Okiseius roseus, Molla & Karmakar, 2021

Molla, Md. Iftiar Hossain & Karmakar, Krishna, 2021, Description of five new species of Amblyseiinae (Acari: Phytoseiidae) associated with medicinal plants from the Northern Himalayan Zone of West Bengal, India, Zootaxa 5057 (3), pp. 364-384 : 374-376

Okiseius roseus sp. nov.

( Figs 17–21 ; 38–41 )

Diagnosis. Dorsal shield strongly sclerotised, rugose on the podosomal area, with seven pairs of solenostomes; r3 on dorsal shield and R1 off shield, without a lateral incision in the margin of the dorsal shield posterior to seta R1, with setae J2 and S4 absent. Setae j4, j5, z5 and J5 short and smooth while setae j1, j3, j6, z2, z4, Z1, S5, r3 and R1 long, and s4, S2, Z4 and Z5 longer and serrated. Peritreme extending up to the base of j1. Calyx of spermatheca pocular shaped. Sternal shield with three pairs of setae and posterior margin of sternal shield wavy with a small median lobe and slightly concave. Fixed digit of chelicera with seven teeth and movable digit of chelicera with two teeth. Ventrianal shield vase-shaped, with one pair of small, circular pre-anal pores (gv3) situated posterior to setae JV2. Genu and tibia of leg IV each with one knobbed rod-like macrosetae and three rod like setae, and tarsus of leg IV with one knobbed rod-like macrosetae and one rod like setae, genu II with seven setae.

Female (n = 4). Dorsum ( Fig. 17 ). Idiosomal setal pattern 10A: 7E/ JV -3: ZV.

Dorsal shield 339 (335–346) long and 186 (183–188) wide, highly sclerotised, with seven pairs of solenostomes (gd1, gd2, gd4, gd5, gd6, gd8 and gd9); 16 pairs of setae on dorsal shield and one pair of setae on unsclerotised cuticle: j1 26 (24–28), j3 41 (39–42), j4 11 (10–11), j5 13 (11–13), j6 26 (24–28), J5 6 (6–7), z2 36 (35–38), z4 40 (38–42), z5 11 (10–12), Z1 39 (38–41), Z4 46 (44–48), Z5 69 (67–72), s4 50 (48–52), S2 49 (47–51), S5 23 (22–25), r3 41 (39–43), R1 33 (32–35). Setae j4, j5, z5 and J5 short and smooth while setae j1, j3, j6, z2, z4, Z1, S5, r3 and R1 long, and s4, S2, Z4 and Z5 longer and serrated.

Peritreme ( Fig. 17 ). Extending up to the base of j1.

Venter ( Fig. 18 ). All shields smooth. Sternal shield 64 (62–66) long and 70 (68–72) wide at level of setae ST1–ST3 and ST3–ST3 respectively, with three pairs of setae and two pairs of lyrifissures; one pair of setae ST4 27 (26–29) on metasternal plate. Posterior margin of sternal shield wavy with small median lobe and slightly concave. Distances between ST1–ST1 53 (51–55), ST2–ST2 59 (58–61), ST5–ST5 70 (68–72). The genital shield smooth broad at the base and narrower at genital opening with one pair of setae ST5 27 (26–29) long. Ventrianal shield vase-shaped and smooth 110 (107–113) long, 59 (57–61) wide at level of ZV2 setae and 60 (58–62) at anus level with three pairs of pre-anal setae JV1 21 (20–23), JV2 19 (18–21), ZV2 20 (19–21) and with one pair of relatively small, circular pre-anal pores (gv3), situated posterior to setae JV2. Distance between pre-anal pores 37 (36–38) and each 4 (4–5) apart from setae JV2. Membrane surrounding ventrianal shield with four pairs of setae ZV1 24 (23–25), ZV3 14 (14–15), JV4 18 (17–19) and JV5 52 (50–54); seta JV5 long and serrated. One pair of metapodal shields 31 (29–32) long.

Chelicera ( Fig.19 ). Fixed digit 23 (22–25) long, with seven teeth and a pilus dentilis, movable digit 24 (23–25) long with two teeth.

Spermatheca ( Fig.20 ). Calyx of spermatheca pocular, 6 (5–6) long, atrium crescent shaped, minor duct and major duct clearly visible.

Legs ( Fig.21 ). Leg IV with knobbed rod-like macrosetae: Sge IV 22 (21–23) plus three rod-like setae, Sti IV 20 (19–22) plus three rod-like setae and St IV 52 (50–54) plus one rod-like setae. Chaetotactic formula of genu II 1 2/0 2/0 2 and genu III 2 2/1 2/0 0. Length of leg I 296 (293–301), leg II 265 (262–269), leg III 226 (223–229), and leg IV 328 (325–332).

Type-specimens. Holotype: female (Acarol.lab/BCKV/8519/2021) deposited in the NZC, collected from Rose plant ( Rosa chinensis Jacq. : Rosaceae ), at Daragaon: 27 o 2’17”N, 88 o 41’43”E, 1140 m a.s.l., Kalimpong, West Bengal on 6 Nov 2020; three paratype females (Acarol.lab/BCKV/8520–8522/2021) deposited in the BCKV, with same collection data as holotype.

Etymology. The specific name roseus refers to the type host plant, Rosa chinensis from where the new species were collected.

Remarks. The new species belongs to the maritimus species group by R1 off the dorsal shield and absence of marginal notch below R1 ( Chant & McMurtry, 2003). The new species is close to O. maritimus ( Ehara, 1967b) ; O. alniseius Wainstein & Begljarov, 1972 and O. juglandis ( Wang & Xu, 1985) among all the species of maritimus species group; however, it differs from its close species by variation in length of dorsal shield setae, shape and pattern of leg setae, variation in the number of denticles of fixed digit, distance between pre-anal pores of ventrianal plate and posterior margin of sternal shield. All the differences between the new species and the close species are given in Table 4 .

Figures

FIGURES 17–21. Okiseius roseus (female). 17. Dorsal view of idiosoma; 18. Ventral view of idiosoma; 19. Chelicera; 20. Spermatheca; 21. Genu, tibia and basitarsus of leg IV.

FIGURES 29–41. 29–33. Amblyseius rishyapensis (female). 29. Dorsal view; 30. Ventrianal shield; 31. Spermatheca; 32. Chelicera; 33. Genu, tibia and basitarsus of leg IV; 34–37. Amblyseiulella tibouchina (female). 34. Dorsal shield; 35. Genu, tibia and basitarsus of leg IV; 36. Chelicera; 37. Spermatheca; 38–41. Okiseius roseus (female). 38. Dorsal view of idiosoma; 39. Spermatheca; 40. Genu, tibia and basitarsus of leg IV; 41. Chelicera.