Archaeoptilomera, Zettel, 2009

Zettel, H., 2009, Three new genera of Ptilomerinae (Hemiptera: Heteroptera: Gerridae) from Southeast Asia, Zootaxa 2046 (1), pp. 26-42 : 37-39

Archaeoptilomera gen. n.

( Figs. 25–34 )

Type species. Archaeoptilomera derlethi sp. n. (by present designation)

Diagnosis. Small Ptilomerinae of predominately yellowish brown to pale yellow colour; thoracic and abdominal dorsum with smooth areas along midline ( Figs. 25, 26 ). Mesonotum in anterior two-thirds of length with pair of narrow black stripes (at medial margins of dull areas). Metanotum without median furrow. Protarsus short, about half length of protibia ( Fig. 28 ), pale. Mesofemur and metafemur subequal in length, both with pale distal portions. Metacoxa without apical spine. Metatarsomeres fused. Abdomen of female moderately shortened, at dorsal midline slightly longer than thorax. Sternite 7 of female at connexival corner with spine ( Figs. 29–32 ), ventrally with broad, short, round medial lobe ( Figs. 33, 34 ).

Description. Only apterous female known. Body length 8.1–8.5 mm. Dorsum yellowish brown; black stripes distributed as in Figures 25, 26 . Dorsum of head brownish yellow, anteclypeus and two small spots on vertex black. Pronotum with black stripe on anterior margin behind vertex. Mesonotum in anterior two-thirds of length with pair of narrow, black stripes lining smooth medial area; meso- and metanotum with distinct lateral stripes and black anterior margin interrupted in middle. All acetabula distally with black marks. Legs mainly yellowish brown to orange, profemur with two distinct stripes, protibia and apex of protarsus blackish, meso- and metafemora each with one thin black stripe at base and distal part pale; tibiae and tarsi of middle and hind legs orange to pale. Lateral areas of tergites black. Distal portions of meso- and metafemora pale. Venter pale. Meso- and metacetabula and lateral portions of tergites 2–5 (strongly reduced on tergite 1) with moderately developed, silvery hair layer ( Figs. 25, 26 ). Head ( Fig. 27 ) with very large eyes and prominent antenniferous tubercles. Antenna slender, antennomere 1 subequal in length with antennomeres 2–4, antennomere 4 without sulcus. Pronotum robust. Metanotum without median furrow. Flexor side of profemur with numerous stout setae at base and one minute tooth subapically ( Fig. 28 ); protarsus short, ca. 0.5 times as long as protibia; first protarsomere 1.7 times as long as second and slightly thicker. Claws or foreleg smooth. Metafemur and mesofemur subequal in length. Metacoxa without spine. Hind leg with two small but distinct claws.

Male. Unknown.

Female. Metanotum, abdominal segments 1–6, and venter of thorax and abdomen without modifications. Abdomen moderately shortened, slightly longer than thorax ( Figs. 25, 26 ). Medial areas of sternites slightly flattened. Connexiva not flapped mediodorsad over tergites 1–6, but slightly so over posterolateral parts of tergite 7 ( Figs. 31, 32 ). Tergites 7 and 8 simple, directed posteriad; proctiger simple, directed posteroventrad or almost ventrad ( Figs. 29, 30 ). Sternite 7 elongate, with short to moderately long spines at connexival corners ( Figs. 29–32 ), with large, but relatively short, posteriorly rounded ventromedial lobe ( Figs. 33, 34 ). Gonocoxae 1 ( Figs. 29, 30 ) large, plate-like, exposed.

Comparative notes and discussion. This new genus is so far only known from female specimens, and for that reason some aspects of its accurate position in a phylogenetic system remain uncertain. However, Archaeoptilomera gen. n. clearly belongs to the Ptilomera genus group (see Comparative notes of Ptilomerella gen. n.). Within this group, it has strong similarities with the Himalayan monotypic subgenus Ptilomera (Proptilomera) himalayensis , which is morphologically distant from the species-rich Ptilomera s.str. and may deserve genus rank, too. Archaeoptilomera gen. n. can be distinguished from Ptilomera s.l. by its small size, the absence of a medial furrow on the metanotum, the subequal length of meso- and metafemur, and by the black sublateral stripes on the mesonotum which line the smooth medial area. Moreover, Ptilomera s.str. can be easily recognized by the prominent metacoxal spines. The sternite 7 of the female of Ptilomera (Proptilomera) himalayensis differs strongly from both species of Archaeoptilomera sp. n. in the unique bifid medial lobe that embraces the proctiger, and by absence of connexival spines. The protarsus of Archaeoptilomera sp. n. is pale as it is in Ptilomerella anderseni sp. n., but the author does not know any other Ptilomerinae with that feature.

Distribution. Borneo.

Etymology. The generic epithet refers to the close relationships with Ptilomera . Gender: feminine.

Included species. Archaeoptilomera derlethi sp. n., Archaeoptilomera kodadai sp. n.

Figures

FIGURES 25–26. Archaeoptilomera gen. n. (25) Habitus of apterous female of A. derlethi sp. n. (holotype, body length 8.1 mm), dorsal aspect. (26) Habitus of apterous female of A. kodadai sp. n. (holotype, body length 8.5 mm), dorsal aspect. © NHMW Hemiptera Image Collection, published with permission.

FIGURES 27–34. Archaeoptilomera gen. n. (holotypes, females). (27) Head of pronotum of A. derlethi sp. n., dorsal aspect. (28) Foreleg of A. derlethi sp. n., posterior aspect. (29–34) Posterior part of abdomen in (29, 30) lateral, (31, 32) dorsal, and (33, 34) ventral aspects. (29, 31, 33) A. derlethi sp. n. (30, 32, 34) A. kodadai sp. n. gc1 = gonocoxa 1; pr = proctiger; s7 = sternite 7; t7, t8 = tergite 7, 8.