Nasutitarsonemus omani Lofego and Moraes, 2011
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publication ID |
https://doi.org/ 10.1080/00222933.2010.534192 |
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persistent identifier |
https://treatment.plazi.org/id/F83F87C4-FFE1-FFF4-3A90-FA87A616FF09 |
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treatment provided by |
Felipe |
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scientific name |
Nasutitarsonemus omani Lofego and Moraes |
| status |
sp. nov. |
Nasutitarsonemus omani Lofego and Moraes , sp. nov.
( Figures 2–7 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 View Figure 7 )
Diagnosis
Females of this new species differ from the two described species of this genus by having dorsal setae, except sc1 and h, smooth; N. brontispae Beer and Nucifora and N. alvuventris Ochoa have all dorsal setae serrate or pilose. Females of the new species further differ from the previously described species by having the sejugal apodeme not continuous medially and by lacking a poststernal apodeme; N. brontispae and N. alvuventris have the sejugal apodeme continuous and poststernal apodeme present.
Specimens examined
Holotype female, five paratype females and one paratype male from Cocos nucifera , collected from Salalah, Sultanate of Oman, on 29 / 11 / 2008, F. Hountondji and D. Ganguly colls; deposited at Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Piracicaba, State of São Paulo, Brazil. One paratype female, data as holotype, deposited at the Departamento de Zoologia e Botânica, Universidade Estadual Paulista ( UNESP), São José do Rio Preto, State of São Paulo, Brazil.
Description
Female (seven specimens measured). Figures 2–4 View Figure 2 View Figure 3 View Figure 4 . Gnathosoma: capsule beaklike, 41 (35–45) long, 22 (22–23) wide at widest region; dorsal apodeme distinct. Setae ch 13 (11–15) and vm 6 (6–7) smooth; seta pp absent. Palpus elongate. Pharynx of moderate width, with well-sclerotized walls, 10 (9–10) long and 5 (5–6) wide at widest region.
Idiosoma: 197 (180–235) long, 96 (90–110) wide at level of c1; prodorsal shield smooth, covering only base of gnathosoma. Dorsal median apodeme well distinct on prodorsum. Stigma near insertion of seta sc1. Lengths of setae: v1 6 (5–7), sc1 19 (18–20), sc2 10 (8–10), c1 10 (9–11), c2 10 (8–11), d 6 (6–7), e 7 (6–8), f 7 (6–7) and h 13 (11–14). All setae setiform and smooth, except h (serrate) and sc1 (capitate and with tiny spines). Distances between dorsal setae: v1–v1 23 (22–24), sc2–sc2 57 (55–61), v1–sc2 46 (45–49), c1–c1 32 (29–34), c2–c2 89 (84–97), c1–c2 29 (25–34), d–d 70 (62–72), f–f 30 (26–33), e–f 17 (14–18) and h–h 35 (35–39).
Coxisternal setae 1a 6 (5–7), near middle of apodeme I; 2a 6 near middle of plate II; 3a 7 (5–8), anterior to apodeme III; 3b 6 (6–8), anterior to apodeme IV; 3c 8 posterior and near end of apodeme III; setae 4b 8 (6–9), near trochanter IV. Apodeme I consolidated into protruding ledge supporting gnathosoma, not united to prosternal apodeme. Apodeme II short, not fused to prosternal apodeme. Prosternal apodeme conspicuous, formed by two parts, anterior third separated from posterior two-thirds; anterior and posterior ends free. Sejugal apodeme medially interrupted. Apodeme III extending diagonally from anterior and proximal level of seta 3c to anterior margin of trochanter III, anterior end hook-like; apodeme IV extending diagonally posterior to seta 3b; anterior and posterior ends free. Poststernal apodeme absent. Coxisternal plates smooth. Tegula well-developed and with posterior end rounded, 22 (20–24) long and 29 (28–30) wide at base. Seta ag placed in middle of distance between end of tegula and posterior extremity, near to anal slit. Seta ps serrate.
Legs: lengths (femur to tarsus): leg I 47 (45–58), leg II 46 (43–55), leg III 51 (48–57), leg IV 41 (39–43). Number of setae (solenidia in parentheses) on femur, genu, tibia and tarsus, respectively: leg I: 3-3-5(2)-8(1), leg II: 3-3-4-4(1), leg III: 2-3-4-4. Tarsal solenidion ω of tibiotarsus I 4 (4–5), capitate. Sensory cluster of tibia I complete, solenidion Φ 1 5, capitate; solenidion Φ 2 3, capitate; famulus k 7 (6–8); all inserted at the same level. Seta d of tibia I 28 (23–30), serrate. Solenidion ω of tarsus II proximal, 4 (4–5) long, stout, wider medially; seta pl“ absent. Seta d of tibia II 13 (12–14), smooth. Femorogenu IV 27 (25–29); tibiotarsus IV 14 (12–16). Length of leg IV setae: v‘F 10 (9–12), v‘G 15 (11–17), v‘Ti 39 (37–47), v“Ti 3 and tc“ 97 (85–110); all setae smooth; v‘Ti laminar, placed on middle of tibiotarsus.
Male (one specimen measured). Figures 5–7 View Figure 5 View Figure 6 View Figure 7 . Gnathosoma: capsule beaklike, 38 long and 22 wide at widest level; dorsal apodeme conspicuous. Setae ch 14 and vm 10, smooth, seta pp indistinct. Palpus elongate. Pharynx of moderate width, with wellsclerotized walls, 9 long and 5 wide at widest region.
Idiosoma: Length 165, maximum width 90. Prodorsal shield trapezoidal, smooth, covering only base of gnathosoma. Length of dorsal setae: v1 11, v2 absent, sc1 18, sc2 18, c1 12, c2 14, d 13, f 15. All setae setiform and serrated. Distances between dorsal setae: v1–v1 15, sc1–sc1 30, sc2–sc2 42, v1–sc1 18, sc1–sc2 20, c1–c1 35, c2–c2 80, c1–c2 23, d–d 42, c1–d 37, f–f 22. Setae c1 posterior and close to imaginary line between bases of setae c2; bases of setae c1 longitudinally aligned with bases of setae d.
Coxisternal seta 1a 10, antero-median to centre of coxisternal plate 1; seta 2a 10, near central region of coxisternal plate 2; seta 3a 8, near anterior end of apodeme III; seta 3b 10, situated laterad of proximal two-fifths length of apodeme IV; seta 3c 7, near posterior end of apodeme III; seta 4b 10, located in front of trochanter IV. Apodeme I fused to anterior end of prosternal apodeme; apodeme II faintly fused to prosternal apodeme. Prosternal apodeme conspicuous between coxisternal plates I and II up to level of seta 2a. Sejugal apodeme medially interrupted. Apodemes III, IV and poststernal strongly developed and fused by anterior ends. Posterior end of poststernal apodeme bifurcate. All ventral plates with faint puncta.
Legs: lengths (femur to tarsus): leg I 53, leg II 50, leg III 60, leg IV 50. Number of setae (solenidia in parentheses) on femur, genu, tibia and tarsus: leg I: 3-3-5(2)-11(1), leg II: 3-3-4-4(1), leg III: 2-3-4-4. Solenidion ω of tarsus I 4, capitate. Sensory cluster of tibia I complete, solenidion Φ 1 6, capitate; solenidion Φ 2 4,capitate; famulus k 8; all inserted at the same level. Seta d of tibia I 25, smooth. Solenidion ω of tarsus II 4, stout, wider medially. Seta pl“ absent. Seta d of tibia II 10, smooth. Leg IV robust. Trochanter IV as long as wide, anterior margin slightly longer, seta v‘ smooth, 15 long. Femorogenu IV, 36 long and 23 wide at widest region, with a flange on posterior margin. Seta v‘F 8 and v‘G 5, smooth; setae l“G 29, serrate. Tibia IV 13 long; solenidion Φ 3, bacilliform; seta v‘Ti 70, smooth. Tarsus IV short, bearing 2 small setae: pv “ 2 long, and u‘ 3 long. Claw well developed.
Etymology
This species is named after the country where the type specimens were collected.
Remarks
Only two other species are known to belong to this genus, N. brontispae Beer and Nucifora and N. alvuventris Ochoa , from Malaysia and Indonesia respectively (Lin and Zhang 2002). Both species have been collected from beetles of the tribe Cryptonychini (Crysomelidae: Hispinae), the former on Plesispa nippie Chapuis and the latter on Callistola dilutipes (Weise) . Plesispa species feed mainly on leaves of several palm species, while Callistola species feed on Pandanaceae trees and on shrubs ( Lindquist 1986). Lindquist (1986) assumed that these mites would be phytophagous, based on the shape of the gnathosoma, which is similar to that of other phytophagous tarsonemids of the genera Suskia and Rhynchotarsonemus . Ochoa (1996) assumed that they would be phoretic on the beetles, mainly because only adult females were found on the latter.
Specimens of the new species here described were found on coconut fruits as well as in the growing tip of coconut seedlings. Although it was not possible to observe the feeding habits of the new species, the occurrence of males and females in a protected microhabitat (tight space between the bracts and the fruit surface, or between the bases of the younger leaves), in the absence of insects, suggests that it is not an insect parasite. In addition, the specimens of the two previously known species described in this genus were mentioned to have the gnathosoma in a camerostome (a space where the gnathosoma fits when retracted), suggesting that they were not feeding on the insects on which they were collected. Whereas all specimens collected in this work, found on the plant rather than on a carrying insect, had the gnathosoma protruded, suggesting that they could have been feeding when collected.
Females of the three known species of Nasutitarsonemus have a modified apodeme I, which is apparently fused to a lobular projection of coxisternum I, at the base of the gnathosoma. This modification of apodeme I could be associated with the capacity of the female to retract the gnathosoma inside the camerostome; the usual type of apodeme I could make it difficult for the mite to retract the gnathosoma. Males have a normal apodeme I, suggesting that they cannot retract the gnathosoma; this could be related to the fact that they do not undergo phoresis. An additional characteristic suggesting adaptation for female but not male phoresis is the attachment of the tarsal claw directly to the tip of the tarsus in the former but to the pulvillus of the latter. It could be implied that female tarsal claws could articulate with the tarsus, allowing females to hold on more strongly to carrier insects, which would not be the case for males. These observations seem consistent with the possible phytophagous or predatory rather than parasitic habit of mites of this group. The co-occurrence of N. omani sp. nov. with A. guerreronis suggests that it could either prey on the latter or feed on the tender coconut tissues on which it was found, though no damage to the fruits was observed. The type specimens and a few others collected on plantlets are the only specimens collected over an intensive search for mites on coconuts over more than two years in the Dhofar region.
Key to females of Nasutitarsonemus
1 Setae d, e and f smooth and shorter than 10 µm; sejugal apodeme interrupted medially; poststernal apodeme absent..................... N. omani sp. nov.
1 ′ Setae d, e and f serrate and longer than 14 µm; sejugal apodeme continuous; poststernal apodeme present............................................. 2
2 Bases of setae c1 and c2 aligned transversely; setae h pilose and about twice as long as c1; prodorsal shield broadly rounded anteriorly; anteromedian projection of coxisternal plates I subtuberculate....................................................................................... N. alvuventris
2 ′ Setae c1 inserted anteriorly to c2; setae h serrate and about 1.5 times as long as c1; prodorsal shield with a narrow rounded anterior projection; anteromedian projection of coxistenal plates I bilobed......... N. brontispae
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