Eotetranychus linderae Gotoh & Arabuli 2019, sp. nov.

Eotetranychus linderae sp. nov.

[Japanese name: Kuromoji-akehadani]

(Figs 46–66)

Diagnosis. Dorsocentral setae simple, acicular, 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 terminates in a simple expanded bulb. 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 both sexes with 9 tactile setae; tibia II of both sexes with 8 tactile setae and femora IV with 3 setae. Empodia of legs I–IV of female and legs II–IV of male split into three pairs of hairs; empodium I of male bifid, each side with 3 equally strong digits. Aedeagus shaft bent ventrally half way along length, ventrally directed portion linear, more or less parallel sided, with an abrupt narrowing at tip to form short fine finger-like tip. Egg with a short thin dorsal stipe on its center.

Description. Female (n=9, paratypes). Body greenish yellow. Length of body including gnathosoma 347–414; gnathosoma 76–89 long; width of body 194–244.

Dorsum. Dorsal body setae long, linear, acicular; length of setae: v 2 43 –53; sc 1 80–91; sc 2 57–68; c 1 72–78; c 2 75–85; c 3 69–76; d 1 65–75; d 2 76–87; e 1 60–69; e 2 76–81; f 1 60–68; f 2 52–56; h 1 40–45. Dorsocentral setae long and thin, much longer than distance between their bases, not set on tubercles (Fig. 46). Prodorsum with longitudinal striation; hysterosomal striation transverse medially; oblique and longitudinal laterally (Fig. 46); lobes on dorsal striae rounded to truncate, broader than tall (Figs 46, 47).

Gnathosoma. Stylophore rounded anteriorly, with longitudinal striation dorsally; peritreme straight, with simple expanded bulb distally, distal enlargement asymmetrical like a golf-club, varying in size and shape among and between specimens (Fig. 49). Terminal sensillum of palptarsus about two times as long as wide, 6.3–6.8 long and 2.7–3.6 wide; dorsal sensillum (solenidion) spindle-shaped, 4.4–5.6 long; eupathidia asymmetrical ul’’ζ longer than ul’ζ, 6.8–8.1 and 4.8–6.2 long, respectively (Fig. 48).

Venter. Genital flap and pregenital area both with transverse striae, typical of the willamettei species group as defined by Tuttle et al. (1976) (Fig. 50).

Legs. Leg I 178–193, leg II 142–167, leg III 146–168; leg IV 171–189 long (from trochanter to tarsus). Length of segments of leg I as follows: femur 58–65, genu 27–34, tibia 31–37, tarsus 54–62 long. Leg setal counts as follows (Figs 52–55):

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 - 3 - 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: 53–60 and 36–42 long, respectively; tactile setae of distal and proximal duplexes equal in length, 11–14 (Fig. 52). 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 28–34 long and tactile seta 9–11; tibia II with 8 tactile setae (Fig. 53).

Empodia I–IV split into 3 pairs of ventrally directed equal hairs (Figs 51–55).

Male (n=11, holotype and 10 paratypes). Body greenish yellow as female. Length of body including gnathosoma 305 (285–336); gnathosoma 85 (72–86) long; width of body 143 (139–159).

Dorsum. Dorsal body setae acicular, longer than distance between bases of consecutive setae, length of setae: v 2 45 (40–51); sc 1 87 (79–91); sc 2 57 (53–57); c 1 67 (60–75); c 2 73 (66–75); c 3 64 (58–69); d 1 70 (58–71); d 2 75 (64– 75); e 1 52 (49–55); e 2 60 (59–70); f 1 42 (36–43); f 2 33 (26–34); h 1 21 (15–22).

Gnathosoma. Peritreme straight, bulbous distally like in female (Fig. 49). Terminal sensillum (spinneret) of palptarsus about two times as long as wide, 2.8 (2.2–2.9) long and 1.3 (1.2–1.7) wide; dorsal sensillum (solenidion) spindle-shaped, 4.6 (3.5–5.9) long; eupathidia asymmetrical with ul’’ζ longer than ul’ζ, 6.5 (5.6–6.8) and 4.9 (4.1– 5.2) long, respectively (Fig. 56).

Legs. Leg I 197 (177–197); leg II 135 (130–144); leg III 134 (132–158); leg IV 178 (165–179) long (from trochanter to tarsus). Length of first leg segments as follows: femur 56 (47–58); genu 29 (27–30); tibia 32 (31–36); tarsus 53 (50–54) long. Leg setal count as follows (Figs 58–61):

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 - 3 - 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 proximal one: 56 (48–56) and 36 (31–36), respectively; tactile setae of distal and proximal duplexes equal in length, 11.1 (11–13) (Fig. 58). Tarsus II with 4 tactile setae and 1 solenidion proximal to duplex seta, one tactile seta near level of proximal duplex seta; tarsus II solenidion of duplex seta 31 (26–32) long, tactile seta 9 (9–11); tibia II with 8 tactile setae (Fig. 59).

Empodium I bifid with each side bearing 3 short teeth of equal length (Figs 57, 58). Empodia II–IV split into 3 pairs of hairs as in female (Figs 59–61).

Aedeagus. Aedeagus shaft bent ventrally half way along length, ventrally directed portion linear, more or less parallel sided, with an abrupt narrowing of dorsal margin at extreme tip to form short fine, finger-like tip, dorsal margin appearing concave in profile (Figs 62–66). Measurements of aedeagus: dorsal margin (shaft/tip) 15.5 (14.7–16.8), ventral margin (shaft/tip) 15.6 (14.8–16.9), width (broadest part of shaft) 4.6 (3.9–4.9).

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

Type series. Holotype: male (voucher specimen no. 0641), Makabe (36°14’N 140°05’E), Sakuragawa City, Ibaraki Pref., 9-IX-2013 (Y. Kitashima leg.), on Lindera umbellata Thunberg (Lauraceae). Paratypes: 19 males and 22 females (voucher specimen no. 0641), data same as for holotype.

Remarks. Eotetranychus linderae sp. nov. shares the abruptly narrowed aedeagus tip with two other species from Mexico: one is Eotetranychus guaymas (Tuttle, Baker, Abbatiello, 1976) in the willamettei group (Tuttle et al. 1976) and the other is Eotetranychus zempoalensis (Tuttle, Baker & Abbatiello, 1976) in the hicoriae species group (Tuttle et al. 1976). Also, this new species has a similar aedeagus tip to a species from Japan, Eotetranychus toyoshimai Ehara & Gotoh, 2006, in the hicoriae species group (Tuttle et al. 1976). Eotetranychus linderae sp. nov. can be easily distinguished from E. guaymas by the number of tactile setae and solenidia on leg segments of both sexes, and by the overall shape of the aedeagus. Eotetranychus guaymas has tarsus I with 4 tactile setae and 1 solenidion proximal to duplex seta (E. linderae sp. nov. 5 tactile setae and 1 solenidion), tibia I with 8 tactile setae and 1 solenidion (E. linderae sp. nov. 9 tactile setae and 1 solenidion) and tibia II with 7 tactile setae (E. linderae sp. nov. 8 tactile setae) for female; tarsus I with 4 tactile setae and 3 solenidia proximal to duplex seta (E. linderae sp. nov. same), tibia I with 8 tactile setae and 3 solenidia (E. linderae sp. nov. 9 tactile setae and 4 solenidia) and tibia II with 7 tactile setae (E. linderae sp. nov. 8 tactile setae) for male; the aedeagus shaft of E. guaymas is bent at a more acute angle than that of E. linderae sp. nov. The new species E. linderae sp. nov. shares the same setal counts on tarsi I–II and tibiae I–II with E. zempoalensis, i.e. tarsus I with 5 tactile setae and one solenidion proximal to proximal duplex seta, tibia I with 9 tactile setae and one solenidion, tarsus II with 4 tactile setae and one solenidion proximally, tibia II with 8 tactile setae; however, the aedeagus of E. linderae sp. nov. is bent at a more obtuse angle than that of E. zempoalensis, which is bent at almost a right angle. Eotetranychus linderae sp. nov. has transverse striae in pregenital area, while E. toyoshimai has irregular (longitudinal and oblique) striae in this area.

Molecular analyses. Phylogenetic analyses were conducted to clarify the position of the new described species using molecular data. After alignment, the COI fragment had 318 nucleotide sites, of which 103 were parsimony informative sites and contained no insertions or deletions. In the COI tree, the taxonomic status of each newly described species was robustly supported because all three species were independently clustered and clearly separated from other Eotetranychus species and from Schizotetranychus cercidiphylli (Fig. 67, bootstrap values = 100).