Steneotarsonemus (Mahunkacarus) mayae, Lin & Zhang, 2005

Lin, Jian-Zhen & Zhang, Zhi-Qiang, 2005, New Zealand species of Steneotarsonemus Beer (Acari: Tarsonemidae), Zootaxa 1028 (1), pp. 1-22 : 12-21

Steneotarsonemus (Mahunkacarus) mayae sp. nov.

( Figs. 13–24 )

Diagnosis. Prodorsal bothridial setae absent. Apodeme 2 not uniting with prosternal apodeme; its posterior extremity divided, forming an inverse cup shape in female. Femurogenu IV with a transparent, crescent­shaped flange in male.

Adult Female. Length 213 (211–214, 214) from anterior end of gnathosoma to posterior end of idiosoma. Combined length of legs I–IV (from tip of tarsus to base of femur excluding trochanters) 143 (135–150, 150).

Dorsal idiosoma ( Fig. 13 ). Idiosoma elliptical, length 191 (190–191, 191), about 2.4 times of maximum width [79 (78–80, 80)] at level of insertion of trochanter III. Prodorsal shield trapezoid, posterior width [55 (53–56, 56)] about equal with medial length [55 (54– 55, 55)]; its anterior margin and lateral margins nearly straight. Stigmata opening anterolaterad of insertions of vertical setae; distance between stigmata opening and v 1 (3); tracheal trunks extending posteriorly through an atrium with a diameter of 2. Setae v 1 located posterolaterad of stigmata opening; their length [13 (11–14, 11)] shorter than distance between insertions v 1 ­v 1 [21 (20–22, 20)]. Bothridial setae sc 1 absent. Scapular setae sc 2 [32 (30–33, 30)] longer than distance between their insertions sc 2 ­sc 2 [30 (29–31, 29)].

Setae of opisthosomal tergites smooth, simple. Setae c 1 inserted near mid­level tergite

C; its length 7 (6–8, 6). Setae c 2 inserted near anterior margin of tergite C; its length (10), distance c 1 ­c 1 [43 (42–43, 42)] about 2/3 of c 2 ­c 2 [67 (66–68, 66)]. Setae d 6 (5–6, 5), shorter than 1/8 of distance d­d [50 (48–52, 48)]. Setae e 4 (3–5, 3) and f 7 (6–7, 6), inserted second half of EF; distance e­e [55 (53–56, 53)] about 1.6 times of f­f [35 (33–37, 33)]. Setae h [7 (6–7, 6)] shorter than distance h­h [30 (29–30, 29)].

Ventral idiosoma ( Fig. 14 ). Prosternal apodeme 22 (21–23, 21) long, extending from its union with apodemes 1 to the level of apodeme 2, forming an inverse cup shape posteriorly. Apodeme 2 not connecting medially with prosternal apodeme. Sejugal apodeme barely discernible vestige. Coxal setae 1a 3 (2–3, 3) long, inserted near inner end of apodeme 1; setae 2a (4) long, inserted inner part of apodeme 2. Posternal apodeme absent. Apodeme 3 length 16 (15–16, 16), extending from articulation point with anterior extremities of trochanters III to level of coxal setae 3a. Apodeme 4 length 16 (15–17, 17), extending for a distance posterolaterad of insertions of coxal setae 3b. Coxal setae 3a (10) about 3 times as long as 3b [4 (3–4, 3)]. Tegula broadly rounded; its length (20) less than basal width (22). Posterolateral extensions of coxisternal plates IV overlapping some part of aggenital plate beneath tegula. Setae ps minute, inserted near posterior margin of pseudanal plate, length [6 (5–6, 5)] about 1/3 as long as distance ps­ps [17 (16–17, 16)].

Legs ( Figs. 15–18 ). Excluding trochanters, leg I 42 (40–43, 40) long and leg II 41 (40– 41, 40) long. Leg III [43 (41–44, 41)] longer than legs I or II. Leg IV 36 (34–38, 34) long, slender, with femorogenu [23 (22–24, 22)] about twice as long as tibiotarsus [12 (10–13, 10)]. Medial claw of leg I strongly developed, unguiform, on well­developed apotele. Legs II–III each with well­developed membranous pulvillus and symmetrically paired lateral claws.

Number of setae and solenidia on leg I (femur to tarsus): 4–4–5(2)–6(1). Femur I with setae d, v’ and pair (l) inserted near mid­length of femur I. Genu I with two pairs of setae: (v) and (l). Tibial sensory cluster with 2 (5), slightly clavate, 1 minute (2), barely discernable and famulus k spinelike, bluntly pointed, 4 (3–4, 4) long. Tibiatarsus with clavate, (3) long, inserted about 4 times of its length to proximal end of tibiotarsus I.

Number of setae and solenidia on leg II (femur to tarsus); 3–3–4–4(1). Femur II with setae d shorter than v”, but longer than l’. Genu II with seta v shorter than pair of l’ and l”. Tibia II with v’ nearly as long as v”, seta d longer than l’; all setae inserted near mid­length of tibia II; Tarsus II with a clavate solenidion (3) long, located basal 1/3 of tarsus II. Seta tc” longer than seta tc’.

Number of setae and solenidia on leg III (femur to tarsus): 1+3–4–3. Femorogenu III with femoral v’ inserted laterally slightly basal part of segment, shorter than l’G and v’G. Tibia III with v’ longer than other setae on the segment, located on the mid­length of tibia III. Tarsus III with pv” longer than tc’.

Femorogenu IV with v’F (3) 1/2 of genual v’G (6). Tibiatarsus with v’Ti 16 (15–16, 15) long, less than 1/4 as long as attenuated tarsal tc” 56 (55–56, 55).

Gnathosoma. Gnathosomal capsule 34 (30–38, 38) long and its maximum width 35 (27–42, 42). Dorsal gnathosomal setae 15 (13–16, 13) long, more than twice as long as ventral pair (6). Palpi short, cylindrical, appressed to rostrum Cheliceral stylets slightly curved basally. Pharynx with thin muscular, sclerotized lateral walls, its length [8 (7–8, 7)] more than twice as long as its width (3).

Adult male. Length 198 (181–211, 211) from anterior end of gnathosoma to posterior end of idiosoma. Combined length of legs I–IV (from tip of tarsus to base of femur excluding trochanters) 175 (166–181, 179).

Dorsal idiosoma ( Fig. 19 ). Idiosoma length 169 (153–180, 180) about 1.7 times of maximum width 101 (93–108, 103) at level of insertion of setae c 2. Prodorsal shield triangular, posterior width 66 (60–70, 70), slightly longer than medial length 55 (52–58, 56); its lateral margins slightly straight. Setae v 1 13 (11–15, 15) shorter than distance between insertions v 1 ­v 1 20 (19–20, 20). Second vertical setae v 2 12 (12–13, 12) slightly shorter than first vertical setae, both pairs longer than distance 10 (10–11, 10) between v 1 and v 2. Scapular setae sc 1 the longest on idiosoma 51 (47–55, 50), about 3.9 times as long as v 1, and about 1.6 times as long as distance 32 (32–33, 33) between their insertions. Second scapular setae sc 2 20 (19–21, 21) longer than vertical setae v 1, second vertical setae v 2 and distance between sc 1 and sc 2. Setae sc 2 inserted in nearly oblique longitudinal alignment with other three pairs. Metapodosomal plate CD with setae c 2 17 (14–20, 18) slender, longer than c 1 9 (8–10, 10) and d 7 (7–8, 7), which are poorly tapered; setae d situated in nearly oblique longitudinal alignment with c 2 and c 1. Subterminal plate EF with cupules im inserted at level of anterior margin of genital capsule, setae f 8 (7–9, 9) long. Genital capsule 33 (30–35, 35) long, 27 (26–27, 27) wide, with caudal setae h minute, 3(2–4, 3) long.

Ventral idiosoma ( Fig. 20 ). Prosternal apodeme extending from its union with apodemes 1 to level of mid­length of apodeme 2, weakly developed and united with sejugal apodeme. Apodeme 2 not connecting medially with prosternal apodeme. Sejugal apodeme fully developed. Coxal setae 1a and 2a subequal in length, 3 (3–4, 4), inserted well behind apodeme 1 and 2 respectively. Posternal apodeme divided posteriorly, its anterior end reaching at level of setae 3b, its middle part weakly developed and anterior extremity arriving at level of 3a. Apodeme 3 length 38 (35–41, 41), extending from articulation point with anterior extremities of trochanters III to the level of coxal setae 3a. Apodeme 4 fully developed at base from articulation point with anterior end of trochanters IV, weakly developed near anterior end of apodeme 3. Coxal setae 3a 10 (8–12, 12) longer than 3b 6 (5–7, 6).

Legs ( Figs. 21–24 ). Excluding trochanters Leg I 54 (50–57, 57) long and leg II 56 (55–57, 57) long. Leg III [67 (63–70, 70)] longer than legs I or II. Leg IV 36 (34–38, 34) long, stubbed, with femorogenu, tibia and tarsus. Medial claw of leg I strongly developed, unguiform, on well­developed apotele. Legs II–III each with well­developed membranous pulvillus and symmetrically paired lateral claws.

Number of setae and solenidia on leg I (femur to tarsus): 4–4–6(2)–7(1). Femur I with setae d, v” and pair (l); all setae inserted near mid­length of femur I; Genu I with 2 pairs of setae (v) and (l), setae (v) situated nearly 1/3 level of top segment, but setae (l) located at 1/3 base of segment. Tibial sensory cluster with 2 6 (6–7, 7), slightly clavate, 1 minute, 3(3) long, barely discernable and famulus k spinelike, bluntly pointed, short (5). Tarsus with a clavate (3), inserted near mid level of segment.

Number of setae and solenidia on leg II (femur to tarsus); 3–3–4–4(1). Femur II with setae d, l’ and v”, all setae situated near mid­length of segment. Genu II with seta v’ shorter than pair of l’ and l”. Tibia II with setae v’ and v” longer than setae l’ or d on the segment, all setae inserted near upper part of tibia II; Tarsus II with a clavate, 4(4–5, 5) long, located 1/3 basal part of tarsus II. Seta pv” longer than seta tc’ and pv’.

Number of setae and solenidia on leg III (femur to tarsus): 1–3–4–2. Femur III with femoral v’ inserted 1/3 upper part of segment. Genu III with setae v’ and pair of l, which are longer than former. Tibia III with seta l’ about equal with seta d; all setae inserted middle part of tibia III. Tarsus III with tc” nearly twice as long as pv’.

Number of setae and solenidia on leg IV (femur to tarsus): 1+2–1(1)–2. Femorogenu IV with l”G slender, 8(6–9, 8), longer than v’F 4 (3–4, 4), but less than genual v’G [11 (10–12, 10)]. Tibia with setae v’Ti stout, 34 (30–38, 38) long and a solenidion 5 (5–6, 6) long. Tarsus with minute setae, tc” and pv”. Terminal claw unguiform.

Types. Holotype, adult female, allotype male, paratypes three females, eight males and two larvae, New Zealand: Awakino 23 April 1966, B. M. May, collected under sheaths and on flower panicles of Dracophyllum strictum Hook ; all types deposited in the New Zealand Arthropod Collection, Auckland.

Etymology. Named after the collector, the late Brenda M. May.

Remarks. This species is similar to Steneotarsonemus (Mahunkacarus) gibber Suski , but it is different from the latter by 1) setae d situated in nearly oblique longitudinal alignment with c 2 and c 1; 2) distance between sc 2 and sc 1 longer than that between v 1 and v 2 in male; 3) posterior extremity of prosternal apodeme divided, forming an inverse cup shape; 4) setae c 2 not more than twice as long as c 1 in female.

Figures

FIGURE 13. Steneotarsonemus (Mahunkacarus) mayae sp. nov. (dorsal view of female).

FIGURE 14. Steneotarsonemus (Mahunkaracus) mayae sp. nov. (ventral view of female).

FIGURE 15–18. Steneotarsonemus (Mahunkaracus) mayae sp. nov. (female legs I–IV). 15, leg I and enlarged tibiotarsus; 16, leg II; 17 leg III; 18 leg IV.

FIGURE 19 Steneotarsonemus (Mahunkacarus) mayae sp. nov. (dorsal view of male).

FIGURE 20. Steneotarsonemus (Mahunkacarus) mayae sp. nov. (ventral view of male).

FIGURE 21–24. Steneotarsonemus (Mahunkacarus) mayae sp. nov. (male legs I–IV). 21, leg I; 22, leg II; 23 leg III; 24 leg IV.