Arctoseius semiscissus Berlese
Creators: name: Rueda-Ramírez, Diana
name: Varela, Amanda
name: De Moraes, Gilberto J.
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Mesostigmata
Ascidae
Arctoseius
Arctoseius semiscissus

description: Arctoseius semiscissus (Berlese)
Laelaps (Iphis) semiscissus Berlese, 1892: 7.
Arctoseius bispinatus Weis-Fogh, 1948: 255 (first synonymised by Bernhard, 1963: 151). Arctoseius bicuspidatus Willmann, 1949: 355 (first synonymised by Halliday et al., 1998: 16). Arctoseius (Arctoseiulus) semiscissus.— Willmann, 1949: 357.
Arctoseius limburgensis Nesbitt, 1954: 20 (first synonymised by Halliday et al., 1998: 16).
Arctoseius sellnicki Karg, 1962: 45 (first synonymised by Bernhard, 1963: 151). Laelaps semiscissus.— Hirschmann, 1962: 48.
Morphology (female, eight specimens measured).
Gnathosoma. Fixed cheliceral digit 30 (29–30) long, with four teeth and setiform pilus dentilis; movable digit 31 (30–33), with two teeth; anterior region of epistome with two subequal, pointed, smooth projections.
Dorsal idiosoma. Dorsal shield smooth, entire, with lateral incisions at line of fusion between podonotal and opisthonotal shields; 392 (345–422) long and 203 (177–224) wide, with 31 pairs of setae. Unsclerotised cuticle with ten pairs of setae (s 2, r 2– r 5, R 1– R 5). Setal measurements: j 1 23 (19–25), j 2 33 (30–35), j 3 40 (37–43), j 4 35 (33–36), j 5 31 (27–35), j 6 32 (28–35), J 1 32 (31–32), J 2 32 (30–34), J 3 35 (35–35), J 4 34 (33–36), J 5 12 (11–12), z 1 16 (15–17), z 2 44 (40–49), z 3 44 (40–50), z 4 44 (41–49), z 5 35 (30–37), z 6 35 (31–39), Z 1 39 (34–43), Z 2 42 (38–45), Z 3 46 (42–49), Z 4 53 (50–57), Z 5 57 (54–60), s 1 27 (24–33), s 2 24 (23–25), s 3 48 (42–50), s 4 49 (45–52), s 5 47 (44–52), s 6 46 (42–49), S 1 44 (40–47), S 2 45 (41–49), S 3 44 (40–47), S 5 50 (46–55), r 2 30 (27–32), r 3 37 (31–40), r 4 31 (28–35), r 5 32 (28–35), R 1 30 (26–35), R 2 29 (25–32), R 3 28 (24–30), R 4 27 (22–31), R 5 29 (24– 32); setae aciculate and smooth.
Ventral idiosoma. Base of tritosternum 18 (17–18) long and 13 (12–13) wide proximally; laciniae 58 (54–62), separated for about 90% of their total length, pilose. Presternal plates large, consolidated with sternal shield, lineate and bearing st 1. Sternal shield smooth; 84 (78–95) long and 71 (65–77) wide at the widest level, with two pairs of setae and three pairs of lyrifissures; setae st 1 29 (25–31), st 2 27 (25–30), st 3 24 (22–26), st 4 20 (18–22). Distances st 1 –st 3 79 (75–84), st 2 –st 2 63 (60–65). Genital shield punctate; 96 (85–100) long and 47 (40–55) wide at the widest level; seta st 5 20 (18–21); distance st 5 –st 5 54 (49–59). One pair of ovoid metapodal plates. Anal shield small, ovate, weakly reticulate; 75 (70–78) long and 74 (66–80) wide, bearing only circumanal setae; para-anal setae 21 (20–23), post-anal 39 (36–40); anus 20 (19–21) long. Unsclerotised cuticle around anal shield with eight pairs of setae (Jv 1 –Jv 5, Zv 1, Zv 2 and Zv 5). Endopodal and exopodal plates indistinct. Peritrematic plate narrow, abutting but not fused anteriorly with dorsal shield at level of z1 and extending posteriorly as a narrow strip behind coxa IV. Peritreme extending anteriorly to the median level of coxa II (level of s 3). Setal measurements: Jv 1 22 (20–25), Jv 2 24 (22–26), Jv 3 24 (20–25), Jv 4 22 (20–23), Jv 5 40 (37–43), Zv 1 19 (15–21), Zv 2 22 (18–26), Zv 4 29 (27–32), Zv 5 31 (26–35); setae aciculate and smooth.
Legs. Setation: genua I–IV: 12, 10, 7, 7; tibiae I–IV: 12, 9, 7, 6.
Material examined. Six and two females, respectively, from soil of the fragment of Andean forest (pH 3.6– 4.4; organic matter 45%; humidity 60–73%; soil temperature 10–11°C), and of the grassland (pH 5.2; organic matter 57%; humidity 57%; soil temperature 13°C) in August and October, 2010.
Remarks. This species was originally described from Italy. The specimens examined are larger than reported by Kalúz & Fenďa (2005) in a complementary description based on mites collected in Slovakia (340 long and 151 wide). Concurrently, the setae are also longer, especially J 5 (5 µ, in Slovakian specimens). Of the 18 specimens collected, eight were fixed by the gnathosoma to an adult Sciaridae (Diptera). This, as well as other species of this genus, have been reported phoretically on adult flies of that family and as predators of sciarid eggs and larvae (Binns 1972, 1974; Dmoch 1995 cited by Rudzińska 1998; Gerson et al. 2003).
description: Published as part of Rueda-Ramírez, Diana, Varela, Amanda & De Moraes, Gilberto J., 2016, Soil mites of the families Ascidae, Blattisociidae and Melicharidae (Acari: Mesostigmata) from mountainous areas of Colombia, pp. 493-514 in Zootaxa 4127 (3) on pages 494-495, DOI: 10.11646/zootaxa.4127.3.5, http://zenodo.org/record/268209