Dichopelmus puncti, Debnath, Pranab & Karmakar, Krishna, 2016

Debnath, Pranab & Karmakar, Krishna, 2016, Eriophyoid mites from Eastern India: description of three new species (Acari: Prostigmata: Eriophyoidea), Zootaxa 4061 (5), pp. 553-568 : 558-559

Dichopelmus puncti n. sp.

( Fig. 1 )

Description. FEMALE (n=10). Body fusiform, 166 (151–185), 57 (49–66) wide, whitish in colour. Gnathosoma projecting straight downwards, 22 (21–23), pedipalp coxal seta (ep) 3 (3–4), dorsal pedipalp genual seta (d) 6 (5– 6), simple, subapical pedipalp tarsal seta (v) minute (less than 1). Prodorsal shield subtriangular 52 (49–56), 49 (46–53) wide, frontal lobe 10 (9–11) broad, triangular in dorsal view and slightly down-curved in lateral view; dorsal shield lines absent except for a short median line with an apical fork forming a Y-shape on anterior half, typical median grooved area with coarse irregular granules dividing dorsal shield into two halves, lateral region ornamented with roundish granules. Scapular seta (sc) 13 (11–15), tubercles on rear shield margin, directed backwards, 35 (31–36) apart. Legs with all usual segments and setae. Leg I 31 (29–33), femur 9 (8–9), basiventral femoral seta (bv) 6 (5–7); genu 5 (4–5), antaxial genual seta (l″) 26 (23–28); tibia 7 (6–7), paraxial tibial seta (l ′) 6 (5–7); tarsus 7 (6–7), paraxial fastigial tarsal seta (ft ′) 15 (14–18), antaxial fastigial tarsal seta (ft′′) 14 (14–18), paraxial unguinal tarsal seta (u ′) 5 (5–6); tarsal empodium (em) 5 (4–5), divided, each branch 5-rayed; tarsal solenidion (ω) 5 (5–6). Leg II 28 (25–30), femur 7 (6–7), basiventral femoral seta (bv) 7 (6–8); genu 7 (6–7), antaxial genual seta (l″) 5 (4–6); tibia 4 (3–4), paraxial tibial seta (l ′) absent; tarsus 6 (5–6), paraxial fastigial tarsal seta (ft ′) 5 (5–6), antaxial fastigial tarsal seta (ft′′) 13 (11–14), paraxial unguinal tarsal seta (u ′) 5 (4–5); tarsal empodium (em) 5 (4–5), divided, each branch 5-rayed; tarsal solenidion (ω) 6 (6–7). Coxal plates ornamented with lines, anterolateral seta on coxisternum I (1b) 7 (7–8), 13 (12–13) apart; proximal seta on coxisternum I (1a) 19 (17–20), 9 (9–10) apart; proximal seta on coxisternum II (2a) 31 (30–35), 23 (22–25) apart. Sternal line 8 (7–8); coxigenital area with 9 (8–9) annuli, microtuberclated. Genital coverflap 22 (20–23) wide, 14 (13–16), 3 transverse lines at base with 14 (13–15) longitudinal ridges, proximal seta on coxisternum III (3a) 13 (12–14).

Opisthosoma with 35 (33–37) dorsal annuli, a median and two lateral longitudinal ridges starting from rear shield margin and extending up to four fifths of opisthosoma. Seta c2 23 (20–26), on annulus 4 (3–4); seta d 32 (31–35), 25 (23–26) apart, on annulus 14 (14–15); seta e 9 (8–10), 11 (10–12) apart, on annulus 28 (26–29); seta f 14 (11– 18), 21 (19–21) apart, on annulus 43 (41–45); with 47 (45–49) ventral annuli, microtuberculated. Seta h2 59 (54– 65); seta h1 absent.

MALE (n=4). Smaller than female, 126–148, 33–39 wide, fusiform, whitish in colour. Gnathosoma projecting straight downwards, 20–22, pedipalp coxal seta (ep) 2–3, dorsal pedipalp genual seta (d) 5–6 simple, subapical pedipalp tarsal seta (v) minute less than 1. Prodorsal shield as in female, 40–46, 34–35 wide; frontal lobe 8 (8–9); scapular seta (sc) 5–6, tubercles on rear shield margin, directed backwards, 25–26 apart. Legs as in female. Leg I 24–27; femur 8–9, basiventral femoral seta (bv) 4; genu 4–5, antaxial genual seta (l″) 20–22; tibia 5–6, paraxial tibial seta (l ′) 5; tarsus 5–6, paraxial fastigial tarsal seta (ft ′) 12–15, antaxial fastigial tarsal seta (ft′′) 15–18, paraxial unguinal tarsal seta (u ′) 5–6; tarsal empodium (em) 4–5, divided, each branch 5-rayed; tarsal solenidion (ω) 5–6. Leg II 20–23, femur 6–7, basiventral femoral seta (bv) 6–7; genu 5, antaxial genual seta (l″) 4–5; tibia 4–5, paraxial tibial seta (l ′) absent; tarsus 5–6, paraxial fastigial tarsal seta (ft ′) 4–5, antaxial fastigial tarsal seta (ft′′) 13– 15, paraxial unguinal tarsal seta (u ′) 5–6; tarsal empodium (em) 4–5, divided, each branch 5-rayed; tarsal solenidion (ω) 5–6. Coxal plates smooth, anterolateral seta on coxisternum I (1b) 7–8, 9–11 apart; proximal seta on coxisternum I (1a) 10–14, 6–7 apart; proximal seta on coxisternum II (2a) 24–29, 19–21 apart. Sternal line 7–8; coxigenital area with 6–7 annuli, microtuberculated. Genital coverflap 15–17 wide, 8–10, smooth, eugenital seta minute, proximal seta on coxisternum III (3a) 10–13. Opisthosoma as in female, 35–38 dorsal annuli; a median and two lateral longitudinal ridges starting from rear shield margin and extended posterior upto four fifth of opisthosoma. Seta c 2 19–22, on annulus 2–3; seta d 28–34, 21–25 apart, on annulus 10–12; seta e 8–10, 9–10 apart, on annulus 20–23; seta f 13–16, 17–20 apart, on annulus 36–39; 42–46 ventral annuli, microtuberculated. Seta h2 45–53; seta h1 absent.

Type host plant. Imperata cylindrica (L.) Raeusch ( Poaceae ).

Relation to host. Vagrant on upper surface of leaf; no visible damage to leaves.

Type locality. Kalyani , India (22°58'54''N, 88°27'36''E).

Type material. Holotype female (marked by encircling with red ink on slide acc. no. AINP /Acar. Lab./ BCKV / 4151/2012); 12 paratype females and 4 paratype males collected on Imperata cylindrica, Kalyani , India by P. Debnath on 19.x.2011; all on 6 microscopic slides. Holotype slide and 12 paratype females and 4 paratype males (acc. no. AINP /Acar. Lab./ BCKV /4151–4156/2012) deposited in the collection of AINP, Acarology Laboratory, BCKV, Kalyani , India. Three paratype females (single slide) deposited in the National Zoological collection of Zoological Survey of India, Kolkata.

Etymology. The specific designation puncti is derived from Latin “punctus”, meaning marked with points, stippled, which refers to the spotted prodorsal shield; masculine in gender.

Differential diagnosis and remarks. Following the classification of Amrine et al. (2003), the new species is placed in Dichopelmus because of its fusiform body shape, prodorsal shield with frontal lobe over gnathosoma, scapular setae placed on the rear shield margin, an opisthosoma divided into broad dorsal annuli and narrow ventral annuli, with the presence of tibial setae and divided empodia on Legs I and II. Although the presence of dorsal opisthosomal ridges is a significant character at the generic level ( Lindquist & Amrine 1996), in the case of Dichopelmus , no such ridges were described by Keifer, 1959. However, the presence of dorsal opisthosomal ridges is an important character to differentiate species in the genus Dichopelmus .

Dichopelmus puncti n. sp. is close to Dichopelmus lotus Xie & Zhu, 2010 and Dichopelmus puerariae Qin, Wang & Wei, 2008 . It can be differentiated by having the prodorsal shield laterad to the median grooved region ornamented with roundish granules whereas, D. lotus and D. puerariae are without such a median groove or granular structure. The prodorsal shield in D. puncti n. sp. also has a short median line present with an apical fork forming a Y-shape. Two curved lines from the base of the dorsal tubercles are indirectly connected by cross lines at 1/3rd behind the anterior shield margin in D. lotus and there are many longitudinal lines on the prodorsal shield of D. puerariae . Each branch of the empodia is 5-rayed in D. puncti n. sp. compared with 3-rayed in D. lotus and 7- rayed in D. puerariae .

Figures

FIGURE 1. Semi-schematic drawings of Dichopelmus puncti n. sp. D. Dorsal habitus, female; L. Lateral habitus, female; CG. Coxigenital region, female; CGM. Coxigenital region, male; IG. L 1. Leg I, female; L 2. Leg II, female; Em. Empodium.