Podaena obscura Ordish, 1984

Delgado, Juan A. & Palma, Ricardo L., 2010, A revision of the genus Podaena Ordish (Insecta: Coleoptera: Hydraenidae), Zootaxa 2678 (1), pp. 1-47 : 30-32

Podaena obscura Ordish, 1984

( Figs 11, 12, 13, 14 , 33, 37 , 47 , 65, 68 , 75, 76 , 92, 93 , 97 , 104)

Podaena obscura Ordish, 1984: 16 , figs 58, 85, 114. Differential diagnosis. Male ( Fig. 104) body length (taken from anterior margin of labrum to elytral apex) 1.93 mm; female body length 2.05 mm. The male maxillary palps are modified ( Figs 11−14 ) and show some variability among populations. However, together with the male foretibiae, they are the best characters to distinguish P. obscura from all other species. In some localities (e.g. Rahu Creek) the third palpomere has a long wide groove with one well expanded margin, appearing as subtriangular on the lateroventral view ( Fig. 12 ). In other populations (e.g. Karamea Bluff) the expanded margin is less developed and the palpomere appears narrower on the lateroventral view ( Fig. 14 ). The fourth palpomere also has a groove, and is laterally constricted in its distal half ( Figs 11, 13 ). This variability was mentioned by Ordish (1984: 16) although he did not illustrate the palp of P. obscura . Males with the more expanded, subtriangular third palpomere ( Fig. 12 ) may be superficially confused with males of P. latipalpis , but in this latter species the fourth palpomere is always laterally compressed and foliaceous ( Figs 7, 9 ).

Male foretibiae are modified ( Figs 33, 37 ), but very similar to those of P. dentipalpis ( Figs 34, 38 ) and P. trochanteralis ( Figs 32, 36 ), all with a pronounced lateral expansion in the anterior view ( Figs 32−34 ) and tibial spines 1 and 2 inserted close together ( Figs 36−38 ). Although there are subtle differences in the male foretibiae of P. obscura , P. dentipalpis and P. trochanteralis ( Figs 32−34, 36−38 ), which assist in their separation, the male maxillary palps are the only reliable means of separating these three species. Furthermore, P. obscura is shorter than P. trochanteralis and the metaventral glabrous area on the disc ( Fig. 47 ) is somewhat different from that of P. trochanteralis ( Fig. 51 ).

The male genitalia are similar and therefore not diagnostic among P. obscura , P. dentipalpis , P. kuscheli and the species of the P. latipalpis complex. The remaining characters that are diagnostic for other species, i.e. the last abdominal male tergite (as in Fig. 54 ), the last abdominal female tergite ( Fig. 65 ), the gonocoxite ( Fig. 68 ), the male genitalia ( Figs 75−76 ) and the spermatheca ( Fig. 92 ), are also very similar among several species and not useful to distinguish P. obscura from its closest congeners.

Distribution. As in Fig. 97 . Widely distributed in the northwest of the South Island, with two additional single records further south. The apparent gap in the centre of the South Island may be due to lack of collecting rather than indicate a true absence of P. obscura in those areas (WD and MK).

Material examined. Type material. Holotype: South Island : Buller ( BR): Male – “Rahu Ck / Rahu Saddle / 600m 6 Apr. 73 / J.S.Dugdale ”.

Paratypes: South Island : Nelson ( NN) : 6 males, 2 females (2 males in alcohol, 4 males dry-mounted: printed labels, 2 females dry-mounted: printed labels) ( NZAC): “Flora Hut, NN / ex small bush strm. / 28 Dec. 1972 G.K.” . 4 males, 6 females (in alcohol) ( NZAC): “Flora Stm NN., at Flora Hut, 28.12.72 G.K.” . 28 males + one head, 13 females (20 males in alcohol, 8 dry-mounted: printed labels, 13 females in alcohol) ( NZAC): “Flora Hut, NN / ex small bush strm / 28 Dec. 1972. G.K.”, “See slide”. Male legs (microslide) ( MONZ) “Flora Hut, NN / ex small bush strm / 28 Dec. 1972. G.K.” . 1 male (dry-mounted) ( NZAC): “Cobb Saddle / 1030 m. / 9 Feb 73, G.K.”, “small slow, strm. in bush” . 1 male, 2 females (in alcohol) ( NZAC): “ Cobb Rd. 330m, 8.2.73 G.K., stm. in bush” . 8 males, 8 females (in alcohol) ( NZAC): “Cobb Rd 330 m., 9.2.73 G.K.” 13 males, 11 females (in alcohol) ( NZAC): “L. Cobb. 800m / 9.2.1973 / G. Kuschel ” [see note below] . 1 male (dry-mounted, teneral), ( NZAC): “Orbit CK 810 m. / mt Kendall / upper Karamea / 10.2.73 A.K. Walker ” . 2 males, 4 females (in alcohol) ( NZAC): “Surveyors ck, Karamea Bluff / 25 Jun 73 / G.K + J.McB.” . 6 males, 5 females (1 male dry-mounted: printed label, 5 males and 5 females in alcohol) ( NZAC): “ 1 km S of Sur− / veyors ck, Kara− / mea Bluff / 25 Jun 73, G.K + J.McB.” . 1 female (in alcohol) ( NZAC): “Anatoki R. / nr. Takaka. / 8 Feb 73 G.K.” . 5 males, 1 female (in alcohol) ( NZAC): “Takaka Hill / West side / 8.2.73, G.K.”. Buller ( BR) : 4 males, 5 females (3 males in alcohol, 1 male dry-mounted: printed label, 5 females in alcohol) ( NZAC): “Maruia Saddle / 430’ 11.4.73 / G. Kuschel” . 13 males, 8 females (11 males in alcohol, 2 males dry mounted: printed labels, 6 females in alcohol, 2 females dry-mounted: printed labels, one slide) ( MONZ): “Lewis Pass / Goings Bridge / 815 m. 11.4.73”, “See Slide” . 1 male (dry-mounted) ( MONZ): “Lewis Pass / 815 m. / 11.4.73” . 5 males, 17 females (1 male dry mounted: printed label, 4 males in alcohol, 2 females dry mounted: printed labels, 15 females in alcohol) ( NZAC): “Rahu CK, 600m / 6 Apr 73, J.S.D. / Rahu Saddle” . 1 male (dry-mounted, one slide) ( MONZ): “Rahu CK 2000’ / Rahu Saddle, in / side fiffles of 20’ / wide stream. Water / depth 1−3’. 6 Apr. 73 / J.S.D. / under dense canopy”, “See Slide”. Otago Lakes (OL) : 1 male (teneral, dry-mounted,), 1 female (teneral, dry-mounted: printed label) ( NZAC): “Dinner CK. / L. Hawea / 29.3.73 G.K.”. Central Otago (CO) : 5 males, 4 females (4 males in alcohol, 1 male dry-mounted: printed label, 4 females in alcohol, one teneral) ( NZAC): “Gorge CK above / cave 15.3.73 / G. Kuschel” .

Additional material examined. South Island: Nelson ( NN): 1 male, 1 female (dry-mounted) ( MONZ): “Cobb Ra. / Nelson. NZ, 9. Feb. 73 / G. Kuschel ”. 1 male (dry-mounted) ( MONZ): “Flora Ck. by put / stones and twigs / in fast. flowing / reaches 23.3.71 / J.S. Dugdale ”. 1 male (dry mounted: printed label) ( NZAC): “Anatoki R. / nr. Takaka / 8 Feb. 73 G.K.”, “in bush in / small side / stream”. Buller ( BR): 1 female (drymounted) ( NMWA): “NEW ZEALAND: S− Isl. BR|NN / Lyell Creek Valley / 10 km NE Inangahua / 7.2.1997 Schuh & Lang”. 1 male, 4 females (1 male dry-mounted: printed label, 4 females in alcohol) ( MONZ): “sp 4 / Hydraenidae 4 Podaena / + undet sp. B 1 Podaena / BR Little Boatman’s CK / above mine 24|7|87 / ADT weed”. 1 male (dry-mounted: printed label) ( CDMS): “ Sandy creek near Kawatiri. Buller / NEW ZEALAND / 1−12−96, 5−S / Beech Forest . J. A. Delgado leg” .

Note. As shown in Table 1, a comparison of paratype numbers given by Ordish (1984: 17) and our counting of the material available shows that 72 paratypes of P. obscura are missing. Numbers given in the LCD are even higher than those in Ordish (1984), but we have to regard numbers in the latter publication as the correct numbers of designated paratypes, not those in the LCD. However, from data available in the LCD, we suggest that a possible source for the large discrepancy in the total number of paratypes was an error in recording a sample with data “L. Cobb. 800m / 9.2.1973 / G. Kuschel” listed in the LCD with a much greater number of specimens than those we have located and examined (see above). Furthermore, we have not been able to locate a sample of three putative paratypes listed in the LCD with data: “Crooked River WD, 1.11.1978, R.R. Scott”.

Figures

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 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.

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 61−68. 61, female valvifers, gonocoxite and last two abdominal tergites of P. maclellani (Ship Cove). 63, ditto of P. trochanteralis (Altimarloch). 62, last female tergite of P. maclellani (Ship Cove). 65, ditto of P.obscura (Flora Hutt). 66, ditto of P. glabriventris (Tuamarina). 64, gonocoxite of P. maclellani (Ship Cove). 67, ditto of P. glabriventris (Tuamarina). 68, ditto of P.obscura (Flora Hutt). Scale = 0.1 mm.

FIGURES 75−78. Male genitalia. 75, P. obscura (lateral view, Rahu Creek). 76, P. obscura (ventral view, Rahu Creek). 77, P. trochanteralis (lateral view, Lewis Pass). 78, P. trochanteralis (ventral view, Lewis Pass). Scale = 0.1 mm.

FIGURES 83−94. Spermathecae: 83̅92. 83, P. glabriventris (ventral view, Tuamarina). 84, P. glabriventris (right lateral view, Tuamarina). 85, P. maclellani (ventral view, Ship Cove). 86, P. maclellani (right lateral view, Ship Cove). 87, P. kuscheli (ventral view, Hercules Creek). 88, P. dentipalpis (ventral view, Serpentine Creek). 89, P. dentipalpis (right lateral view, Serpentine Creek). 90 P. trochanteralis (ventral view, Altimarloch). 91, P. trochanteralis (right lateral view, Altimarloch). 92, P. obscura (ventral view, Flora Hutt). Distal outline of elytra: 93–94. 93, P. obscura (Gorge Creek). 94, P. moanaiti. 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 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.