulacrum, n =10); leg I, 638.5 (610–665); leg II, 615 (585–680); leg III, 573.5 (525–625); leg IV, 847.5 (815–930).

Sacculus foemineus ( Fig. 2F ). Pair of sacculi present; cornu distinct, small and rounded distally; spermatheca oval.

Male and other stages. Unknown.

Etymology. This specific name alludes to its occurrence around the Wain River.

Remarks. The sternal punctate ornamentation of the present species is similar in pattern to that of Macrocheles adenostictus Krantz and Whitaker, 1988 ( Krantz and Whitaker 1988) recorded from the USA. However, M. riparius is distinguishable by the following characters (corresponding conditions of M. adenostictus in parentheses): 1) most dorsal setae, including setae of z-Z and s-S series, simple (all z-Z and s-S series setae strongly pilose distally); and 2) ophisthogastric setae simple (weakly pilose distally).

Figures

Fig. 2. Macrocheles riparius Dwibadra and Takaku, sp. nov., female, holotype (MZB. Acar. 7566). A, dorsal shield (paratype, MZB. Acar. 7565.2); B, ventral shield; C, ventral view of gnathosoma (paratype, MZB. Acar. 7565.2); D, chelicera; E, tectum; F, sacculus foeminus (paratype, MZB. Acar. 8205). Scale bars: 50µm.