Euseius astrictus

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: 58-60

publication ID

https://doi.org/10.11646/zootaxa.4422.1.3

publication LSID

lsid:zoobank.org:pub:68D70470-6E6C-498D-AAF6-DA3CA8F93D2E

persistent identifier

http://treatment.plazi.org/id/93548244-FF83-FF8C-588E-FE668BBB220C

treatment provided by

Plazi

scientific name

Euseius astrictus
status

sp. nov.

Euseius astrictus  sp. nov.

( Figs 43–49 View Figure , 92–93 View Figure )

Female (n = 10). Dorsum ( Fig. 43 View Figure ). Dorsal shield 342, 340 (335–345), long and 238, 236 (230–241), wide, strongly reticulated, with lateral parallel lines, broader at the prodorsum with lateral irregular extension at the prominent waist region, with five pairs of solenostomes (gd2, gd5, gd6, gd8 and gd9); 17 pairs of dorsal setae and two pairs of sublateral setae: j1 37, 37 (37–38), j3 37, 37 (36–38), j 4 12, 13 (11–15), j 5 14, 14 (14–15), j 6 17, 16 (15–17), J 2 17, 18 (16–20), J5 7, 7 (7–8), z 2 25, 26 (25–27), z 4 29, 29 (28–30), z 5 13, 14 (13–15), Z 1 17, 17 (16–18), Z 4 25, 24 (24–25), Z5 71, 68 (63–73), s4 35, 37 (34–40), S 2 24, 24 (24–25), S 4 27, 27 (26–28), S5 38, 37 (35–39), r 3 17, 16 (16–17), R 1 14, 14 (14–15). All setae smooth, setae j1, j3, s4, S5 and Z5 are longer where the seta Z5 is the longest and the remaining setae are medium to small.

Peritreme ( Fig. 43 View Figure ). Extending forward nearly to base of j3.

Venter ( Fig. 44 View Figure ). All shields smooth, sternal shield 59, 59 (58–60) long and 80, 80 (80–81) 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) on the metasternal plates; posterior margin of sternal shield indistinct. Distances between ST2–ST2 63, 64 (62–65), ST5–ST5 76, 77 (76–78). One pairs of metapodal shields, primary shield 25, 24 (24–25) long. Ventrianal shield 108, 107 (105–109) long, 49, 50 (48–51) wide at level of ZV2 setae and 80, 80 (79–81) 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 40, 41 (38–43) long, smooth.

Chelicera ( Figs 45 View Figure , 92 View Figure ). Fixed digit 24, 25 (24–26) long, with three teeth and pilus dentilis; movable digit stout 24, 24 (24–25) long, with one tooth.

Spermatheca ( Figs 46 View Figure , 93 View Figure ). Calyx tubular, elongate thick at the middle part, constricted 12, 12 (11–13) long, atrium indistinct, major duct visible.

Legs ( Fig. 47 View Figure ). Legs IV with three smooth macrosetae with blunt rounded tip, the terminal parts of which are transparent and of the following lengths: genu 48, 49 (47–50), tibia 43, 44 (42–45), basitarsus 65, 64 (63–65). Chaetotactic formula of genu II: 1–2/1, 2/0–1; genu III: 1–2/1, 2/0–1. Length of leg I: 371, 369 (363–375), leg II: 290, 289 (286–292), leg III: 296, 294 (288–300), leg IV: 415, 413 (406–419).

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

Dorsum. Dorsal shield 273, 263 (250–275) long and 165, 176 (163–188) wide, reticulated, with 19 pairs of setae on dorsal shield: j 1 27, 28 (25–30), j 3 32, 29 (25–33), j 4 12, 12 (10–13), j 5 11, 12 (11–13), j 6 14, 15 (13–16), J 2 13, 12 (10–13), J5 8, 7 (6–8), z 2 20, 20 (20–21), z 4 28, 29 (28–30), z 5 12, 12 (11–13), Z 1 18, 17 (16–18), Z 4 18, 18 (18–19), Z5 51, 50 (48–52), s4 37, 38 (37–39), S 2 23, 23 (23–24), S 4 25, 25 (24–26), S 5 29, 30 (28–31), r 3 15, 15 (14–16), R 1 15, 15 (15–16). All setae smooth.

Peritreme. Extending forward to base of j3.

Venter ( Fig. 48 View Figure ). Sternogenital shield with a few lateral lines, ventrianal shield striated. Sternogenital shield with five pairs of setae and three pairs of distinguishable lyrifissures. Ventrianal shield triangular, wide at the anterior part tapering posteriorly 105, 106 (102–110) long, 117, 118 (116–120) wide at the level of ZV2 setae, 74, 73 (70–75) 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 and of following lengths; genu 37, 38 (36–39), tibia 29, 30 (28–32), basitarsus 50, 51 (48–53). Chaetotactic formula of genu II and genu III are identical to the female. Length of leg I: 353, 355 (350–360), leg II: 238, 242 (235–248), leg III: 249, 251 (245–256), leg IV: 318, 317 (313–321).

Chelicera ( Fig. 49 View Figure ). Spermatodactyl with an elongated shaft 19, 20 (18–21) long terminating with a toe, 8, 8 (7–9) long.

Type specimens. Holotype: female (Acar.lab/BCKV/8254/2017) (Registration number 4407/17, deposited in the NZC, Zoological Survey of India, Kolkata) collected from Duranta, Duranta  sp., ( Verbenaceae  ) at Namkhana: 21°76’99”N 88°23’15”E, 4 m above mean sea level South 24 Parganas, West Bengal, on 18 March 2017; 2 paratype females (Acar.lab/BCKV/8255 /2017) (Registration number 4408/17 deposited in the NZC, Zoological Survey of India, Kolkata) collected from Jackfruit, Artocarpus heterophyllus  ( Moraceae  ) with same locality and date as holotype female; 6 paratype females (Acar.lab/BCKV/8256, 8258-8260/2017) collected from Jackfruit, Artocarpus heterophyllus  , ( Moraceae  ), 2 paratype females (Acar.lab/BCKV/8257,8261/2017) collected from Pomegranate, Punica granatum  ( Punicaceae  ), at same location and date as holotype; 1 paratype male (Acar.lab/BCKV/8258/ 2017) (Registration number 4409/17 deposited in the NZC, Zoological Survey of India, Kolkata) collected from Jackfruit, Artocarpus heterophyllus  , ( Moraceae  ) at the same locality and collection date as holotype female; 2 paratype males (Acar.lab/BCKV/8259/2017) collected from Jackfruit, Artocarpus heterophyllus  , ( Moraceae  ) at the same locality and collection date as holotype female.

Etymology. The specific name astrictus  refers to the unique character of spermatheca where calyx is constricted in this new species.

Remarks. E. astrictus  is close to E. victoriensis (Womersely, 1954)  , E. neovictoriensis ( Schicha, 1979)  and E. unisetus Moraes & McMurtry, 1983  but the former species differs from the latter species in the dorsal shield striation pattern, length of shield setae and shape of spermatheca. In case of the former species the dorsal shield setae S5, Z4, Z5 are longer than all the latter closely related species. The dorsal shield of the former species is strongly reticulated with lateral parallel lines which differs from E. victoriensis  and E. neovictoriensis  by their smooth and lightly reticulated dorsal shield respectively while in case of E. unisetus  the dorsal shield imbricated and without lateral parallel lines. Euseius astrictus  is also distinguished from other species of Euseius  by its distinct constricted spermatheca.