Tenuipalpus omani, S, De M Orae & Silva, Da, 2011

S, De M Orae & Silva, Da, 2011, A new flat mite (Acari: Prostigmata: Tenuipalpidae) from date palm in the Sultanate of Oman, Zootaxa 2962, pp. 63-68 : 64-65

Tenuipalpus omani n. sp. Moraes, Al-Shanfari & Silva

Diagnosis. Both sexes: dorsal opisthosomal setae c1, c3, d1, d3, e1, e3, f2, f3, h1, h2 present; dorsal idiosomal setae spatulate, pilose, except h2, whip-like, barbed proximally; a pair of circular pores anterolaterad of setae e1; seven 4a setae present ventrally (3 pairs and an unpaired central seta); trochanter III with 2 setae. Female: central area of prodorsum with broad, regular transverse bands (= taeniate, as cited in Harris, 1979); lateral area with irregular transverse bands that become taeniate posteriorly; central area of dorsal opisthosoma rugose-taeniate, surrounded by an area with mostly diagonal bands; ventral podosoma mostly with small rounded structures (= colliculate, as cited in Harris, 1979); rounded structures becoming elongate or fusing to each other to form wavy, broken longitudinal ridges between setae 1a -3a; band laterad of ventrigenital plate and between genital and anal openings smooth. Male: prodorsum smooth anteriorly, taeniate posterocentrally and posterolaterally; anterior dorsal opisthosoma smooth with diagonal lateral bands; central dorsal opisthosoma with diagonal bands up to the base of f2; posterior dorsal opisthosoma smooth; ventral podosoma mostly with elongate and aligned structures, forming wavy, broken longitudinal ridges, except for a colliculate lateral band with small rounded structures; anterior ventral opisthosoma also with small rounded structures; posterior ventral opisthosoma smooth.

Adult female. ( Figure 1 ) (3 specimens measured)

Gnathosoma ( Fig. 1 A): Infracapitulum short, buccal cone extending to base of femur I, with tip visible from a dorsal view. Palpus 3-segmented, distal segment with a terminal prominent rod-like solenidion 7 (7-8); penultimate segment with a dorso-distal pectinate seta; basal segment without setae. Subcapitular seta (m) 8 (7-10), pectinate; adoral setae (ad) absent.

Idiosoma ( Fig. 1 B–C): 310 (310–310) long, 172 (170–175) wide at widest level of prodorsum and 147 (145– 150) wide immediately behind coxa IV. Rostral shield deeply cleft (internal depth ca. 36). Central area of prodorsum with broad, regular, transverse bands (= taeniate); lateral area with irregular transverse bands that becomes taeniate posteriorly. Setae v2 12 (11–12), sc1 11 (10–12) and sc2 10 (10–11), all spatulate and pilose. Central area of dorsal opisthosoma rugose-taeniate, surrounded by an area with mostly diagonal bands. A pair of distinct circular pores anterolaterad of e1. With 10 pairs of dorsal opisthosomal setae, of the following lengths: c1 30 (30–31), c3 11 (10–12), d1 22 (20–24), d3 11 (10–13), e1 14 (14–14), e3 8 (7–9), f2 10 (9–10), f3 10 (9–10), h1 13 (12–14), h2 240 (220–260); all dorsal setae spatulate, pilose, except h2 whip-like, barbed proximally.

Ventral cuticle of idiosoma mostly with small rounded structures (= colliculate), except for the central region between setae 1a -3a, where rounded structures become elongate or fuse to each other to form wavy, broken longitudinal ridges, and for the regions laterad of ventrigenital plate and between genital and anal openings, smooth. Ventrigenital plate also with small rounded structures. Ventral podosomal setae smooth: 1a (= IC1a) 72 (70–75), 3a (= IC3a) 22 (20–25),, 4a (= IC4a) from central unpaired seta to lateral: 98 (95–101), 86 (76–91), 77 (68–87) and 71 (61–87), smooth. Ventral opisthosomal setae pectinate, except for ps2, apparently smooth: ag 38 (37–39), g1 35 (35–35), g2 29 (28–30), ps1 23 (20–25), ps2 23 (20–25).

Legs ( Figs 1 D–K): Leg setal counts, from coxa to tarsus – leg I: 2 (not including 1a), 1, 4, 3, 5, 8 setae+1 solenidion; leg II: 2, 1, 4, 3, 5, 8+1; leg III: 1 (not including 1a), 2, 2, 2, 3, 5; leg IV: 1 (not including the multiple 4a), 1, 0, 2, 3, 5. Setal lengths: 1b 15 (13–19), 1c 15 (14–15), 2b 30 (27–32) smooth; 2c 19 (17–20) pectinate; 3b 22 (20–25), 4b 27 (25–30) pectinate.

Adult male. ( Figure 2 ) (1 specimen measured)

Gnathosoma: As in female, subcapitular setae (m) 9, pectinate; rod-like solenidion 8.

Idiosoma ( Fig. 2 A–B): Idiosoma 285 long, 130 wide at widest level of propodosoma and 65 wide immediately behind coxa IV. Rostral shield as in female (internal depth ca. 30). Prodorsum smooth anteriorly, taeniate posterocentrally and posterolaterally. Anterior dorsal opisthosoma smooth with diagonal lateral bands; central dorsal opisthosoma with diagonal bands up to the base of f2; posterior dorsal opisthosoma smooth. A pair of distinct circular pores anterolaterad of e1. Number of opisthosomal setae as in female, and of the following lengths: v2 15, sc1 13, sc2 10; c1 20, c3 10, d1 20, d3 14, e1 12, e3 10; f2 10, f3 10, h1 15, h2 225; all dorsal setae spatulate, pilose, except h2 whip-like, barbed proximally.

Ventral podosoma mostly with elongate and aligned structures, forming wavy, broken longitudinal ridges, except for a lateral band with small rounded structures; anterior ventral opisthosoma also with small rounded structures; posterior ventral opisthosoma smooth. Genital valves prominent. Ventral podosomal setae smooth: 1a 140, 3 a 15, 4 a, from central (unpaired) to most lateral: 110, 98, 87 and 65. Setae ag 35, g1 30, pectinate; g2 15, ps1 10, smooth; ps2 absent.

Legs ( Figs 2 C–J): Leg setal counts, from coxa to tarsus – leg I: 2 (not including 1a), 1, 4, 3, 5, 8 setae+2 solenidia; leg II: 2, 1, 4, 3, 5, 8+2; leg III: 1 (not including 3a), 2, 2, 2, 3, 5+1; leg IV: 1 (not including the multiple 4a), 1, 0, 2, 3, 4+1. Setal lengths: 1b 15, 1 c 20, 2 b 20, smooth; 2c 20, pectinate; 3b 20, 4 b 25, pectinate.

Material examined. Holotype female and 2 paratype females, from Phoenix dactylifera L.( Arecaceae ), Hasik, Oman, G.J. de Moraes; allotype male, same collection data – deposited in the reference collection of Departamento de Entomologia e Acarologia, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Piracicaba-SP, Brazil. A paratype female and a paratype male of Tenuipalpus pareriophyoides from P. dactylifera, En Yahav , Israel, 10-XI-1980, U. Gerson (81/1216), borrowed from ARC-PPRI, Pretroria, South Africa. Photographs of a female and a male identified as Colopalpus eriophyoides from P. dactylifera , Baghdad, Iraq, 18-I-1965, I. Ismail Mohamed; photographs of a female identified as C. eriophyoides from P. dactylifera , 1 mile east of Gholki, Pakistan, 28-X-1972, W.M. Chaudhri.

Etymology. This new species is named after the country where the types were collected, the Sultanate of Oman.

Remarks. This new species can be assigned to the eriophyoides species subgroup ( Meyer 1993) of the caudatus species group ( Baker & Tuttle 1987). The eriophyoides subgroup was characterized by Meyer (1993) as having a pair of intercoxal setae at the level of leg III (IC3a = 3a) and four pairs of intercoxal setae at the level of leg IV (IC4a = 4a). However, one of the two species in the subgroup at the time, Tenuipalpus scitulus Meyer , was originally described in that paper with six to nine 4a setae (eight setae being representative). Tenuipalpus omani n. sp. is most similar to T. eriophyoides Baker, 1948 [according to Chaudhri et al. (1974), senior synonym of Tenuipalpus lapidosus Siddiqui & Chaudhri, 1972 ] from Iraq, T. pareriohyoides Meyer & Gerson, 1980 from Israel and T. yarensis Hasan, Bashir & Wakil 2003 from Pakistan, all collected from P. dactylifera .

The original description of T. eriophyoides was based on a deutonymph, and thus could not be used for comparisons with the species collected in this study; however, based on the redescriptions of Baker & Tuttle (1972), Chaudhri et al. (1974), Meyer & Gerson (1980), Al-Gboory (1987) and Khosrowshahi & Arbabi (1997) as well as on the examination of photographs of females and males collected from Iraq and Pakistan, T. eriophyoides differs from T. omani n. sp. by having the following characteristics: females and males with the dorsal idiosomal setae shorter (except for setae sc2, distinctly longer) and more slender, and trochanter III with a single seta; females with longitudinal striation on the ventral podosoma and transverse striation on ventrigenital plate; males with opisthosoma narrowing only slightly behind leg IV, g1 smooth and only slightly longer than g2, tarsi III and IV with 2 solenidia each. Based on the original description and on the examination of a paratype female and a paratype male, T. pareriophyoides differs from the new species by the following characteristics: females and males with the dorsal idiosomal setae shorter and more slender, genua of legs I–IV with 2, 2, 1, 1 setae; females with broken longitudinal lines between setae 3a–4a, transverse striation on ventrigenital plate; males with transverse striation over most of the venter of the opisthosoma, g1 smooth and about as stout as g2 and tarsi III and IV with 5 (+ 2 solenidia) setae and 3 (+ 2 solenidia) setae, respectively. Based on the original description, T. yarensis differs from the new species by the much shorter c1 and h2 setae, by the aciculate c1, d1 and e1 setae,by the longitudinal striation on the whole venter of the podosoma and by the smooth ventrigenital plate. Some variations have been observed in the number of 4a setae in species of the eriophyoides subgroup. Thus, it would not be surprising if other specimens of the species here described have either 6 or 8 setae of this type. Examination of the types of representative specimens of Tenuipalpus yarensis was not done because they were not available for loan.

The male of T. eriophyoides examined in this study showed the striae laterad of setae g1, g2 and ps1 form an oval structure, which is not clearly shown in the redescriptions provided in the literature ( Baker & Tuttle 1972; Al- Gboory 1987). The male of T. pareriophyoides also have that same pattern as well as seta d3, neither of which shown in the original description; tarsus III of this specimen has 5 setae and 2 solenidia instead of 4 setae and 2 solenidia mentioned in the original description. For both males and females of this species, the numbers of setae on the trochanters are not given in the original description; in the specimens examined in this study, for both sexes those numbers are: 1, 1, 2 and 1, respectively for legs I–IV.

The type specimens of this new species were found in a small plot of date palms, causing no visible damage to the plants. They were the only specimens found in the single sampling conducted in this area. The association of this species with these plants is mainly assumed by what is known about the species taxonomically closest to it.

Figures

FIGURE 1. Tenuipalpus omani n. sp., female. A, Venter of gnathosoma; B, dorsum of idiosoma; C, venter of idiosoma; D, dorsum of leg I; E, venter of leg I; F, dorsum of leg II; G, venter of leg II; H, dorsum of leg III; I, venter of leg III; J, dorsum of leg IV; K, venter of leg IV.

FIGURE 2. Tenuipalpus omani n. sp., male. A, Dorsum of idiosoma; B, venter of idiosoma; C, dorsum of leg I; D, venter of leg I; E, dorsum of leg II; F, venter of leg II; G, dorsum of leg III; H, venter of leg III; I, dorsum of leg IV; J, venter of leg IV.