Ploiaria ritsemae Kirkaldy 1901

Pleias ritsemae Kirkaldy, 1901

(Figs 1–8)

ritsemae Kirkaldy, 1901: 56 [Sumatra; holotype (Ψ) RMNH!].

perfuga Miller, 1941: 776 (Ploiaria) [Selangor; holotype (Ψ) BMNH] (new synonym).

Type material examined. Holotype (Ψ): “Dr. B. Hagen. \ Tandjong Morawa. \ Serdang \ (N. O. Sumatra).“ [printed]; “Holo \ type.” [blue square, handwritten]; “Pleias ritsemae \ Kirk. Type.” [handwritten], deposited in RMNH.

Redescription. Macropterous female.

Colour. Head, thorax, fore wings, fore legs rather uniformly light brown; antennal segments I and II somewhat darker brown (remaining segments missing in holotype); mid and hind femora as general body colour, tibiae slightly darker, femorotibial articulation narrowly whitish; ventral surface of abdomen light yellowish brown.

Structural characteristics. Body relatively stout; rather dull, smooth, with only a few, very short, hardly visible hairs.

Head (Figs 1 and 2) rather short, about 1.15 times longer than diatone, with deep interocular furrow; preocular part about 1.75 times longer than postocular in dorsal aspect, gradually declivent anteriorly, with small median tubercle close to interocular furrow; postocular part very short, transversal, dorsal outline forming distinct angle with neck. Eyes large, semiglobular, laterally strongly prominent, remote from ventral and dorsal outlines of head in lateral aspect; diatone about 2.15 times as wide as interocular distance. Labium straight, relatively slender, first visible segment reaching about level of antenniferous tubercles, far remote from level of anterior border of eye; second visible segment not reaching level of anterior border of eye; third visible segment projecting between bases of fore coxae, about 1.2 times as long as first, about 1.1 times as long as second visible segments. Antenna gracile; segment I about 1.4 times longer than segment II. Thorax: Pronotum (Figs 1–3) rather short and stout, about 1.45 times longer than humeral width, subdivided into anterior and posterior lobes; anterior lobe about 1.25 times longer than posterior lobe; humeral width about 1.25 times wider than greatest width of fore lobe. Legs: Fore leg (Fig. 4) rather stout; coxa cylindrical, straight, unarmed; trochanter simple, with only two macrochaetae; femur elongate, about 6.35 times longer than its greatest width, about 1.5 times longer than coxa, ventral surface armed with two rows of spiniferous tubercles. Armature of fore femur (Fig. 5) composed of long, gracile, bristle-like spines inserted on very small, insignificant basal tubercles; anteroventral series composed of nearly 50, posteroventral series of about 65 spiniferous tubercles, posteroventral series also with a few additional spiniferous tubercles basally; spines of subequal size, a few longer spines occurring at base of the two series; posteroventral series beginning at base of femur; anteroventral series not interrupted at base. Tibia about 0.55 times as long as femur, its ventral surface with a single row of small, deflexed spiniform setae; tarsus (Fig. 6) unarmed, nearly bare except a fascia of setae at base of segment I; slightly more than 0.7 times as long as tibia; three-segmented; segment I about 2.45 times as long as segments II and III measured together. Pretarsus with two short and curved claws subequal in shape and size. Mid and hid legs elongate and delicate; tarsi minute. Abdomen of female elongated; apex as in Fig 8.

Measurements (in mm): Body length 7.2. Length of head 0.96, preocular part 0.39, postocular part 0.22, width across eyes 0.83, interocular distance 0.39; lengths of visible labial segments I, II and III 0.32, 0.35 and 0.38; lengths of antennal segments I and II 4.9 and 3.4 (remaining segments missing). Length of pronotum along meson 1.42, of anterior lobe 0.80, of posterior lobe 0.62; greatest width of anterior lobe 0.79, humeral width 0.97. Length of fore wing 4.9. Lengths of fore coxa, femur, tibia, and tarsus (segments I, II and III) 1.48, 2.22, 1.19 and 0.87 (0.63, 0.14 and 0.15), greatest widths of fore femur and tibia 0.35 and 0.16; lengths of hind femur, tibia, and tarsus 7.25, 6.25 and 0.17. Length of abdomen 3.7, greatest width 1.2.