Aceria pycnocomi, Ripka, Géza & Sánchez, Iňigo, 2017

Ripka, Géza & Sánchez, Iňigo, 2017, A new Aceria species (Acari: Eriophyidae) from Spain on Pycnocomon rutifolium (Dipsacaceae) and supplementary descriptions of Aceria eucricotes and A. kuko from Lycium spp. (Solanaceae), Zootaxa 4244 (2), pp. 195-206 : 197-200

Aceria pycnocomi sp. nov.

( Figure 1 )

Description. Female (n= 10). Body whitish yellow, ochre, vermiform, 295 (232–305), 76 (68–76) wide, 69 (62– 77) thick. Gnathosoma 18 (17–22), projecting obliquely downwards; chelicerae 15 (14–16), dorsal palp genual setae d 3 (2–3), simple, pedipalp coxal setae ep 1 (1–2). Prodorsal shield 32 (31–35), 36 (36–37) wide, half circle; shield pattern composed of a short, faint, incomplete median line on rear tenth and two faint, incomplete admedian lines beginning at posterior margin on rear fourth. Tubercles of scapular setae sc on rear shield margin, 27 (25–27) apart, diverging, scapular setae sc 39 (35–39), directed backwards. Legs with all usual segments and setae present. Leg I 30 (30–32), femur 10 (8–10), basiventral femoral setae bv 8 (8–10), genu 4 (4–5), antaxial genual setae l″ 22 (21–25), tibia 7 (7–8), paraxial tibial setae l ′ located at ½ (½–¾) from dorsal base, 2 (2–3), very fine, tarsus 7 (7–8), paraxial, unguinal tarsal setae u ′ 3, solenidion ω 10 (9–10), distally rounded or with a minute knob, slightly curved, empodium simple, bilaterally symmetrical, 7 (6–7), 4-rayed. Leg II (hind leg) 27 (25–30), femur 9 (7–9), basiventral femoral setae bv 6 (6–9), genu 4 (3–5), antaxial genual setae l″ 7 (7–10) very fine, tibia 5 (5–6), tarsus 5 (5–7), paraxial, unguinal tarsal setae u ′ 3 (3), solenidion ω 9 (9–10) subequal with solenidion ω on leg I, distally rounded or with a minute knob, slightly curved, empodium simple, bilaterally symmetrical, 6 (6–7), 4-rayed. Coxisternae I and II smooth; anterolateral setae on coxisternum I, setae 1b 7 (6–10), tubercles 1b 10 (10–11) apart; proximal setae on coxisternum I, setae 1a 15 (15–17), tubercles 1a 7 (7–8) apart, proximal setae on coxisternum II, setae 2a 40 (32–40), tubercles 2a 22 (22–25) apart. Subcapitular plate anteriorly rounded, smooth, without granules. Prosternal apodeme 8 (7–8). Coxigenital area with 4–5 microtuberculate semiannuli. Opisthosoma with 66 (62–68) dorsal annuli, 68 (62–68) ventral annuli. Dorsal and ventral annuli microtuberculate. Posterior 6–8 dorsal annuli with only a few indistinct microtubercles dorsally, almost smooth, laterally with small microtubercles. Microtubercles round and pointed close to rear annular margin, except for 4–6 ventral annuli near anal lobes, which are elongate, linear and pointed. Caudal lobe normal in size and shape. Setae c2 30 (18–30), on ventral annulus 10 (8–11), 55 (55–62) apart. Setae d 40 (30–40), on ventral annulus 24 (21–24), 47 (46–47) apart; setae e 9 (9–12), on ventral annulus 40 (35–40), 27 (23–27) apart; setae f 28 (25–28), on ventral annulus 63 (57– 63), or 5 (5–6) from rear, 28 (27–32) apart, all very fine towards apex. Setae h2 73 (60–73), 14 (13–14) apart; setae h1 4 (4–5), 7 (7) apart. Genital plate 15 (13–17), 24 (20–24) wide, genital coverflap smooth. Setae 3a 7 (7–9), 20 (17–20) apart.

Male (n= 3). Similar to female, 195–218, 57 wide, 60–64 thick. Gnathosoma 19–22, projecting obliquely downwards; dorsal palp genual setae d 2, unbranched; pedipalp coxal setae ep 1. Prodorsal shield 27–32, 30 wide, half circle, ornamentation similar to female. Tubercles of scapular setae sc on rear shield margin, 25 apart, diverging, scapular setae sc 25–27, directed to the rear. Legs with all usual segments and setae present. Leg I 26– 28, femur 8–9, basiventral femoral setae bv 7, very fine, genu 4, antaxial genual setae l″ 20–21, tibia 7, paraxial tibial setae l ′ located at ¼–½ from dorsal base, 2–3, very fine, tarsus 5–7, solenidion ω 8–9, slightly curved, distally rounded or with a minute knob, empodium simple, bilaterally symmetrical, 6, 4-rayed. Leg II 22–25, femur 7–8, basiventral femoral setae bv 7, very fine, genu 4, antaxial genual setae l″ 5–7, very fine, tibia 5–6, tarsus 5, solenidion ω 7–8, slightly curved, distally rounded or with a minute knob, empodium simple, bilaterally symmetrical, 5–6, 4-rayed. Coxisternae I and II smooth; setae 1b 8, setae 1a 11, setae 2a 21–22, all very fine. Subcapitular plate anteriorly rounded, smooth, without granules. Prosternal apodeme 10. Coxigenital area with 4–5 microtuberculate semiannuli. Opisthosoma with 55–61 dorsal, 56–58 ventral annuli. Microtuberculate dorsal and ventral annuli. Posterior 6–8 dorsal annuli with only a few indistinct microtubercles dorsally, almost smooth, laterally with small microtubercles. Round microtubercles on rear annular margin minute, pointed, except for 4–6 ventral annuli of anal lobes, which are elongate, linear and pointed. Caudal lobe normal in size and shape. Setae c 2 14–16, on ventral annulus 8, 50 apart; setae d 19–26, on ventral annulus 17–19, 31 apart; setae e 7–8, on ventral annulus 30–32, 20 apart; setae f 23–25, on ventral annulus 51–53, or 4 from rear, 19 apart. Setae h2 56–58, 8 apart; setae h1 3–4, 6 apart. Genitalia 11–15, 20–21 wide, posteriorly minute granules, setae 3a 5–7.

Nymph (n= 2). White, vermiform, 180–197, 51–52 thick. Prodorsal shield 25–28. Gnathosoma 17–20, chelicerae 14–15. Tubercles of scapular setae sc on rear shield margin, scapular setae sc 14–22, directed to rear. Leg I 22, leg II 18–20. Opisthosoma with 48–51 dorsal, 49–52 ventral annuli. Setae c 2 8–10, on ventral annulus 10; setae d 13–22, on ventral annulus 20; setae e 4–5, on ventral annulus 28–31; setae f 15–17, on ventral annulus 45– 47, or 4–5 from rear. Setae h2 57, setae h1 2. Dorsal annuli with minute microtubercles like dots. Posterior 5 dorsal annuli with only a few microtubercles, almost smooth. Setae 3a 2–3.

Host plant. Pycnocomon rutifolium (Vahl) Hoffmans. et Link (Dipsacaceae) , a perennial herb in Southern Spain on maritime sands. It is a characteristic species of dry habitat. It should be mentioned that the genus Pycnocomon Hoffmans. et Link is now included in the Caprifoliaceae by some botanists.

Relation to the host plant. The mite was found in all stages of development in the erinea on the leaflets. Definite symptoms were observed: the plant became swollen and distorted with visible erinea on the margin of the leaflets, giving yellowish appearance to the plant ( Figures 2–3 ).

Type locality. Punta de Montijo, Sanlúcar de Barrameda, Cádiz province , Southern Spain, 36°45'38.21" N, 6°24'22.96" W, 2 m elev. on 15 March 2013 . The host plant grows on sand dunes. The symptoms were also seen in Rota, Cádiz province , Southern Spain, 29AQA 45, 7 m elev. 36°37'23.25" N, 6°16'51.45" W, on 07 March 2013. Type material. 27 females , 4 males, 2 nymphs as follows. Holotype: female (circled with black ink) among 6 females and 1 male paratypes on the same slide (slide # 1380b), coll. I. Sánchez, 15 March 2013. Paratypes: 3 females, 2 males and 1 nymph (slide # 1380a), and 13 females and 1 nymph (slide # 1380c) data same as for holotype, deposited in the Department of Pest Management Development and Coordination, Directorate of Plant Protection, Soil Conservation and Agri-environment, National Food Chain Safety Office , Budapest, Hungary, 4 females and 1 male, and 2 tydeid and 1 phytoseiid mites on same slide (slide # 1380d) deposited in the Hungarian Natural History Museum , Budapest, Hungary.

Etymology. The species is named after the generic name of the host plant.

Differential diagnosis. Aceria pycnocomi sp. nov. are the most similar to Aceria squalida (Nalepa, 1892) because they share numerous features, particularly body shape, the number of dorsal and ventral annuli, and prodorsal shield ornamentation but can be differentiated by having longer setae c 2 18–30 (whereas 13–23 in A. squalida ), shorter setae d 30–40 and setae h1 3–5 (versus 51–55 and 6–7 in A. squalida , respectively) ( Ripka 2013). According to the original description of A. squalida , the length of scapular setae sc is 1.5 times longer than the prodorsal shield ( Nalepa 1892a, b), and it is 50 according to Farkas (1966), whereas Aceria pycnocomi sp. nov. has setae sc 35–39 long, which is only slightly longer than prodorsal shield, 31–35. Aceria pycnocomi sp. nov. caused definite symptom on the leaflets, i.e. erinea, deformation of the leaflets and yellowing (apparently A. squalida causes either flower deformation and flower greenings or no visible symptom) ( Nalepa, 1892a, b; Farkas 1966; Ripka 2013).

Until now, there were no eriophyoid species recorded on the representatives of the genus Pycnocomon . Aceria pycnocomi sp. nov. is the first species to be found inhabiting this dipsacaceous host.

Figures

FIGURE 1. Aceria pycnocomi sp. nov., semischematic drawings. (Géza Ripka) Scale bar: 23 µm for AL; 19 µm for AD, 21 µm for CG, 20 µm for LO; 13 µm for IG; 11 µm for L 1, 24 µm for PM; 10 µm for GM; 4 µm for em.

FIGURES 2 – 3. Symptoms of Aceria pycnocomi sp. nov. on Pycnocomon rutifolium. (Photo: Iňigo Sánchez).