Prohydrometra moorea D. Polhemus 2022, n. sp.

Prohydrometra moorea D. Polhemus n. sp.

Figs. 21, 25, 29

Apterous male. Length 6.90, width 0.60.

Color. Ground color brown to blackish-brown; abdominal mediotergites light-brown medially, matte. Head heavily tinged with blackish except base. Thorax anteriorly and medially light colored dorsally; each laterotergite with light area anteriorly. Venter of thorax and abdomen dark. Legs light-brown, antennae light-brown to brown; coxae and trochanters mostly light-brown.

Structure. Head relatively long (2.18), widest at antenniferous tubercles (0.43); set with bristly setae beneath; gular lobe large, rounded; labium reaching well caudad of eyes, onto prosternum; head with anteocular portion slightly longer than postocular portion, ratio of anteocular/postocular portions: 1.20/0.80; interocular space/width of an eye: 0.12/0.13; anteclypeus small, broadly rounded anteriorly. Antennae with lengths of antennomeres I:II:III:IV = 0.40: 0.67: 3.20: 1.65. Pronotum length 0.83; remainder of thorax 0.43 (to lateral suture behind metacetabulae); abdomen length 3.40. Wing pads, if present, very small, not visible, hidden under pronotum. Thoracic and abdominal sterna with short bristly setae, about equally dense on all segments. Distance between anterior and middle coxae (measured between closest margins) 0.25; between middle and hind coxae 0.38. Acetabula without pits. Venter without black denticles.

Proportions of legs as follows: Femur, tibia, tarsomere I, tarsomere II, tarsomere III of fore-leg, 2.10: 2.90: 0.05: 0.25: 0.22; of middle-leg, 2.80: 3.760: 0.05: 0.30: 0.20; of hind-leg, 3.70: 5.55: 0.05: 0.30: 0.20.

First abdominal segment short, transverse, clearly delineated by a suture posteriorly. Mediotergites longer than wide. Male abdominal sternum VII with two large erect curved spines, widely separated, tipped with black bristles, arising near the anterior margin of segment (Fig. 21); segment VIII cylindrical, unmodified, lacking distal process.

Micropterous female. Length 7.20, width across abdomen 1.20. Similar in most respects to male, but abdomen broader, deeper, segment VII very slightly curved upward, tergum VIII distally truncate, without distal process; margins of laterotergites without setae. Abdominal terminalia simple, without modification.

Brachypterous and macropterous forms. Unknown.

Type material examined (all micropterous). Holotype, male: FRENCH POLYNESIA, Society Islands, Moorea, small gulch immediately W. of Mt. Tohiea summit (headwaters of Mahaeru River), 1150 m, 17°33'04"S, 149°49'22"W, 12 September 2006, 10:40–15:00 hrs., CL 7500, D. A. Polhemus (BPBM). Paratypes: FRENCH POLYNESIA, Society Islands, Moorea, 3 males, 6 females, same data as holotype, CL 7500, D. A. Polhemus (BPBM, USNM); 1 female, Moorea, Mt. Tohiea, 17°33'04"S, 149°49'23"W, 1120 m, 12 September 2006, lot 05, from rotten Freycinetia fronds and leaves, J. K. Liebherr (CUIC).

Distribution. French Polynesia, Society Islands, endemic to the island of Moorea (Fig. 29).

Etymology. The species name “ moorea ” is a noun in apposition, and refers to the Moorea island type-locality.

Discussion. Males of P. moorea are similar to those of P. gagnei from Tahiti in having a pair of curved, sclerotized processes on male abdominal ventrite VII (compare Figs. 19, 21), suggesting that the two species may be members of the same clade within the genus. However, in comparison to P. gagnei, the processes in P. moorea are more widely separated, and set further back from the anterior margin of the segment (compare Figs. 19–21).

Ecological notes. The type series of P. moorea was taken in company with that of P. tohiea by localized pyrethrin fogging in a small pocket of tangled, wet forest at the summit of Mt. Tohiea, the highest point on the island of Moorea (Fig. 25). For additional details of that site and associated species see the previous discussion under the latter species.