Aceria noxia, Flechtmann & Tassi, 2020

Flechtmann, Carlos H. W. & Tassi, Aline D., 2020, An Aceria species (Prostigmata, Eriophyidae) from Amaranthus in Brazil, Persian Journal of Acarology 9 (4), pp. 311-319 : 312-318

Aceria noxia sp.nov. ( Figs. 1–6 )

Female (n = 7, holotype + 6 paratypes)

Idiosoma – Color while alive light yellowish-white. 224 (160–227), 61 (50–62) wide, vermiform. Rostrum projecting obliquely down, dorsal palp genual (antapical) (d) seta 6 (5–6); oral stylets 8 (8–13). Prodorsal shield rounded anteriorly, 31 (28–33), 49 (43–49) wide, without anterior lobe. Median and admedian shield lines complete, slightly sinuose, submedian lines indicated as broken lines of thick elongate granules. Shield laterally beset with irregular, thick and somewhat elongate and more rounded granules. Tubercles of scapular setae (sc) are on shield rear margin, 26 (20–26) apart; sc setae 18 (18–23).

Leg I – 38 (40–33); femur 10 (7–10), femoral seta (bv) 11 (8–11); genu 4 (4–5), genual seta (l”) 25 (18–26); tíbia 6 (6), tibial seta (l’) 5 (5–8), basal; tarsus 6 (5–6), dorsal seta (ft’) 22 (17–23), lateral seta (ft”) 15 (11–16), unguinal seta (u’) 5 (5), empodium 7 (5–7), solenidion slightly arched, distally

blunt, 9 (8–9), empodium 5-rayed.

Leg II – femur 9 (6–9), bv 10 (8–10); genu 4 (4), l” 11 (8–11), tibia 5 (4–6); tarsus 6 (5–7), ft’ 23 (19–23), ft” 8 (7–8), u’ 3 (3–4), solenidion 10 (8–10), empodium 6 (7–6), 5-rayed, distally split.

Coxisternal region – Coxae ornamented with coarse granules; coxae I apodemes meet mesally forming an internal apodeme resembling a sternal line (6–9). Fused coxisternal plates extend anteriorly in a cervical plate (suboral plate), with the same sculpture. Coxal seta I (1b) 8 (8–10), 9 (9– 11) apart; coxal seta II (1a) 27 (18–27), 11 (9–11) apart; coxal seta III (2a) 40 (40–45), 23 (23–26) apart. Coxigenital annuli 7 (6–7), microtuberculate.

Opisthosoma – Lateral seta (c2) 40 (28–40), on annulus 4 (4–6) counting from immediately behind genitalia. Ventral seta I (d) 57 (42–58), on annulus 28 (15–28); ventral seta II (e) 14 (11–15), 24 (18–24) apart, on annulus 44 (29–44); ventral seta III (f) 27 (26–28), on annulus 62 (51–67) or 9 th (7 th –9 th) from rear. Caudal seta (h2) 77 (65–77), accessory seta (h1) 4 (4). Genitalia 15 (15–18), 21 (21–24) wide, coverflap basally with two transverse bands of coarse granules and distally with 16 (14 –16) longitudinal ridges; genital seta (3a) 18 (13–18); transverse trapezoidal genital apodeme, spermathecae oval with short tubes. Total dorsal annuli 93 (76–93) from prodorsal rear margin; total ventral annuli 71 (61–76), with beadlike microtubercles except for the annuli caudad of seta f with narrow elongate microtubercles.

Male (n = 3)

Smaller than female, 150–186, 45–48 wide.

Gnathosoma – Dorsal palp genual seta 4, oral stylets 8–12. Prodorsal shield 26–28, 39–42 wide, sc 14–18, scapular tubercles 13–23 apart.

Leg I – 27–30; femur 5–9, bv 6–9; genu 4, l” 18–21; tibia 4–5; tarsus 5, ft’ 18–22, ft” 10–13, u’ 4, solenidion slightly arched, blunt, 6–7. Empodium 5, 5-rayed. Leg II 25–26; femur 4–6; bv 7–10; genu 3–4, l” 8–9; tibia 4; tarsus 4–5, ft’ 15–18, ft” 4–5, u’ 3, solenidion 6–7, empodium 4–6, 5-rayed.

Coxisternal region – Coxal seta 1b 7–10, 9 apart; 1a 18–19, 9–10 apart; 2a 27–35, 19–22 apart; internal apodeme resembling a sternal line, 4–6, coxisternal annuli 5–6.

Opisthosoma – Lateral seta (c2) 21–22, on annulus 4; ventral seta d 40 - 49, on annulus 11–13; e 9–11, 18–19 apart, on annulus 23–27; f 19–23, on annulus 46–53 or 7 th –8 th from rear. Total ventral annuli 52–60, total dorsal annuli 62–63, microtuberculate as in female. Caudal seta (h2) 53–57, accessory seta (h1) 4. Genitalia 9–10 long, 17–18 wide, genital seta (3a) 10–13.

Type material

Holotype female (its position marked on the microscopic preparation), 28 female and 6 male paratypes, from Amaranthus viridis L. ( Amaranthaceae ), slender amaranth, on 15 microscopic preparations.

Relation to host The infested host plant leaves exhibited chlorotic patches and slight deformation ( Fig. 6 ). Etymology

The specific designation is from the Latin noxius, a, um, meaning harmful and refers to the mite being either directly responsible for the leaf distortion or, perhaps, acting as a virus vector.

Remarks

This is the third species of Aceria reported from Amaranthus species; Abou-Awad and El- Banhawy (1992) described Aceria amaranthi on Amaranthus sp. from Tanzania, Africa, infesting both leaf surfaces and causing numerous galls ( A. noxia sp. nov. is vagrant). This species differs in the prodorsal shield ornamentation pattern, not showing dots or granules (which are numerous in A. noxia sp. nov. prodorsal shield); it also has shorter opisthosomal and caudal setae and no caudal accessory seta (present in A. noxia sp. nov.). It also differs in the genitalia coverflap, with only 12 longitudinal markings, in contrast with A. noxia sp. nov. which has 14–16 in the distal part and basally with two transverse bars. This species resembles A. amaranthi in 5-rayed empodium and in the beadlike microtubercles on dorsal and ventral annuli. Kiedrowicz et al. (2016) described Aceria vanensis Denizhan & Kiedrowicz from Amaranthus retroflexus L. from Turkey. It was vagrant on leaves but without any apparent indications. The prodorsal shield of A. vanensis is smooth and presents only two short submedian lines (whereas A. noxia sp. nov. is with median, submedian lines and granules); in A. vanensis the opisthosomal ventral seta e is numerous (45–55, versus 11–15 in noxia sp. nov.) and the coxisternal and cervical plates are smooth while A. noxia sp. nov. has coarse granules on these regions.

Figures

Figure 1. Aceria noxia sp. nov. – DA, female dorso-anterior aspect; GM, genital region of male; IG, internal genital structure of female; L1, leg I of female; L2, leg 2 of female; VA, ventral-anterior, female.

Figure 2. Aceria noxia sp. nov. – A. Scanning electron micrograph (SEM) of female, dorsal view; B. SEM of female, ventral view. Scale bars: A = 20 µm, B = 10 µm.

Figure 3. Aceria noxia sp. nov. – SEM of prodorsal shield of female. Scale bar 10 µm.

Figure 4. Aceria noxia sp. nov. (female) – A. SEM of legs I and II; B. SEM of solenidion and empodium. Scale bars A and B = 5 µm.

Figure 5. Aceria noxia sp. nov. (female) – SEM of antero-ventral part; CP, cervical plate; GF, female genitalia; 1b, 1a, 2a coxiternal plates setae. Scale bar = 10 µm.

Figure 6. Amaranthus viridis – A. Aerial part of plants; B. Part of inflorescence; C. Flower with one Aceria specimen; D. Detail of flower with one Aceria specimen; E. Close-up of Aceria noxia. Scale bars: B = 0.5mm; C = 430 µm; D = 230 µm; E = 40 µm.