Tetranychus Dufour, 1832

Genus Tetranychus Dufour, 1832 View in CoL View at ENA

Type species: Tetranychus lintearius Dufour 1832 , by original designation.

Tetranychus merganser Boudreaux, 1954 View in CoL Diagnosis: Male: Empodia of leg I-IV with free proximoventral hair, appearing tri digitate with prominent mediodorsal spur. Tarsus I bears 5 tactile setae and 2 solenidia proximal to the proximal duplex setae. Palpfemur setae d PFe clavate with sparsely barbed. Aedeagal knob lacking anterior projection, posterior projection with a pointed tip which forms an angle of 40 o with the shaft, the dorsal margin of knob convex. Female: Striation pattern between setae e1-f1 forming a diamond-shaped pattern. Striation in the pregenital region is longitudinal, oblique and continuous. Peritreme hook length 30 (26−34). Tarsus I with 4 setae positioned behind proximal duplex setae. Empodia of each leg split into 6 proximoventral hairs with prominent dorsomedian spurs. Spinneret length and width are almost the same 6 (5–7) x 5 (4–6).

Material Examined: 12 male (Acarol. lab/ BCKV /3026−38/23) and 12 females (Acarol. lab/ BCKV /3036−3047/23), Areca catechu (LINN.) ( Arecaceae ) from Ramnagar (21° 40’ 36’’ N 87° 31’ 14’’ E with elevation of 4m asl), Purba Medinipur, West Bengal, India 27 September 2023, coll. Subhra Samanta.

Female ( Figures 1-9 View Figures 1-9 ): Dorsum ( Figure 1 View Figures 1-9 ): Length of the idiosoma from v2 to h2 340−371, width at the level of c setae 278−313, Propodosomal striae forming U-pattern. Hysterosomal striation pattern transverse medially and longitudinal posteriorly, between e1−e1 and f1−f1 striation pattern longitudinal or oblique, striation pattern between dorsocentral setae e1-f1 forming a diamond-shaped pattern. Dorsal idiosoma with a total of 14 pairs of long setae, three pairs of prodorsal setae (v 2, sc 1, sc 2) and 11 pairs of dorsal opisthosomal setae (c1-3, d1-2, e1-2, f1- 2, h2-3). Length of dorsal setae: v2 73−93, sc1 142−167, sc2 110−135; c1 120−145, c2 117−136, c3 124−142, d1 121−142, d2 126−137, e1 115−128, e 2 121−140, f1 97−114, f2 74−85, h2 46−56, h3 34−45. Distance between dorsal setae: v2−v2 76 −85, v2−sc1 17−25, sc1 – sc2 60−72, sc1− sc1 78−93, sc2−sc2 209−230, c1−c1 62−80, c1−c2 41−55, c2−c3 67−80, c2−c2 156−180, c3−c3 275−290, d1−d1 88 −106, d1−d2 61−76, d2−d2 207−230, c1−d1 35−50, c3−d2 49−60, e1 − e1 39−50, e1−e2 61−75, e2−d2 45−56, e2−e2 139−158, f1−f1 35−44, f2−f2 69−80, f1−f2 42−53, f1−d1 97−109, h2−h2 24−34, h3−h3 98−109. Venter ( Figures 2 View Figures 1-9 , 32 View Figures 30-36 ): Ventral setae slender, smooth. Lengths- 1a 42−55, 1b 59−69, 1c 56−66, 2b 70−88, 2c 91−110, 3a 56−67, 3b 67−79, 4a 64−77, 4b 65−75, ag 58−70, g1 27−38, g2 35−44, ps1 11−19, ps2 14−22. The striation pattern between the intercoxal region is simple and transverse; striation in the pregenital region is longitudinal, oblique, and continuous. Distance between intercoxal setae- 1a −1a 33−41, 3a−3a 66−84, 4a−4a 61−73, ag−ag 71−81, g1−g1 28−40, g2−g2 91−103, g1−g2 34−45, ps1−ps1 5−7, ps2−ps2 5−6. Gnathosoma ( Figures 3, 4 View Figures 1-9 ): Stylophore rounded, with only longitudinal striation. Peritreme distally hooked, hook length 26−34; palpfemur, palpgenu with one setae only, palpfemur d PFe 47−55, palpgenu l’’ PGe 39−50, palptibia with three setae and d PTi 22−28, l’ PTi 7−11, l” PTi 8−11 and a claw; palptarsus (length 9−15, wide 8−12) with three setae a 8−10, b 8−10, c 9−11; 1 spinneret suζ length 5−7 width 4−6; 1 solenidion ω 4−6; two eupathidia ul’ζ 7−9, ul”ζ 8−10. Spinneret length is slightly shorter than two eupathidia. The ratio of length and width of the palptarsus is equal. Ventral infracapitulum bears subcapitular setae m 45-48 long, distance between m–m 62-66. Leg ( Figures 5-9 View Figures 1-9 ): Leg I length 352−381, leg II length 252−279, leg III length 275−300, leg IV length 331−359, (from trochanter to tarsus). Setal pattern on leg I–IV coxa 2−2−1−1, trochanter 1−1−1−1, femur 10−6−4−4, genu 5−5−4−4, tibia 9 (1) −7−6−7, tarsus 13(1) +2 duplex setae- 13(1) + 1 duplex setae−9 (1) − 10 (1). Tarsi I with 10 tactile setae, 3 eupathidia, 1 solenidion and 2 sets of proximal duplex setae, 3 tactile setae and 1 solenidion proximal to proximal duplex setae; tarsi II with 10 tactile setae, 3 eupathidia, 1 solenidion, 1 set of duplex setae, 3 tactile setae and 1 solenidion proximal to the duplex setae; tarsi III having 9 tactile setae and 1 solenidion and IV with 10 tactile setae and 1 solenidion. Empodia of leg I–IV each with a dorsal spur and split into 3 pairs of proximoventral hairs.

Male: Aedeagus ( Figures. 16 View Figures 10-16 , 31 View Figures 30-36 ): Aedeagal knob with anterior projection absent, posterior projection with a pointed tip, dorsal margin of knob convex, main shaft maximum length 7 (5−7), maximum width 5 (4−5), maximum neck length 2 (1−2), neck width 1 (0.5−1), head length 2 (2−3), axis of the head forming angle with the shaft, 400. Leg ( Figures 11–15 View Figures 10-16 , 30 View Figures 30-36 ): Leg I length 278 (262−295), leg II length 226 (211−239), leg III length 216 (204−230), leg IV length 252 (239−265), (from trochanter to tarsus). Setal pattern on leg I–IV coxa 2−2−1−1, trochanter 1−1−1−1, femur 10−6−4−4, genu 5−5−4−4, tibia 9 (1) −7−6−7, tarsus 13(3) +2 duplex setae- 13(1) + 1 duplex setae−9 (1) − 10 (1). Tarsus I with 10 tactile setae, 3 solenidia, 3 eupathidia, and 2 sets of duplex setae. Tibiae I with 4 solenidia 9 tactile setae. Tarsus II with 10 tactile setae, 1 solenidion, 3 eupathidia, and 1 set of duplex setae. Tibiae II with 7 tactile setae. Empodia split with a prominent spur. Tarsus I has 5 tactile setae and 2 solenidia proximal to the proximal duplex setae. In tarsus II 4 tactile setae 1 solenidion adjacent to the duplex setae. Gnathosoma ( Figure 10 View Figures 10-16 ): Peritreme as in female but slightly smaller, long. Palpal setation from femur to tibiae d PFe 9 (8−10), l’’ PGe 24 (21−27), d PTi 14 (13−15), l’ PTi 10 (8−11), l” PTi 11 (10−13). Palpfemur setae d PFe modified into a clavate with a sparsely barbed structure. palptarsus length 13 (11−15), wide 12 (10−13); palptarsus with 3 setae a 8 (7−9), b 8(7−9), c 9 (8−10), 1 spinneret su ζ (length 5 (4−6), wide 2 (1−2), 1 solenidion 4 (3−5) and 2 eupathidion ul’ζ 4 (3−5), ul”ζ 3 (2−3). Spinneret length and width ratio 2:1. Ventral infracapitulum bears subcapitular setae m 46 (45−47) distance m–m 47 (46− 48).

Remarks: This species was described by Boudreaux, 1954 from the United States,on Ligustrum sp. We have identified the species as Tetranychus merganser Boudreaux, 1954 by comparing the structure of the aedeagus, tarsus of leg I and II mainly the number of setae proximal to the proximal duplex setae, and the length and width of the idiosoma. We have redescribed the species with proper measurements.

Tetranychus megauncinatus Feres and Flechtmann, 1986 View in CoL

Diagonosis: Female: Dorsum of the propodosoma set with longitudinal striation with semicircular lobe. Hysterosomal striation between setae e1−f1 forms a diamond-shaped pattern. Striation in the intercoxal region transverse; pregenital striae oblique, longitudinal, sparse medially. Peretreme hooked distally, hook length 50 (45−60). Palptarsus length and width are almost equal. Spinneret is slightly shorter than two eupathidia. Empodia has 6 proximoventral hairs and a prominent spur. Tarsus I has 3 tactile setae and one solenidion proximal to proximal duplex setae. Male: Tarsus I has 3 solenidia whereas tarsus II has 1 solenidion. Empodia split with a prominent spur. Palptarsus length and width are almost equal. Palpfemur setae d PFe modified into a peg-like structure. Spinneret suζ length is twice than width. Posterior projection of the aedeagus knob absent, anterior projection of the knob with a blunt tip, dorsal margin of knob rounded. Axis of the head of the knob forms an angle with the shaft 600.

Material Examined: 14 females (Acarol. lab/ BCKV /4123−37/23) 10 males (Acarol. lab/ BCKV /4138−48/23) collected from Cucumis sativus L. ( Cucurbitaceae ) Block Seed Farm, BCKV, Kalyani (22° 58’ 30.3024’’ N, 88° 26’ 4.2324’’ E) Nadia, West Bengal, 18 th September, coll. Subhra Samanta.

Female: Dorsum ( Figure 17 View Figures 17-25 ): Length of the idiosoma from v2 to h1 415−454, width at the level of c setae 305−336 Propodosomal striae forming U-pattern. Hysterosomal striation transverse medially and longitudinal posteriorly, between e1−e1 and f1−f1 striation pattern longitudinal or oblique, striation between setae e1-f1 forming a diamond-shaped pattern. Length of dorsal setae: v2 50−60, sc1 64−74, sc2 120−140; c1 115−135, c2 105−125, c3 90−100, d1 108−132, d2 112−132, e1 110−130, e2 105−125, f1 90−110, f2 115−135, h1 90−100, h3 47−54. Distance between dorsal setae: v2 −v2 40−47, v2 −sc1 18−25, sc1 – sc2 28−35, sc1−sc1 78−88, sc2−sc2 70−80, c1−c1 75−85, c1−c2 40−47, c2−c3 38−45, c2−c2 160−180, c3−c3 215−245, d1−d1 75−85, d1−d2 65−75, d2−d2 210−230, c1−d1 50−60, c3−d2 100−120, e1 − e1 40−47, e1− e2 22−27, e2−d275 −85, e2− e2 55−65, f1−f1 54−64, f2−f2 180−200, f1−f2 80−90, f1−d1 110−130, h1−h1 106−126, h3−h3 24−28. Venter ( Figure 18 View Figures 17-25 , 36 View Figures 30-36 ): Ventral setae slender, smooth. Lengths- 1a 57−62, 1b 56−62, 1c 60−68, 2b 75−82, 2c 76−82, 3a 55−62, 3b 65−72, 4a 71−77, 4b 58−65, ag 52−58, g1 45−50, g2 42−46, ps1 21−25, ps2 19−23. Striation pattern between intercoxal region simple, transverse; striation in the pregenital region longitudinal, oblique, broken medially. Distance between intercoxal setae- 1a −1a 35−42, 3a −3a 65−75, 4a −4a 80−90, ag −ag 70−80, g1−g1 23−28, g2−g2 100−110, g1−g2 42−49, ps1− ps1 32−38, ps2−ps2 27−32. Gnathosoma ( Figures 19 – 20 View Figures 17-25 ; 35 View Figures 30-36 ): Stylophore rounded, with only longitudinal striation. Peretreme distally hooked, hook length 45−60; palpfemur, palpgenu with one setae only, palpfemur d PFe 28−33, palpgenu l’’ PGe 23−28, palptibia with three setae and d PTi 19−23, l’ PTi 10−14, l” PTi 11−14 and a claw; palptarsus (length 5−7, wide 5−7) with three setae a 5−7, b 5−7, c 4−6; 1 spinneret su ζ length 2−4width 1−3; 1 solenidion ω 3−5; two eupathidia ul’ζ 3−5, ul”ζ 3−5. Spinneret length is slightly shorter than two eupathidia. The ratio of length andwidthofthepalptarsusisequal.Ventralinfracapitulum bears subcapitular setae m 49 – 52 long, distance between m–m 45− 47. Leg ( Figures 21-25 View Figures 17-25 ): Leg I length 285−320, leg II length 205−225, leg III length 355−385, leg IV length 340−360, (from trochanter to tarsus). Setal pattern on leg I–IV coxa 2−2−1−1, trochanter 1−1−1−1, femur 10−6−4−4, genu 5−5−4−4, tibia 9 (1) −7−6−7, tarsus 13(1) +2 duplex setae- 13(1) + 1 duplex setae−9 (1) − 10 (1). Tarsi 1 with 10 tactile setae, 3 eupathidia, 1 solenidion and 2 sets of proximal duplex setae, 3 tactile setae and one solenidion proximal to proximal duplex setae; tarsi II with 9 tactile setae, 3 eupathidia,1 solenidion, 1 set of duplex setae, 1 tactile seta adjacent to duplex setae; tarsi III having 9 tactile setae and 1 solenidion and IV with 10 tactile setae and 1 solenidion. Empodia of leg I–IV each with a prominent spur and split into 3 pairs of hair-like proximoventral hairs. Male: Aedeagus ( Figures 27 View Figures 26-29 , 34 View Figures 30-36 ): Posterior projection of the aedeagus knob absent, anterior projection of the knob with a blunt tip, dorsal margin of knob rounded. Main shaft maximum length 32 (27−38), maximum width 13 (11−16), maximum neck length 2