Dendrolaelaps linjianzheni, Ma, Li-Ming, Ho, Chyi-Chen & Wang, Shun-Cheng, 2014

Ma, Li-Ming, Ho, Chyi-Chen & Wang, Shun-Cheng, 2014, Two new species of Digamasellidae from Taiwan (Acari: Mesostigmata), Zootaxa 3768 (1), pp. 43-58 : 52-56

Dendrolaelaps linjianzheni n. sp.

( Figs 27–41 )

Diagnosis. Movable cheliceral digit with four teeth in addition to the apical tooth; seta s1 on soft cuticle between podonotal and peritrematic shields, and s2, r2 and r3 on peritrematic shield; setae Z3, Z5 and S5 longer than other dorsal idiosomal setae, Z5 slightly longer than S5 and Z3. Adult female with anterior margin of opisthonotal shield with two central V-shaped incisions, without transverse covering plates; with Jv1–Jv3, Jv5, Zv2, and Zv3 on ventrianal shield, Zv1 on soft cuticle along anterior margin of ventrianal shield. Adult male with anterior margin of opisthonotal shield without incisions; anterior margin of ventrianal shield with a pair of deep, oblique incisions between Zv1 and Jv1; spermatodactyl sickle shaped, not exceed movable cheliceral digit.

Description. Adult female ( Figs 27–36 ) (five specimens measured). Yellow coloured, idiosoma elliptical, 360–386 (375) long and 188–225 (206) wide.

Gnathosoma: Tectum with three anterior prongs, barbed distally; central prong shorter and from more ventral level than lateral prongs ( Fig. 27 ). Palp apotele two-tined. Movable cheliceral digit 27–31 (28) long, with four well-spaced teeth in addition to apical tooth; fixed cheliceral digit 24–30 (26) long, with 4-5 teeth in addition to apical tooth and a setiform pilus dentilis ( Fig. 28 ). Corniculi horn-like. Deutosternum with six roughly transverse rows ( Fig. 29 ); anterior row smooth, rows 2–6 each with fine, multiple and not countable denticles; rows 2, 5, and 6 with lateral line outside, lateral line of row 6 with denticles. Hypostomal setae smooth, h 1 16–24 (21), h 2 6–11 (8), h 3 15–21 (17), sc 15–18 (17).

Dorsal idiosoma ( Fig. 30 ): Dorsal shield divided. Podonotal shield 169–199 (179) long and 150–195 (170) wide, smooth; fused anterolaterally with peritrematic shield; with 18 pairs of setae (j1–j6, z1–z6, s3–s6, r4 and r5); with four scleronoduli, two pairs of distinguishable lyrifissures [posterior to z1 (idz1) and laterad to j4–j5 (idj4)] and two pairs of pores [between j3, z1, z2, s1 (gdj3) and between z3, z4, s2, s3, r2 (gdz4)]. Seta s1 on soft cuticle between podonotal and peritrematic shields, s2, r2 and r3 on peritrematic shield; r1 and r6 absent (one specimen with r4 on soft cuticle). Opisthonotal shield 188–206 (197) long and 150–169 (165) wide, smooth, with punctations posterior to J4 and Z4; anterior margin with two central V-shaped incisions; with 19 pairs of setae (J1– J5, Z1–Z5, S1–S5 and R2–R5); with three pairs of pores [anterior to and mediad of Z1 (gdz6), posterior to and laterad of Z4 (gdZ4) and anterior to and laterad of S5 (gdS4). Seta R1 on soft cuticle along lateral margins of opisthonotal shield. Measurements of setae: j 1 8–13 (11), j 2 10–16 (14), j 3 14–17 (16), j 4 12–18 (16), j 5 14–18 (15), j 6 14–16 (15), z 1 6–12 (9), z 2 12–18 (15), z 3 14–18 (17), z 4 13–20 (16), z 5 12–17 (15), z 6 15–18 (16), s 1 10 – 15 (13), s 2 9 –17 (14), s 3 12 –18 (16), s 4 15 –18 (16), s 5 15 –18 (17), s 6 13 –22 (17), r 2 11–16 (13), r 3 17–23 (20), r 4 12–15 (13), r 5 11–17 (13), J 1 9–18 (15), J 2 13–16 (14), J 3 9–15 (11), J 4 8–11 (10), J 5 7–11 (9), Z 1 13–19 (16), Z 2 15–19 (16), Z 3 28–34 (31), Z 4 10–13 (11), Z 5 31–44 (39), S 1 14 –16 (15), S 2 15 –18 (15), S 3 13 –17 (15), S 4 13 –15 (14), S5 33 –42 (37), R1 5–7 (6), R2 5–8 (6), R3 6–8 (7), R 4 6–12 (10), R 5 11–19 (15).

Ventral idiosoma ( Fig. 31 ): Base of tritosternum 13–26 (22) long and 9–12 (11) wide, laciniae 34–47 (39) long, totally separated ( Fig. 32 ). Sternal shield 105–111 (108) long and 70–81 (75) wide, weakly sclerotised and smooth; anterior margin concave and posterior margin straight; with four pairs of setae and three pairs of lyrifissures (iv1 posterior to st1, iv2 anterior to lateral protrusion at level between coxae II– III and iv3 anterior to st4). Genital shield 44–52 (47) wide, weakly sclerotised and smooth; with a pair of setae (st5); contracted posterior to st5, posterior margin straight. Soft cuticle posterolaterad of st5 with a pair of lyrifissures. Ventrianal shield large, subrectangular, 120–131 (125) long and 113–131 (121) wide, reticulated except a punctate area lateral and posterior to anus; anterior margin slightly convex, lateral margins bulged anterior to Zv3, and posteriorly fused to opisthonotal shield; with six pairs of setae (Jv1–Jv3, Jv5, Zv2, and Zv3) in addition to circum-anal setae; without distinguishable lyrifissures or pores; para-anal setae at level slightly anterior to median of anus. Soft cuticle along margins of ventrianal shield with a pair of setae (Zv1) and with three pairs of lyrifissures (posterior to and laterad of Zv1, posterior to and laterad of Zv2 and anterior to and laterad of Jv 5) Metapodal plates elongated. A pair of lyrifissures laterad of metapodal plates. Peritreme extends anteriorly to level of s1. Peritrematic shield fused anteriorly with podonotal shield and sharp-ended posterior to stigma; bearing s2, r2 and r3. Exopodal shields fragmented in two parts: between coxa II and III and between coxa III and IV. Measurements of setae: st 1 11–18 (16), st 2 9–17 (15), st 3 12–17 (15), st 4 12–17 (15), st 5 11–16 (14), Jv 1 10–19 (15), Jv 2 11–21 (16), Jv 3 12–18 (16), Jv 5 18–28 (23), Zv 1 11–16 (13), Zv 2 15–17 (16), Zv 3 11–20 (13), para-anal 19 –33 (24), post-anal 15–22 (19).

Spermatheca: Not distinguishable.

Legs ( Fig. 33–36 ): Lengths excluding pretarsi: leg I 264–283 (269), leg II 193–213 (205), leg III 174–185 (181), leg IV 220–245 (232). Numbers of setae on legs I-IV: coxa 2-2-2-1, trochanter 6-5-5-5; femur, genu, tibia of leg I: 2 3/2 3/2 2, 2 3/2 2/1 2, 2 3/1 2/2 2; leg II: 2 3/1 2/2 1, 2 3/1 2/1 1, 2 2/1 2/1 2; leg III: 1 2/1 1/0 1, 2 2/1 2/0 1, 2 1/1, 2/1 1; leg IV: 1 2/1 1/0 1, 1 2/1 2/0 1, 1 1/1 2/1 1. Setae al1 of femur II and genu II, pl and pd of femur III, ad1 and pl of femur IV, pd1 of genu IV spine- or spur-like, ventral setae of genu and tibia usually thick. All legs with pretarsi, each with claws well sclerotised and pulvilli well developed.

Adult male ( Figs 37–41 ) (one specimen measured): Idiosoma 338 long and 185 wide.

Gnathosoma: Tectum and palp as in adult female ( Fig. 38 ). Movable cheliceral digit 20 long, with one tooth in addition to apical tooth, fixed cheliceral digit 17 long, with four well separated teeth in addition to apical tooth and a setiform pilus dentilis; spermatodactyl 14 long, sickle shaped, as long as movable cheliceral digit. Corniculi more slender than in female. Hypostome as in adult female, except second and fifth rows without lateral extensions. Measurements of setae: h1 13, h2 7, h3 14, sc 13 ( Fig. 39 ).

Dorsal idiosoma ( Fig. 40 ): Dorsal shield divided. Podonotal shield 159 long, fused with peritrematic shield, reticulated laterally; with 22 pairs of setae (j1–j6, z1–z6, s1–s6 and r2–r5; r1 and r6 absent); with four scleronoduli and without distinguishable lyrifissures or pores. Opisthonotal shield 169 long, fused laterally and posteriorly with ventrianal shield, reticulate in upper exterior corner and punctate between J and Z series; chaetotaxy, lyrifissures and pores as in adult female, except R1 on shield. Measurements of setae: j1 9, j2 12, j3 13, j4 14, j5 12, j6 13, z1 8, z2 23, z3 13, z4 14, z5 15, z6 15, s1 14, s2 13, s3 15, s4 16, s5 15, s6 14, r2 11, r3 15, r4 11, r5 11, J1 11, J2 11, J3 9, J4 5, J5 8, Z1 15, Z2 11, Z3 26, Z4 9, Z5 30, S1 12, S2 12, S3 11, S4 11, S5 33, R1 6, R2 7, R3 7, R4 8, R5 10.

Ventral idiosoma ( Fig. 41 ): Base of tritosternum 15 long and 8 wide, laciniae 30 long, totally separated. A pair of weakly sclerotised presternal plates with transverse striae. Sternogenital shield 131 long and 68 wide, smooth; with four pairs of setae (st1-st4) and three pairs of lyrifissures (iv1 posterior to st1, iv2 anterior to lateral protrusion at level of between coxae II–III, and iv3 anterior to st4); anterior margin truncate. Seta st5 on a separate, triangular and striated plate posterolaterad of sternogenital shield. Ventrianal shield 150 long, reticulated; anterior margin with two oblique incisions laterad to Zv1; fused laterally and posteriorly with opisthonotal shield; with seven pairs of setae (Jv1–Jv3, Jv 5 and Zv1–Zv3) in addition to circum-anal setae and without distinguishable lyrifissures or pores. Peritreme extending anteriorly over s1. Peritrematic shield fused anteriorly and laterally with podonotal shield. Measurements of setae: st1 12, st2 13, st3 12, st4 12, st5 10, Jv1 12, Jv2 12, Jv3 14, Jv5 18, Zv1 10, Zv2 13, Zv3 9, para-anal 15, post-anal 16.

Legs: Lengths excluding pretarsi: leg I 258, leg II 183, leg III 164, leg IV 212. Numbers of setae on legs I-IV as in female, except femur I 2 3/2 2/2 2, femur II 2 3/1 2/1 1, genu II 2 3/1 2/1 2; all setae aciculate, except femur II with a thumb-like ventral seta and genu, tibia and tarsus II with a button like seta each ( Fig. 37 ). Pretarsi as in adult female.

Material examined. Holotype female from soil under eggplant at Jiuru, Pintung County, 17 September 1992. Paratypes: one adult female from soil under citrus of plot fruit-trial 2 of experimental field of Taiwan Agricultural Research Insititute, Wufeng, Taichung City, 0 8 September 1998; one adult female and one adult male from soil of plot fruit-trial 35 of experimental field of Taiwan Agricultural Research Insititute, Wufeng, Taichung City, 7 February 2001; one adult female from soil under lily of plot fruit-trial 22 of experimental field of Taiwan Agricultural Research Insititute, Wufeng, Taichung City, 27 July 1998; one adult female from soil under Allium cepa L. ( Alliaceae ) at Checheng, Pintung County, 15 March 2001. All types collected by C. C. Ho.

Etymology. The name linjianzheni is an honor of Chinese acarologist Dr. Jianzhen Lin for his contribution to acarology.

Remarks. Gwiazdowicz (2004) lists seven species under the subgenus Foveodendrolaelaps . This report adds Dendrolaelaps (Foveodendrolaelaps) linjianzheni n. sp. to subgenus Foveodendrolaelaps . In addition, D. rectus Karg fulfills the characteristics of the subgenus Foveodendrolaelaps and should be placed there, to make a total of nine species in this subgenus. All of these species have setae s1, r4 and r5 on the podonotal shield and have peritreme extending forward to level of z1-s1, except that D. (F.). brevipiloides has these three setae located outside the podonotal shield and has peritreme extend forward only to level of s3-r3, two characters that shared with Dendrolaelaps (Monodendrolaelaps) monodentatus Hirschmann & Wiśniewski.

Dendrolaelaps (Foveodendrolaelaps) linjianzheni n. sp. is most similar to Dendrolaelaps (Foveodendrolaelaps) stammeri Hirschmann , but the latter has an adult female with s1 on the podonotal shield; seta S5 1.3 times as long as Z5 and 1.7 times as long as Z3 1; Jv1, Jv5, and Zv3 on soft cuticle along margins of ventrianal shield; adult male with spermatodactyl curved, slender and longer than movable cheliceral digit, and anterior margin of opisthonotal shield with two V-shaped incisions. It is also similar to Dendrolaelaps (Foveodendrolaelaps) rectus Karg , but the latter has a transverse cover plate over each of the two V-shape incisions in the anterior margin of opisthonotal shield and has the seta Jv1 on soft cuticle along anterior margin of ventrianal shield.

Figures

FIGURES 27 – 32. Dendrolaelaps linjianzheni n. sp. Adult female: 27. Epistome, 28. Lateral (antiaxial) view of chelicera, 29. Hypostome, 30. Dorsal idiosoma, 31. Ventral idiosoma, 32. Tritosternum.

FIGURES 33 – 37. Dendrolaelaps linjianzheni n. sp.: 33. Anterodorsal view of femur, genu, tibia of leg I of adult female, 34 Anterodorsal view of femur, genu, tibia of leg II of adult female, 35. Dorsal view of femur, genu, tibia of leg III of adult female, 36. Dorsal view of femur, genu, tibia of leg IV of adult female, 37. Dorsal view of femur, genu, tibia and tarsus of leg II of adult male.

FIGURES 38 – 41. Dendrolaelaps linjianzheni n. sp. Adult male: 38. Epistome, 39. Hypostome, 40. Dorsal idiosoma, 41. Ventral idiosoma.