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The genus Dendroseius Karg (Acari: Digamasellidae) in Iran, with description of the male and deutonymph of Dendroseius amoliensis

Mohammadi, Leila1 and Hajizadeh, Jalil 2

1Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran.
2✉ Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran.

2022 - Volume: 62 Issue: 3 pages: 637-652

https://doi.org/10.24349/aws7-hhka
ZooBank LSID: 7CA38D40-3228-4532-8A75-57514A327E81

Original research

Keywords

Gamasida morphometric data new record Rhodacaroidea Guilan

Abstract

We provide the first descriptions of the adult male, deutonymphal stage and extended morphometric data for adult female of Dendroseius amoliensis Faraji, Sakenin-Chelav & Karg, collected from the rotten stump in Guilan province, Iran. Moreover, Dendroseius vulgaris Ma, Ho & Wang is recorded for the first time from Iran, collected from the livestock manure and decayed rice bran. Morphometric measurements of D. vulgaris based on specimens collected in Iran are given. An updated key to all known species of the genus is also presented.


Introduction

Predaceous mites of family Digamasellidae are widespread in soil and decaying organic material such as compost, manure and debris. Some species are found in galleries of bark beetles, bracket fungi or in association with wood-boring beetles. Digamasellid mites feed on collembolans, nematodes, arthropod eggs and possibly fungi (Walter et al., 1988; Lindquist et al., 2009; Walter and Proctor, 2013). Family Digamasellidae currently contains 14 genera, including the genus Dendroseius (Castilho et al., 2012; Faraji et al., 2021).

Dendroseius was initially described by Karg (1965), as a subgenus of Dendrolaelaps Halbert, 1915 and considered at the generic level by Hirschmann (1974), Lindquist (1975), Evans and Till (1979), Shcherbak (1980), Karg (1993), Faraji et al. (2006) and Mašán (2020). Most species of the genus Dendroseius are found in soil detritus (D. amoliensis, D. reticulatus, D. vulgaris), wood substrates (D. congoensis, D. vulgaris, D. redectus), and manure or cow dung (D. badenhorsti, D. vulgaris), deutonymphs of D. gujarati was found on an unidentified scarabaeid beetle (Sheals, 1956, 1958; Ryke, 1962; Wiśniewski and Hirschmann, 1989; Wiśniewski and Hirschmann, 1992; Karg, 1993; Faraji et al., 2006; Ma et al., 2014; Mašán, 2020).

During a faunistic survey on Rhodacaroidea in Guilan Province, northern Iran, in 2021–2022, the species Dendroseius amoliensis Faraji, Sakenin-Chelav & Karg, 2006 was collected from the rotten stumps. This species was originally described based on female specimens collected from soil and debris in Amol, northern Iran (Faraji et al., 2006). In this paper, we provide the first descriptions of the adult male and deutonymphal stage and extended morphometric data for adult female of Dendroseius amoliensis Faraji, Sakenin-Chelav & Karg. Moreover, Dendroseius vulgaris Ma, Ho & Wang, 2014 is recorded for the first time from Iran. An updated key to all known species of the genus is also presented.

Material and methods

Samples were taken weekly from various areas and habitats in Guilan Province, northern Iran. The samples were collected from 2021 to 2022. Mites were extracted from samples of the rotten stump, cow and poultry manure, and decayed rice bran using a Berlese/Tullgren funnel. Mite specimens were preserved in 70% ethanol, cleared in Nesbitt's fluid and mounted in Hoyer's medium on microscope slides. Mites were identified according to Faraji et al. (2006) and Mašán (2020). Setal nomenclature for dorsal and ventral idiosomal setae follows Lindquist & Evans (1965), and that for leg and palp setae follows that of Evans (1963a, 1963b). Identification of pore-like structures on the idiosomal integument is based on the morphological observations of Athias-Henriot (1969); notation for these structures such as adenotaxy and poroidotaxy follows Johnston and Moraza (1991). All measurements are given in micrometers (μm). The length of the idiosoma and shields were taken from the anterior to posterior margins along the midline and from widths at their broadest point. The length of legs (I–IV) were taken from the base of the coxa to the apex of the tarsus, without the pretarsus. Setae were measured from the base of their insertions to their tips. The mean of the measurements is given followed by the range in parentheses. Morphological observations, measurements, and illustrations were made using a compound laboratory biological microscope model HP-41 (China) equipped with differential interference contrast and phase contrast optical systems and an Olympus microscope model BH-2 (Japan) equipped with drawing tube, and a Canon camera (EOS Kiss X5; Japan). The voucher specimens of each species were preserved as slide-mounted specimens deposited in the Acari collection of the Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan and Jalal Afshar Zoological Museum, Tehran, Iran.

Results

Digamasellidae Evans, 1957

Dendroseius Karg, 1965

Dendrolaelaps (Dendroseius) Karg, 1965: 297.

Dendrolaelaps (Dendroseius) Karg, 1971: 317.

Dendroseius Lindquist, 1975: 12; Shcherbak, 1980: 172.

Type species: Dendrolaelaps scotarius Sheals, 1958, by original designation (objective junior synonym of Digamasellus reticulatus Sheals, 1956).

Diagnosis — Dorsal setae j2 situated between setae j1 and j3, not in a transverse setal row between j1 and z1; deutosternum with seven transverse furrows of which none is reaching beyond the lateral borders of the groove; movable digit of chelicera with three teeth in addition to the apical tooth; opisthonotal shield with straight anterior margin; sperm induction system associated with coxae IV.

Dendroseius amoliensis Faraji, Sakenin-Chelav & Karg, 2006

Description

Adult male — five specimens measured. (Figures 1, 3A–B and 4)

Figure 1. Dendroseius amoliensis male: A – Idiosoma, dorsal view; B – Idiosoma, ventral view; C – Tritosternum; D-F – Epistome; G – Chelicerae; H – Hypostome. Scale bar: 90 µm for A and B; 15 µm for C; 30 µm for D, E and F; 20 µm for G; 40 µm for H.

Pale yellow colored, idiosoma oval, length 303 (296–312), width 197 (180–212). All setae smooth.

Dorsal idiosoma (Figures 1A, 4A) – Dorsal shield divided to podonotal and opisthonotal. Podonotal shield 162 (158–168) long with 21 pairs of setae (j1j6, z1z6, s1s6, r2 and r4r5), five pairs of lyrifissures (id1, id2, id4, id5, id6) and two pairs of gland pores (gd1, gd2). Opisthonotal shield 146 (140–148) long with 20 pairs setae (J1J5, Z1Z5, S1S5 and R1R5) and nine pairs of lyrifissures (idm2, idm3, idm4, idm5, idm6, idl1, idl2, idl3, idl4). Measurements of setae: j1 11 (8–14), j2 18 (17–20), j3 20, j4 18 (16–20), j5 18 (16–19), j6 17 (16–19), z1 8 shortest, z2 19 (18–20), z3 19 (18–20), z4 20, z5 18, z6 19 (16–20), s1 15 (12–17), s2 18 (16–20), s3 20, s4 21 (20–22), s5 21 (20–22), s6 19 (18–20), r2 17 (16–18), r3 24, r4 15 (12–18), r5 16 (14–20), J1 18, J2 19 (17–20), J3 19 (18–20), J4 20, J5 14, Z1 19 (17–20), Z2 20, Z3 21, Z4 22, Z5 29 (28–30) longest, S1 18 (16–19), S2 20, S3 20, S4 20, S5 21 (20–22), R1 13 (12–14), R2 16 (14–17), R3 16, R4 17 (16–18), R5 18 (17–20). Setae r3 on soft cuticle along dorsal shield lateral margins. All setae smooth. Two pairs of scleronoduli are located between setae j5 and j6.

Ventral idiosoma (Figures 1B, 4B) – Tritosternum (Figure 1C) 44 (40–46) long, base 9 (8–10) long and 7 (4–6) wide, laciniae 35 (32–38) long, totally separated. Sternogenital shield 146 (140–150) long and 80 (78–84) wide, smooth but slightly striated on the lateral sides, with four pairs of setae, st1 23 (20–24), st2 21 (20–22), st3 19 (18–20), st4 17 (16–18) and three pairs of lyrifissures (iv1 posterior to st1, iv2 the level between coxae II–III and iv3 anterior to st4). Setae st5 16 on a pair of separate subtriangular plates posterolateral of sternogenital shield, a pair of lyrifissures located in soft cuticle posterior to st5 plates (iv5). Ventrianal shield 126 (122–130) long, reticulated; fused laterally and posteriorly with opisthonotal shield, with seven pairs of preanal setae, Jv1 16, Jv2 16, Jv3 17 (16–18), Jv4 16, Zv1 13 (10–14), Zv2 16 (14–17), Zv3 15 (14–16), para-anal 26, post-anal 13 (12–14) and three pairs of lyrifissures (ivo1, ivo2, ivp). Peritreme shortened 56 (52–60) long, with anterior end reaching to the anterior level of coxa III. Peritrematic shield well developed, free from podonotal shield with narrowed ends. Exopodal shield fragmented in two parts: between coxa II and III and between coxa III and IV.

Gnathosoma – Epistome (Figures 1D–F, 4E and F) with three-pointed prongs, middle prong 11 (8–13) shorter than the lateral prongs 16 (12–19); variations in the shape of the epistome were observed. Palp apotele two-tined. Fixed cheliceral digit 30 (26–32) long, with two teeth in addition the apical tooth and a setiform pilus dentilis; movable cheliceral digit 31 (28–32) long, with one tooth in addition to apical tooth; spermatodactyl 34 long, sickle-shaped, slightly longer than movable cheliceral digit (Figures 1G, 4D). Corniculi horn-like. Deutosternum with seven rows; six rows (2–7) with tiny denticles. Hypostomal setae smooth, h1 17 (16–20), h2 10 (8–11), h3 17 (16–18), pc 17 (16–18) (Figures. 1H, 4G).

Legs – All legs with pretarsi, claws well sclerotized and pulvilli well developed. Lengths, excluding pretarsi: leg I 294 (280–300), leg II 222 (220–228), leg III 202 (200–208), leg IV 276 (272–280). Chaetotactic pattern of legs: leg I – coxa 0 0/1, 0/1 0 (2), trochanter 1 1/1, 0/2 1 (6), femur 2 3/2, 2/2 2 (13), genu 2 3/2, 2/1 2 (12), tibia 2 3/2, 2/1 2 (12); leg II – coxa 0 0/1, 0/1 0 (2), trochanter 1 0/1, 0/2 1 (5), femur 2 2/1, 2/2 1 (10), genu 2 3/1, 2/1 2 (11), tibia 2 2/1, 2/1 2 (10); leg III – coxa 0 0/1, 0/1 0 (2), trochanter 1 1/1, 0/2 0 (5), femur 1 2/1, 1/0 1 (6), genu 2 2/1, 2/1 1 (9), tibia 2 1/1, 2/1 1 (8); leg IV – coxa 0 0/1, 0/0 0 (1), trochanter 1 1/1, 0/2 0 (5), femur 1 2/1, 1/0 1 (6), genu 1 2/1, 2/0 1 (7), tibia 1 1/1, 2/1 1 (7). All leg setae aciculate, except femur II, genu II and tibia II each with a spur-like macrosetae (Figures. 3A–B, 4C).

Deutonymph — five specimens measured. (Figures 2, 3C–D and 5)

Figure 2. Dendroseius amoliensis deutonymph: A – Idiosoma, dorsal view; B – Idiosoma, ventral view; C – Tritosternum; D – Epistome; E – Chelicerae; F – Hypostome. Scale bar: 80 µm for A and B; 15 µm for C; 20 µm for D and E; 30 µm for F.

Pale yellow colored, idiosoma oval, length 282 (272–300), width 163 (152–168).

Dorsal idiosoma (Figures 2A, 5A) – Dorsal shield divided to podonotal and opisthonotal. Podonotal shield 157 (152–164) long, slightly reticulated; with 19 pairs of setae (j1j6, z1z6, s1s6 and r2) and five pairs of lyrifissures (id1, id2, id4, id5, id6) and two pairs of gland pores (gd1, gd2). Opisthonotal shield 129 (124–136) long, slightly reticulated with 15 pairs of setae (J1J5, Z1Z5 and S1S5) and nine pairs of lyrifissures (idm2, idm3, idm4, idm5, idm6, idl1, idl2, idl3, idl4). Measurements of setae: j1 15 (14–16), j2 16, j3 18 (16–20), j4 16, j5 15 (14–16), j6 14, z1 7 (6-8), z2 18, z3 15 (14–16), z4 17 (16–18), z5 14 (12–16), z6 14, s1 14 (12–16), s2 14 (10–16), s3 17 (16–18), s4 19 (18–20), s5 19 (18–20), s6 14 (12–16), r2 14, r3 20, r4 13 (12–14), r5 13 (12–15), J1 14, J2 14, J3 16, J4 17 (16–18), J5 12, Z1 16, Z2 17 (16–18), Z3 17 (16–18), Z4 20, Z5 31 (28–32), S1 14 (12–16), S2 17 (16–18), S3 15 (14–16), S4 17 (16–18), S5 18 (16–20), R1 11 (10–12), R2 10, R3 11 (10–12), R4 11 (10–12), R5 12. Setae r3-r5 and R1-R5 on soft cuticle along lateral margins of dorsal shield. All setae smooth. Peritreme extending anteriorly to level of s1.

Ventral idiosoma (Figures 2B, 5B) – Tritosternum (Figure 2C) base 20 (18–22), laciniae 32 (30–34) long, totally separated. Sternal shield 147 (144–150) long and 64 (62–66) wide, smooth, with four pairs of setae st1 15 (14–16), st2 13 (12–14), st3 11 (10–12), st4 10 and three pairs of lyrifissures (iv1, iv2, iv3). Setae st5 9 (8–10) on soft cuticle posterolaterad of sternal shield. Ventrianal shield approximately round-shaped, 66 (64–70) long, 62 (60-64) wide, reticulated, with two pairs of pre-anal setae Jv2 10 and Jv3 10 in addition to para-anal setae 21 (20–24) and post-anal seta 10 (10–12). Soft cuticle along margins of the ventrianal shield with five pairs of setae Jv1 10, Jv4 15 (14–17), Zv1 10, Zv2 11 (10–12), Zv3 10, and six pairs of lyrifissures (iv5, ivo1, ivo2, ivo3, ivo4, ivp). Metapodal plates pear-shaped; one pair of lyrifissures laterad of metapodal plates. Peritreme located on the lateral margin of the podonotal shield, extending anteriorly to the level of setae s1. Exopodal shield fragmented in two parts: between coxa II and III and between coxa III and IV.

Gnathosoma – Epistome (Figures 2D, 5E) with three prongs, middle prong 9 (8–10) shorter than the lateral prongs 13 (12–14). Palp apotele two-tined. Fixed cheliceral digit 30 (28–32) long, with five teeth in addition to the apical tooth and a setiform pilus dentilis; movable cheliceral digit 29 (28–30) long, with three teeth in addition to the apical tooth (each with the same number of the tooth as female) (Figures 2E, 5D). Corniculi horn-like. Deutosternum with seven rows, anterior row smooth, and rows 2–7 with tiny denticles. Hypostomal setae smooth, h1 16 (14–18), h2 9 (8–10), h3 15 (12–18), pc 16 (14–18) (Figures 2F, 5C).

Legs – Lengths of legs, excluding pretarsi: leg I 249 (240–260), leg II 194 (180–208), leg III 177 (164–192), leg IV 234 (224–240). Chaetotactic pattern of legs: leg I – coxa 0 0/1, 0/1 0 (2), trochanter 1 1/1, 0/2 1 (6), femur 2 2/2, 2/2 2 (12), genu 2 3/2, 2/1 2 (12), tibia 2 3/2, 2/1 2 (12); leg II – coxa 0 0/1, 0/1 0 (2), trochanter 1 0/1, 0/2 1 (5), femur 2 2/1, 2/2 1 (10), genu 2 3/1, 2/1 2 (11), tibia 2 2/1, 2/1 2 (10); leg III – coxa 0 0/1, 0/1 0 (2), trochanter 1 1/1, 0/2 0 (5), femur 1 2/1, 1/0 1 (6), genu 2 2/1, 2/1 1 (9), tibia 2 1/1, 2/1 1 (8); leg IV – coxa 0 0/1, 0/0 0 (1), trochanter 1 1/1, 0/2 0 (5), femur 1 2/1, 1/0 1 (6), genu 1 2/1, 2/0 1 (7), tibia 1 1/1, 2/1 1 (7). All leg setae are aciculate. All legs with pretarsi, each with two claws and pulvilli well developed (Figures 3C–D).

Figure 3. Dendroseius amoliensis (Male): A – Femur, genu, tibia of leg II, B – Femur, genu, tibia of leg IV; (Deutonymph): C – Femur, genu, tibia of leg II, D – Femur, genu, tibia of leg IV. Scale bar: 35 µm for A-D.

Figure 4. Dendroseius amoliensis male, photomicrographs: A – Idiosoma, dorsal view; B – Idiosoma, ventral view; C – Leg II; D – Chelicerae; E-F – Epistome; G – Hypostome. Scale bar: 90 µm for A and B; 85 µm for C; 40 µm for D; 25 µm for E and F; 75 µm for G.

Figure 5. Dendroseius amoliensis deutonymph, photomicrographs: A – Idiosoma, dorsal view; B – Idiosoma, ventral view; C – Hypostome; D – Chelicerae; E – Epitome. Scale bar: 70 µm for A and B; 55 µm for C; 30 µm for D; 20 µm for E.

Female — five specimens measured. (Figure 6)

Figure 6. Dendroseius amoliensis female, photomicrographs: A – Idiosoma, dorsal view; B – Idiosoma, ventral view; C – Ventrianal shield; D – Epistome. Scale bar: 80 µm for A and B; 50 µm for C; 20 µm for D.

Dorsal idiosoma (Figure 6A) – Dorsal shield, 354 (344–364) long; j1 19 (16–20), j2 20 (18–22), j3 20 (18–22), j4 20, j5 19 (18–20), j6 20, z1 9 (8–10) shortest, z2 20 (18–21), z3 21 (18–24), z4 22 (20–24), z5 20, z6 21 (20–22), s1 16 (15–18), s2 17 (16–18), s3 18, s4 20 (18–22), s5 22 (20–24), s6 21 (20–22), r2 18 (14–20), r3 29 (28–30), r4 19 (18–20), r5 20, J1 21 (20–22), J2 23 (22–24), J3 23 (22–25), J4 24 (22–25), J5 19 (18–20), Z1 22, Z2 23 (22–24), Z3 25 (22–26), Z4 28, Z5 40 (38–42) longest, S1 21 (18–23), S2 23 (21–25), S3 24 (22–25), S4 28 (26–29), S5 29 (28–30), R1 16 (14–17), R2 20, R3 21 (20–22), R4 23 (21–24), R5 24 (22–25). Ventral idiosoma (Figure 6B): Sternal shield 105 (102–108) long and 80 (76–82) wide, with four pairs of setae, st1 24 (20–26), st2 24 (20–26), st3 23 (20–24), st4 22 (20–23). Genital shield 54 wide, setae st5 22 (20–24); ventrianal shield 120 (118–122) long; with seven pairs of preanal setae, Jv1 18 (16–20), Jv2 19 (16–20), Jv3 19 (16–20), Jv4 23 (20–26), Zv1 16, Zv2 18 (16–19), Zv3 17 (16–18), para-anal 27 (24–30), post-anal 13 (12–14). Metapodal plate length 24 (20–26). Anus length 16 (14–18). Gnathosoma: Epistome (Figure 6D) with three-pointed prongs, middle prong 13(12–14) shorter than the lateral prongs 18 (17–20). Palp apotele two-tined. Fixed cheliceral digit 38 (36–40) long, with five teeth in addition the apical tooth and a setiform pilus dentilis; movable cheliceral digit 37 (36–39) long, with three teeth in addition to apical tooth. Corniculi horn-like; deutosternum with seven rows; six rows (2–7) with tiny denticles; hypostomal setae smooth, h1 18 (16–20), h2 10, h3 18 (15–20), pc 17(16–18). Legs: All legs with pretarsi, claws well sclerotized and pulvilli well developed. Lengths, excluding pretarsi: leg I 287 (272–304), leg II 226 (220–240), leg III 196, leg IV 270 (260–280).

Material examined

Nineteen females, 11 males, ten deutonymphs, Rasht County, Saravan forest, (37°04′15.8″N, 49°37′50.2″E, alt. 72 m), rotten wood, 11 December, 2021, collector: Leila Mohammadi.

Remarks

Comparison of some metric characters of Dendroseius amoliensis female specimens collected in Guilan province Iran, with those of the original description shows similarities for most of the measurements, only a small difference observed in the size of z1 (9 vs. 11), st1 (24 vs. 28), st2 (24 vs. 27), Jv4 (23 vs. 25), Zv3 (17 vs. 20), h1 (18 vs. 22), h2 (10 vs. 13), pc (17 vs. 20), para-anal (27 vs. 32) and post-anal (13 vs. 18) setae and width of ventrianal shield (117 vs. 123) that are slightly shorter in our specimens. Also, length of S4 (28 vs. 26), r3 (29 vs. 27) setae, length of ventrianal shield (120 vs. 116) and fixed digit of chelicerae (38 vs. 35) are slightly longer in our specimens. We consider these negligible differences in size as intraspecific morphological variation. Despite these, we could find a significant difference in the position of setae Zv3 which in the original description, Zv3 are off the ventrianal shield while in the examined specimens Zv3 located on the ventrianal shield (Figure 6C).

Dendroseius vulgaris Ma, Ho & Wang, 2014

Female — five specimens measured (Figure 7)

Figure 7. Dendroseius vulgaris female, photomicrographs: A – Idiosoma, dorsal view; B – Idiosoma, ventral view; C – Hypostome and tritosternum; D – Chelicerae and palp; E – Epitome. Scale bar: 85 µm for A and B; 38 µm for C; 57 µm for D; 23 µm for E.

Dorsal idiosoma (Figure 7A) – Dorsal shield, 352 (336–376) long. Podonotal shield 167 (160–174) long and 179 (170–190) wide; opisthonotal shield 194 (180–208) long and 176 (160–190) wide; j1 21 (20–22), j2 25 (23–28), j3 33 (30–35), j4 28 (26–30), j5 30, j6 26 (24–28), z1 16 (12–24) shortest, z2 30, z3 32, z4 35 (34–36), z5 28 (26–32), z6 26 (23–28), s1 19 (14–24), s2 27 (26–28), s3 33 (32–34), s4 33 (30–36), s5 33 (32–36), s6 31 (30–32), r2 21 (14-24), r3 31 (26–34), r4 20 (18–22), r5 22 (20–24), J1 27 (26–30), J2 32, J3 32 (30–34), J4 40, J5 30, Z1 37 (34–40), Z2 38 (36–40), Z3 36 (34–40), Z4 42 (40–44), Z5 48 (44–50) longest, S1 34 (32–36), S2 34, S3 35 (32–38), S4 37 (34–42), S5 37 (34–44), R1 20 (16–22), R2 26 (24–28), R3 30, R4 32 (30–34), R5 35 (34–36). Ventral idiosoma (Figure 7B): Tritosternum (Figure 7C) base 20 and Laciniae 38 (34–40) long; sternal shield 69 (64–74) long and 70 (62–74) wide, with four pairs of setae, st1 24 (22–26), st2 24 (22–26), st3 24 (22–26), st4 24; genital shield 56 (52–62) wide, Setae st5 21 (20–22); ventrianal shield 128 (118–144) long and 118 (104–125) wide; with seven pairs of preanal setae, Jv1 20 (18–22), Jv2 26, Jv3 29 (28–30), Jv5 34 (28–36), Zv1 18 (16–20), Zv2 18 (12–22), Zv3 22, para-anal 32 (30–34), post-anal 19 (16–22). Gnathosoma: Epistome (Figure 7E) with three-pointed prongs; palp apotele two-tined; fixed cheliceral digit 32 long, with seven teeth in addition the apical tooth and a setiform pilus dentilis; movable cheliceral digit 33 (32–36) long, with three teeth in addition to apical tooth (Figure 7D); corniculi horn-like; deutosternum with seven rows; hypostomal setae smooth, h1 19 (18–20), h2 9 (8–10), h3 21(20–22), pc 19 (16–20) (Figure 7C). Legs: Lengths, excluding pretarsi: leg I 289 (280–296), leg II 202 (200–208), leg III 174 (160–184), leg IV 248 (240–260).

Male — five specimens measured. (Figure 8)

Figure 8. Dendroseius vulgaris male, photomicrographs: A – Idiosoma, dorsal view; B – Idiosoma, ventral view; C – Chelicerae and palp; D – Hypostome and tritosternum; E – Leg II; F – Epitome. Scale bar: 77 µm for A and B; 52 µm for C; 53 µm for D; 98 µm for E; 20 µm for F.

Dorsal idiosoma (Figure 8A) – Dorsal shield, 298 (284–320) long and 189 (176–200) wide. Podonotal shield 146 (140–160) long; opisthonotal shield 157 (146–170) long; j1 15 (14–16), j2 23 (22–24), j3 29 (28–30), j4 24 (22–25), j5 24 (22–25), j6 22 (20–24), z1 15 (12–18) shortest, z2 26 (20–30), z3 28 (26–30), z4 30, z5 23 (22–24), z6 23 (22–24), s1 22 (20–26), s2 26 (24–28), s3 29 (28–30), s4 31 (30–34), s5 28 (26–30), s6 27 (26–30), r2 24 (20–26), r3 30 (26–32), r4 23 (18–26), r5 22 (20–24), J1 20, J2 25 (24–28), J3 25 (22–30), J4 30 (28–32), J5 24, Z1 28 (26–30), Z2 28 (26–30), Z3 28 (26–30), Z4 32 (30–34), Z5 40 longest, S1 28 (20–30), S2 27 (26–30), S3 29 (26–32), S4 28 (26–30), S5 29 (27–32), R1 18 (14–20), R2 20 (18–24), R3 24 (20–28), R4 25 (22–26), R5 24 (22–26). Ventral idiosoma (Figure 8B): Tritosternum (Figure 8D) base 6 (4–8) and laciniae 29 (24–32) long; sternogenital shield 118 (116–120) long and 65 (62–70) wide, with four pairs of setae, st1 19 (14–22), st2 22 (20–26), st3 18 (16–20), st4 18 (14–21); setae st5 16 (14–20); ventrianal shield 124 (116–132) long; with seven pairs of preanal setae, Jv1 18 (16–20), Jv2 21 (20–22), Jv3 24 (22–26), Jv5 26 (24–28), Zv1 16 (14–18), Zv2 17 (16–20), Zv3 18 (16–20) para-anal 31 (30–32), post-anal 16 (14–18). Gnathosoma: Epistome (Figure 8F) with three-pointed prongs; fixed cheliceral digit 27 (26–30) long, movable cheliceral digit 24 (22–26) long, each with the same number of teeth as the adult female, spermatodactyl 22 long (Figure 8C); deutosternum with seven rows; hypostomal setae smooth, h1 17 (14–20), h2 8, h3 18 (16–20), pc 16 (14–18) (Figure 8D). Legs: Lengths, excluding pretarsi: leg I 277 (260–284), leg II 197 (180–204), leg III 170 (160–172), leg IV 246 (240–252).

Material examined

Eleven females, three males and four deutonymphs, Iran, Guilan Province, Rasht County, (37°16′41.1″N, 49°36′23.4″E, alt. –7 m), livestock manure and decayed rice bran, 22 September, 2021; 14 October, 2021; 27 September, 2021; 13 August, 2021. Four females, Kuchesfahan district (37°15′25″N, 49°46′30″E, alt. 0 m), decayed rice bran, November 15, 2021. Four females, one male, Lashtnesha district (37°21′57.7″N, 49°51′28.0″E, alt. 24 m), livestock manure and decayed rice bran, 15 November, 2021. One female, Khomam district, (37°21′56.2″N, 49°41′12.1″E, alt. –17 m), decayed rice bran, 15 November, 2021. Sixteen females, three males and one deutonymph, Sangar district (37°10′18.5″N, 49°42′48.3″E, alt. 31 m), livestock manure and decayed rice bran, 14 October, 2021, all specimens collected by Leila Mohammadi.

Remarks

Comparison of some metric characters of Dendroseius vulgaris female specimens collected in Guilan province Iran, with those of the original description shows that most measurements are similar, only a small difference observed in the size of z1 (16 vs. 20), z6 (26 vs. 29), Z5 (48 vs. 52), s1 (19 vs. 24), r2 (21 vs. 23), r3 (31 vs. 35), r4 (20 vs. 28), r5 (22 vs. 25), R1 (20 vs. 22), R2 (26 vs. 28), st2 (24 vs. 27), Jv1 (20 vs. 22), Jv5 (34 vs. 36), Zv2 (18 vs. 23), h2 (9 vs. 11), idiosoma length (352 vs. 360), idiosoma width (189 vs. 232), fixed cheliceral digit (32 vs. 35) ventrianal length (128 vs. 138), ventrianal width (118 vs. 131), and post-anal seta (19 vs. 23) that are slightly shorter in our specimens. Also, length of j1 (21 vs. 16), J1 (27 vs. 24), z3 (32 vs. 29), Jv2 (26 vs. 24), and para-anal (32 vs. 30) setae are slightly longer in our specimens. For males of this species like females, some small differences observed in the size of, J4 (30 vs. 32), J5 (24 vs. 26), idiosoma length (298 vs. 315), idiosoma width (189 vs. 204), tritosternum base (6 vs. 10), laciniae (29 vs. 23), sternogenital shield length (118 vs. 128), sternogenital shield width (65 vs. 68), ventrianal length (124 vs. 139), and post-anal seta (16 vs. 22) that are slightly shorter in our specimens. Also length of j3 (29 vs. 27), j5 (24 vs. 20), J1 (20 vs. 18), J2 (25 vs. 21), z3 (28 vs. 24), z4 (30 vs. 28), z5 (23 vs. 21), z6 (23 vs. 20), Z2 (28 vs. 25), Z5 (40 vs. 37), s2 (26 vs. 24), s3 (29 vs. 25), s4 (31 vs. 26), s5 (28 vs. 25), s6 (27 vs. 21), S5 (29 vs. 26), R2 (20 vs. 17), Jv2 (21 vs. 19), Jv3 (24 vs. 19), Zv2 (17 vs. 15), h1 (17 vs. 15), h3 (18 vs. 15), para-anal (31 vs. 29) setae, fixed cheliceral digit (27 vs. 25) and spermatodactyl length (22 vs. 18) are slightly longer in our specimens. We consider these slight differences in size as geographical intraspecific variation.

Updated key to world species of Dendroseius (deutonymph and female)

The key to the world species of the Dendroseius (females) presented by Mašán (2020), is modified here to accommodate the deutonymph stage (only for species with described deutonymph stage).

1. Female stage
...... 5

— Deutonymph stage
...... 2

2. Setae Z5 twice the length of j4
...... 3

— Setae Z5 more than twice the length of j4
...... 4

3. Fix digit of chelicerae with two teeth
...... Dendroseius congoensis Wiśniewski et Hirschmann, 1992 (Africa)

— Fix digit of chelicerae with three teeth
...... Dendroseius amoliensis Faraji, Sakenin-Chelav & Karg, 2006 (Iran)

4. Setae Z5 2.4 times the length of j5, fix digit of chelicerae with seven teeth, length of idiosoma 308 μm long
...... Dendroseius vulgaris Ma, Ho & Wang, 2014 (Taiwan)

— Setae Z5 3⅓ times the length of j5, fix digit of chelicerae with four teeth, length of idiosoma 325 μm long
...... Dendroseius gujarati Wiśniewski et Hirschmann, 1989 (India)

5. Ventrianal shield nearly triangular, with posterior margin convex, peritreme anteriorly reaches to the level of the middle of coxa III, length of idiosoma 367 μm
...... Dendroseius amoliensis Faraji, Sakenin-Chelav & Karg, 2006 (Iran)

— Ventrianal shield subquadrate or subrectangular, with posterior margin only moderately curved, peritreme relatively longer, anteriorly reaches to the level coxae II
...... 6

6. Podonotal soft integument with at most two pairs of setae (r4, r5); r2 situated on dorsal shield; length of idiosoma 364 µm
...... Dendroseius badenhorsti (Ryke, 1962) (South Africa)

— Podonotal soft integument with at least three pairs of setae (r2, r4, r5); sometimes s1 situated on soft integument
...... 7

7. Dorsal shield setae shorter (J1J4 normally less than 15 µm in length); setae r5 and Z5 similar in length (26–32 µm); ventrianal shield wider than long (L 95–100 µm; W 120–135 µm), length of idiosoma 260–290 µm
...... Dendroseius reticulatus (Sheals, 1956) (Europe, North Africa)

— Dorsal shield setae longer (J1J4 normally more than 18 µm in length); setae r5 1.5–2 times shorter than Z5 (r5 23–28 µm, Z5 35–55 µm); ventrianal shield similar in width and length (L 105–143 µm; W 112–135 µm), length of idiosoma 315–375 µm
...... 8

8. Central process of epistome shortened (about 1/2 length of the lateral process); dorsal shield setae generally shorter: j5 17–20 µm, J1J4 19–23 µm, J5 17–19 µm, S1-S3 21-25 µm; Z5 35–40 µm; ventrianal shield slightly wider than long (L 105–115 µm; W 112–130 µm); length of idiosoma 315–345 µm
...... Dendroseius reductus Mašán (Slovakia)

— Epistome with three well-developed prongs, central process slightly longer than lateral ones; dorsal shield setae generally longer: j5 25–30 µm, J1J4 23–42 µm, J5 26–38 µm, S1-S3 24-30 µm; Z5 48–55 µm; ventrianal shield slightly longer than wide (L 131–143 µm; W 128–135 µm); length of idiosoma 353–375 µm
...... Dendroseius vulgaris Ma, Ho & Wang, 2014 (Taiwan)

Acknowledgements

We wish to express our gratitude to Dr. Farid Faraji (Eurofins MITOX, Science Park 408, Amsterdam, The Netherlands) and two anonymous referees for critically reviewing the manuscript and their helpful comments. The project was supported by the Department of Plant Protection, College of Agricultural Sciences, University of Guilan, Rasht, Iran, which is greatly appreciated.



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Article editorial history
Date received:
2022-04-06
Date accepted:
2022-06-02
Date published:
2022-06-09

Edited by:
Faraji, Farid

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This work is licensed under a Creative Commons Attribution 4.0 International License
2022 Mohammadi, Leila and Hajizadeh, Jalil
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