Vollenhovia pwidikidika

Identification
Vollenhovia pwidikidika most closely resembles Vollenhovia brachycera Emery 1914 (originally described as brevicorne by Emery in 1893) in size and overall sculpturing, and brachycera even appears to have 11-segmented antennae (no mention of antennal segments is made in the brachycera description, nor is there a figure). However, pwidikidika has an unsculptured strip above the clypeus that continues nearly to the vertex, while brachycera has striae in the same location; in addition, brachycera has larger, more distinct smooth patches on the dorsal pronotum, mesonotum and propodeum, and brachycera lacks punctures for a significant area around propodeal spiracle; pwidikidika is also smaller than brachycera. In color, shape, and general appearance, pwidikidika also resembles Vollenhovia kaselela (above), and specimens of both species were treated as one for quite some time. However, the genae, striate in kaselela and glossy in pwidikidika, are a useful feature for telling them apart. (Clouse 2007)

Distribution based on Regional Taxon Lists
Indo-Australian Region: Micronesia (Federated States of).

Nomenclature

 *  pwidikidika. Vollenhovia pwidikidika Clouse, 2007a: 17, pl. 6D-F (w.) MICRONESIA (Pohnpei I.). [Also described as new by Clouse, 2007b: 192, 225.]

Worker
HOLOTYPE: TL 1.48, HL 0.50, HW 0.40, CI 80, SL 0.27, SI 68, PW 0.30, ML 0.16, PL 0.18, DPW 0.13, PWI 72, PPL 0.15, PPW 0.15, PPWI 100. Mandible outer margin straight, curved at apical tip. Masticatory margin with five teeth, decreasing in height from apex, distinct diastemata between basal three. Anterior clypeus angled down to central tip, median clypeus elevated to upper level of antennal insertions. Head rectangular, slightly tapering toward mandibles, median vertex concave. Eyes lateral, upper margin of eyes at mid-level of head. Antennae 11-segmented with distinct three-segmented club; first segment of club twice as large as previous, second segment of club 25% larger, and terminal antennal segment three times as large as previous. Frontal lobes small, not completely hiding torulus, stopping at insertions. Mesosoma nearly flat in profile, hint of metanotal groove, gently sloping at propodeal declivity but with small latero-dorsal corners. Propodeal lobes large, nearly halfway up declivity and extending posteriorly the same distance. Petiole (not including keel) cylindrical, anterior face of node nearly vertical, small tooth in profile at location of spiracle, then angled up to dorsal surface; tapered dorsally and ridged around posterior socket. Peduncle indistinct. Ventral petiolar keel large, constituting one third total petiolar height, dropping vertically at anterior, then sloping up at 60 degrees to point just anterior to postpetiolar insertion, lower extreme of keel with distinct, translucent area distinctly thinner than remainder of keel. Postpetiole lobular, anterior edge concave, with lip ventrally at petiolar juncture. Gaster elliptical, 80% covered by first tergite. Color: Most of head, mesosoma, petiole, postpetiole, gaster, forecoxae, and femora orange-brown; anterior mesepisternum and posterior dorsal petiole black; mandibles, clypeus and anterior head around mandibular insertions, and remainder of legs yellow-orange. Pilosity: Covered mostly in a mixture of long, fairly straight, standing hairs and short hairs curved back to the body surface. Clypeus with two long, straight hairs immediately below antennal insertions. Hairs on face shorter and more depressed than remainder of body, pointed toward vertical midline. Pilosity on dorsal mesosoma similar to head, low and curved toward center, but mixed with a few very long, standing hairs along the dorso-lateral edge. Hairs becoming fewer and longer on dorsal petiole and postpetiole. Lateral propodeum and mesepisternum hairless, as are lateral and anterior faces of petiole. Dorsal and ventral gaster with mixture of curved, short hairs and longer, straighter ones. Mandibles, antennae, lateral pronotum, and legs with short, curved hairs. Sculpturing: Head with fine striae among large punctures. Striations absent above median clypeus almost to vertex, punctures continuing to underside of head, but gena smooth, hairless, and glossy. Lateral mesosoma with hints of rugae toward anterior, but mostly covered in dense, deep punctures, even on declivity. Petiole similarly punctured, postpetiole with irregular rugae and punctures. Small smooth patches located in very center of dorsal pronotum, mesonotum, propodeum, and petiole. Gaster smooth.

PARATYPES: TL 1.54–1.58, HL 0.47–0.50, HW 0.37–0.41, CI 79–82, SL 0.26–0.27, SI 66–70, PW 0.29, ML 0.19–0.21, PL 0.16, DPW 0.12–0.13, PWI 75–81, PPL 0.15–0.16, PPW 0.16–0.15, PPWI 93–101. Shape and position of translucent area on keel variable, possibly due to wear.

Type Material
Type locality: Ponape Agriculture and Trade School (PATS) farm, Pohnpei Island, Federated States of Micronesia

Type series: Holotype worker: FSM Pohnpei: Pohnpei I., PATS (leaf litter among swamp taro, collected by Berlese funnel, Clouse, 20-X-1995). Paratype workers (2): FSM Pohnpei: Pohnpei I., PATS (from leaf litter under pandanus tree, collected by Berlese funnel, Clouse, 20-X-1995)

Etymology
Pwidikidik is Pohnpeian for “tiny,” and this species is the smallest of all Micronesian species. Indeed, it is one of the smallest Vollenhovia yet described. This word demonstrates an attractive feature of Pohnpeian and many other Pacific island languages, which is the melodic repetition of syllables, especially in adjectives (e.g., reirei = tall, lapala = large, tikitik = small, mororo = “fat”).