Podaena latipalpis

Delgado, Juan A. & Palma, Ricardo L., 2010, A revision of the genus Podaena Ordish (Insecta: Coleoptera: Hydraenidae), Zootaxa 2678 (1), pp. 1-47 : 33-35

Podaena latipalpis complex

This complex includes four species which share a very similar morphology in most characters, and can only be separated by differences in the male maxillary palps ( Figs 1−10 ) and in the male foretibiae ( Figs 39−46 ). Furthermore, these four species have a serrate distal edge in the elytra ( Fig. 94 ), not present in the remaining seven species ( Fig. 93 ). The male foretibiae in the species of this complex show an expansion of the proximal half and a constriction of the distal half, both best observed in the lateral view ( Figs 43−46 ), a marked invagination between the expanded proximal half and the constricted distal half, and two thick spines (tibial spines 1 and 2) also best seen in the lateral view. In addition, there is a lateral expansion bearing rows of thin setae and some thicker setae at the distal end, best seen in the anterior view ( Figs 39−42 ).

Besides differences among the male maxillary palps ( Figs 1−10 ), the four species in this complex can be separated by the morphology of the male foretibiae, in particular by a combination of characters such as the shape and position of the invagination, the relative length and width of the proximal expansion and the distal constriction ( Figs 43−46 ), and the shape and chaetotaxy of the distal expansion ( Figs 39−42 ). Admittedly, differences among species are subtle and should be studied under high magnification, but they are consistent and sufficient for a satisfactory species diagnosis.

Three of the four species placed in this complex are described as new, and are mostly based on material identified by Ordish (1984: 16) as Podaena latipalpis . Ordish appears to have interpreted the subtle differences we found in the male maxillary palps and foretibiae as intraspecific variability. All the species of this complex have been found in the North Island, with the exception of one population of P. latipalpis recorded from Nelson, in the north of the South Island.

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 39−46. Male left foretibiae. 39, P. aotea (anterior view). 40, P. hauturu (anterior view). 41, P. moanaiti (anterior view). 42, P. latipalpis (anterior view, Waitomo). 43, P.aotea(lateral view). 44, P. hauturu (lateral view). 45, P. moanaiti (lateral view). 46, P. latipalpis (lateral view, Waitomo). 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.