Metaseiulus (Metaseiulus) smithi ( Schuster, 1957 )

Faraji, Farid & Hoekstra, Paul H., 2021, Some new species records of the predatory mite family Phytoseiidae (Acari: Mesostigmata) from The Netherlands, Soil Organisms 93 (1), pp. 35-57 : 54

Metaseiulus (Metaseiulus) smithi ( Schuster, 1957)

For other names and synonyms see Demite et al. (2021)

( Fig. 13 : A–E)

Female– Five specimens measured.

Idiosomal setal pattern: 12A:6B/JV–4:ZV–3.

Dorsal idiosoma ( Fig. 13A ) – Dorsal shield reticulated 405 (373–423) long and 212 (195–224) wide at j 6 level, with 18 pairs of dorsal setae (r 3 and R 1 included); dorsal shield setae smooth, except for Z 4 and Z 5 slightly serrated; lengths: j 1 31 (30–32), j 3 37 (35–38), j 4 27 (26–28), j 5 29 (26–32), j 6 38 (35–41), J 2 46 (39–49), J 5 13 (11–14), z 2 32 (31–35), z 3 36 (32–41), z 4 41 (38–44), z 5 30 (27–32), Z 4 57 (52–65), Z 5 66 (60–72), s 4 47 (46–49), s 6 52 (46–57), S 5 24 (23–24), setae r 3 33 (30–37) and R 1 54 (51–59) on lateral integument; dorsal shield with 4 pairs of solenostomes (gd 2, gd 6, gd 8, gd 9) and 10 pairs of small poroids.

Peritreme – Extending to the level between setae z 3 and z 4 ( Fig. 13A ).

Ventral idiosoma ( Fig. 13B ) – Sternal shield smooth, wider than long, posterior margin almost straight, 73 (71–75) long, 82 (76–87) wide at level of setae ST 2, with two pairs of setae and two pairs of pores (iv 1 and iv 2), ST 1 34–37, ST 2 35–36; distances between ST 1 –ST 2 34 (32–35), ST 1 –ST 1 50 (49–51) and ST 2 –ST 2 57 (55–58); ST 3 33–36 on the integument, metasternal setae ST 4 32–38 and a pair of pores (iv 3) on small platelets; genital shield smooth, width at widest point 73 (70–74), ST 5 35–36; two pairs of metapodal shields, primary 36 (33–40) long and accessory 13–16 long; ventrianal shield smooth, pentagonal with anterior margin straight ( Fig. 13B ), length 117 (109–130), width at level of setae ZV 2, 73 (63–81), and width at level of paranal setae 89 (77–103); with two pairs of preanal setae (JV 2 27–34, JV 3 29–33); three pairs of setae surrounding ventrianal shield on integument (JV 1 27–35, JV 5 65 (63– 68), ZV 1 28–32), pores and small platelets surrounding ventrianal shield not visible. Ventrianal shield with a pair of small round pores (gv 3) posteromesad to JV 2, distance between these pores 40 (36–46).

Spermatheca – Calyx saccular 17–21 long, calyx 11–13 in diameter at vesicle and 5 at the middle part; atrium inserted at the base of calyx ( Fig. 13C ).

Chelicera – Fixed digit 31–32 long with 3 teeth and a pilus dentilis; movable digit 33 long with 1 tooth ( Fig. 13D ).

Legs – Leg IV ( Fig. 13E ) with one pointed macroseta, StIV 61 (55–66); legs I, II and III with no recognizable macrosetae; length of legs from the base of coxae to the tip of claws: leg I 449 (436–475), leg II 357 (340–368), leg III 365 (354–377), leg IV 487 (460–507); chaetotactic formulae of genua and tibiae I–II–III–IV with 11 (2-2/2, 2/1-2) – 8 (2-2/1, 2/0-1) – 7 (1-2/1, 2/0-1) – 7 (1-2/1, 2/0-1) and 10 (2-2/1, 2/1-2) – 7 (1-1/1, 2/1-1) – 7 (1-1/1, 2/1-1) – 6 (1-1/1, 2/0-1) setae respectively.

Distribution – Canada, The Netherlands (this study), USA.

Specimen examined – Two females, 05 June 2018 and three females, 29 June 2018, unidentified weeds of a grassland meadow, situated near the village of Ooij , The Netherlands (51°50’45.8”N 5°55’56.6”E), collector: Bogdan Dehelean.

Remarks – This is a new species record for Dutch fauna. This species has three noticeable features: ventrianal shield with two pairs of preanal setae, relatively short peritreme and tibia I with 11 setae. Chant & Yoshia-Shaul (1984) provided a re-description of M. smithi based on a paratype. Compared to that description, the Dutch specimens have slightly longer dorsal setae. There is also one extra pair of solenostomes (gd 9) instead of three pairs mentioned by Chant & Yoshia-Shaul (1984). This is the first record of M. smithi from Europe. We think this species has been introduced to The Netherlands from North America. Since almost all of the species of the genus Metaseiulus are distributed in North, Central and South America and because M. smithi has only been found in Canada and USA.

Figures

Figure 13. Metaseiulus(Metaseiulus)smithi (Schuster) (Female):(A)Idiosoma,dorsal view;(B) Idiosoma,ventral view;(C)Spermathecae; (D) Chelicera; (E) Leg IV.