Eotetranychus carpinicolus, Gotoh & Arabuli, 2019

Gotoh, Tetsuo & Arabuli, Tea, 2019, New species of the genus Eotetranychus (Acari, Prostigmata, Tetranychidae) from Japan, Zootaxa 4555 (1), pp. 1-27 : 10-17

Eotetranychus carpinicolus sp. nov.

[Japanese name: Shide-akehadani]

( Figs 23–43 )

Diagnosis. Dorsocentral setae simple, acicular, much longer than longitudinal intervals between their bases; striation pattern transverse on both genital flap and pregenital area (in willamettei species group as defined by Tuttle et al. (1976)). Peritreme hooked distally. Duplex setae on tarsus I distal and adjacent; tarsus I of female with 5 tactile setae and one solenidion proximal to duplex seta; tibia I of female and male each with 9 tactile setae; tibia II of both sexes with 8 tactile setae and femora IV with 4 setae. Empodia of all legs of both sexes bear small but distinct mediodorsal spurs; male empodium I bifid, each half bearing 3 equally strong digits. Aedeagus almost linear, with dorsal and ventral margins of shaft relatively parallel, shaft bent ventrally at slight angle near tip, with ventrally directed portion short, nearly straight, narrowing to a truncate tip. Egg with a short thin dorsal stipe on its center.

Description. Female (n=7, paratypes). Body greenish yellow. Length of body including gnathosoma 414–473; gnathosoma 80–91 long; width of body 250–301.

Dorsum. Dorsal body setae long, linear, acicular; length of setae: v 2 62 –68; sc 1 102–110; sc 2 73–77; c 1 89–97; c 2 98–102; c 3 83–87; d 1 88–93; d 2 95–102; e 1 86–92; e 2 90–97; f 1 71–80; f 2 65–76; h 1 57–63. Dorsocentral setae long and thin, much longer than distance between their bases, not set on tubercles ( Fig. 23 ). Prodorsum with longitudinal striation; hysterosomal striation transverse medially; oblique and longitudinal laterally ( Fig. 23 ); lobes on dorsal striae square-shaped (truncate), broader than tall ( Figs 23, 24 ).

Gnathosoma. Stylophore rounded anteriorly, with longitudinal striation dorsally; peritreme strongly hooked, with short U-shaped distally ( Fig. 26 ). Terminal sensillum of palptarsus long, about one and one-half times as long as wide, 6.2–7.1 long and 3.8–4.1 wide; dorsal sensillum (solenidion) spindle-shaped, 3.9–5.1 long; eupathidia asymmetrical ul’’ζ longer than ul’ζ, 8.2–9.2 and 5.8–6.9 long, respectively ( Fig. 25 ).

Venter. Genital flap and area immediately anterior with transverse striae, typical of willamettei species group as defined by Tuttle et al. (1976) ( Fig. 27 ).

Legs. Leg I 218–229, leg II 180–192, leg III 174–183; leg IV 207–220 long (from trochanter to tarsus). Length of segments of leg I as follows: femur 71–75, genu 36–40, tibia 39–45, tarsus 68–72 long. Leg setal count as follows ( Figs 29–32 ):

I 2 - 1 - 10 - 5 - 9 + (1) - 14 + (1) + 2 duplexes

II 2 - 1 - 7 - 5 - 8 - 13 + (1) + 1 duplex

III 1 - 1 - 4 - 4 - 6 - 10 + (1)

IV 1 - 1 - 4 - 4 - 7 - 10 + (1)

Tarsus I with 5 tactile setae and 1 solenidion proximal to proximal set of duplex setae; distal duplex solenidion of tarsus I longer than proximal one: 65–70 and 41–45 long, respectively; tactile setae of distal and proximal duplexes equal in length 12–15 ( Fig. 29 ). Tarsus II with 4 tactile setae and 1 solenidion proximal to duplex seta, one tactile seta near level of duplex seta; solenidion of duplex seta 34–37 long and tactile seta 9–11; tibia II with 8 tactile setae ( Fig. 30 ).

Empodia I–IV split into 3 pairs of ventrally directed hairs of equal size and length, with a small but distinct mediodorsal spur ( Figs 28–32 ).

Male (n=7, holotype and 6 paratypes). Body greenish yellow as is female. Length of body including gnathosoma 374 (343–405); gnathosoma 82 (70–88) long; width of body 167 (167–177).

Dorsum. Dorsal body setae simple, acicular, longer than distance between bases of consecutive setae, length of setae: v 2 58 (54–58); sc 1 94 (90–96); sc 2 62 (60–68); c 1 79 (73–80); c 2 87 (82–94); c 3 78 (72–83); d 1 76 (72–79); d 2 87 (83–92); e 1 66 (63–67); e 2 79 (77–83); f 1 54 (51–56); f 2 29 (28–32); h 1 23 (20–23).

Gnathosoma. Peritreme with short recurved hook distally as in female ( Fig. 26 ). Terminal sensillum of palptarsus about two times as long as wide, 3.1 (2.9–3.2) long and 1.6 (1.4–1.7) wide; dorsal sensillum (solenidion) spindle-shaped, 3.8 (3.5–4.1) long; eupathidia asymmetrical ul’’ζ longer than ul’ζ, 6.9 (6.8–7.1) and 4.8 (4.6–5.3) long, respectively ( Fig. 33 ).

Legs. Leg I 224 (208–230); leg II 163 (156–168); leg III 173 (164–177); leg IV 215 (193–215) long (from trochanter to tarsus). Length of first leg segments as follows: femur 71 (65–74); genu 31 (30–35); tibia 37 (35–39); tarsus 60 (57–64) long. Leg setal count as follows ( Figs 35–38 ):

I 2 - 1 - 10 - 5 - 9 + (4) -13 + (3) + 2 duplexes

II 2 - 1 - 7 - 5 - 8 - 13 + (1) + 1 duplex

III 1 - 1 - 4 - 4 - 6 - 10 + (1)

IV 1 - 1 - 4 - 4 - 7 - 10 + (1)

Tarsus I with 4 tactile setae and 3 solenidia proximal to proximal set of duplex setae; distal duplex solenidion of tarsus I longer than the proximal one: 59 (58–62) and 40 (39–42), respectively; tactile setae of distal and proximal duplexes equal in length 11.4 (11–13) ( Fig. 35 ). Tarsus II with 4 tactile setae and 1 solenidion proximal to duplex seta, one tactile seta near level of duplex seta; tarsus II solenidion of duplex seta 35 (35–38) long, tactile seta 10.2 (10–12); tibia II with 8 tactile setae ( Fig. 36 ).

Empodium I bifid with each side bearing 3 equally strong digits, with small mediodorsal spur ( Figs 34, 35 ). Empodia II–IV split into 3 pairs of hairs, with distinct mediodorsal spur as in female ( Figs 36–38 ).

Aedeagus. Aedeagus almost linear, with dorsal and ventral margins of shaft relatively parallel, shaft bent ventrally at slight angle near tip, with ventrally directed portion short, nearly straight, narrowing to a truncate tip ( Figs 39–43 ). Measurements of aedeagus: dorsal margin (shaft/tip) 10.6 (8.4–11.8), ventral margin (shaft/tip) 12.2 (11.7–12.9), width (broadest part of shaft) 3.1 (2.7–3.6).

Etymology. This species is named after the generic name of the host plant, Carpinus .

Type series. Holotype: male (voucher specimen no. 0864), Sekimoto (36°53’N 140°36’E), Kita-ibaraki City, Ibaraki Pref., 16-VIII-2015 (M. Morishita leg.), on Carpinus laxiflora (Siebold et Zuccuccarini) (Betulaceae) . Paratypes: 6 males and 5 females (voucher specimen no. 0864) on C. laxiflora and 2 males and 2 females (voucher specimen no. 0857) on Carpinus cordata Blume , data same as for holotype; 3 males and 11 females (voucher specimen no. 0867), 17-VIII-2017 (M. Morishita & Y. Kitashima leg.), on C. cordata , data same as for holotype.

Remarks. Eotetranychus carpinicolus sp. nov. shares some character states with E. cornicola (in the willamettei species group) which has the following character states—striae on genital flap and pregenital area both transverse; tibiae II–IV with same setal counts; similar general shape of the aedeagus, except the distal bent portion is much shorter in E. carpinicolus sp. nov. than in E. cornicola ; both species have green females.

Eotetranychus carpinicolus sp. nov. shares some character states with E. boreus (in the pallidus species group) which has the following character states—peritreme with short U-shaped tip; striae on genital flap transverse, striae on pregenital area more or less transverse; similar general shape of the aedeagus, except the distal bent portion is much shorter in E. carpinicolus sp. nov. than in E. boreus ; both species have green females.

Eotetranychus carpinicolus sp. nov. closely resembles E. asiaticus (in the sexmaculatus species group) which has the following character states—tibiae II–IV with same setal counts; similar general shape of the aedeagus, except the distal bent portion is much shorter in E. carpinicolus sp. nov. than in E. asiaticus ; both species with green females.

Eotetranychus carpinicolus sp. nov. shares some character states with E. rubricans Ehara, 1999 (in the hicoriae species group), which was recorded from a plant in the same genus, Carpinus tschonoskii Maximowicz , such as: peritreme with short U-shaped hook distally; same leg setal counts; empodia with short but distinct mediodorsal spur. However, they can be separated by the following character states: the shape of the aedeagus shaft more or less linear, bent slightly ventrally, narrowing to a truncate tip in E. carpinicolus sp. nov. ( Figs 39–43 ), versus shaft abruptly bent ventrally distally to form weakly sigmoid, tapering finger-like tip in E. rubricans ( Figs 44, 45 ); genital flap and pregenital area both with transverse striae in E. carpinicolus sp. nov. versus genital flap with transverse striae and pregenital area with longitudinal striae in E. rubricans ; male E. rubricans lacks a terminal sensillum on palp tarsus, while it is well developed (two times as long as wide) in E. carpinicolus sp. nov.; the female body color of E. carpinicolus sp. nov. is greenish-yellow versus red for E. rubricans .

Figures

FIGURES 23–24. Eotetranychus carpinicolus sp. nov., 23. Female (dorsum), 24. Lobes on dorsal striation.

FIGURES 25–29. Eotetranychus carpinicolus sp. nov., female—25. Distal segment of palpus, 26. Peritremes, 27. Genital flap and pregenital area, 28. Empodium I, 29. Leg I, left leg, adaxial view.

FIGURES 30–32. Eotetranychus carpinicolus sp. nov., female—30. Leg II, left leg, adaxial view, 31. Leg III, right leg, adaxial view, 32. Leg IV, right leg, adaxial view.

FIGURES 33–36. Eotetranychus carpinicolus sp. nov., male—33. Distal segment of palpus, 34. Empodium I, 35. Leg I, left leg, adaxial view, 36. Leg II, right leg, adaxial view.

FIGURES 37–45. Eotetranychus carpinicolus sp. nov., male—37. Leg III, right leg, adaxial view, 38. Leg IV, right leg, adaxial view, 39. Aedeagus (holotype), 40–43. Aedeagi (paratypes, four variations), 44–45. Aedeagi of Eotetranychus rubricans.