Agistemus rodriguezi Paktinat-Saeij & Cruz

Paktinat-Saeij, Saeid, Barroso, Geovanny & Cruz, Wilton Pires Da, 2017, Two new species of Stigmaeidae (Acari: Trombidiformes: Rhaphignathoidea) from Brazil, Zootaxa 4242 (2), pp. 372-382: 373-375

publication ID

https://doi.org/10.11646/zootaxa.4242.2.9

publication LSID

lsid:zoobank.org:pub:7312498B-EC54-4580-9D5E-472D34F4BAC3

persistent identifier

http://treatment.plazi.org/id/224787F8-3259-FFBB-FF28-FE1BFC99492D

treatment provided by

Plazi

scientific name

Agistemus rodriguezi Paktinat-Saeij & Cruz
status

sp. nov.

Agistemus rodriguezi Paktinat-Saeij & Cruz  sp. nov.

( Figs. 1–8View FIGURES 1 – 4View FIGURES 5 – 8, 26–27View FIGURES 26 – 27)

Diagnosis. Prodorsal and hysterosomal shields smooth; length of seta c 1 longer than the distance between the base of c 1 and d 1; the ratio vi / vi –vi 2.4 (2.1–2.5); the ratio c 1 / c 1 –c 1 2.2 (2.1–2.8). Aggenital shield entire, bearing one pair of setae (ag 1); seta g 1 reaching base of ps 3; femora I –IV 5-4 -2-2.

Description. Female (n = 7): Length of idiosoma 260 (227–303); width of idiosoma 200 (181–231); gnathosoma (including palp) 139 (126–136); subcapitulum 78 (66–79); palp 102 (92–101); chelicera 91 (90–97). Length of legs I –IV: 296 (277–290); 260 (237–261); 230 (220–233); 252 (240–255). Femur I 80 (75–82), genu I 24 (19–23), tibia I 54 (48–53), tarsus I 75 (70–78).

Dorsum of idiosoma ( Figs. 1View FIGURES 1 – 4, 26 – 27View FIGURES 26 – 27). Idiosoma broadly oval in dorso-ventral view. Prodorsal shield triangular, indented posteriorly and smooth ( Figs. 1View FIGURES 1 – 4). Prodorsal shield with 3 pairs of setae (vi, ve and sci), one pair of eyes 10 (8–10) in diameter and one pair of postocular bodies (pob) 14 (13–15) in diameter; humeral shields smooth, bearing c 2. Hysterosomal shield smooth, with five pairs of setae (c 1, d 1, d 2, e 1 and e 2); intercalary shields smooth, with setae f 1; suranal shield entire and smooth, with two pairs of setae, h 1 and h 2. Dorsal setae set on tubercles, long and barbed, with blunt tips, h 1 and h 2 are distinctly shorter. Lengths of dorsal setae: vi 53 (51–56); ve 74 (73–82); sci 63 (68–77); c 1 66 (65–67); c 2 48 (50–51); d 1 70 (67–72); d 2 68 (67–72); e 1 75 (72–75); e 2 73 (73–79); f 1 53 (54–57); h 1 34 (31–33); h 2 23 (20–23). Distances between dorsal setae: vi – vi 22 (20–26); ve –ve 52 (50–59); vi –ve 23 (16–24); ve –sci 33 (31–38); sci –sci 100 (97–105); c 1 –c 1 30 (23–29); c 1 –d 1 58 (47–56); c 1 –c 2 80 (75–83); c 1 –d 2 60 (53–61); d 1 –d 1 79 (67–79); d 1 –d 2 27 (26–30); d 1 – e 1 55 (47–56); d 1 – e 2 32 (26–32); d 2 –d 2 131 (121–129); d 2 – e 2 45 (38–45); e 1 – e 1 28 (21–26); e 2 –e 2 103 (97–105); e 1 –f 1 22 (24–32); f 1 –f 1 52 (47–65); f 1 –h 1 32 (28–45); h 1 –h 1 13 (12–13); h 1 –h 2 18 (16–20); h 2 –h 2 46 (38–44). Ratios: pob / eye: 1.4 (1.4–1.6); vi / vi –vi 2.4 (2.1–2.5); c 1 / c 1 –c 1 2.2 (2.1–2.8); d 1 / d 1 –d 1 0.9 (0.8–1.0); e 1 / e 1 – e 1 2.6 (2.7–3.0); f 1 / f 1 –f 1 1.0 (0.9–1.2); h 1 / h 1 –h 1 2.6 (2.3–2.6); c 1 –c 1 / d 1 –d 1 0.3 (0.3–0.4); c 1 –c 1 / e 1 – e 1 1.0 (0.9–1.1); d 1 –d 1 / e 1 – e 1 2.8 (2.7–3.0); h 1 / h 2 1.4 (1.3–1.6); c 1 –c 1: d 1 –d 1: e 1 –e 1: f 1 –f 1 = 1.0 (1.0–1.1): 2.8 (2.8–3.1): 1.0: 1.8 (1.7–2.1).

Venter of idiosoma ( Figs. 2, 3View FIGURES 1 – 4). Ventral surface ornamented with striations; bearing three pairs of setae (1a, 3a and 4a). Aggenital shield entire, horseshoe-shaped, bearing one pair of setae (ag 1). Anogenital valves with one pair of genital (g 1) setae and three pairs of pseudanal (ps 1–3) setae. Seta g 1 reaching base of ps 3. Setae ps 1 robust and slightly barbed ( Fig. 3View FIGURES 1 – 4). Measurements of setae: 1a 25 (22–26); 3a 25 (21–28); 4a 25 (20–26); ag 1 12 (10–13); g 1 13 (11–14); ps 1 13 (12–15); ps 2 16 (13–16); ps 3 14 (13–14); g 1 –ps 3 9 (8–9); g 1 –ps 3 17 (15–17).

Gnathosoma. Subcapitulum ( Fig. 4View FIGURES 1 – 4) bearing subcapitular setae m 28 (28–31) and n 38 (38–44) and adoral setae or 1 17 (16–17) and or 2 17 (16–17). Distance m –m 39 (40–41), n –n 30 (32–35) and m –n 7 (7). Palpus ( Fig. 4View FIGURES 1 – 4), five segmented; palptrochanter without setae; palpfemur with two smooth and one barbed seta; palpgenu with one seta; palptibia with two tactile setae + one well-developed claw + one spine-like accessory claw; palptarsus with four tactile setae + one solenidion (ω), one subapical eupathidium and one distal trifid eupathidium.

Legs ( Figs. 2View FIGURES 1 – 4, 5–8View FIGURES 5 – 8). Dorsalmost seta on femur I (dFI) barbed, 50 (48–50), 1.5 times length of h 1; dorsalmost seta on genu I (dGI) barbed, 36 (36–40). Chaetotaxy: coxae (excluding 1a, 3a and 4a) 2(+1elcl)-1-2-2, trochanters 1-1-1-1, femora 5-4-2-2, genua 3(+1κ)-1-0-0, tibiae 5(+1φp)-5(+1φp)-5(+1φp)-5(+1φp), tarsi 12(+1ω)-9(+1ω)- 7(+1ω)-7. Length of solenidia: ωI 25 (24–25); ωII 23 (23–25); ωIII 15 (15–18).

Immature stages and male: Unknown.

Remarks. The new species resembles A. brideliae Gonzalez-Rodriguez, 1965  and A. striolatus  Gonzalez- Rodriguez, 1965 in having dorsal shields without reticulations, one pair of aggenital setae (ag 1) and the same femora, genua and tibiae chaetotaxy; however, it can be distinguished from A. brideliae  by: 1) having most of dorsal setae at least 20% longer than those in A. brideliae  ; 2) length of seta c 1 longer than the distance between the base of c 1 and d 1 (c 1> c 1 –d 1) vs. shorter in the A. brideliae  ; 3) seta d 1 surpassing the base of e 1 (d 1> d 1 –e 1) vs. shorter in the A. brideliae  ; 4) length of seta d 2 distinctly longer than the distance between the base of d 2 and e 2 (d 2> d 2 –e 2 or d 2 / d 2 –e 2: 1.5) vs. equal (d 2 / d 2 –e 2: 1.0) in the latter.

Agistemus rodriguezi  sp. nov. differs from A. striolatus  by: 1) the ratio c 1 / c 1 –c 1 2.2 (2.1–2.8) instead of 1.0 in the latter; 2) the ratio e 1 / e 1 – e 1 2.6 (2.7–3.0) whereas approximately 1.3 in the latter; 3) setae ag 1 on entire aggenital shield vs. setae ag 1 being on separate small platelets in the A. striolatus  .

Etymology. The species is named in honor of Prof. Roberto H. Gonzalez-Rodriguez (University of Chile, Maipu, Chile), for his great contribution to Acarology.

Type materials. Holotype female and six paratype females from leaves of Caiaué ( Elaeis oleifera (Kunth) Cortés  , Arecaceae  ) trees, 11 Dec. 2012 at experimental field Urubu river in Rio Preto da Eva, state of Amazonas, Brazil were collected by Wilton Pires da Cruz  . Holotype and four paratype females are deposited in the Acarological collection of Departamento de Entomologia e Acarologia, ESALQ-USP, Piracicaba, São Paulo State, Brazil and two paratype females are deposited in the Acarological Collection , Department of Plant Protection , Faculty of Agriculture , University of Maragheh, Maragheh, Iran  .