Disella ilicicola, Navia, Denise & Flechtmann, Carlos H. W., 2005

Navia, Denise & Flechtmann, Carlos H. W., 2005, A new eriophyoid mite in the genus Disella from Ilex paraguariensis in Brazil, Zootaxa 1037, pp. 23-28 : 24-28

Disella ilicicola n. sp.

( Figs. 1 and 2 )

Diagnosis — Six­rayed empodia; short sternal line; dorsal shield tubercles well ahead of rear shield margin, scapular setae (sc) shorter than distance of its bases to rear shield margin; microtubercles on ventral opisthosomal annuli absent on two longitudinal bands extending back from sides of rear end of genitalia, merging at half the distance of ventral seta I (d) to II (e) and ending at ca. half the distance of ventral seta II (e) to III (f).

Female (Measurements of holotype and ranges of eight paratypes) — Body robust, fusiform, 188 (169–197) long, 78 (76–80) wide; colour in life yellowish. Gnathosoma projecting downwards, 20 (20–23) long; basal seta (ep) 3 (2–3) long; antapical seta (d) 3 (3–4) long. Chelicerae 20 (20–22) long; oral stylets 12 (12–16) long. Prodorsal shield 43 (42–46) long, 75 (71–77) wide, subretangular. Scapular seta (sc) 8 (7–8) long on prominent tubercles 31 (28–33) apart, directing setae up and backwards; tubercles placed ahead of rear shield margin on 2/3 posterior shield. Shield design of complete median line, admedian lines slightly sinuous, two transversal lines connecting median and admedian lines delimiting six median cells; irregular, curved submedian lines; many curved and discontinuous lines and dashes present on lateral and rear shield; in a lateral view, large cells occupy anterior shield margin. Frontal lobe broadly rounded anteriorly, 4 (4–5) long, base 24 (24–28) wide. Legs with tibia fused to tarsus. Leg I 20 (19–21) long; femur 9 (8– 10) long, femoral seta (bv) 5 (5–6) long; genu 4 (3–4) long, genual seta (l”) 21 (20–23) long; tarsus 4 (4–5) long, lateral seta (ft”) 20 long, dorsal seta (ft’) 16 (15–18) long, unguinal seta (u’) 6 (5–7) long, solenidion 6 (6–7) long; empodium 6 (5–7) long, 6­ (6–7) rayed. Leg II 17 (17–19) long; femur 9 (8–9) long, bv 6 (5–8) long; genu 3 long, l" 7 (6–8) long; tarsus 5 long, ft" 20 (19–20) long, ft’ 2 (2–3) long, u’ 4 (4–5) long, solenidion 6 (5– 6) long; empodium 5 long, 6­ (5–6) rayed. Coxigenital area smooth. Sternal line 4 (4–6) long. Coxal seta I (1b) absent; coxal seta II (1a) 18 (16–19) long, 11 (9–11) apart; coxal seta III (2a) 26 (25–28) long, 26 (23–27) apart. Four coxigenital semi annuli, smooth. Genitalia 20 (19–20) wide, 19 (17–21) long; coverflap with one or two transverse arched lines on the rear portion; central area smooth; 3 (3–4) semi­annuli, microtuberculate, on anterior coverflap; genital seta (3a) 8 (7–9) long. Opisthosoma with two slight ridges extending on first 2 (2–4) annuli and evenly arched on median and posterior region; 42 (40–45) dorsal annuli, smooth; ventrally with 42 (40–45) annuli, microtubercles absent in two longitudinal bands extending back from sides of rear end of genitalia, merging at half the distance of ventral seta I (d) to II (e) and ending at ca. half the distance of ventral seta II (e) to III (f), placed slightly ahead of rear border of annuli, more elongated on telosome (caudad of line across bases of seta f). Lateral seta (c2) 20 (17–20) long, on annulus 1–2. Ventral seta I (d) 20 (19–21) long, 37 (36–41) apart, 4 (4–6) microtubercles apart, on annulus 10 (10–13); ventral seta II (e) 7 (6–8) long, 20 (16–20) apart, on annulus 22 (20– 26); ventral seta III (f) lateral, 17 (17–18) long, 19 (16–20) apart, 11 (11–15) microtubercles apart, on annulus 37 (35–40). Caudal seta (h2) 37 (36–40) long; accessory seta (h1) minute.

Male (n=1) — Smaller than female, 106 long, 69 wide. Gnathosoma 19 long; basal seta (ep) 3 long; antapical seta 4 long. Chelicerae 18 long; oral stylets 12 long. Prodorsal shield 44 long, 67 wide. Scapular seta (sc) 7 long, 26 apart. Frontal lobe 4 long, base 22 wide. Legs as in female. Leg I 20 long; femur 9 long, femoral seta (bv) 4 long; genu 3 long, genual seta (l") 23 long; tarsus 5 long, lateral seta (ft") 18 long, dorsal seta (ft’) 15 long, unguinal seta (u’) 5 long, solenidion 6 long; empodium 6 long, as in female, 6­rayed. Leg II 17 long; femur 8 long, bv 5 long; genu 3 long, l" 7 long; tarsus 4 long, ft" 19 long, ft’ 2 long, u’ 4 long, solenidion 5 long; empodium 5 long, 5­rayed. Coxigenital area smooth. Coxal seta I (1b) absent; coxal seta II (1a) 16 long, 8 apart; coxal seta III (2a) 24 long, 22 apart. Genitalia 16 wide, 11 long, smooth, papillae as figured; genital seta (3a) 9 long. Opisthosoma with 40 dorsal annuli; 42 ventral annuli. Lateral seta (c2) 15 long, on annulus 1. Ventral seta I (d) 16 long, 30 apart, 5 microtubercles apart, on annulus 10; ventral seta II (e) 8 long, 14 apart, on annulus 22–23; ventral seta III (f) 12 long, 18 apart, on annulus 37. Caudal seta (h2) 37 long; accessory seta (h1) minute.

Type material — female holotype, 8 female and 1 male paratypes, from Ilex paraguariensis Saint Hilaire (Aquifoliaceae) , Chapecó, Santa Catarina, Brazil, 20 January 2004, collected by L. A. Chiarardia and J. M. Milanez, on 7 microscopic preparations, in the collection of Departamento de Entomologia, Fitopatologia e Zoologia Agrícola, Universidade de São Paulo, ESALQ, Piracicaba, São Paulo, Brazil and paratypes in the reference collection of Laboratorio de Quarentena Vegetal, Embrapa Recursos Genéticos e Biotecnologia, Brasília, Distrito Federal, Brazil.

Relation to host — vagrant on inner surface of mature leaves causing chlorosis.

Etymology — The specific designation ilicicola is derived from the genus, Ilex , of the host plant, plus cola, L. ­ colus, a, um, dwelling in, inhabitant.

Remarks — Disella ilicicola n. sp. is, so far, the only species in the genus with a 6­ rayed empodium; this structure being 4­, 5­ or 7­rayed in the other known species. It is close to D. talisiae ( Keifer 1969) in the absence of ventral microtubercles in two longitudinal bands (in the other known species the ventral annuli are entirely microtuberculate), but differs in the opisthosomal annulation: 22 dorsal and 34 ventral annuli in D. talisiae and 40 – 45 dorsal and ventral annuli in D. ilicicola n. sp.. It also shares with D. talisiae the presence of one or two transverse arched lines on the rear portion of the otherwise smooth coverflap; in the other known species the coverflap is either smooth, beset with longitudinal lines or is granulated in addition to the presence of crescent lines.

Figures

FIGURE 1. Disella ilicicola n. sp. D. — Dorsal habitus of female. V. — Ventral habitus of female.

FIGURE 2. Disella ilicicola n. sp. L. — Lateral habitus of female. GM. — Genitalia of male. L 1. — Leg I. L 2. — Leg II. E. — empodium.