Phytoseius, Ribaga, 1904

Kar, Anamika & Karmakar, Krishna, 2021, Description of eleven new species of phytoseiid mites (Acari: Mesostigmata) from Meghalaya state, north eastern India, Zootaxa 5068 (3), pp. 301-354 : 327-330

Phytoseius clavus sp. nov.

( Figs 31–37 ; 85–87 )

Female (n=4). Diagnosis. The new species is characterised by dorsum strongly reticulated, all the dorsocentral setae arising from distinct pin head-shaped tubercles, ventrianal shield sole-shaped with three pairs of pre-anal setae, fixed digit of chelicerae with six teeth including pilus dentilis and movable digit with two teeth, all setae including three macrosetae of leg IV rod-like and blunt.

Dorsum ( Figs 31 ; 85–86 ). Dorsal shield 328 (326–329) long and 146 (145–147) wide, strongly reticulated, with five pairs of pores (gd2, gd5, gd6, gd8 and gd9); 15 pairs of setae on the dorsal shield: j1 32 (29–33), j3 37 (35–38), j4 8 (8–9), j5 8 (8–9), j6 8 (8–9), J5 22 (21–23), z2 21 (20–23), z3 33 (32–33), z4 20 (20–21), z5 8 (8–9), Z4 68 (67–70), Z5 78 (77–80), s4 72 (72–75), s6 91 (89–92), r3 48 (47–50). All setae serrated except the setae j4, j5, j6, and z5 which are smooth and pointed.

Peritreme ( Fig. 31 ; 85–86 ). Extended upto the bases of j1.

Venter ( Fig. 32 ). All the shields are smooth. The sternal shield square-shaped, posterior margin of sternal shield indistinct. Sternal shield 60 (58–60) long and 77 (74–78) wide at level of setae st1-st3 and st3-st3 respectively, with three pairs of setae and two pairs of poroids; one pair of setae (st4) on unsclerotised membrane 23 (22–25) long. Distances between st2-st2 58 (58–60), st5-st5 62 (60–65). Base of genital shield broad, posterior margin little convex with a notch at lateral margin below ST5. Metapodal shields not visible, genital shield smooth, broad at base and narrow at genital opening with semicircular flap. Ventrianal shield smooth, sole-shaped 84 (83–85) long, 32 (31–33) wide at level of ZV2 and 49 (48–50) wide at anus level with three pairs of pre-anal setae, JV1 14 (13–15), JV2 12 (11–13), ZV2 10 (10–11) and one pair of pre-anal pores on longitudinal line below JV2, 10 (9–12) apart. Membrane surrounding ventrianal shield with three pairs of setae ZV1 16 (15–18), ZV3 9 (8–10), and JV5 66 (65–68); seta JV5 long and serrated.

Chelicera ( Fig. 33 ). Fixed digit 28 (26–30) long with two teeth and distinct pilus dentilis, movable digit 28 (26–29) long with two teeth.

Spermatheca ( Fig. 34 ). Calyx short 8 (7–9) long, funnel-shaped, wide at base of vesicle, atrium indistinct, minor duct not visible while the major duct long and very distinct.

Legs ( Fig. 35 ). The genu, tibia and tarsus of leg IV with rod-like macrosetae with blunt tip of following lengths: genu 22 (21–24), tibia 35 (34–36) and tarsus 35 (34–36). Chaetotactic formula of genu II 1 2/1. 2/0 1 and genu III 1 2/1. 2/0 1. Length of leg I 243 (242–245), leg II 220 (217–222), leg III 236 (235–238) and leg IV 388 (387–390).

Male (n=1). Dorsum. Dorsal shield 228 long and 142 wide strongly reticulated, prodorsum wide, smooth lateral margin with 15 pairs of setae on the dorsal shield: j1 22, j3 28, j4 8, j5 7, j6 7, J5 14, z2 16, z3 29, z4 19, z5 7, Z4 32, Z5 35, s4 50, s6 47, r3 36. All setae serrated, setae j4, j5, j6, and z5 are smooth.

Peritreme. Extended beyond the bases of j1.

Venter ( Fig. 36 ). Sternogenital shield smooth with five pairs of setae and three pairs of distinguishable poroids. Ventrianal shield 100 long, 111 wide at level of ZV2, 52 wide at level of anus, with three pairs of pre-anal setae, JV1 7, JV2 7, ZV2 7 and a pair of pores below JV2, 13 apart. Unsclerotised membrane surrounding the ventrianal shield with one pair of setae JV5 23 long and serrated.

Chelicera ( Fig. 37 ). Spermatodactyl with an elongated shaft 20 long terminating with a wide toe.

Leg. Leg IV with three macrosetae of blunt tip of following lengths: genu 14, tibia 14 and tarsus 27. Chaetotactic formula of genu II 1 2/1. 2/0 1 and genu III 1 2/1. 2/01. Length of leg I 224, leg II 206, leg III 191 and leg IV 302.

Type specimens. Holotype: female (Acarol.lab/ BCKV/8391 /2019) deposited in the NZC, Zoological Survey of India, Kolkata), collected from Rhododendron , ( Rhododendron sp. ), at Upper Shillong : 25°32'9"N, 91°49'29"E, 1589m AMSL, Upper Shillong , Meghalaya on 2 May 2019; two paratype females (Acarol.lab/ BCKV/8391– 8392 /2019) and one paratype male (Acarol.lab/ BCKV/8393 /2019) with same collection data as holotype deposited in the Acarological laboratory, Department of Entomology , BCKV, Mohanpur , Nadia , West Bengal, India.

Etymology. The specific name clavus refers to the “pin-shaped” prodorsal setae of this new species.

Remarks. The new species Phytoseius clavus is notable from all the species under horridus species group by all the dorsocentral setae arising from distinct pin head-shaped tubercles and all setae including three macrosetae of leg IV rod-like and blunt. However, this new species is close to P. corniger Wainstein, 1959 ; P. nipponicus Ehara, 1962 ; P. meyerae Gupta, 1977 ; P. domesticus Rather, 1985 and P. dorsospinosus Pramanik & Karmakar, 2016 by having similar pattern of dorsal shield ornamentation, dorsocentral setae smooth, sole-shaped ventrianal shield with three pairs of setae. The new species differs from these close species by the length, shape and pattern of dorsal shield setae, serration of setae z2 and z4, number of metapodal shield, denticles in fixed and movable digit of chelicerae, macrosetae on leg IV and shape of spermatheca. All the differences between the new and close species are given in Table 8.

Figures

FIGURES 31–37. Phytoseius clavus (female). 31. Dorsal view of idiosoma; 32. Ventral view of idiosoma; 33. Chelicera; 34. Spermatheca; 35. Genu, tibia and basitarsus of leg IV. 36. Ventral view of idiosoma (male), 37. Spermatodactyl (male).

FIGURES 85–87. Phytoseius clavus (female). 85. Dorsal view of idiosoma; 86. Dorsal anterior view of idiosoma; 87. Ventrianal shield; 88–91. Phytoseius aonlae (female). 88. Dorsal posterior view of idiosoma; 89. Genu, tibia and basitarsus of leg IV; 90. Chelicera; 91. Spermatheca.