# Two new species of the genus Agistemus Summers
(Acari: Stigmaeidae) from Saudi Arabia

Muhammad Kamran, Jawwad Hassan Mirza, Nasreldeen Ahmed Elgoni,
Fahad Jaber Alatawi

► To cite this version:

Muhammad Kamran, Jawwad Hassan Mirza, Nasreldeen Ahmed Elgoni, Fahad Jaber Alatawi. Two new species of the genus Agistemus Summers (Acari: Stigmaeidae) from Saudi Arabia. Acarologia, 2023, 63 (2), pp.580-590. 10.24349/srli-y7eg. hal-04096423

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Submitted on 12 May 2023

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# Two new species of the genus *Agistemus* Summers (Acari: Stigmaeidae) from Saudi Arabia

Muhammad Kamran<sup>ID<sup>a</sup></sup>, Jawwad Hassan Mirza<sup>ID<sup>a</sup></sup>, Nasreldeen Ahmed Elgoni<sup>ID<sup>a</sup></sup>, Fahad Jaber Alatawi<sup>ID<sup>a</sup></sup>

## Original research

### ABSTRACT

Two new predatory mites of the genus *Agistemus* Summers (Acari: Prostigmata: Stigmaeidae) namely *A. neocollyerae* n. sp. and *A. arabensis* n. sp. are described and illustrated based on adult females. Additionally, two species namely *A. simplex* González-Rodriguez and *A. floridanus* González-Rodriguez are reported as new records for the stigmaeid mite fauna of Saudi Arabia. A regional key to reported species of the genus *Agistemus* is also provided.

**Keywords** description; neocollyerae; simplex; floridanus; new records

**Zoobank** http://zoobank.org/56FCDA82-619D-4E9B-904E-05355A578427

## Introduction

Stigmaeid mites (Acari: Trombidiformes: Stigmaeidae) are important predators of wide range of prey species and play potential role in the control of phytophagous mites after the family Phytoseiidae (Santos and Laing 1985). They are distributed worldwide and are found in variety of different habitats i.e. plant canopy, soil, leaf litter and crevices etc. (Gerson et al. 2003; Fan and Zhang 2005; Dönel and Doğan 2011).

The family Stigmaeidae includes 34 genera and more than 578 described species (Fan et al. 2016). The genus *Agistemus* Summers 1960, the third largest stigmaeid genus, includes 88 species worldwide (Bizarro et al. 2022). Many species of the genus *Agistemus* are economically important and are known as efficient egg predators of many phytophagous mite species (Gerson et al. 2003; Matioli et al. 2002; Fan and Flechtmann 2015).

A total of five species of the genus *Agistemus* have been reported from Saudi Arabia so far viz. *A. aimogastaensis* Leiva, Fernandez, Theron & Rollard, *A. exsertus* González-Rodriguez, *A. fleschneri* Summers, *A. jawadi* Rehman et al., *A. macrommatus* González-Rodriguez and *A. vulgaris* nomen nudum Soliman & Gomaa (Alatawi and Kamran 2017; Rehman et al. 2018). The present study reports two new species; *A. neocollyerae* n. sp. and *A. arabensis* n. sp. described and illustrated based on adult females. Two new records (*A. simplex* González-Rodriguez and *A. floridanus* González-Rodriguez) were reported from Saudi Arabia in the current study. A regional key to reported species of the genus *Agistemus* is given.

## Material and methods

The specimens were collected from the leaves of different host plants and preserved in 70% ethanol. The collected mite specimens were directly mounted on slides in Hoyer's medium under a stereomicroscope (SZX10, Olympus, Tokyo, Japan), and identified under a phase

Received 01 March 2023

Accepted 03 May 2023

Published 11 May 2023

Corresponding author
Fahad Jaber Alatawi ID:
falatawi@ksu.edu.sa

Academic editor
Faraji, Farid

https://doi.org/10.24349/srli-y7eg

ISSN 0044-586X (print)

ISSN 2107-7207 (electronic)

<figure><img src="image_6.png" /></figure>

Kamran M. et al.

Licensed under
Creative Commons CC-BY 4.0

<footnote><sup>a</sup> Acarology Research Laboratory, Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, P.O. Box 2460, Riyadh, 11451, Saudi Arabia.</footnote>
contrast microscope (DM2500, Lieca, Wetzlar, Germany). Different mite body parts were pictured using an auto-montage software system (Syncroscopy, Cambridge, UK) and then drawn with Adobe Illustrator (Adobe System Inc., San Jose, CA, USA). The nomenclature for gnathosomal and leg chaetotaxy followed that of Grandjean (1944) and for the idiosomal setae followed those of Kethley (1990). All measurements of the holotype and paratypes (as ranges in parenthesis) are given in micrometers (µm). All specimens of new species and new records have been deposited in KSMA (King Saud University Museum of Arthropods, Acarology section), Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia.

## Results

### Family Stigmaeidae Oudemans

### Genus Agistemus Summers

Type species: *Caligonus terminalis* Quayle, 1912, by original designation.
*Agistemus terminalis* (Quayle), Summers 1960: 234.

### Diagnosis

As defined by Fan & Zhang (2005).

### Species group terminalis Rehman et al. (2018)

#### Diagnosis (Based on female)

As defined by Rehman et al. 2018.
Two pairs of aggenital setae (*ag*₁₋₂) present.

### *Agistemus neocollyerae* n. sp.

Zoobank: 9256F920-C2F4-4288-A80D-D1FAB8F070C9
Figures 1–3

#### Diagnosis

Dorsal shield reticulated, setae *f*₁ and *h*₁ longer than other dorsocentral setae, setae *v*ᵢ shorter than the distance *v*ᵢ−*v*ᵢ, setae *v*ᵢ reaching the base of *sce*, two pairs of aggenital setae (*ag*₁₋₂), gential setae (*g*) long, extending pass the bases of anal setae *ps*₂.

### Description of female (n=8)

**Idiosomal dorsum** — (Figure 1a). Idiosoma broadly oval. Length of idiosomal dorsum excluding gnathosoma 260 (258–262); including gnathosoma from base to tips of chelicerae 340 (339–342), width of idiosoma at the level of setae *c*₂ 180 (178–181). Prodorsal shield subtriangular with polygonal reticulations, with one pair of eyes 10 (8–10); post ocular bodies *pob* not clearly visible, and three pairs of setae (*vi*, *ve* and *sce*), humeral shields smooth, small and bearing setae *c*₂. Median hysterosomal shield with polygonal reticulations, bearing five pairs of setae (*c*₁, *d*₁, *d*₂, *e*₁ and *e*₂), intercalary shields smooth and with setae *f*₁, suranal shield entire and smooth, with two pairs of setae, *h*₁ and *h*₂. Dorsal setae barbed, shorter than the distance to the setae next in line.

*Length of dorsal setae:* *vi* 16 (15–17), *ve* 24 (22–25), *sce* 30 (27–32), *c*₁ 21 (20–22), *c*₂ 30 (29–33), *d*₁ 26 (24–28), *d*₂ 25 (22–26), *e*₁ 31(28–32), *e*₂ 24 (22–25), *f*₁ 35 (33–36), *h*₁ 35 (34–36), *h*₂ 34 (33–35).

*Distances between dorsal idiosomal setae:* *vi–vi* 33 (30–34), *ve–ve* 62 (61–64), *vi–ve* 23 (20–24), *ve–sce* 28 (27–29), *sce–sce* 99 (97–98), *c*₁-*c*₁ 32 (31–33), *c*₁-*d*₁ 44 (41–44), *c*₁-*d*₂
<figure><img src="image_7.png" /><figcaption>**Figure 1** *Agistemus neocollyerae n. sp.*, female, a – dorsum; b – venter.</figcaption></figure>

49 (47–51), *d*<sub>1</sub>–*d*<sub>1</sub> 67 (66–67), *d*<sub>1</sub>–*d*<sub>2</sub> 32 (31–33), *d*<sub>1</sub>–*e*<sub>1</sub> 46 (44–46), *d*<sub>1</sub>–*e*<sub>2</sub> 31 (31–33), *d*<sub>2</sub>–*d*<sub>2</sub> 116 (110–115), *d*<sub>2</sub>–*e*<sub>2</sub> 44 (42–45), *e*<sub>1</sub>–*e*<sub>1</sub> 29 (27–29), *e*<sub>1</sub>–*e*<sub>2</sub> 32 (30–33), *e*<sub>2</sub>–*e*<sub>2</sub> 88 (87–88), *f*<sub>1</sub>–*f*<sub>1</sub> 64 (64–66), *h*<sub>1</sub>–*h*<sub>1</sub> 21 (20–24), *h*<sub>1</sub>–*h*<sub>2</sub> 10 (10–11).

Ratios: *vi*/*vi*–*vi* 0.5 (0.4–0.5), *ve*/*ve*–*sce* 0.8 (0.7–0.9), *c*<sub>1</sub>/*c*<sub>1</sub>–*c*<sub>1</sub> 0.65 (0.6–0.7), *d*<sub>1</sub>/*d*<sub>1</sub>–*d*<sub>1</sub> 0.4 (0.38–0.42), *e*<sub>1</sub>/*e*<sub>1</sub>–*e*<sub>1</sub> 0.96 (0.9–1), *f*<sub>1</sub>/*f*<sub>1</sub>–*f*<sub>1</sub> 0.54 (0.5–0.57), *h*<sub>1</sub>/*h*<sub>1</sub>–*h*<sub>1</sub> 1.6 (1.6–1.8), *c*<sub>1</sub>–*c*<sub>1</sub>/*d*<sub>1</sub>–*d*<sub>1</sub> 0.5 (0.5–0.6), *c*<sub>1</sub>–*c*<sub>1</sub>/*e*<sub>1</sub>–*e*<sub>1</sub> 1 = *d*<sub>1</sub>–*d*<sub>1</sub>/*e*<sub>1</sub>–*e*<sub>1</sub> 2.3 (1.5–2.7), *h*<sub>1</sub>/*h*<sub>2</sub> 1 (0.9–1.1).

**Idiosomal venter** — (Figure 1b). Ventral surface ornamented with simple striations; bearing three pairs of simple sub equal setae (*1a*, *3a* and *4a*), length of setae as follows: *1a* 14 (13–14), *1b* 21 (20–23), *1c* 18 (17–21), *2c* 22 (20–24), *3a* 20 (20–21), *3b* 16 (15–17), *3c* 12 (10–12), *4a* 20 (19–22), *4c* 12 (10–12); aggenital plate each side with two setae, *ag*<sub>1</sub> 13 (10–13), *ag*<sub>2</sub> 19 (18–20), anogenital covers with one pair of genital setae, *g* 21 (20–24) and three pairs of pseudoanal setae, *ps*<sub>1</sub> 14 (13–14), *ps*<sub>2</sub> 15 (14–15), *ps*<sub>3</sub> 17 (15–16); distances between setae:
<figure><img src="image_8.png" /><figcaption>**Figure 2** *Agistemus neocollyerae n. sp.*, female, palp.</figcaption></figure>

g-g 9 (8-10), *ps*₁-*ps*₁ 14 (13-15), *ps*₂-*ps*₂ 20 (20-21), *ps*₃-*ps*₃ 13 (12-14), *ps*₁-*ps*₂ 10 (8-9), *ps*₂-*ps*₃ 11 (10-12).

**Gnathosoma** — (Figure 2). Subcapitulum bearing subcapitular setae *m* 17 (16–17), *n* 21 (20–21), adoral setae *or*₁ 10 (10–12) and *or*₂ 12 (9–12). Distance *m*m 24 (21–25), *n*n 21 (21–23), *m*n 11 (10–11), *or*₁-*or*₁ 5 (4–5), *or*₂-*or*₂ 10 (8–9), *or*₁-*or*₂ 4 (3–4) *elcp* 1.6(1–2) (Figure 1b). Palp five-segmented, palp trochanter without setae; palp femur with two smooth setae (*l*', *v''*) and one barbed seta (*d*); palp genu with one smooth seta (*d*); palp tibia with two simple setae (*v''*, *l''*), one well-developed claw, one seta associated with claw (*l*T); palptarsus with four simple setae (*ba*, *bp*, *va* and *lp*), one solenidion (*ω*), subapical eupathidium (*acmζ*) and three eupathidia (*sulζ*, *ul*′*ζ*, *ul*″*ζ*), fused at basis, trifid distally (Figure 2).

**Legs** — (Figures 3a–d). Length of legs I–IV from trochanter to tip of empodium: 144 (141–144), 140 (140–142), 145 (143–146), and 147 (147–149), respectively; dorsal seta on leg femur (*dF*) I–IV and dorsal seta on leg genu I (*dGI*) barbed; tibiae and tarsi on leg IV lack solenidion. Number of setae on leg segments as fellows (specialized setae are in parentheses): coxae 2–1–2–1, trochanter 1–1–1–1, femora 4–4–2–2, genua 2(+1κ)–0–0–0, tibiae 5(+1φ)–5(+1φ)–5(+1φ)–4, tarsi 11(+1ω)–9(+1ω)–7(+1ω)–7. Length of specialized setae on legs: κI 5 (4–5), φI 8.8 (8–9), φII 4.4 (3–4), φIII 3.2 (3–4), ωI 8 (6–8), ωII 8 (7–8), ωIII 4 (3–5).

Etymology

The specific epithet (*neocollyerae*) is derived from the closely related species *A. collyerae*.
<figure><img src="image_9.png" /><figcaption>**Figure 3** *Agistemus neocollyerae n. sp.*, female, a – Leg I; b – Leg II; c – Leg III; d – Leg IV.</figcaption></figure>

**Type materials**

Holotype female, one paratype female, weeds, Wadi Shora, Al-Bahah 19.49351°N, 41.46529°E, October 28, 2019, coll. M. Kamran & H.M.S. Mushtaq; two paratype females, from *Conocarpus* (Combretaceae), Bani Kabir, Al-Bahah 19.59252°N, 41.31964°E, September 12, 2021, coll. E.M. Khan & N. A. Elgoni; one paratype female, from *Convolvulus* spp. (Convolvulaceae), Buljershi, Al-Bahah, 19.53752°N, 41.34423°E, September 12, 2021, coll. E.M. Khan & N. A. Elgoni; one paratype female, from *Acacia* (Fabaceae), Ghora, Asir, 19.13116°N, 42.04608°E, October 29, 2019, coll. M. Kamran & H.M.S. Mushtaq; one paratype female, from grasses, Ghora, Asir, 18.37286°N, 42.16217°E, October 29, 2019, coll. M. Kamran & H.M.S. Mushtaq; one paratype female, from Olive, *Olea europaea* (Oleaceae), Sakaka, Al-Jouf, 29.57251°N,
40.0548°E, June 21, 2021, coll. J. H. Mirza.

## Remarks

The new species *A. neocollyerae n. sp.* is close to three species; *A. aimogastaensis* Leiva *et al.*, *A. collyerae* González-Rodriguez and *A. manjilicus* Khanjani based on the following set of characteristics; tibia IV with four setae, genu I with two setae (excluding solenidion) and dorsal shields entirely reticulated. The new species differs from *A. aimogastaensis* by the number of setae on coxae IV (1 vs 2), distance of *ve/ve-sce* (*ve* reaching base of setae *sce* vs *ve* half as long as *ve-sce*). The new species differs from *A. manjilicus* based on the length of genital setae (*g* extending beyond the bases of *ps*₁ vs *g* reaching the base of *ps*₂), *vi/vi-ve* = 0.6 vs *vi/vi-ve* = 0.9–1.08, setae *ag*₂ long, *h*₁/*h*₁–*h*₁ 1.6 in new species vs *h*₁/*h*₁–*h*₁ 2.33 in *A. manjilicus*. The new species differs from *A. collyerae* by the length and position of setae; *vi*<*vi-ve* vs. *vi*=*vi*, setae *ve* not reaching the base of *sce* vs. *ve* extending well beyond the base of setae *sce*, *c*₁ reaching less than half the distance *c*₁–*d*₁ vs. *c*₁ longer than the distance *c*₁–*d*₁, setae *f*₁ and *h*₁ equally long vs. *f*₁ the longest dorsal setae.

## Agistemus arabensis n. sp.

Zoobank: B5693A44-4399-49C3-B8E0-EF4E0559091B

Figures 4–6

**Diagnosis:** All dorsal shields with weak longitudinal irregular striations, dorsal setae not set on tubercles, femur I with four setae and femur IV with one seta, all dorsal body setae reaching or longer than distance between the setae next in line,

## Description of female (n=5)

**Idiosomal dorsum** — (Figure 4a). Idiosoma broadly oval. Length of idiosomal dorsum excluding gnathosoma 320 (315–325); including gnathosoma from base to tips of chelicerae 410 (400–418), width of idiosoma at level of setae *c*₂ 210 (208–217). Prodorsal shield subtriangular without reticulations and with weak irregular longitudinal striae, with one pair of eyes 8 (7–8); post ocular bodies *pob* present 12 (11–12) and three pairs of setae (*vi*, *ve* and *sce*), humeral shields smooth, small and bearing setae *c*₂. Median hysterosomal shield with fine longitudinal striations, bearing five pairs of setae (*c*₁, *d*₁, *d*₂, *e*₁ and *e*₂), intercalary shields smooth and with setae *f*₁, suranal shield entire and smooth, with two pairs of setae, *h*₁ and *h*₂. Dorsal setae barbed, longer than distance to setae next in line.

*Length of dorsal setae:* *vi* 31 (30–32), *ve* 60 (58–61), *sce* 48 (47–49), *c*₁ 47 (45–49), *c*₂ 43 (43–44), *d*₁ 50 (49–51), *d*₂ 44 (43–45), *e*₁ 49 (47–51), *e*₂ 49 (47–49), *f*₁ 47 (44–46), *h*₁ 41 (41–43), *h*₂ 35 (34–36).

*Distances between dorsal idiosomal setae:* *vi–vi* 15 (12–14), *ve–ve* 46 (44–46), *vi–ve* 20 (20–21), *ve-sce* 32 (31–33), *sce-sce* 89 (90–92), *c*₁-*c*₁ 53 (51–54), *c*₁-*d*₁ 58 (56–60), *c*₁-*d*₂ 62 (61–62), *d*₁-*d*₁ 82 (80–83), *d*₁-*d*₂ 24 (21–25), *d*₁-*e*₁ 52 (50–55), *d*₁-*e*₂ 37 (36–38), *d*₂-*d*₂ 123 (120–125), *d*₂-*e*₂ 41 (40–43), *e*₁-*e*₁ 40 (38–41), *e*₁-*e*₂ 33 (31–33), *e*₂-*e*₂ 100 (97–101), *f*₁-*f*₁ 69 (67–71), *h*₁-*h*₁ 21 (20–21), *h*₁-*h*₂ 67 (66–68).

*Ratios:* *vi/vi–vi* 2 (2.2–2.8), *ve/ve-sce* 2 (1.8–2.1), *c*₁/*c*₁–*c*₁ 0.8 (0.7–1), *d*₁/*d*₁–*d*₁ 0.6 (0.5–0.8), *e*₁/*e*₁–*e*₁ 1.2 (1.1–1.4), *f*₁/*f*₁–*f*₁ 0.7 (0.6–0.9), *h*₁/*h*₁–*h*₁ 1.9 (1.7–2), *c*₁-*c*₁/*d*₁-*d*₁ 0.5 (0.5–0.6), *c*₁-*c*₁/*e*₁-*e*₁ 1.3 (0.9–1.6), *d*₁-*d*₁/*e*₁-*e*₁ 2 (1.9–2.3), *h*₁/*h*₂ 1.2 (1–1.5).

**Idiosomal venter** — (Figure 4b). Ventral surface ornamented with simple striations; bearing three pairs of simple setae (*1a*, *3a* and *4a*), length of setae as follows: *1a* 36 (35–36), *1b* 28 (27–29), *1c* 33 (30–33), *2c* 32 (31–32), *3a* 28 (27–29), *3b* 25 (21–24), *3c* 20 (18–22), *4a* 25 (23–26), *4b* 26 (24–26), *4c* 21 (18–20); agenital plate each side with two pair of setae, *ag*₁ 17 (16–17), *ag*₂ 29 (27–29), anogenital covers with one pair of genital setae, *g* 29 (27–30) and three pairs of pseudoanal setae, *ps*₁ 17 (15–16), *ps*₂ 17 (16–17), *ps*₃ 16 (15–16); distances between setae: *g–g* 8 (8–9), *ps*₁-*ps*₁ 15 (14–15), *ps*₂-*ps*₂ 22 (21–22), *ps*₃-*ps*₃ 16 (14–15), *ps*₁-*ps*₂ 14 (13–14), *ps*₂-*ps*₃ 10 (8–9).
<figure><img src="image_10.png" /><figcaption>**Figure 4** *Agistemus arabensis* n. sp., female, a – dorsum; b – venter.</figcaption></figure>

**Gnathosoma** — (Figure 5). Subcapitulum bearing subcapitular setae *m* 22 (21–22), *n* 33 (30–32), adoral setae *or*₁ 12 (11–12) and *or*₂ 12 (10–11). Distances *m–m* 36 (34–35), *n–n* 28 (26–29), *m–n* 11 (9–10), *or*₁–*or*₁ 5 (4–6), *or*₂–*or*₂ 7 (6–8), *or*₁–*or*₂ 4 (3–4) (Figure 4b). Palp five-segmented, palp trochanter without setae; palp femur with two smooth setae (*l''*, *v''*) and one barbed seta (*d*); palp genu with one smooth seta (*d*); palp tibia with two simple setae (*v'', *l''*), one well-developed claw, one seta associated with claw (*l'T*); palptarsus with four simple setae (*ba*, *bp*, *va* and *lp*), one solenidion (*ω*), subapical eupathidium (*acmζ*) and three eupathidia (*sulζ*, *ul'ζ*, *ul» ζ*), fused at basis, trifid distally (Figure 5).

**Legs** — (Figures 6a–d). Length of legs I–IV from trochanter to tip of empodium: 200 (197–201), 180 (178–182), 185 (182–187), and 215 (209–216), respectively; dorsal seta on leg femur (*dF*) I–IV and dorsal seta on leg genu I (*dGI*) barbed; tarsi on leg IV lack solenidion. Number of setae on leg segments as follows (specialized setae are in parentheses): coxae 2–1–2–2, trochanters 1–1–1–1, femora 4–4–2–1, genua 3(+1κ)–1–0–0, tibiae 5(+1φ)–5(+1φ)–
<figure><img src="image_11.png" /><figcaption>**Figure 5** *Agistemus arabensis* n. sp., female, palp.</figcaption></figure>

5(+1φ)–5(+1φ), tarsi 12(+1ω)–9(+1ω)–7(+1ω)–7. Length of specialized setae on legs: κI 5 (4–5), φI 10 (9–10), φII 12 (11–12), φIII 9 (7–8), φIV 9 (8–9), ωI 16 (15–16), ωII 16 (14–15), ωIII 10 (9–10).

**Type materials**

Holotype female, two paratype females, from *Convolvulus* spp. (Convolvulaceae), Bashayer, Asir, 19.36194°N, 42.53823°E, October 29, 2019, coll. M. Kamran & H.M.S. Mushtaq; Two paratype females, from *Cordia* spp. (Boraginaceae), Zarq Valley, Al-Baha, 20.11329°N, 41.17463°E, September 10, 2020, coll. J.H. Mirza, H.M.S. Mushtaq & H.M.S. Ali.

**Etymology**

The specific epithet (*arabensis*) is derived from the type region, Saudi Arabia.

**Remarks**

The new species *Agistemus arabensis* n. sp. closely resembles *A. iburiensis* Ehara 1985, based on the number of setae on femur I and IV (4 and 1), dorsal setae not set on tubercles, setae *c*₂ on humeral plate and dorsal shield without reticulations. However, the new species differs from the later based on a very distinct morphological character; length of dorsal setae (all setae longer than distances to their bases vs. distinctly shorter, far behind the bases of next consecutive setae), ratio *vi*/*vi*–*vi* = 2 vs *vi*/*vi*–*vi* = 0.6; *ve*/*ve*–*sce* = 2 vs *ve*/*ve*–*sce* = 0.8 in *A. iburiensis*.
<figure><img src="image_12.png" /><figcaption>**Figure 6** *Agistemus arabensis* n. sp., female, a – Leg I; b – Leg II; c – Leg III; d – Leg IV.</figcaption></figure>

**New Records**

**Agistemus simplex** González-Rodriguez

*Agistemus simplex* González-Rodriguez 1965:33

**Material Examined**

Two females, fig, *Ficus carica* (Moraceae), Hijra, Al-Bahah 20.14154°N, 41.08445°E, September 11, 2020, coll. J. H. Mirza, H.M.S. Mushtaq & H. M. S. Ali; two females, grasses (Poaceae),
Thamod, Al-Madinah 24.542751°N, 39.00928°E, March 28, 2021, coll. M. Kamran & H.M.S. Mushtaq; one female, grasses, Al-Bahra, Al-Madinah, 24.35897°N, 39.23875°E, August 25, 2020, coll. F.J. Alatawi, J. H. Mirza & E.M. Khan. one female, *Zaleya* spp. (Aizoaceae), Dil Khansa, Al-Madinah, 24.54639°N, 39.00000°E, March 28, 2021, coll. M. Kamran & H.M.S. Mushtaq.

**Distribution**

Mexico (González-Rodriguez 1965).

**Agistemus floridanus González-Rodriguez**

*Agistemus floridanus* González-Rodriguez 1965:42; Matioli, Ueckermann and Oliveira 2002: 103.

**Material Examined**

One female, Brinjal, *Solanum melongena* (Solanaceae), Al-Amaria, Riyadh 24.47405°N, 46.25324°E, March 21, 2016, coll. H.M.S. Mushtaq; one female, *Acacia* (Fabaceae), Unyza, Al-Qasim 26.23618°N, 44.13713°E, May 03, 2018, coll. M. Kamran & J. H. Mirza.

**Distribution**

Florida (USA) (Matioli *et al.* 2002), Mexico (González-Rodriguez 1965)

**Key to Saudi Arabian species of the genus Agistemus Summers**

The following corrections should be made to the key to world species of the genus *Agistemus* published by Rehman *et al.* (2018). The number ‘31’ at the couplet 15 should be replaced by ‘33’. The number ‘67’ at the couplet 57 should be replaced by ‘68’.

The species *A. manjilicus* Khanjani *et al.* at the couplet 25 and the species *A. collyerae* González-Rodriguez at the couplet 26 should replace each other.

1. One pair of aggenital setae (ag) ......................................................... species group *fleschneri*; median hysterosomal shield reticulated, ratio $c_1/c_1-c_1$ 1.0, setae $e_1$ crossing the bases of $h_1$ and reaching almost half length of $h_1$, $e_1/e_1-e_1$ = 1.8: *fleschneri* Summers

— Two pairs of aggenital setae ($ag_{1-2}$) ................................. species group *terminalis* — 2

2. Median hysterosomal shield reticulated .................................................... 3

— Median hysterosomal shield without reticulations .................................... 5

3. Ratio vi/vi-vi ≥ 2.1 ................................................................ jawadi Rehman *et al.*

Ratio vi/vi-vi ≤ 1.6 .................................................................................. 4

4. Setae $e_1$ extending to or crossing the bases of $h_1$, genital setae (g) very small (17), not reaching to the bases of $ps_3$ ......................................................... *aimogastaensis* Leiva *et al.*

— Setae $e_1$ about half of the distance $e_1-h_1$, genital setae (g) very long, extending to the bases of $ps_1$ ......................................................................................... *neocollyerae* n. sp.

5. Dorsal idiosomal setae not set on tubercles .................................................... 6

— Dorsal idiosomal setae set on tubercles ......................................................... 7

6. Femur I with four setae, femur IV with one setae .................................... *arabensis* n. sp.

— Femur I with five setae, femur IV with two setae ................................. *simplex* González-Rodriguez
<table><tr><td>7. Ratio vi/vi-vi ≥ 2.1</td><td>exsertus González-Rodriguez</td></tr><tr><td>— Ratio vi/vi-vi ≤ 1.7</td><td>8</td></tr></table>

<table><tr><td>8. Setae e<sub>1</sub> at least reaching to the bases of f<sub>1</sub></td><td>floridanus González-Rodriguez</td></tr><tr><td>— Setae e<sub>1</sub> at least reaching to the bases of h<sub>1</sub></td><td>macromatus González-Rodriguez</td></tr></table>

## Acknowledgement

The authors would like to extend their sincere appreciation to the researchers supporting project number (RSPD2023R807), King Saud University, Riyadh, Saudi Arabia.

## ORCID

Muhammad Kamran https://orcid.org/0000-0001-6084-203X

Jawwad Hassan Mirza https://orcid.org/0000-0002-1726-4331

Nasreldeen Ahmed Elgoni https://orcid.org/0009-0007-7698-1377

Fahad Jaber Alatawi https://orcid.org/0000-0002-6824-2650

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