Eriocaenus ramosissimi, Petanović, Radmila U., Amrine Jr, James W., Chetverikov, Philipp E. & Cvrković, Tatjana K., 2015

Petanović, Radmila U., Amrine Jr, James W., Chetverikov, Philipp E. & Cvrković, Tatjana K., 2015, Eriocaenus (Acari: Trombidiformes: Eriophyoidea), a new genus from Equisetum spp. (Equisetaceae): morphological and molecular delimitation of two morphologically similar species, Zootaxa 4013 (1), pp. 51-66 : 54-59

Eriocaenus ramosissimi n. sp. Petanović & Amrine

( Figs. 2 , 3 , 4 A–C, E & F; 5F)

Female (n=10). Body wormlike 225 (219–274), 60 (57–61) wide, white in colour. Gnathosoma 25 (23–28), downcurved, dorsal pedipalp genual setae d 11 (9–15), palpcoxal setae ep 4, apical setae v 1, cheliceral stylets 22 (19–25). Prodorsal shield 32 (32–40), 40 (33–42) wide. Posterior part semi-elliptic, anterior half triangular, with short lobe over basal parts of chelicerae. Prodorsal shield tubercles ahead of rear shield margin 18 (14–19) apart, scapular setae sc 2 (1–2), directed upward and slightly forward. Shield with numerous granules, some present in central part of shield between scapular tubercles, forming median, admedian and submedian lines; lateral fields covered with granules, irregularly distributed. Legs with all usual segments and setae, except basiventral femoral setae bv. Leg I 38 (37–42); femur 7 (7–11), basiventral femoral setae bv absent; genu 7(6–7), antaxial genual setae l" 31 (31–43); tibia 8 (7–9), paraxial tibial setae l' 3 (2–6); tarsus 6 (6–8), paraxial fastigial tarsal setae ft' 14 (9–15), antaxial fastigial tarsal setae ft" 25 18–25, ventromesal setae u ′ 2; tarsal solenidion ω 6 (6–8), rod-like, distally rounded; tarsal empodium 5 (5–7), 7-rayed. Leg II 30 (27–36); femur 7 (6–9), basiventral femoral setae bv absent; genu 5 (4–6), antaxial genual setae l" 15 (12–15); tibia 7 (5–8); tarsus 7 (6–7), paraxial fastigial tarsal setae ft' 11, antaxial fastigial tarsal setae ft" 23 (16–31), ventromesal seta u ′ 2; tarsal solenidion ω 7 (6–8), rod-like, distally rounded; tarsal empodium 5 (5–7), 7-rayed. Coxigenital region with 4 (4–7) coxigenital annuli. Coxae with numerous dashes; prosternal apodeme indistinct; subcapitular plate ( Fig. 4 C) sub-rectangular, anteriorly rounded; with microtubercules/microgranulations on the plate surfac anterolateral setae on coxisternum I 1 b 6 (5–7), 14 (14– 16) apart; proximal setae on coxisternum I 1a 24 (16–27), 10 (9–11) apart; proximal setae on coxisternum II 2 a 45 (28–47), 26 (18–27) apart. External genitalia 11 (11–17), 20 (20–23) wide, genital coverflap with 12 (10–14) longitudinal ridges striae in a single row; proximal setae on coxisternum III 3a 11 (8–14), 15 (13–16) apart. Spermathecal apparatus typical for eriophyids comprising spherical spermathecae and short spermathecal tubes directed postero-laterad. Opisthosoma with subequal annuli: 83 (83–110) dorsal and 89 (89–116) ventral annuli. Dorsal annuli with oval microtubercles, ventral annuli with rounded microtubercles. Setae c2 21 (17–27), 46 (38– 51) apart, on annulus 13 (13–15); setae d 28 (21–51), 38 (33–467) apart, on annulus 39 (29–40); setae e 2 (1–2), 22 (19–23) apart, on annulus 46 (46–66); setae f 48 (37–63), 36 (25–39) apart, on annulus 77 (77–107); setae h2 87 (57–105), 12 (13–15) apart; setae h1 4 (3–6), 8 (8–9) apart.

Male (n=2). Body wormlike, 207–215, 49–53 wide. Gnathosoma 19–20, dorsal pedipalp genual setae d 8–10, cheliceral stylets 16–19. Prodorsal shield shape and design similar to female, 30–33, 26–37 wide. Prodorsal shield tubercles ahead of rear shield margin 15–16 apart, scapular setae sc 1–2, directed upward and slightly forward. Leg I 30–34; femur 7, basiventral femoral setae bv absent; genu 4–5, antaxial genual setae l" 29–29; tibia 6, paraxial tibial setae l ′ 3; tarsus 6, paraxial fastigial tarsal setae ft' 6, antaxial fastigial tarsal setae ft" 20–22; tarsal solenidion ω 6, distally rounded; tarsal empodium 6, 7-rayed. Leg II 29; femur 6–7, bv absent; genu 4–5, l" 11–25; tibia 4–5; tarsus 4–6, ft" 18–19; tarsal solenidion ω 6–7, distally rounded; tarsal empodium 5, 7-rayed. Coxigenital area with 6 coxigenital annuli, similar to female. Anterolateral setae on coxisternum I 1 b 3–6, 12–15 apart; proximal setae on coxisternum I 1a 17–24, 8 apart; proximal setae on coxisternum II 2a 26–38, 23–24 apart. External genitalia 16– 18 wide, proximal setae on coxisternum III 3a 6 –8, 15–18 apart. Opisthosoma with subequal annuli: 90–94 dorsal annuli, 88–98 ventral annuli. Annuli with microtubercles similar to female. Setae c 2 15–19, 37–41 apart, on annulus 12–15; setae d 24–25, 29–31 apart, on annulus 28–29; setae e 1–2, 17–18 apart, on annulus 46–50; setae f 40–46, 25–27 apart, on annulus 78–87; setae h2 35–64, 11–13 apart; setae h1 3, 5–6 apart.

Nymph (n=2). Body wormlike 174–254, 36–50 wide. Gnathosoma 19–20, downcurved, dorsal pedipalp genual setae d 4, cheliceral stylets 14–19. Prodorsal shield shape and design similar to adult female, 25–28, 22–27 wide. Scapular setae sc 1, 12–18 apart directed upward and slightly forward. Leg I 24–26; femur 5, basiventral femoral setae bv absent; genu 3, antaxial genual setae l" 21; tibia 3; tarsus 3–5, antaxial fastigial tarsal setae ft" 14; tarsal solenidion ω 4–6, distally rounded, tarsal empodium 4–6, 6–7-rayed. Leg II 18–21; femur 5, basiventral femoral setae bv absent; genu 3–4; tibia 4; tarsus 4, antaxial fastigial tarsal setae ft" 12–16; tarsal solenidion ω 5–6, distally rounded; tarsal empodium 4–5, 6–7-rayed. Coxigenital area with 18 coxigenital annuli. Anterolateral setae on coxisternum I 1 b 3–4, 9–17 apart; proximal setae on coxisternum I 1a 12–13, 8–9 apart; proximal setae on coxisternum II 2a 20–23, 21–24 apart. Opisthosoma with 98–105 dorsal annuli, 94–115 ventral annuli. Setae c 2 10–15, 34–38 apart, on annulus 18–25; setae d 12–18, 29–30 apart, on annulus 36–46; setae e 1–2, 16–23 apart, on annulus 54–70; setae f 25–31, 20–27 apart, on annulus 86–104; setae h 2 28–44, 8–11 apart; setae h1 2–3, 4–5 apart.

Larva (n=2). Body wormlike 127–138, 41–45 wide. Gnathosoma 18–20, downcurved, cheliceral stylets 15– 15. Prodorsal shield shape and design similar female, 19–21, 20–25 wide. Scapular setae sc minute, 11 apart. Leg I 18–21; femur 4, basiventral femoral setae bv absent; genu 2; tibia 3; tarsus 3, antaxial fastigial tarsal setae ft" 9; tarsal solenidion ω 4–6, distally rounded, tarsal empodium 4, 5-rayed. Leg II 16–19; femur 4–5, basiventral femoral setae bv absent; genu 3–4; tibia 4; tarsus 4; tarsal solenidion ω 4(3–5), distally rounded; tarsal empodium 4–5, 5-rayed. Anterolateral setae on coxisternum I 1 b 8 apart; proximal setae on coxisternum I 1a 8 apart; proximal setae on coxisternum II 2a 12–13, 20 apart. Opisthosoma with 65–101 dorsal annuli, 80–101 ventral annuli. Setae c 2 7, 29 apart, on annulus 18; setae d 4, 24 apart, on annulus 33; setae e minute, on annulus 48; setae f 13–19, 21– 23 apart, on annulus 75; setae h 2 16–25, 9–10 apart; setae h1 2, 4–5 apart.

Type material. Female holotype on microscope slide #1431/1 and paratypes: 7 females on slides #473/8, #473/10, #473/11, #473/13, #473/19, #473/16 and #473/27; 2 males on slides #473/7 and #1431/8; 4 nymphs on slides #473/4, #1431/7a, #1431/7b and 1431/11; 2 larvae on slides #437/29 and #1431/12. All collected from Equisetum ramosissimum Desf. (Equisetaceae) in Zemun, Altina, Serbia (44o50' 26.3N ", 20o21'34.8"E, elevation 90 m) on 13 September 2013 by D. Smiljanić [slide series #1431] and Mramorak Deliblato sands, Serbia (44o56'38"N, 20o59'57.7"E) on 27 June 2013 by D. Smiljanić and B. Vidović [slide series #473]. Deposited in the Acarological Collection of the Department of Entomology and Agricultural Zoology, Faculty of Agriculture, University of Belgrade, Serbia. Other paratypes on slides (#473a 1 male; #473b 1 male, 2 nymphs; #473c 1 female, 1 nymph) are deposited in the Acarological Collection of the Zoological Institute of the Russian Academy of Sciences, Saint Petersburg, Russia ( ZIN RAS). Two paratype slidemounts (#473/ 1 male and #473/ 12 female) are deposited in the Acarological Collection of the West Virginia University, Division of Plant & Soil Sciences, Morgantown, West Virginia, USA.

Additional material. 19 females, 6 males, 4 nymphs and a single larva (30 specimens altogether) collected from the same host, E. ramosissimum, Mramorak Deliblato sands, Serbia (N 44o56'38" E 20o59'57.7") on 27 June 2013 by D. Smiljanić and B. Vidović.

Etymology. The species name " ramosissimi " is a neutral noun (generis neutrium) in genitive corresponding to the plant species name on which the new mite was found.

Host plant. Equisetum ramosissimum Desf. (Equisetaceae) .

Relation to plant host. The mites were found living under scale-like leaves which were joined together to form a special envelope, known as an “ohrea” ( Sarić 1992). Browning or russeting of these plant parts were observed ( Fig. 6 ).

Figures

FIGURE 2. Semi-schematic drawings of Eriocaenus ramosissimi n. sp. female: AD. Antero-dorsal view; AL. Antero-lateral view; CG. Coxal-genital region; em. Empodium; GM. Genital region, male; IG. Internal genitalia, female; L 1. Leg I; LO. Lateral opisthosoma; PM. Postero-lateral mite (telosoma). Scale bar: 25 µm (except for em = 5 µm).

FIGURE 3. Semi-schematic drawings of Eriocaenus ramosissimi n. sp.: N. Nymph; L. Larva.

FIGURE 4. Eriocaenus ramosissimi n. sp. (DIC images): A. Dorsal view of whole mite; B. Dorsal view of anterior section; C. Anterior section of male, ventrally; E. Genital coverflap; F. Internal female genitalia; D. Genital coverflap of E. equiseti.

FIGURE 6. Location of Eriocaenus ramosissimi n. sp. on Equisetum ramosissimum, showing a group of mites inside the scale-like leaves which are joined together to form a special envelope known as an “ ohrea.