Tetranychus canadensis, Pritchard & Baker 1952: 267

Liu, Man, Yi, Tian-Ci, Gulbronson, Connor, Bauchan, Gary R. & Ochoa, Ronald, 2020, Ontogenetic and morphological studies on Tetranychus canadensis (Acari: Tetranychidae), Zootaxa 4857 (1), pp. 215-250 : 221-237

publication ID	https://doi.org/ 10.11646/zootaxa.4857.1.11
publication LSID	lsid:zoobank.org:pub:310E4D42-C8DE-406B-8FEC-37E107ECEA18
DOI	https://doi.org/10.5281/zenodo.4421587
persistent identifier	https://treatment.plazi.org/id/03E987B8-4667-4F36-A0E5-A5F2FF0828F9
treatment provided by	Plazi
scientific name	Tetranychus canadensis, Pritchard & Baker 1952: 267
status	comb. nov.

Treatment

Tetranychus canadensis ( McGregor, 1950) ( Figs 1–35 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 View FIGURE 13 View FIGURE 14 View FIGURE 15 View FIGURE 16 View FIGURE 17 View FIGURE 18 View FIGURE 19 View FIGURE 20 View FIGURE 21 View FIGURE 22 View FIGURE 23 View FIGURE 24 View FIGURE 25 View FIGURE 26 View FIGURE 27 View FIGURE 28 View FIGURE 29 View FIGURE 30 View FIGURE 31 View FIGURE 32 View FIGURE 33 View FIGURE 34 View FIGURE 35 )

Septanychus canadensis, McGregor 1950: 319 View in CoL , original description.

Tetranychus canadensis, Pritchard & Baker 1952: 267 , new combination; Baker & Pritchard, 1953: 221; Pritchard & Baker 1955: 393; Tuttle & Baker 1964: 41; Baker & Tuttle 1994: 289; Seeman & Beard 2011: 24 View Cited Treatment .

Description

Measurements are given based on the specimens ex. Liriodendron tulipifera , from 49 th Place, College Park City, Maryland, U.S.A.

Female (n = 10)

Dorsum ( Figs 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 ). Idiosomal length from v 2 to h 2 380 (317–424), width from c 3 to c 3 282 (244–311). Propodosoma with broadly truncate anterior margin, with longitudinal medial lobed striae anteriorly and posteriorly flanked by a narrow strip of transverse lobed striae ( Fig. 1 View FIGURE 1 ). Prodorsum with three pairs of barbed setae. Length of prodorsal setae: v 2 68 (64–73), sc 1 118 (114–123), sc 2 88 (79–96). Distance between setal bases: v 2 – v 2 67 (60–73), sc 1 – sc 1 78 (72–82), sc 2 – sc 2 193 (169–210).

Hysterosoma with transverse striae between c 1 – f 1, longitudinal between f 1 – f 1 followed by transverse ( Fig. 2 View FIGURE 2 , 3C View FIGURE 3 ), arched ( Figs 3B, D View FIGURE 3 ) or irregular striae ( Fig. 3A View FIGURE 3 ). Length of longitudinal striae between f 1 – f 1 varies among female mites ex. Liriodendron tulipifera (Magnoliaceae) , usually ending at the level of f 2 - f 2 ( Fig 3D View FIGURE 3 ), sometimes not reaching the level of f 2 - f 2 ( Figs 2 View FIGURE 2 , 3B, C View FIGURE 3 ). Dorsal setae on hysterosoma similar to prodorsal setae. Para-anal setae h 2 sub-terminal, h 3 terminal, located ventrally. Length of setae: c 1 108 (101–114), c 2 106 (100–111), c 3 96 (88–103), d 1 106 (91–113), d 2 107 (100–112), e 1 106 (101–110), e 2 106 (98–114), f 1 94 (85–100), f 2 85 (78–98), h 2 33(28–38), h 3 35 (25–40). Distances between setal bases: c 1 – c 1 69 (62–79), c 2 – c 2 143 (129–154), c 3 – c 3 282 (244–311), d 1 – d 1 80 (76–90), d 2 – d 2 107 (100–112), e 1 – e 1 51 (45–56), e 2 – e 2 157 (131–151), f 1 – f 1 51 (45–58), f 2 – f 2 94 (84–113). Three pair of lyrifissures (ia, im, ip) visible.

Venter ( Figs 4–6 View FIGURE 4 View FIGURE 5 View FIGURE 6 ). Ventral striae without lobes, transverse except for pregenital region with longitudinal broken ( Figs 5 View FIGURE 5 , 6A, C, D, E View FIGURE 6 ) or, in other populations, weakly broken or entire striae ( Figs 6B, F View FIGURE 6 ). Genital flap with transverse fine striae. Coxal setal chaetotaxy 2-2-1-1. Three pairs of intercoxal barbed setae 1a, 3a and 4a. Setae 1a 45 (43–47) longer than distance 1a–1a 34 (32–36). Setae 3a 51 (47–53) shorter than distance 3a–3a 69 (66–74). Setae 4a 72 (62–79) as long as distance between 4a–4a 72 (66–78). Two pairs of barbed genital setae (g 1 & g 2), subequal in length, g 1 43 (39–47) and g 2 40 (37–42). Two pairs of anal setae (ps) nude, subequal in length, ps 1 18 (15–20) and ps 2 17 (16–19).

Gnathosoma ( Figs 7–8 View FIGURE 7 View FIGURE 8 ). Stylophore with longitudinal striae only. Peritreme groove hook-like; four or five peritrematal septa visible ( Fig.7A View FIGURE 7 , arrows a, b). Subcapitular setae m smooth, subequal in length [46 (44 – 47)] to distance m–m 48 (46–51). Three pairs of adoral setae (or 1–3) conspicuous, or 1 dorsal, spine-like; or 2 lateral, leaf-like, or 3 ventral, leaf-like. Hole-like rostral fossette visible on ventral subdistal rostrum ( Fig. 7B View FIGURE 7 arrow e).

Palp striate dorsally and ventrally, but membranes between palpal segments punctate ventrally. Dorsal surface of palp base with supracoxal seta (ep), eupathidial form. Setae d PFe and l″ PGe barbed. All three palptibial setae finely barbed; l′ PTi located near base of tibial claw. Tibial claw each side with lateral hole ( Fig. 7B View FIGURE 7 , arrows c) and lateral spur ( Fig. 7B View FIGURE 7 , arrows d). Terminal eupathidium (suζ) sub-conical, 6.7 (6.0–7.0) long and 3.6 (3.1–3.8) in diameter at widest level. Two lateral eupathidia (ul′ζ and ul″ζ) subequal in length, ul′ζ 6.9 (6.5–7.4), ul″ ζ 7.3 (7.1– 7.6). Solenidion (ω) 4.6 (4.3–5.0) long, about twice as long as wide 1.7 (1.5–1.8). Three normal setae (a, b, c) nude ( Figs 8A, B View FIGURE 8 ).

Legs ( Figs 9 View FIGURE 9 , 10 View FIGURE 10 ). Coxa I dorsally with a supracoxal seta (el), eupathidial form ( Fig. 7A View FIGURE 7 ). Claws of I–IV pad like, each with a dorsal spur ( Fig. 9A View FIGURE 9 , arrow a) and a pair of tenet hairs. Empodia I–IV each with a small dorsal spur and three pairs of proximoventral hairs ( Figs 9 View FIGURE 9 A–D, arrows b–e). Tarsus I with two pairs of duplex setae; tarsus II with one pair of duplex setae; tarsus III and IV each with a solenidion. Dorsal seta on tibia I (db) with trichobothridial aspect ( Fig. 10A View FIGURE 10 ).

Male (n =10)

Dorsum ( Figs 11–13 View FIGURE 11 View FIGURE 12 View FIGURE 13 ). Length of idiosoma (v 2 – h 2) 202 (190–217); width of idiosoma (c 3 – c 3) 151 (134–160). Prodorsal striae longitudinal, with lobes; hysterosomal striae transverse, without lobes. Shape of dorsal setae as in female, h 2 dorsal, h 3 laterodorsal ( Figs 13 View FIGURE 13 & 14A View FIGURE 14 ). Length of setae: v 2 51 (46–56), sc 1 91 (82–101), sc 2 65 (54–75), c 1 77 (69–85), c 2 77 (67–85), c 3 71 (63–78), d 1 75 (69–80), d 2 76 (66–91), e 1 72 (67–78), e 2 74 (66–81), f 1 59 (52–63), h 2 19 (16–23), h 3 15 (13–17). Distances between setal bases: v 2 – v 2 51 (46–56), sc 1 – sc 1 61 (54–65), sc 2 – sc 2 121 (110–129), c 1 – c 1 54 (49–59), c 2 – c 2 94 (80–97), c 3 – c 3 151 (134–160), d 1 – d 1 53 (47–56), d 2 – d 2 101 (93–107), e 1 – e 1 31 (27–33), e 2 – e 2 76 (67–83), f 1 – f 1 30 (24–34), f 2 – f 2 46 (41–50).

Venter. Ventral striate including pregenital region transverse, without lobes; ventral setae barbed excepting smooth ps 1 and ps 2 ( Fig. 14A View FIGURE 14 ): 1a 35 (30–39), 3a 37 (33–41), 4a 50 (45–55), ag 41 (33–47), g 1 16 (14–17), g 2 14 (14–15), ps 1 9 (8–10), ps 2 9 (8–10). Distances between setal bases: 1a–1a 23 (21–26), 3a–3a 45 (40–49), 4a–4a 49 (41–67).

Gnathosoma ( Figs 14B View FIGURE 14 , 15A, B View FIGURE 15 , 16 View FIGURE 16 ). Peritreme groove hook-like ( Figs 15A View FIGURE 15 , 16A View FIGURE 16 ); sometimes hook bifurcate ( Fig. 15A View FIGURE 15 ). Subcapitular setae m smooth, length 36 (30 – 41) subequal with distance m–m 36 (34–41). Three pairs of adoral setae (or 1–3) conspicuous, or 1 dorsal, spine-like; or 2 lateral, leaf-like, or 3 ventral, leaf-like.

Palp ( Figs 14B View FIGURE 14 , 15A View FIGURE 15 ). Supracoxal seta (ep) eupathidial form. Seta d PFe peg-like. Palpal tarsus with coneshaped spinneret (suζ) slightly thinner than female, 5.8 (5.4–6.5) in length, 2.1 (1.9–2.2) in diameter at base; single solenidion 4.4 (4–4.7) in length and 1.4 (1.3–1.5) width; two eupathidia, ul′ζ 5.5 (5.1–5.9), ul″ζ 6.5 (5.7–7.2) and three normal setae (a, b, c).

Legs ( Figs 17–18 View FIGURE 17 View FIGURE 18 ). Coxa I dorsally with a supracoxal seta (el), eupathidial form ( Figs 15A, C View FIGURE 15 ). Empodium I with one dorsal spur and two pairs of ventral spurs. Empodia II–IV with one dorsal spur and three pairs of proximoventral hairs. Tarsus I with two pairs of duplex setae ( Fig. 17A View FIGURE 17 ) and tarsus II with one pair of duplex setae; tarsus III and IV each with one solenidion. Dorsal seta on tibia I, a trichobothrium, with cup shaped base and broken striae on inner integument ( Fig. 17B View FIGURE 17 ).

Aedeagus ( Figs. 19–21 View FIGURE 19 View FIGURE 20 View FIGURE 21 ). Dorsal margin of knob of aedeagus convex, anterior projection shorter than posterior.

A thin, long ejaculatory duct connecting aedeagus to a cup-shaped seminal vesicle.

Deutonymph (n =5)

Dorsum ( Fig.22 View FIGURE 22 ). Length of idiosoma (v 2 – h 2) 259 (240–277); width of idiosoma (c 3 – c 3) 204 (198–214). Prodorsal striae longitudinal and without lobes, posteriorly flanked by a narrow strip of transverse lobed striae or smooth striae; Hysterosoma with transverse striae between c 1 – e 1, arched between f 1 – f 1 following by transverse striae. Hysterosomal striae smooth except for lobed striae between c 1 – c 1. Length of setae: v 2 54 (50–57), sc 1 98 (96–100), sc 2 69 (66–73), c 1 81 (66–92), c 2 82 (75–86), c 3 57 (69–81), d 1 84 (81–87), d 2 88 (85–89), e 1 83 (79–87), e 2 81 (79–83), f 1 70 (64–74), f 2 57 (55–59), h 2 29 (28–30), h 3 25 (24–27). Distances between setal bases: v 2 – v 2 56 (54–58), sc 1 – sc 1 67 (65–69), sc 2 – sc 2 159 (152–164), c 1 – c 1 61 (58–62), c 2 – c 2 118 (114–122), c 3 – c 3 204 (198–214), d 1 – d 1 68 (65–73), d 2 – d 2 142 (137–148), e 1 – e 1 40 (38–43), e 2 – e 2 110 (104–121), f 1 – f 1 32 (29–35), f 2 – f 2 64 (61–69).

Venter ( Fig. 23 View FIGURE 23 ). Most ventral striae transverse except for pregenital region with longitudinal entire striae. Ventral setae: 1a 34 (34–35), 3a 38 (37–39), 4a 45 (38–52), ag 54 (53–56), g 1 25 (23–29), ps 1 14 (13–15), ps 2 14 (13–15). Distances between setal bases: 1a–1a 23 (21–26), 3a–3a 52 (47–55), 4a–4a 52 (50–55), ag–ag 46 (46– 47).

Gnathosoma ( Figs. 24C, D View FIGURE 24 ). Subcapitular setae m length 36 (33–39) slightly shorter than distance m -m 39 (35–43). Spinneret (suζ) 5.8 (5.5–6.1) in length and 2.2 (2–2.4) in diameter; single solenidion 4.4 (4–4.8) in length and 1.5 (1.4–1.5) in diameter, and two eupathidia ul′ζ 5.7 (5.2–6.1), ul″ζ 6.5 (6.4–6.5).

Legs ( Fig. 25 View FIGURE 25 ). Coxa I dorsally with a supracoxal seta (el), eupathidial form. Claws of I–IV pad-like, each with a dorsal spur and a pair of tenet hairs. Empodia I–IV each with a small dorsal spur and three pairs of proximoventral hairs. Tarsus I with two pairs of duplex setae; tarsus II with one pair of duplex setae; tarsus III with a solenidion and tarsus IV without solenidion.

Protonymph (n=2)

Dorsum ( Fig. 26 View FIGURE 26 ). Length of idiosoma (v 2 – h 2) 184 (183–184); width of idiosoma (c 3 – c 3) 170 (165–174). Prodorsal striae longitudinal and without lobes, posteriorly flanked by a narrow strip of transverse striae. Hysterosoma with transverse striae. Length of setae: v 2 51 (49–53), sc 1 81 (80–82), sc 2 58 (57–58), c 1 70 (68–71), c 2 63 (61–65), c 3 60 (57–62), d 1 62 (57–66), d 2 67 (65–69), e 1 59 (58–59), e 2 65 (61–69), f 1 56 (55–56), f 2 47 (44–49), h 2 22 (20–24), h 3 22 (21–22). Distances between setal bases: v 2 – v 2 51 (50–52), sc 1 – sc 1 63 (62–64), sc 2 – sc 2 126 (115–137), c 1 – c 1 58 (57–59), c 2 – c 2 110 (109–111), c 3 – c 3 170 (165–174), d 1 – d 1 60 (58–62), d 2 – d 2 123 (118–128), e 1 – e 1 35 (34–35), e 2 – e 2 84 (82–85), f 1 – f 1 20 (18–21), f 2 – f 2 42 (41–42).

Venter ( Fig. 27 View FIGURE 27 ). Venter with transverse striae except for pregenital region with longitudinal entire striae. Ventral setae: 1a 30 (29–30), 3a 35 (32–38), ps 1 12 (11–12), ps 2 13 (12–13). Distances between setal bases: 1a–1a 27 (26–28), 3a–3a 48 (47–49).

Gnathosoma ( Figs. 28 View FIGURE 28 , 29 View FIGURE 29 ). Subcapitular setae m length 30 (29–31) subequal to distance m -m 32 (31–33). Spinneret (suζ) 4.6 (4.5–4.6) in length and 1.9 (1.8–2.0) in diameter; single solenidion 3.9 (3.8–4.0) in length and 1.3 (1.2–1.3) in diameter, and two eupathidia ul′ζ, 4.5 (4.4–4.6), ul″ζ 5.7 (5.6–5.7).

Legs ( Fig. 30 View FIGURE 30 ). Claws of I–IV pad like, each with a dorsal spur and a pair of tenet hairs. Empodia I–IV each with a small dorsal spur and three pairs of proximoventral hairs. Tarsus I with two pairs of duplex setae; tarsus II with on pair of duplex setae; tarsus III and IV without solenidion.

Larva (n = 5)

Dorsum ( Figs 31 View FIGURE 31 , 32A, B View FIGURE 32 ). Length of idiosoma (v 2 – h 2) 140 (127–157); width of idiosoma (c 3 – c 3) 147 (133–157). Doral striae and shape of dorsal setae similar to that of protonymph. Length of setae: v 2 46 (38–55), sc 1 68 (67–68), sc 2 56 (45–70), c 1 51 (50–53), c 2 48 (47–49), c 3 47 (45–51), d 1 48 (47–51), d 2 48 (47–49), e 1 45 (41–47), e 2 45 (43–48), f 1 41 (41–41), f 2 35 (33–38), h 2 22 (18–24), h 3 22 (21–25). Distances between setal bases: v 2 – v 2 41 (37–44), sc 1 – sc 1 56 (53–61), sc 2 – sc 2 99 (89–108), c 1 – c 1 45 (43–50), c 2 – c 2 87 (77–93), c 3 – c 3 147 (133–157), d 1 – d 1 42 (39–46), d 2 – d 2 95 (84–102), e 1 – e 1 24 (28–31), e 2 – e 2 67 (57–75), f 1 – f 1 12 (10–13), f 2 – f 2 37(33–41).

Venter ( Fig. 32C View FIGURE 32 ). Ventral striae entirely transverse. Ventral setae: 1a 30 (28–32), 3a 26 (26–27), ps 1 12 (12–13), ps 2 12 (12–13). Distances between setal bases: 1a–1a 26 (26–27), 3a–3a 34 (31–36).

Gnathosoma ( Figs. 33B, C View FIGURE 33 ). Spinneret (suζ) 5.4 (4.9–5.8) in length and 1.4 (1.4–1.4) in diameter; single solenidion 3.9 (3.7–4.2) in length and 1.2 (1.1–1.3) in diameter, and two eupathidia ul′ζ 4.2 (3.9–4.5), ul″ζ acuminate, 5.0 (4.6–5.7).

Legs ( Fig. 34 View FIGURE 34 ). Claws of I–IV pad-like, each with a dorsal spur and a pair of tenet hairs. Empodia I–IV each with a small dorsal spur and three pairs of proximoventral hairs. Tarsus I and II each with one pair of duplex setae; tarsus III and IV without solenidion.

Ontogenetic development of leg setae

Larva. Setae counts: femora, 3-3-2; genua, 4-4-2; tibiae, 5(1 ω)-5-5; tarsi, 6(1 ω)(2 ζ)-6(1 ω)(2 ζ)-6. Trochanters I–III nude, without seta. Femora I–II with three setae (d, v′, bv″), one dorsal and two ventral, respectively, and femur III with two setae (d, ev′). Genua I–II with four setae (l′, l″, v′, v″) respectively, and genu III with two setae (l′, v′). Tibiae I–III with five tactile setae (d, l′, l″, v′, v″), tibia I with solenidion (φ). Tarsus I with six tactile setae, unguinals (u′, u″), primiventrals (pv′, pv″) and fastigials (ft′, ft″), one solenidion (ω″), two eupathidial prorals (p′ζ, p″ζ). One fastigianl ft″ and solenidion (ω″) forming duplex setae.

Protonymph. A total of seven setae added on leg I–III in protonymph— tc′, tc′′ and v′ 1 on tarsus I, tc′ and tc′′ on tarsus II and III. Leg IV with a total 16 tactile setae: femur with 2, genu 2, tibia 5 and tarsus 6. Setal counts: femora, 3-3-2-2; genua, 4-4-2-2; tibiae, 5(1 ω)-5-5-5; tarsi, 8(2 ω)(3 ζ)-7(1 ω)(2 ζ)-6-6.

Deutonymph. A total of 20 setae and solenidia added on leg I–IV in deutonymph— v′ on trochanters I–III; l′, l″, v″ on femur I; d on genua I–IV; l′ 1, l″ 1 on tibia I; l′ 1, l″ 1, v″ 1, ω″ 1 on tarsus I; v′ 1 on tarsus II; ω′ on tarsus III; tc′, tc″ on tarsus IV. Setal counts: trochanters, 1-1-1-0, femora, 6-3-2-2; genua, 5-5-3-3; tibiae, 7(1 ω)-5-5-5; tarsi, 11(3 ω)(3 ζ)- 8(1 ω)(2 ζ)-6(1 ω)-6.

Female. A total of 28 tactile setae and two solenidia added on legs I–IV— l′ 1, l″ 1, v′ 1, v″ 1 on femur I; v′ 1, v″ 1 on tibia I; v′ 2 on tarsus I; l′ 1, l″ 1, v″ 1 on femur II; v′ 1, l′ 1 on tibia II, l′ 1, v″ 1, v′ 2 and one solenidia on tarsus II; l′ 1, v′ on femur III; v″ on genu III; v″ 1 on tibia III; v′ 1 on tarsus III; v′ on trochanter IV; l′ 1, v′ on femur IV; v″ on genu IV; l″ 1, v′ 1 on tibia IV; v′ 1, v″ 1 and one solenidia on tarsus IV. Setal counts: trochanters, 1-1-1-0, femora, 10-6-4-4; genua, 5-5-4-4; tibiae, 9(1 ω)-7-6-7; tarsi, 12(3 ω)(3 ζ)-11(1 ω)(2 ζ)-9(1 ω)-10(1 ω).

Male. A total of 28 tactile setae and seven solenidia added on legs I–IV— l′ 1, l″ 1, v′ 1, v″ 1 on femur I; v′ 1, v″ 1 and three solenidia on tibia I; v′ 2 and two solenidia on tarsus I; l′ 1, l″ 1, v″ 1 on femur II; l′ 1, v′ 1 on tibia II, l′ 1, v″ 1, v′ 2 and one solenidia on tarsus II; l′ 1, v′ on femur III; v″ on genu III; v″ 1 on tibia III; v″ 1 on tarsus III; v′ on trochanter IV; l′ 1, v′ on femur IV; v″ on genu IV; l″ 1, v′ 1 on tiba III; v′ 1, v″ 1 and one solenidia on tarsus IV. The male of spider mites has extra solenidia normally on tarsus I and tibia I and rarely in femora I and II, genua I and II (Zhang & Jacobson 2010; Yi & Ochoa 2018). In T. canadensis , two extra solenidia added on tarsus I and two or three on tibia I. Setal counts: trochanters, 1-1-1-0, femora, 10-6-4-4; genua, 5-5-4-4; tibiae, 9(3-4 ω)-7-6-7; tarsi, 12(5 ω)(3 ζ)-11(1 ω)(2 ζ)-9(1 ω)- 10(1 ω).