Euseius finlandicus Oudemans, 1915

Ahmad-Hosseini, Mohammad, Khanjani, Mohammad & Karamian, Roya, 2019, Study on predatory mites of Aceria tristriatus (Nalepa, 1890) from Hamedan and Lorestan provinces, Western Iran, Persian Journal of Acarology 8 (2), pp. 125-145 : 127-129

Euseius finlandicus Oudemans, 1915 ( Figs. 1–7 )

Diagnosis (female)

Dorsal shield with six pairs of solenostomes (gd2, gd4, gd5, gd6, gd8, gd9); setae r3 and R1 on dorsal integument, setae j5 and j6 are equal in length, peritremes relatively short and extending to the level of setae j1, calyx of spermatheca short and bulged, movable and fixed digits of chelicera with five and one teeth, respectively. Genu IV, tibia IV and basitarsus IV each on with one sharptipped macroseta.

Female ( Figs. 1–5 )

Idiosoma oval; setal pattern: 10A-9B/JV-3: ZV. All setae smooth.

Dorsum ( Fig. 1 ) – Dorsal shield reticulated, concave near R1, 345–358 long, 198–207 wide at level of setae R1. Length of setae: j1 30–32, j3 33–35, j4 17–18, j5 16–17, j6 16–18, J2 20–22, J5 6–7, z2 25–27, z4 27–29, z5 16–17, Z4 19–22, Z5 55–58, s4 39 –41, S2 24 –27, S4 22 –23, S5 22 –24, r3 18–19, R1 15–16.

Venter ( Fig. 2 ) – Venter of idiosoma with 13 pairs of setae or 27 setae (postanal seta unpaired), sternal shield smooth, with 3 pairs of equally long setae ST1- ST3 (31–33) and two pairs of lyrifissures (iv1–2); without posterior margin, distance between of setae: ST1–ST1 56–61, ST1– ST2 31–34, ST1–ST3 59–63. The fourth sternal setae ST4 (29–30) set on soft integument. Genital shield 130–137 long, 80–86 wide at level setae ST5, with one pair setae, ST5 31–33 long. Venter of idiosoma with two pairs of elongate metapodal platelets (29–33 and 14–16 long). Ventrianal shield 107–112 long, 56–60 wide at level of Zv2 and 70–74 wide at level of anus. Pre-anal region with three pairs of pre-anal setae JV1 24–26, JV2 25–27 and ZV2 23–25 long and with one pair pre-anal pores; anal opening surrounded with 3 setae, paranal setae PA 17–18 and post anal seta PST 19–21 long. Opisthogastric cuticle bearing four pairs of setae, JV4 14–15 and JV5 35–38, ZV1 29–31, ZV3 13–14, long, all smooth, and six pairs of lyrifissures.

Chelicerae 94–98 long; fixed digit with five teeth and 25–27 long, pilus dentilis 5–6 long, movable digit 23–24 long and with a one tooth ( Fig. 3 ). Calyx of spermatheca ( Fig. 4 ) bulged and 10–11 long, minor and major ductus are well visible. Peritreme stippled, extending to level of setae r3, 168–173 long. Length of legs I–IV (excluding pretarsus): 368–375, 298–305, 303–309, 402– 406, respectively. Legs IV with three smooth and sharp-tipped macrosetae, genua (SgeIV) 38–42, tibia (StiIV) 36–39, basitarsus (StIV) 63–67 ( Fig. 5 ). Setal formulae of legs (I-IV): femur 12-10-6-6, genu 10-7-7-7, tibia 10-7-7-6.

Male ( Figs. 6, 7 )

Setal pattern: 10A-9B/JV-3,4: ZV-1,3. All setae smooth, setae r3 and R1 on dorsal integument.

Dorsum – Dorsal shield reticulated, concave near R1 , 335–343 long, 193–205 wide at level of setae R1 . Length of setae: j1 29, j3 31, j4 18, j5 17, J2 16, J5 5, z4 27, z5 15, Z4 20, Z5 44, s4 36, S2 20, S4 19, S5 20, r3 16, R1 14.

Venter ( Fig. 6 ) – Sternogenital shield smooth, with 5 pairs of setae (ST1 25, ST2 26, ST3 23, ST4 24, ST5 23) and two pairs of lyrifissures (iv1–2). Ventrianal shield triangular, reticulated in anterior half and smooth in posterior half, anterior margin convex, 95 long, 147 wide at level of setae ZV2, with three pairs of pre-anal setae (JV1 20, JV2 21 and ZV2 19); one pair of lyrifissures and one pair pre-anal pores. Para-anal setae PA 12 and post anal seta PST 17 long. Opisthogastric cuticle with one pair of setae (JV5 26) and three pairs of lyrifissures.

Chelicerae 82 long; fixed digit 22 long, with four teeth; pilus dentilis 4 long; movable digit 19 long, with one tooth, shaft of spermadactyl 24 long, straighten and inflated distally ( Fig. 7 ). Length of legs I–IV (excluding pretarsus): 313, 250, 248, 330, respectively. Legs IV with three smooth and sharp-tipped macrosetae, genua (Sge IV) 30, tibia (Sti IV) 32, basitarsus (St IV) 52. Setal formulae of legs (I-IV) are identical to the female.

Remarks

Knowledge about this species is fragmentary, though the short bulged spermatheca seems to be its major distinguishing character. Our specimens resemble the re-description (figures) of Papadoulis et al. (2009) from Greece in all respects. However, in the Iranian specimens, the fixed cheliceral digit has five teeth instead of three in the specimens from Greece.

Material examined

Hamedan Province: Heydareh village (34° 48’ N; 48° 28’ E) – 19 Sep. 2014 (n = 5) , 9 Oct. 2015 (n = 3) , 3 Dec. 2015 (n = 7), 29 Oct. 2016 (n = 3); Shahrestaneh village (34° 70’ N; 48° 35’ E) – 18 Nov. 2014 (n = 12) , 15 Aug. 2017 (n = 6) ; Avarzaman village (34° 17’ N; 48° 49’ E) – 2 Oct. 2016 (n = 3) , Ganjnameh (34° 45’ N; 48° 26’ E) – 1 Nov. 2015 (n = 5) . Lorestan Province: Kahman canyon (33° 57’ N; 48° 19’ E) – 30 Aug. 2015 (n = 5) , 4 Sep. 2015 (n = 4) , Aleshtar county (33° 32’ N; 49° 27’ E) – 4 Sep. 2015 (n = 6) , Kakareza village (33° 43’ N, 48° 15’ E) – 25 Sep. 2016 (n = 5).

Figures

Figures 1–7. Euseius finlandicus (Oudemans, 1915) – 1. Dorsal view of idiosoma (adult female); 2. Ventral view of idiosoma (adult female); 3. Chelicera (adult female); 4. Spermatheca (adult female); 5. Leg IV (adult female); 6. Ventral view of idiosoma (adult male); 7. Chelicera (adult male).