Euseius tubuliferus, Kar & Karmakar, 2022

Kar, Anamika & Karmakar, Krishna, 2022, Description of nine new species of phytoseiid mites (Acari: Mesostigmata) from Sikkim, a north eastern States of India, Zootaxa 5182 (3), pp. 201-237 : 211-213

Euseius tubuliferus sp. nov.

( Figs. 16–20 ; 60–63)

Diagnosis. Dorsum reticulated; peritreme extends between z2 and j3; fixed digit of chelicerae with four distinct teeth and a pilus dentilis; spermatheca unique elongated, tubular; leg IV with three pointed macrosetae.

Description. Female (n = 10). Dorsum ( Fig. 16 ). Dorsal shield 360 (358–362) long and 223 (222–225) wide, reticulated, with marks of sigilla mostly on prodorsal area, prodorsum wide with five pairs of solenostomes (gd2, gd4, gd5, gd8 and gd9); 17 pairs of setae on dorsal shield and two pairs of setae on unsclerotised cuticle: j1 33 (31–34), j3 28 (27–30), j4 12 (9–12), j5 12 (9–12), j6 14 (13–15), J2 17 (15–18), J5 4 (3–5), z2 16 (13–16), z4 20 (16–20), z5 12 (10–13), Z1 17 (16–18), Z4 16 (15–18), Z5 52 (50–54), s4 27 (25–28), S2 20 (18–21), S4 18 (17–20), S5 20 (19–21), r3 15 (13–16), R1 12 (10–13). All setae smooth, setae j1, j3, z2, z4, s4, S2, S4 and S5 long, seta Z5 longest, all other setae medium.

Peritreme ( Fig. 16 ). Extending between z2 and j3.

Venter ( Fig. 17 ). Sternal shield square shaped, posterior margin of sternal shield indistinct and forms a groove at the lateral part of the posterior margin of sternal shield. Sternal shield 68 (65–69) long and 86 (84–88) 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 unsclerotised membrane 28 (26–29) long and conspicuous lyrifissures on distinct metasternal plate. Distances between st2-st2 73 (72–75), st5-st5 86 (85–88). Two pairs of metapodal shields present. Primary metapodal shield 18 (17–20) long and 4 (3–4) wide, secondary metapodal shield 6 (5–8). Genital shield smooth, broad at base and narrow at genital opening with irregular circular flap touching sternal loop anteriorly. Ventrianal shield smooth, 110 (108–111) long, 56 (55–58) wide at level of ZV2 and 72 (70–74) wide at anus level with three pairs of pre-anal setae, JV1 22 (22–25), JV2 27 (26–29), ZV2 27 (26–29) and one pair of large elliptical pre-anal pores (gv3) 28 (27–30) apart just below JV2. Membrane surrounding ventrianal shield with four pairs of setae ZV1 26 (24–27), ZV3 16 (15–18), JV4 14 (12–15) and JV5 28 (27–30); seta JV5 long and smooth.

Chelicera ( Fig. 18 ). Fixed digit 22 (21–24) long with four teeth clubbed anteriorly and distinct pilus dentilis, movable digit 22 (22–24) long with one tooth.

Spermatheca ( Fig. 19 ). Calyx unique, elongated, tubular 42 (40–44) long, minor duct and major duct visible.

Leg ( Fig. 20 ). Length of leg I 375 (372–380), leg II 300 (298–305), leg III 280 (278–283) and leg IV 400 (396–404). Chaetotactic formula of genu II 1 2/1 1/1 1 and genu III 1 1/1 2/1 1. The genu, tibia and tarsus of leg IV with pointed tip macrosetae of following lengths: SgeIV 43 (41–44), StiIV 39 (38–41) and StaIV 55 (54–56).

Type specimens. Holotype: female (Acarol.lab/ BCKV/8647 /2021) deposited in the NZC, Zoological Survey of India, Kolkata, collected from unidentified plant at East Sikkim: 27°22’52”N, 88°38’15”E, 1733 m AMSL, Sikkim on 6 th February , 2021; 9 paratype females (Acarol.lab/ BCKV/8647-8648 /2019) with same collection data as holotype deposited in Acarology laboratory of BCKV, Mohanpur.

Etymology. The specific name tubuliferus refers to the long tubular spermatheca of the new species.

Remarks. The new species is closed to Euseius delhiensis ( Narayanan & Kaur, 1960) , E. rhododendronis Gupta, 1970 and E. alstoniae (Gupta, 1975) ; by having similar type of venter and spermatheca but differs from these species by the length of dorsal shield setae, ventrianal shield, number of teeth in chelicera, shape of spermatheca and leg macrosetae. All the differences between the new species and the close species are presented in table 4.

Figures

FIGURES 16–20. Euseius tubuliferus (female). 16. Dorsal view of idiosoma; 17. Ventral view of idiosoma; 18. Chelicera; 19. Spermatheca; 20. Genu, tibia and basitarsus of leg IV.