Gynaeseius ricini (Ghai & Menon)

Bhowmik, Sagarika & Karmakar, Krishna, 2021, Five new species and re-description of eight species belonging to the family Phytoseiidae (Acari: Mesostigmata) from West Bengal, India, Zootaxa 4975 (3), pp. 401-450 : 413-416

Gynaeseius ricini (Ghai & Menon)

Indoseius ricini Ghai & Menon, 1969: 348 .

Gynaeseius ricini Chant & McMurtry, 2006: 13 .

( Figs 22–26 , 89–92 )

Female (n = 10). Dorsum ( Fig. 22 ). Dorsal shield 362 (355–368) long and 210 (207–213) wide, without any constriction at the waist region, smooth, with seven pairs of solenostomes (gd1, gd2, gd4, gd5, gd6, gd8 and gd9); 18 pairs of setae on the dorsal shield and two pairs of setae on the unsclerotised cuticle: j1 18 (18–19), j3 19 (19–20), j4 15 (15–16), j5 16 (15–17), j6 17 (17–18), J2 17 (17–18), J5 8 (7–9), z2 18 (16–19), z4 18 (17–19), z5 16 (15–17), Z1 19 (19–20), Z4 17 (16–18), Z5 27 (25–28), s4 19 (19–20), S2 21 (21–22), S5 20 (20–21), r3 15 (15–16), R1 18 (18–19). All setae smooth and short, setae Z5 longest.

Peritreme ( Fig. 22 ). Peritremes extending between the bases of setae z2 and j3.

Venter ( Fig. 23 ). All shields smooth. Sternal shield with 74 (73–75) long and 78 (77–79) 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 metasternal plate with a pair of conspicuous lyrifissures in the anterior part; posterior margin of sternal shield inconspicuous. Distances between ST2–ST2 69 (68–70), ST5–ST5 83 (80–85). One pair of metapodal shields, 24 (24–25) long. Posterior margin of genital shield wider than the ventrianal shield. Ventrianal shield very indistinct, 95 (92–97) long, 54 (51–56) wide at level of ZV2 setae and 48 (47–49) 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: ZV1, ZV3, JV4 and JV5; the latter 23 (23–24) long, smooth.

Chelicera ( Fig. 24 ). Fixed digit 30 (30–31) long, with eleven teeth, pilus dentilis distinct; movable digit 32 (32–33), with three teeth.

Spermatheca ( Fig. 25 ). Calyx elongate 19 (17–20) long, tubular and flared at the base of vesicle, slightly narrowed at the middle with thickened atrium from where the distinct minor and major duct arises.

Legs ( Fig. 26 ). Legs IV with three smooth macrosetae, pointed distally and of the following lengths: SgeIV 35 (33–36), StiIV 47 (46–48), StIV 44 (43–45). Chaetotactic formula of genu II: 0 2/1, 2/1 1; genu III: 1 2/1, 2/0 1. Length of leg I: 409 (405–413), leg II: 366 (360–375), leg III: 366 (360–375), leg IV: 459 (445–473).

Specimens examined. 13 female specimens (Acar.lab/BCKV/8323–8328/2017) collected from Wasteland weed, Tephrosia purpurea (Fabaceae) at Ballavpur, Bolpur: 23°40’09” N, 87°40’58” E, 58 m above mean sea level, Birbhum, West Bengal on 13 October 2017. Voucher slides of three female specimens (Acar.lab/BCKV/8323/2017) have been deposited in the National Zoological Collection (NZC), Zoological Survey of India, Kolkata with same collection data as above.

Distribution. Asia: India: Arunachal Pradesh: Gupta (1986); Gupta (1987b); Bihar: Gupta & Nahar (1981); Gujarat: Gupta (1977c); Himachal Pradesh: Gupta (1986); Tamil Nadu: Ghai & Menon (1969); Uttar Pradesh: Gupta (1977c, 1981, 1982); West Bengal: Gupta (1986, 1992).

Remarks. Measurements of the present specimens are compared with the measurements of those reported from India and also with the species earlier recorded from India by Gupta, 1986 ( Table 4 ). The setal measurements of our species are similar to those reported previously from India but the number of teeth on the movable digit is greater in our specimens than the original species. Other setal measurements are not available in the original description, so more detail illustrations and description are provided here.

Ecological notes. This species is recorded only from the red and laterite zone of West Bengal and is found to be associated with leguminous weeds Tephrosia purpurea , Cassia tora , Cassia sophera infested by eriophyoid mites, and was found to feed on them and other phytophagous mite species.

Figures

FIGURES 22–26. Gynaeseius ricini, female. 22. Dorsal idiosoma; 23. Ventral idiosoma; 24. Chelicera; 25. Spermatheca; 26. Genu, tibia and basitarsus IV.

FIGURES 82–92. 82. Euseius alstoniae, female, leg IV; 83. Euseius alstoniae, female, spermatheca; 84. Paraphytoseius orientalis, female, leg IV; 85. Paraphytoseius orientalis, female, chelicera; 86. Paraphytoseius orientalis, female, spermatheca. 87. Amblyseiulella heveae, female, leg IV; 88. Amblyseiulella heveae, female, chelicera; 89. Gynaeseius ricini, female, leg IV; 90. Gynaeseius ricini, female, chelicera; 91. Gynaeseius ricini, female, spermatheca; 92. Gynaeseius ricini, female, chelicera.