Oligonychus neotylus, Zeity & Srinivasa & Gowda, 2016

Zeity, Mahran, Srinivasa, N. & Gowda, C. Chinnamade, 2016, New species, new records and re-description of spider mites (Acari: Tetranychidae) from India, Zootaxa 4085 (3) : -

Oligonychus neotylus sp. nov. Zeity & Srinivasa

( Figs. 1–11 )

General diagnosis. Based on Pritchard and Baker (1955), this new species belongs to the pratensis group defined by the aedeagus bent dorsad, and females with tibia I with nine tactile setae, tarsus I with two tactile setae on the venter at or just beyond the distal set of duplex setae, longitudinal striae between setae f1; they inhabit the under surface of monocotyledonous host plants. The species is defined by having: pre-genital striae longitudinal; striae transverse on posterior part of genital area, longitudinal anteriorly between g1. Peritreme ends in simple elongate bulb. Knob of aedeagus similar to bird’s head with beak.

Description. Male. Holotype. Near grayish in color.

Gnathosoma. Terminal sensillum of palpus (3.9–4.3µm) twice as long as broad; dorsal sensillum (3.8–4.0µm) fusiform, smaller than terminal sensillum (spinneret). Peritreme ends in simple elongated bulb.

Dorsum. Idiosoma length 390 µm (including gnathosoma), range 388–391 µm (2 paratypes properly mounted and measured). Idiosomal setae slightly barbed, longer than distance between their bases. Measurements of dorsal setae (3 males measured): v2 50 (48–51), sc1 99 (95–100), sc2 61 (60–65), c1 89 (88–95), c2 90 (88–98), c3 85 (81–87), d1 95 (91–96), d2 90 (88–94), e1 77 (75–80), e2 85 (81–87), f1 53 (50–57), f2 45 (40–45), h1 25(21–26).

Aedeagus. Aedeagal shaft broad at base, narrowing and bent dorsad. Aedeagal knob similar to bird’s head with beak. Posterior projection long and tapering, anterior projection short and acute; dorsal margin of knob round to acute. Aedeagus measurements for holotype: a-7.87–8.10, b-12.59–13.2, c-7.30–7.55, d-28.2–29.8, length of knob 3.26–3.55 ( Fig. 7a ).

Legs. Number of tactile setae and solenidia (in parenthesis) on leg I–IV: I 2 – 1 – 10– 5– 9 + (4) – 13 + (3) + 2 duplex

II 2 – 1 – 6 – 5 – 7 – 13 + (1) + 1 duplex

III 1 – 1 – 4 – 4 – 6 – 9 + (1)

IV 1 – 1 – 4 – 4 – 7 – 9 (or 10) + (1)

Tarsus I with 4 tactile setae and 2 solenidia proximal to proximal duplex setae, 1 solenidion level with proximal duplex setae. Tarsus II with 3 tactile setae and 1 solenidion proximal to duplex setae. Tarsus I with proximoventral hairs fused, forming ventral spur.

Female. Near grayish in color.

Gnathosoma. Terminal sensillum (spinneret) pointed (4.9–5.2µm), twice as long as broad, dorsal sensillum short and fusiform (3.9–4.1µm). Peritreme ends in simple elongated bulb.

Dorsum. Body length with gnathosoma 475–500 µm, width 292–312 µm. Idiosomal setae slightly barbed, longer than distance between their bases, striae between dorsocentral setae (c1, d1 and e1) transverse, longitudinal between f1. Measurements of dorsal setae: v2 63 –76, sc1 104–120, sc2 80–86, c1 87–100, c2 93–108, c3 84–99, d1 83–97, d2 94–100, e1 81–96, e2 94–100, f1 77–88, f2 73–85, h1 44–46, distance between dorsal setae v2 -h1 346– 352, v2-v2 63 –68, sc1–sc1 88–94, sc2-sc2 210–214, c1-c1 71–72, c2-c2 166–170, c3-c3 290–299, d1-d1 77–80, d2-d2 181–190, e1- e1 50–55, e2-e2 146–147, f1-f1 40–49, f2-f2 88–93, h1-h 1 28–35.

Venter. Genital flap with transverse striae posteriorly, oblique striae anteriorly. Pre-genital area with entire longitudinal striae. Measurments of ventral setae, 1a 45–48, 1b 56–60, 1c 62–63, 2b 85–83, 2c 62–68, 3a 54–55, 3b 55–58, 4a 52–56, 4b 66–67, ag 66–68, g1 43–47, g2 44–45, ps 1 26–28, ps 2 26–27.

Legs. Number of tactile setae and solenidia (in parentheses) on legs I–IV:

I 2 − 1 − 10 − 5 − 9 + (1–2) – 13 + (1–3) + 2 duplexes

II 2 − 1 – 6 – 5 – 7 – 12 (13) + (1) + 1 duplex

III 1 − 1 − 4 − 4 – 6 – 9 + (1)

IV 1 − 1 − 4 − 4 – 7 – 9 (10) + (1)

Tarsus I with 4 tactile setae and 1 solenidion proximad to proximal duplex setae. Tarsus II with 3 tactile setae and 1 solenidion proximad to duplex setae. The number of tactile setae and solenidia on tibia and tarsus I & II showed asymmetrical variations.

Type material. Holotype one male, from Zea mays, Narendra, Dharwad, south India, (N15o30 ' 17.4''; 74o 85 ' 22''; elevation 688 m), September 2015, coll. Mahran Zeity. Paratypes, 3 males and 8 females, data same as for holotype ( AINP 1337).

Other material examined: Eight females and seven males from Zea mays, Doddaballapur, south India (N 13o17 ' 94''; E 77o 32 ' 88''; elevation 895 m) October 2013, coll. Mahran Zeity ( AINP1354 ) ; three males, from Pennisetum purpureum , GKVK campus, Bangalore (N 13o 04 ' 27''; E 77o 34 ' 43''; elevation 940 m) November 2014, coll. Mahran Zeity ( AINP1660 ) .

All type material deposited in AINP Agricultural Acarology collection , UAS Bangalore , India .

Etymology. Named after Oligonychus tylus Baker & Pritchard, 1960 , being the nearest species.

Remarks. This species resembles O. tylus in having a relatively small aedeagal knob, but it differs in having a small anterior projection and much longer posterior projection, while in O. tylus the anterior projection is absent and the posterior projection is minute. Like Oligonychus tylus , the new species is not monophagous. Oligonychus tylus is known from Panicum maximum, Sorghum and an unidentified wild grass ( Poaceae ), and also Phoenix dactylifera ( Arecaceae ) ( Baker & Pritchard 1960; Gerson et al., 1983; Sirsikar & Nagabhusanam 1986).

Figures

FIGURES 1 – 7. Oligonychus neotylus sp. nov. (1) Dorsal view of female; (2) Peritreme; (3) Dorsal striae between f 1 - f 1; (4) Palp tarsus of female; (5) Palp tarsus of male; (6) Genital area of female; (7 a) Male aedeagus; (7 b) male aedeagus of Oligonychus tylus (from Baker and Pritchard 1960).

FIGURES 8 – 11. Oligonychus neotylus sp. nov. Legs (8) Tibia and tarsus I of female (9) Tibia and tarsus II of female (10) Tibia and tarsus I of male (11) Tibia and tarsus II of male.