Euseius sundarbanensis, Karmakar & Bhowmik, 2018

Karmakar, Krishna & Bhowmik, Sagarika, 2018, Description of eight new species and re-description of four species belonging to the family Phytoseidae (Acari: Mesostigmata) from West Bengal, India, Zootaxa 4422 (1), pp. 41-77 : 55-58

Euseius sundarbanensis sp. nov.

( Figs 36–42 , 89–91 )

Female (n = 10). Dorsum ( Fig. 36 ). Dorsal shield 353, 347 (338–355) long and 252, 247 (238–255) wide, strongly reticulated, with marks of sigilla mostly on prodorsal area, prodorsum wide, with prominent waist and six pairs of solenostomes (gd1, gd2, gd5, gd6, gd8 and gd9); 17 pairs of setae on the dorsal shield and two pairs of setae on the unsclerotised cuticle: j 1 29, 29 (28–30), j 3 26, 27 (25–28), j4 9, 9 (9–10), j5 8, 8 (7–9), j 6 11, 12 (11–13), J 2 9, 10 (8–11), J5 6, 6 (6–7), z 2 20, 19 (19–20), z 4 21, 22 (20–23), z5 9, 8 (6–9), Z 1 11, 11 (11–12), Z 4 16, 17 (15–18), Z5 69, 65 (60–70), s4 33, 34 (33–35), S 2 17, 17 (16–18), S 4 20, 19 (19–20), S 5 24, 24 (24–25), r 3 13, 13 (12–14), R 1 12, 13 (11–14). All setae smooth, setae j1, j3 and s4 are long while seta Z5 is the longest and all other setae mediun to small.

Peritreme ( Fig. 36 ). Extending forward to level between bases of j3 and z2.

Venter ( Fig. 37 ). All shields smooth. Sternal shield 66, 65 (63–66) long and 80, 80 (80–81) wide at the level of setae ST1–ST3 and ST3–ST3 respectively, with three pairs of setae and two pairs of lyrifissures; one pair of setae (ST4) on unsclerotised membrane; posterior margin of sternal shield indistinct in all specimens. Distances between ST2–ST2 67, 67 (65–68), ST5–ST5 82, 81 (81–82). One pair of metapodal shields 24, 24 (24–25) long, 6 wide. Ventrianal shield 112, 105 (95–115) long, 55, 58 (53–63) wide at level of JV2 setae and 81, 79 (75–82) wide at level of anus; with three pairs of pre-anal setae, JV1, JV2 and ZV2, and one pair of large elliptical pre-anal pores. Membrane surrounding ventrianal shield with four pairs of setae: ZVl, ZV3, JV4 and JV5; the latter 34, 36 (33–38) long and smooth.

Chelicera ( Figs 38 , 89 ). Fixed digit 27, 26 (25–27) long, with five anterior teeth and distinct pilus dentilis, movable digit 26, 25 (23–26) long with a single tooth.

Spermatheca ( Figs 39 , 90 ). Calyx fundibular, elongated, 16, 18 (15–20) long, wider at base of vesicle and gradually tapering towards conspicuous atrium, minor duct and major duct distinctly visible.

Legs ( Fig.40 ). Legs IV with three smooth macrosetae. Tips of macrosetae on genu and tibia are pointed distally while tip of macroseta on basitarsus is blunt; of the following lengths: genu 37, 37 (37–38), tibia 41, 43 (40–45), basitarsus 62, 62 (61–63). Chaetotactic formula of genu II: 2 2/0, 2/0 1; genu III: 1 2/0, 2/1 1. Length of leg I: 385, 393 (380–405), leg II: 322, 323 (320–325), leg III: 335, 334 (330–338), leg IV: 440, 447 (435–447).

Male (n = 3). Adult male is sclerotised with 19 pairs of dorsal setae. Idiosomal setal pattern: 10A:9B/ JV –3,4: ZV –1,3.

Dorsum. Dorsal shield 274, 273 (270–275) long and 198, 195 (190–200) wide, strongly sclerotised with lateral lines on prodorsum and six pairs of distinct pores and three pairs lyrifissures, 19 pairs of setae on dorsal shield: j1 32, 32 (30–33), j 3 31, 32 (30–33), j 4 10, 11 (10–12), j 5 10, 11 (10–12), j 6 11, 12 (10–13), J 2 11, 12 (10–13), J5 6, 5 (4–6), z 2 20, 20 (19–21), z 4 21, 22 (20–23), z 5 10, 12 (10–13), Z 1 11, 12 (10–13), Z 4 17, 17 (15–18), Z5 48, 49 (48–50), s 4 31, 32 (30–33), S 2 20, 20 (20–21), S 4 20, 20 (19–21), S 5 24, 25 (23–26), r 3 15, 14 (13–15), R 1 14, 14 (14–15). All setae smooth short, setae ji, j3, s4 medium long while seta Z5 longest.

Peritreme. Extending beyond level of z2.

Venter ( Fig. 41 ). The sternogenital shield with a few lateral lines and the ventrianal shield strongly reticulated. The anterior part of ventrianal shiled is much wider than the posterior part with a notch on the lateral margin at the level of anus. Sternogenital shield with five pairs of setae and three pairs of distinguishable lyrifissures. Ventrianal shield 103, 102 (100–103) long, 106, 107 (105–108) wide at the level of ZV2 setae, 62, 64 (60–68) wide at the level of anus with three pairs of pre-anal setae, JV1, JV2, and ZV2, one pair of pores and two pairs of distinguishable lyrifissures. Unsclerotised membrane surrounding ventrianal shield with one pair of setae, JV5, at level with anal opening.

Legs. Leg IV with three smooth macrosetae of following lengths; genu 32, 32 (30–33), tibia 32, 32 (30–33), basitarsus 54, 53 (51–55). Chaetotactic formula of genu II: 1 2/0, 2/1 1; genu III: 1 2/1, 2/0 1. Length of leg I: 354, 353 (350–355), leg II: 272, 269 (263–275), leg III: 253, 255 (250–268), leg IV: 353, 353 (350–355).

Chelicera ( Figs 42 , 91 ). Spermatodactyl with an elongated shaft 28, 27 (23–30) long terminating with an upwardly bent pointed toe, 8, 9 (8–10) long.

Type specimens. Holotype: Female (Acar.lab/BCKV/8237/2017), (Registration number 4404/17 deposited in the NZC, Zoological Survey of India, Kolkata), collected from China Rose, Hibiscus sp., (Malvacae), at Namkhana: 21°76’99”N 88°23’15”E, 4 m above mean sea level South 24 Parganas, West Bengal, on 9 April 2017; 1 paratype female (Acar.lab/BCKV/8238/2017) (Registration number 4405/17 deposited in NZC, Zoological Survey of India, Kolkata) collected from Ziziphus mauritiana (Rhamnaceae) with same collection data as holotype; 2 paratype females (Acar.lab/BCKV/8239,8249/2017) collected from Jamun, Syzygium cumini (Myrtaceae) , 6 paratype females (Acar.lab/BCKV/8240,8246,8247,8250/2017) collected from Banana, Musa sp., ( Musaceae ), 2 paratype females (Acar.lab/BCKV/8241,8244/2017) collected from Moringa, Moringa oleifera (Moringaceae) , 1 paratype female (Acar.lab/BCKV/8242/2017) collected from Habul, 1 paratype female (Acar.lab/BCKV/8243/ 2017) collected from China rose, Hibiscus sp., ( Malvaceae ), 1 paratype female (Acar.lab/BCKV/8245/2017) collected from Rangoon creeper, Combretum indicum (Combretaceae) , 1 paratype female (Acar.lab/BCKV/8248/ 2017) collected from Jatropha Jatropha carcus (Euphorbiaceae) , at same locality and collection date as holotype; 1 paratype male (Acar.lab/BCKV/8251/2017) (Registration number 4406/17 deposited in the NZC, Zoological Survey of India, Kolkata) collected from Banana, at same locality and collection date as holotype; 1 paratype male (Acar.lab/BCKV/8253/2017) collected from Jatropha carcus (Euphorbiaceae) at the same locality and collection date as holotype female.

Etymology. The specific name sundarbanensis refers to “Sundarban" (The famous forest and the habitat of Royal Bengal Tiger) of West Bengal, India, the type locality of this species.

Remarks. Euseius sundarbanensis is close to Euseius aizawai ( Ehara & Bhandhufalck, 1977) but differs in the dorsal shield reticulation pattern, shape of ventrianal shield and shape of spermatheca. The dorsal shield is strongly reticulated in the former species while dorsal shield is almost smooth in case of latter species and the spermatheca is fundibuliform, elongate, gradually tapers towards atrium in the former species and it is funnel-shaped, more flared at the base of vesicle in latter species. The former species also close to E. australis (Wu & Li, 1983) but differs from dorsal reticulation pattern, length of dorsal shield setae, shape of ventrianal shield and shape of spermatheca which are not match with the former species.

Figures

FIGURES 36–42. Euseius sundarbanensis (FEMALE). 36. DORSAL VIEW OF IDIOSOMA; 37. VENTRAL VIEW OF IDIOSOMA; 38. CHELICERA; 39. SPERMATHECA; 40. GENU, TIbIA AND bASITARSUS IV; 41. VENTRAL VIEW OF IDIOSOMA (MALE); 42. SPERMATODACTYL.

FIGURES 79–99. 79–80. Amblyseius crotalariae (GUPTA, 1977), CHELICERA, SPERMATHECA; 81–82. Amblyseius guajavae (GUPTA, 1978), CHELICERA, SPERMATHECA; 83–84. Typhlodromips syzygii (GUPTA, 1975), CHELICERA, SPERMATHECA; 85–86. Scapulaseius moraesi sp. nov.; CHELICERA, SPERMATHECA; 87–88. Scapulaseius asiaticus (EVANS, 1953), CHELICERA, SPERMATHECA; 89–91. Euseius sundarbanensis sp. nov.; CHELICERA, SPERMATHECA, SPERMATODACTYL; 92–93. Euseius astrictus SP. NOV;. CHELICERA, SPERMATHECA; 94–96. Asperoseius latericulus sp. nov.; CHELICERA, SPERMATHECA, VENTRIANAL SHIELD; 97–99. Asperoseius jujubae sp. nov., CHELICERA, SPERMATHECA, SPERMATODACTYL.