Metatarsonemus megasolenidii Lofego & Ochoa

Lofego, A. C., Ochoa, R. & Moraes, G. J., 2005, “ Cerrado ” vegetation, with descriptions of three new species, Zootaxa 823, pp. 1-27 : 7-15

Metatarsonemus megasolenidii Lofego & Ochoa , sp. nov.

( Figs. 7–18 )

Diagnosis: Females of this new species are similar to Metatarsonemus simplicissimus Attiah in the shape of gnathossoma (subcircular) and idiosoma (oval), and by having several fissures on the ventral plates, but differ by having the fissure of the coxisternal plates III and IV larger and bifurcate posteriorly. Males of the new species differ from M. simplicissimus by having solenidion of tarsus II approximately twice as large.

Adult female (5 specimens measured).

Gnathosoma: subcircular in dorsoventral view, length 23 (21–25), maximum width 24 (23–25); dorsal apodeme distinct. Setae ch 12 (11–13) and vm 7 (7–8) smooth, seta pp not observed. Palpus short, with 2 small subterminal setae and terminal cone­shaped structures. Pharynx subfusiform, 13 (12–14) long by 7 (7–8) wide at widest region.

Idiosoma ( Figs. 7 and 8 ): length 180 (173–185), maximum width 97 (95–100). Prodorsal shield completely covering gnathosoma. Stigma lateral, equidistant to bases of setae v1 and sc 2. All tergites smooth. Lengths of setae: v1 24 (20. –28), sc1 13,5 (13–14), sc2 27 (24–30), c1 16 (13–18), c2 16 (14–20), d 13 (13–14), e 7, f 13 (12–14), h 10 (10–11). All setae setiform, stout and serrate, except sc2, smooth, and botridial seta sc1, capitate and with tiny spines. Distances between dorsal setae: v1–v1 28 (26–30), sc2–sc2 51 (50–53), v1 –sc2 24 (23–25), c1–c1 48 (45–52) c2–c2 73 (68–79), c1–c2 31 (30–33), d–d 32 (28– 38), f–f 20 (18–21), e–f 12 (11–13), h–h 22 (21–23). Seta sc1 inserted at same level or posterior to sc2.

Coxisternal setae 1a 6 (5–7), near middle of apodeme I; 2a 11 (10–12), near anterior end of apodeme II; 3a 11(8–15), near anterior end of apodeme III; 3b 9 (9–10), on posterior end of apodeme IV. Apodeme I conspicuous, fused to anterior end of prosternal apodeme, wider at region between bases of setae 1a; apodeme II short not fused to prostenal apodeme. Prosternal apodeme conspicuous from junction with apodemes I to level of posterior end of apodeme II, but diffuse from this point to level of sejugal apodeme; conspicuous section with a median node; diffuse section widened. Sejugal apodeme uninterrupted. Apodeme III extending diagonally from proximity of base of seta 3a to anterior margin of trochanter III; apodeme IV extending diagonally from the middle of poststernal apodeme to basis of seta 3b. Poststernal apodeme bifurcate anteriorly. Coxisternal plates smooth. Coxisternal plate I with 2 fissures, one very short, antero­medially to seta 1a, and one relatively long, postero­lateral on the coxisternal plate. Coxisternal plates III and IV with a fissure that extends postero­laterally from area near junction of apodeme IV with poststernal apodeme, crosses apodeme IV and bifurcates at level of posterior margin of trochanter III. An ellipsoidal fissure is situated adjacent to the posterior end of the poststernal apodeme. Tegula 10 (10–11) long and 12 (12–13) wide; posterior margin rounded; lateral margins slightly concave, under which arise a pair of sharp structures. Seta ps serrate.

Legs ( Figs. 9–12 ): lengths (femur to tarsus): leg I 41 (40–42), leg II 38 (35–40), leg III 49 (47–50), leg IV 35 (34–36). Number of setae (solenidia in parentheses) on femur, genu, tibia and tarsus, respectively: leg I: 4­4­6(1)­8(1), leg II: 3­3­4­5(1), leg III: 1­3­4­5. Solenidion of tibiotarsus I 5 (5–6), stout, wider medially. Sensory cluster of tibia I composed only of solenidion, very short (2), and famulus k (4), both inserted at approximately the same level. Seta d of tibia I 31 (30–32), smooth. Solenidion of tarsus II proximal, 5 (4–5) long, stout, wider medially; seta pl´´not observed. Seta d of tibia II serrate, 12 (11–14). Femorogenu IV 25 (23–26); tibiotarsus IV 10 (9–11). Leg IV with setae v´F 6 (4–7) and v´G 11 (10–12) smooth, and setae v´Ti 19 (24–30) and tc´´26 (24–30) slightly serrate.

Adult male (6 specimens measured).

Gnathosoma: subcircular in dorsoventral view, length 20 (19–22), maximum width 21(20–23); dorsal apodeme distinct. Setae ch 11 (10–12), serrate, vm 6 (6–7), smooth, pp not observed. Palpus short, bearing 2 small subterminal setae and terminal cone­shaped structures. Pharynx 10 (9–11) long and 6 (5–6) wide in the widest region.

Idiosoma ( Figs. 13 and 14 ): length 134 (129–140), maximum width 76 (71–83). Prodorsal shield trapezoidal. Length of dorsal setae: v1 21 (18–23), v2 13 (12–15), sc1 20 (18–23), sc2 22 (18–25), c1 18 (14–22), c2 20 (15–25), d 19 (15–24), f 13 (11–16). All setae setiform, stout and serrate. Distances between dorsal setae: v1–v1 12 (12–13), v2–v2 23 (22–23), sc1–sc1 27 (25–28), sc2–sc2 37 (35–38), v1–v2 10 (10–10), v2 –sc2 9 (8–9), sc1–sc2 4,5 (4–5), c2–c2 72 (65–77), c1–c1 60 (55–63), d–d 31 (29–34), c1–d 18 (16–21), c1–c2 34 (31–38), f–f 20 (20–21). Seta sc2 laterad and slightly posterior to sc1; seta c1 closer to d than to c2, antero–lateral to the latter.

Coxisternal seta 1a 6 (5–6), in the middle of anterior half of coxisternal plate 1; seta 2a 10 (8–11), in the center of coxisternal plate 2; seta 3a 13 (11–16), near anterior end of apodeme III; seta 3b 12 (10–14), near middle of apodeme IV. Apodeme I fused to anterior end of prosternal apodeme; apodeme II not fused to prosternal apodeme. Prosternal apodeme conspicuous between coxisternal plates I but very thin between coxistenal plates II, extending to sejugal apodeme. Sejugal apodeme conspicuous, with 2 lightly sclerotized sections posterior to setae 2a. Lines of fusion between coxae III and IV with venter of idiosoma mostly conspicuous (apodemes III and IV, poststernal apodeme and connecting apodeme between apodemes III and IV); connecting apodemes between apodemes IV and poststernal diffuse. For the most part, venter of idiosoma punctate; punctation most prominent immediately anterior to sejugal apodeme and anterolateral of apodeme III.

Legs ( Figs. 15–18 ): lengths (femur to tarsus): leg I 44 (42–45), leg II 40 (38–41), leg III 46 (41–50), leg IV 55 (39–80). Number of the setae (solenidia in parentheses) on femur, genu, tibia and tarsus, respectively: leg I: 4­4­6(1)­8(1), leg II: 3­3­4­5(1), leg III: 1­3­4­5. Solenidion of tarsus I 4 (3–4), stout, wider medially. Two minute setae present, probably the fastigial setae ft' and ft", placed near. Sensory cluster of tibia I composed only of solenidion 2 (2–3), and famulus k (4), both inserted at approximately same level. Seta d of tibia I 25 (20–30), serrate. Solenidion of tarsus II proximal 9 (9–10) long, stout, wider medially. Seta pl´´not observed. Seta d of tibia II 12 (10–13), serrate.

Trochanter IV slightly wider than long, anterior margin slightly longer (12) than posterior margin (9), seta ví 14 (10–18), smooth. Femorogenu IV 37 (26–53) long and 14 (11– 20) wide at v´F level; anterior margin convex, posterior margin slightly convex at proximal third and slightly concave at 2 distal thirds, without flange or projection. Seta v´F 7 (5–10), smooth. Setae v'G 20 (15–25) and l"G 15 (11–18), serrate. Tibia IV 14 (10–22) long; solenidion 6 (5–8), bacilliform; seta v'Ti 24 (20–30), serrate. Tarsus IV short, bearing 3 smooth setae of the following length: tc" 4 (3–5), pv" 6 (5–7) and u' 5 (4–6). Claw well developed.

Type material: holotype female, from Campomanesia pubescens (DC.) Berg and 1 paratype female from Myrcia guianensis (Aubl.) DC., Luiz Antonio, State of São Paulo, Brazil, 26/VII/2000, A.C. Lofego; 1 paratype female from M. guianensis , 02/V/2000, same location and collector as holotype; 2 paratype females, 26/I/2000, other collection data as holotype; 1 allotype male and 9 paratype males, 16/V/2002, other collection data as holotype; 2 paratype females and 5 paratype males from M. guianensis , 16/V/2002, same location and collector as holotype; 2 paratype females from Myrcia venulosa DC., São Carlos, State of São Paulo, 25/V/2000, A.C. Lofego; all deposited at ESALQ / USP. One paratype female and 1 paratype male, same collection data as holotype, deposited at USNM.

Etymology: the species name megasolenidii refers to the large solenidion on tarsus II of the male.

Figures

FIGURE 7. Metatarsonemus megasolenidii sp. nov. (female). Dorsal surface.

FIGURE 8. Metatarsonemus megasolenidii sp. nov. (female). Ventral surface.

FIGURES 9 – 12. Metatarsonemus megasolenidii sp. nov. (female). 9, leg I; 10, leg II; 11, leg III; 12, leg IV.

FIGURE 13. Metatarsonemus megasolenidii sp. nov. (male). Dorsal surface.

FIGURE 14. Metatarsonemus megasolenidii sp. nov. (male). Ventral surface.

FIGURES 15 – 18. Metatarsonemus megasolenidii sp. nov. (male). 15, leg I; 16, leg II; 17, leg III; 18, leg IV.