Digitipes kalewaensis Siriwut, Edgecombe and Panha

Siriwut, Warut, Edgecombe, Gregory D., Sutcharit, Chirasak, Tongkerd, Piyoros & Panha, Somsak, 2015, First record of the African-Indian centipede genus Digitipes Attems, 1930 (Scolopendromorpha: Otostigminae) from Myanmar, and the systematic position of a new species based on molecular phylogenetics, Zootaxa 3931 (1), pp. 71-87 : 76-82

Digitipes kalewaensis Siriwut, Edgecombe and Panha n. sp.

Figs. 1–3

Type specimens. Holotype CUMZ 0 0 233 and GenBank ID for COI and 16S as KP204116 and KP204112 , respectively; adult male from the type locality (length 43 mm, width 3.8 mm; Figs. 2 D, 2E–G, 2I, 3A, 3B, 3E, 3G and 3H). Paratypes CUMZ 0 0 234 (adult male), CUMZ 0 0 235 (adult male), CUMZ 0 0 236 (two females), CUMZ 0 0 237 (juvenile), CUMZ 00238.1–2 (two juveniles), CUMZ 0 0 240 (adult female), CUMZ 0 0 241 (adult male). All paratypes are from the type locality.

Etymology. The name “ kalewaensis ” refers to the northwestern Burmese town which is the type locality.

Type locality. Semi-arid dry-dipterocarp forest on the bank of the Chindwin River, Kalewa Township, Sagaing Division, northwestern Myanmar (23º12’52.2” N, 94º18’7.2” E). It is located at the tip of drainage between two river systems, the Mayittha and Chindwin Rivers.

Diagnosis. 17 antennal articles, basal 2.7 glabrous dorsally. Tooth-plate with four main teeth; suture at base of tooth-plate extending laterally subparallel to margin of coxosternite. Tergite surfaces smooth. Tergite of ultimate leg-bearing segment with weak depression on posterior part. Sternites with incomplete paramedian sutures occupying 15 to 25% of anterior part of sternite, posterior part with circular pit. Lateral and dorsal spines on coxopleural process absent. Ultimate legs lacking M and DM spines. Locomotory legs with accessory spurs; legs 1–5 with two tarsal spurs, legs 6–20 with one tarsal spur; ultimate legs without tarsal spurs.

Description. Body length ranges from 23–47 mm. Body colour of preserved material greenish-brown; only cephalic plate and anterior three trunk segments dark blue. Locomotory legs light blue. Sternites 4–21 light yellowish. Cephalic plate with small, fine setae. Anterior median part of cephalic plate with short, straight sulcus without bifurcation posteriorly.

Antenna with 17 articles, basal 2.5–2.7 articles glabrous dorsally; 2.5 articles glabrous ventrally. Antenna reaches only to T2 ( Fig. 2 D). Process of forcipular trochanteroprefemur bearing one apical and one or two inner teeth. Coxosternal tooth-plate ( Figs. 2 A, 3B–C) wider than long, with four main teeth, separated into two groups, two inner and two outer; basal part with a clear, fine seta on each side or without. Interior part of article 2 of telopodite of second maxilla with a fine pigmented spine ( Fig. 3 D). Coxosternite ( Figs. 2 A, 3B) without median suture, coxosternal median diastema reaching to base of tooth-plate, basal part of tooth-plate with curved sutures extending laterally subparallel to margin of coxosternite. Angulation of basal sutures ca 130º–135º.

T1 ( Figs. 2 D, 3A) overlapping cephalic plate, without transverse suture. Tergites with paramedian sutures complete from TT7–8; margination starting on TT8–9. Tergite of ultimate leg-bearing segment ( Fig. 2 M) usually without median furrow on posterior part (furrow present in one specimen). Sternites with short paramedian sutures on anterior part ( Figs. 2 C, 3F), occupying 15–25% length of sternite. Surface of sternites with two discontinuous longitudinal median sulci ( Fig. 3 F). Sternite of ultimate leg-bearing segment with sides converging posteriorly, posterior margin slightly concave ( Figs. 2 L, 3H).

Coxopleural process ( Figs. 2 K–L, 3G) moderately long, with two apical spines; lateral and dorsal spines absent. Dense pore field covering whole area of coxopleuron except on ventro-distal part of coxopleural process ( Figs. 2 L, 3H), pore-free area reaching to 10% the distance to margin of sternite of ultimate leg-bearing segment. On lateral side of coxopleura, dense pore area not covered by lateral margin of tergite of ultimate leg-bearing ( Fig. 2 K) Ultimate legs ( Fig. 2 H–I) long and slender with ratio of ultimate leg articles as follow; 1:1.9 between tarsus 1 and tarsus 2, 1.9:2.1 between tarsus 2 and tibia, 2.1:2.4 between tibia and femur and 2.4:2.7 between femur and prefemur. Prefemoral spines in two rows, arranged as VL-1 or 2, VM-1 to 2, without M and DM spines.

Locomotory legs with short setae on anterior segments; legs 1 to 5 usually with two tarsal spurs (occasionally, two tarsal spurs on only one side), subsequent legs to leg 20 with one tarsal spur. One tibial and femoral spur on leg 1. Two accessory spurs and pretarsal claw present on all legs. Ultimate leg femur with conical projection in male ( Fig. 2 I). Pretarsus and tarsus 2 of ultimate legs with or without small setae ( Fig. 3 H–I). Spiracles oval or rounded ( Fig. 2 E–G), present on segments 3, 5, 8, 10, 12, 14, 16, 18 and 20. Spiracle of segment 3 ( Fig. 2 E) oval shape and largest; spiracles on segments 5 and 8 rounded ( Fig. 2 F, 2G).

Remarks. Digitipes kalewaensis n. sp. is the first record of Digitipes from outside central Africa and western India ( Fig. 1 ). By comparing the species with the closely related Indian Digitipes species, D. kalewaensis n. sp. differs from D. chhotanii Jangi & Dass, 1984 and D. pruthii Jangi & Dass, 1984 by having 2.5–2.7 glabrous antennal articles, without a posterior bifurcated sulcus on the anterior-medial part of the cephalic plate, having femoral, tibial and tarsal spurs on leg 1, and a prefemoral spine arrangement on the ultimate legs as VL 1–2, VM 2(1), with M and DM absent.

The variability of some morphological characters such as the number of glabrous antennal articles, number of teeth on the coxosternal tooth-plates, margination of tergites, spinulation of the coxopleural process, and numbers of legs with tarsal spurs may cause problems for species delimitation. An inconsistency in several characters indicates the need to further clarify the extent of intraspecific variability within this group. For this reason, a summary of comparative diagnostic characters for each previously named species with D. kalewaensis n. sp. is given in Table 3.

First tergite with complete paramedian TT5–7 T7 TT6–8 TT5(4)

sutures

Type of longitudinal median sulcus on Anterior groove posteriorly straight; two

Posteriorly straight Posteriorly bifurcate Posteriorly straight

cephalic plate pairs of furrows on posterior part

First tergite with complete margination TT5–8 (T2) T7 TT7-9 TT8, 9 (7) –13 Longitudinal median ridges, keels Punctate with longitudinal

Tergite surface Smooth Smooth and tubercles median ridges

Surface of sternites? Punctate??

Shape and surface of tergite of ultimate Smooth and convex lateral Smooth and convex lateral

Longer than broad Smooth and convex lateral margin

LBS margin margin

Maximum percent completeness of 10–20%? 10–25% 20–35%

sternal PS

Shape and surface of sternite of ultimate Elongate trapezoidal, sides Trapezoidal, sides converging Sides converging posteriorly Sides converging posteriorly

LBS converging posteriorly posteriorly

AP-2 AP-2 AP-2 AP-2

Arrangement of spines on coxopleural SAP-0 SAP-0 SAP-0 SAP-0

process (AP, SAP, DP, LP) DP-0 DP-0 DP-0 DP-0 LP-1 LP-0 LP-1(0) LP-1 or 0

Length of coxopleural process Short Moderately long Moderately long Long and slender Strongly beneath to dorsal

Pore field on coxopleuron (CP) Reaching margin of CP Not reaching margin of CP Reaching close to margin of CP

margin of CP

VL-3(2) VL-3 VL-3(4) VL-3(1,2)

Prefemoral spine formula on ultimate VM-2 VM-2 VM-2(3) VM-2(1) M-0 M-0 M-0 M-0 No. with femoral spur 1 Absent 1 Usuallyabsent

Bluntly conical, extending to Bluntly conical, extending to Bluntly conical, extending to Bluntly conical, not extending to distal end

Projection on ultimate leg femur distal end of femur distal end of femur distal end of femur of femur Suranganar reserve, Tamil Nadu,

Type locality Maharashtra, India Tamil Nadu, India Karnataka, India India

……continued on the next page AP-2 AP-2 AP-2 field on coxopleuron (CP) Not reaching margin of CP Strongly beneath to dorsal margin of CP Not reaching margin of CP

VL-3(2) VL-3 VL-0 VM-2(1) VM-2(3) VM-5

Prefemoral spine formula on ultimate legs M-0 M-0 M-0 TABLE 3. (Continued)

Characters D. krausi 5 D.reichardti 1,7 D.verdascens 2,3 D.kalewarensis n. sp.

. of antennal articles 17/17 17/17 16/16 17/17

. of glabrous antennal articles 3 3 3 2.5–2.7 4+4

Teeth on tooth-plates 4+4 4+4 4+4 (rarely 5)

First tergite with complete paramedian T6 TT6 or 9 T6 TT7 or 8

sutures

Type of longitudinal median sulcus on ??? Posteriorlystraight

cephalic plate

First tergite with complete margination Only 21 Only 21 T5 TT8 or 9

Tergite surface Smooth Smooth Short streak with punctate Longitudinal median ridges Weak median oval and posterior Small setae, median furrow and

Surface of sternites Three furrows?

median depressions depression-like pit on posterior

Shape and surface of tergite of ultimate Smooth and convex lateral Smooth and convex lateral Convex lateral margin Convex lateral margin

LBS margin margin

Maximum percent completeness of? 45%-complete Complete 15-25%

sternal PS

Shape and surface of sternite of ultimate Trapezoidal, sides converging Sides converging posteriorly with small

Trapezoidal Sides converging posteriorly

LBS posteriorly setae AP-2 AP-2 AP-2 AP-2

Arrangement of spines on coxopleural SAP-0 SAP-0 SAP-0 SAP-0

process (AP, SAP, DP, LP) DP-0 DP-0 DP-0 DP-0 LP-0 LP-1 LP-0 LP-0

Length of coxopleural process? Short? Short or moderately long

Pore field on coxopleuron (CP) ??? Not reaching margin of CP

VL-3 VL-2 or 3 VL-2 VL-1 or 2

Prefemoral spine formula on ultimate VM-2 VM-1 to 3 VM-0 VM-2(1) M-0 M-0 M-1 M-0 DM-2 DM-0 DM-0 DM-0

Legs No. with two tarsal spurs Absent 1–2(3) 1–3 1–5 Note: Superscript refers to the following literature citations: 1= Kraepelin (1903); 2= Attems (1930a); 3= Attems (1930b); 4= Verhoeff (1938); 5= Dobroruka (1968); 6= Jangi and Dass (1984); 7= Lewis 2004); 8= Joshi and Edgecombe (2013).

Figures

FIGURE 1. Collecting area of Digitipes kalewaensis n. sp.; A. Location of collection area in Myanmar. B. Collecting locality (expanded magnification). C. Habitat type.

FIGURE 2. Morphological characters of Digitipes kalewaensis n. sp.; A. Forcipular coxosternite (Paratype; CUMZ 00234). B- C. Tergites and sternites 9 – 11 (Paratype; CUMZ 00241). D. Antenna, cephalic plate and T 1 (Holotype). E-G. Spiracles 3, 5 and 8, respectively (Holotype). H, J. Ultimate legs (Paratypes; CUMZ 00234 - 00235). I. Projection on femur of ultimate leg in male (Holotype). K. Pore-field of coxopleuron (left and right; Paratype; CUMZ 00235). L-M. Ventral and dorsal view of ultimate leg-bearing segment (Paratype; CUMZ 00234).

FIGURE 3. Drawings depicting variation in some morphological characters; A. Cephalic plate and T 1 (Holotype). B. Forcipular segment (Holotype). C. Tooth-plate with five teeth on right side (Paratype; CUMZ 00234). D. Articles 1 – 3 of telopodite of second maxilla (Paratype; CUMZ 00241). E. Tergites 9 – 11 (Holotype). F. Sternite 10 (Paratype; CUMZ 00240). G. Coxopleural pore area (Holotype). H. Sternite of ultimate leg-bearing segment with ultimate legs (Holotype; ventral view). I. Left ultimate leg (Paratype; CUMZ 00234).