Podaena mariae Delgado and Palma, 2010

Delgado, Juan A. & Palma, Ricardo L., 2010, A revision of the genus Podaena Ordish (Insecta: Coleoptera: Hydraenidae), Zootaxa 2678 (1), pp. 1-47 : 28-30

Podaena mariae Delgado and Palma , new species

( Figs 19, 20 , 27, 28 , 49 , 55, 59 , 69, 70 , 97 , 103 )

Description. Male as in Fig. 103 .

Body length (taken from anterior margin of labrum to elytral apex) 2.30mm. Colour: head, pronotum and elytra dark brown to black; elytra uniformly coloured, without lighter marks on the shoulders; legs and palps dark reddish-brown.

Head prognathous, quite elongate, with a short neck region not retracted into the prothorax; evenly convex dorsally with rather fine but distinct punctures, smooth and glabrous; occipital region with the same micro-sculpture as on the dorsal region; postocular ridges present and prominent; clypeus long, 0.7 times as long as frons anterior to compound eyes, glabrous and very sparsely punctuated; frontoclypeal (epistomal) suture straight, not grooved and not deeply impressed; frons with slightly impressed paraocular reticulate areas, continuing towards the genae; compound eyes moderately protruding; labrum wider than long, bilobed, with a deep anteromedian incision; maxillary palps ( Figs 19−20 ) with penultimate and distal palpomeres not modified (not grooved).

Thorax: Body elongate with distinct pronoto-elytral angle. Pronotum posteriorly constricted, with distinct pronoto-elytral angle; surface smooth but sparsely punctuated, with shallow anterior and posterior pits; anterior area, next to the neck, markedly convex, forming a gibbosity separated from the remainder of the pronotum by a clear transversal depression. Foretibiae ( Figs 27−28 ) not modified, with tibial spines 1 and 2 less developed than in other species (e.g. P.obscura , Fig. 37 ). Middle tibiae slightly curved in their distal half. Hind tibiae slightly curved inwards. Middle and hind tarsi rather long. Elytra long, 2.7 times the length of the thorax, with a smooth lateral rim and well defined rows (striae) of serial punctures, fading towards the distal area; a pronounced carina on the 7 th interstria, and a short distal carina on the 6 th interstria. Metaventrite with a subtriangular glabrous area on the disc, including a central, oval and shallow concavity not reaching the apex or the base of the glabrous area ( Fig. 49 ).

Abdomen: Last tergite subtrapezoidal, with the distal margin emarginate bearing a tuft of setae of various lengths on each side, including a few strong peg-like setae ( Fig. 55 ). Ventrite 7 with a long and firmly attached spiculum ( Fig. 59 ). Genitalia ( Figs 69−70 ) with a long sclerotized main piece; distal lobe long and wide with a sinuous upper margin on lateral view ( Fig. 69 ); transparent ejaculatory pump associated to the everted ejaculatory duct, forming a long, thin, curved flagellum. Parameres long and slender, inserted close to phallobase, with sclerotized and slightly widen apices bearing a tuft of short setae.

Female unknown.

Differential diagnosis. Podaena mariae is the largest and most robust among all species in the genus, and also has the greatest elytron-length / thorax-width ratio of all species (2.7). The other large species, P. trochanteralis , has shorter elytra (elytron-length / thorax-width ratio = 2.5), longer middle and hind legs, especially the tarsi, and the middle and hind tibiae clearly curved inwards. The morphology of the maxillary palps ( Figs 19−20 ) allows clear separation of P.mariae from all species with highly modified palps, including P. trochanteralis ( Figs 17−18 ). Among the remaining species with slightly or not modified maxillary palps ( P. aotea , P. kuscheli , P. maclellani and P. glabriventris ), P. mariae can be distinguished from P. aotea and P. kuscheli by having slightly modified foretibiae ( Figs 27−28 ) and a unique genitalia ( Figs 69−70 ); and from P. maclellani and P. glabriventris by tergite X ( Fig. 55 ), the glabrous area on the metaventrite ( Fig. 49 ), and by the genitalia.

The male genitalia of P. mariae ( Figs 69−70 ) are morphologically closest to those of P. maclellani ( Figs 71−72 ). Both are well sclerotized in their distal halves; both have long thin parameres, and a permanently everted flagellum. The main difference is the thickness and shape of the flagellum: in P. mariae it is much thinner, curved, and lacks apical microdenticules (pruinosity), which are characteristic in P. maclellani . Furthermore, these two species have a very similar ventrite 7, both with a very long spiculum ( Figs 58−59 ).

Etymology. The species epithet is a noun in the genitive case after Mrs María Martínez-Esparza, who assisted in fieldwork, including the collection of the paratype of this species.

Distribution. As in Fig. 97 . Known only from two localities in the West Coast of the South Island.

Material examined. Holotype: South Island : Mackenzie ( MK): Male (dry-mounted) ( NZAC): “Mt Cook Nat. Pk. / Black Birch 820 m / 8 tm. 2 Apr. 1977 / J.S. Dugdale ”, “From 2 m / of side strm., funnel”.

Paratype: South Island : Westland ( WD): 1 male (dry-mounted) ( MONZ): “New Zealand, small stream / near Fox Glacier. Westland. / 4−12−1996 / J.A. Delgado & M. Martínez-E. leg” .

Figures

FIGURE 103. Habitus of P.mariae (Mt. Cook National Park). Scale = 0.5 mm.

FIGURES 1−24. Male right maxillary palps in ventral and lateroventral views. 1, P. aotea (ventral view). 2, P. aotea (lateroventral view). 3, P. moanaiti (ventral view). 4, P. moanaiti (lateroventral view). 5, P. hauturu (ventral view). 6, P. hauturu (lateroventral view). 7, P. latipalpis (ventral view, Karori). 8, P. latipalpis (lateroventral view, Karori). 9, P. latipalpis (ventral view, Mangamuka Gorge). 10, P. latipalpis (lateroventral view, Mangamuka Gorge). 11, P. obscura (ventral view, Rahu Creek). 12, P. obscura (lateroventral view, Rahu Creek). 13, P. obscura (ventral view, Karamea Bluff). 14, P. obscura (lateroventral view, Karamea Bluff). 15, P. dentipalpis (ventral view, Maitai Valley). 16, P. dentipalpis (lateroventral view, Maitai Valley). 17, P. trochanteralis (ventral view, Rahu Creek). 18, P. trochanteralis (lateroventral view, Rahu Creek). 19, P. mariae (ventral view, stream near Fox Glacier). 20, P. mariae (lateroventral view, stream near Fox Glacier). 21, P. kuscheli (ventral view, Hercules Creek). 22, P. kuscheli (lateroventral view, Hercules Creek). 23, P. maclellani (lateroventral view, Maitai valley). 24, P. glabriventris (lateroventral view, Maungakotukutuku). Scale = 0.2 mm.

FIGURES 25−30. Male left foretibiae. 25, P. maclellani (anterior view, Dodson’s Valley). 26, P. maclellani (lateral view, Dodson’s Valley). 27, P. mariae (anterior view, stream near Fox Glacier). 28, P. mariae (lateral view, stream near Fox Glacier). 29, P. glabriventris (anterior view, Maungakotukutuku). 30, P. glabriventris (lateral view, Maungakotukutuku). Scale = 0.1 mm.

FIGURES 47−51. Metaventrites. 47, P. obscura (Rahu Creek). 48, P. glabriventris (Tuamarina). 49, P.mariae (stream near Fox Glacier). 50, P. maclellani (Dodson’s Valley). 51, P. trochanteralis (Lake Paringa). Scale = 0.1 mm.

FIGURES 52−60. Last abdominal male tergites: 52−55. 52, P. glabriventris (Maungakotukutuku). 53, P. maclellani (Shakespeare Bay). 54, P. kuscheli (Mount Hercules). 55, P. mariae (stream near Fox Glacier). Male ventrite 7 and spiculum: 56−60. 56, P. glabriventris. 57, P. latipalpis (Waiomio Cave). 58, P. maclellani (Rata Creek). 59, P.mariae (stream near Fox Glacier). 60, P. trochanteralis (Lewis Pass). Scale = 0.1 mm.

FIGURES 69−74. Male genitalia. 69, P.mariae (lateral view, Mount Cook). 70, P. mariae (ventral view, Mount Cook). 71, P. maclellani (lateral view, Ship Cove). 72, P. maclellani (ventral view, Ship Cove). 73, P. glabriventris (lateral view, Maungakotukutuku). 74, P. glabriventris (ventral view, Maungakotukutuku). Scales = 0.1 mm.

FIGURES 95−98. Distribution maps for all species of Podaena. New Zealand is subdivided in areas as proposed by Crosby et al. (1976, 1998).

FIGURES 31−38. Male left foretibiae. 31, P. kuscheli (anterior view, Hercules Creek). 32, P. trochanteralis (anterior view, Lake Paringa). 33, P. obscura (anterior view, Rahu Saddle). 34, P. dentipalpis (anterior view, Wharfedale). 35, P. kuscheli (lateral view, Hercules Creek). 36, P. trochanteralis (lateral view, Lake Paringa). 37, P. obscura (lateral view, Rahu Saddle). 38, P. dentipalpis (lateral view, Wharfedale). Scale = 0.1 mm.