Xenotarsonemus demitei, Pitton, Thafarel, Lofego, Antonio C. & Rezende, José M., 2016

Pitton, Thafarel, Lofego, Antonio C. & Rezende, José M., 2016, Three new species of Xenotarsonemus (Acari: Tarsonemidae) from the northwestern region of São Paulo State, Brazil, Zootaxa 4138 (3), pp. 534-548 : 535-539

Xenotarsonemus demitei n. sp.

( Figs. 1–6 )

Diagnosis. Females of this new species resemble X. brachytegula by the similar lengths of dorsal setae and solenidion ω of tibiotarsus I. It differs by having a longer spearhead-like tegula, by the absence of carinae anterior to the tegula, and by having seta k shorter (0.6 times) than X. brachytegula . Females of X. demitei also resemble Xenotarsonemus biangulus Lin, Zhang & Lin, 2000 by having a pair of pointed projections anterolaterally to the propodosoma, tegula reaching the first third of the femorogenu IV and absence of carinae anterior to the tegula, but it differs by having setae 1a inserted directly on the coxisternal plate, while they are located on small tubercles in X. biangulus ; and by the dorsal setae d, f and e shorter and setae h longer than those of X. biangulus . Females of this new species also resemble X. kaingang sp. n. in the absence of carinae anterior to the tegula, and by having dorsal setae sc2 and v1 with the same lengths. It differs from X. kaingang by having the tegula longer and lance-like, while the tegula is v-shaped in X. kaingang ; by the tarsal solenidion ω of tibiotarsus I, 1.5 times longer than in X. kaingang and by the dorsal setae c1 shorter than c2, while in X. kaingang they have the same length.

Adult female (5 specimens measured)

Gnathosoma: capsule subtriangular, length 36, 37 (35 – 39), maximum width 33, 32 (29 – 34), dorsal apodeme visible, distinctly positioned at middle of gnathosoma. Setae dgs 9, 9 (9–10) and vgs 7, 7 (6 – 7), smooth; setae pp not observed. Palpi very short, with two small subterminal setae. Pharynx fusiform 18, 17 (16 – 19) long and 8, 7 (6 – 8) wide at widest region.

Idiosoma—dorsum ( Fig. 1 ): Length 185, 175 (150 – 190), width at level of c1 145, 150 (143 – 160); anteromedial prodorsal shield covering gnathosoma. Stigmata positioned between setae v1 and sc2. Lengths of setae: v1 22, 22 (21 – 24), sc 1 16, 15 (15 – 16), sc 2 27, 27 (24–30), c 1 15, 14 (13 – 15), c 2 21, 19 (17 – 21) laterally positioned, d 13, 12 (11 – 13), e 10, 9 (8 – 10), f 12, 11 (11 – 12), h 11, 10 (10-11). Setae v1, d, e, f and h serrate. Other setae smooth. Distances between dorsal setae: v1–v1 34, 35 (34 – 36), sc2–sc2 68, 63 (61 – 69), v1 –sc 2 23, 20 (19 – 24), c1–c1 85, 81 (80 – 86), c2–c2 112, 106 (105–112), c1–c2 40, 36 (35 – 40), d–d 39, 40 (39 – 40), f–f 17, 18 (16 – 20), e–f 26, 26 (25 – 26), h–h 34, 31 (30 – 34).

Idiosoma—venter ( Fig. 2 ): Coxisternal setae 1a 10, 8 (8 – 10) on anterior portion of plate; 2a 15, 13 (12 – 15), inserted on middle of apodeme 2; vestigial setae 1b not observed, and vestigial setae 2b located near basis of trocanter of leg II; 3a 12, 13 (12 – 14) inserted near proximal extremity of apodeme 3; 3b 9, 8 (7 – 9) on posterior end of apodeme 4. Apodeme 1 conspicuous, fused to anterior end of prosternal apodeme. Apodeme 2 not fused to prosternal apodeme. Prosternal apodeme alternating conspicuous and inconspicuous portions, weakly fused to sejugal apodeme. Sejugal apodeme uninterrupted. Apodeme 3 extending diagonally from bases of setae 3a to anterior margin of trochanter III. Apodeme 4, barely visible, extending diagonally from anterior third of poststernal apodeme to bases of setae 3b. Poststernal apodeme bifurcated anteriorly and diffuse in middle region. Coxisternal plates ponctuated. Tegula spearhead-shaped, long and pointed 11, 12 (11 – 13) long and 5, 5 (4 – 5) wide. Carinae absent. All ventral setae smooth.

Legs ( Figs. 3 – 6 ): Lengths (femur to tarsus): leg I 60, 60 (59 – 60), leg II 59, 60 (57 – 60), leg III 101, 98 (92 – 104), leg IV 32, 32 (31 – 34). Number of setae (solenidia in parentheses) on femur, genu, tibia and tarsus, respectively: Leg I: 4-4-6(2)-8(1), leg II: 3-3-4-6(1), leg III: 1+3-4-6. Tarsal solenidion ω of tibiotarsus I 9, 9 (9 – 10), cylindrical and elongate, narrow near base. Sensory cluster of tibia I complete, solenidion ϕ1 5, 5, slender, capitate; solenidion ϕ2 4, 4, fusiform and stout; famulus ĸ 3. Setae d of tibia I 35, 33 (31 – 36), serrate. Solenidion ω of tarsus II proximal, 7, 7 (6–8) long, cylindrical and slightly elongate, narrow near base; setae pl” 7, 6 (6 – 7), spine-like and stout, inserted on the middle of tarsus II. Setae d of tibia II 11, 11 (11 – 12), serrate. Femorogenu IV 25, 25 (23 – 25), tibiotarsus IV 5, 5 (4 – 6). Lengths of setae of leg IV: v’F 9, 10 (8 – 11), v’G 14, 14 (13 – 15), v’Ti 30, 30 (31 – 32) and tc” 45, 44 (42 – 46); all setae smooth.

Adult male and larval instars. Unknown.

Type material. Holotype from Guettarda uruguensis (Rubiaceae) , Novo Horizonte, State of São Paulo, Brazil, 8/III/2008. One paratype from Trichillia casaretti (Meliaceae) , Novo Horizonte, State of São Paulo, Brazil, 12/IV/ 2008. Two paratypes from T. casaretti , Nova Granada, State of São Paulo, Brazil, 12/IV/2008. All deposited at DZSJRP except one paratype, same collection data as holotype, deposited at USNM. All types are females.

Etymology. The species name demitei refers to Dr. Peterson Rodrigo Demite, a young Brazilian acarologist who helped collecting the specimens.

Figures

FIGURE 1. Xenotarsonemus demitei (Female). Dorsum.

FIGURE 2. Xenotarsonemus demitei (Female). Venter.

FIGURES 3 – 6. Xenotarsonemus demitei (Female). 3, leg I; 3 ’, tibial sensory cluster; 4, leg II; 5, leg III; 6, leg IV.