Redescription of the littoral genus and species of Neochthebius granulosus (Satô), and the first larval description for the genus (Coleoptera: Hydraenidae: Ochthebiinae)
Author
Park, Sun-Jae
Author
Ahn, Kee-Jeong
text
Journal of Natural History
2008
2008-10-31
42
39 - 40
2501
2514
http://dx.doi.org/10.1080/00222930802354803
journal article
10.1080/00222930802354803
1464-5262
4590517
Genus
Neochthebius
d’Orchymont
Neochthebius
d’Orchymont, 1932: 43
;
Perkins, 1980: 408
;
Hansen, 1991: 42
.
Type
species:
Ochthebius vandykei
Knisch, 1924
.
See
Perkins (1980)
for other synonymy and references.
Figures 3–8.
Neochthebius granulosus
. (3) antenna, dorsal aspect; (4) labrum, dorsal aspect; (5) mandible, dorsal aspect; (6) maxilla, ventral aspect; (7) aedeagus, dorsal aspect; (8) aedeagus, lateral aspect. Note: Scales50.1 mm.
Description
Length about
1.4–1.6 mm
. Body (
Figures 1–2
) almost unicolour, dark brown to dull black; elongate, narrow, convex; dorsum covered with some distinct white setae. Head (
Figures 15–16
) widest across eyes; two distinct punctures present between eyes; strongly microreticulate and granular. Clypeus (
Figures 15–16
) with finely impressed clypeal line; apical margin truncate; strongly microreticulate and granular. Eyes small; facets relatively large. Antennae (
Figure 3
) with nine Figures 9–14. (9–11) antennomere 2; (12–14) maxillary palpomere 3. (9–10 and 12–13)
Neochthebius granulosus
; (11 and 14)
N. vandykei
.
antennomeres; apical five antennomeres clubbed and pubescent; scape longest, clearly imbricate; pedicel strongly bulbed basally, narrowed apically, weakly or clearly imbricate (Figures 9–11); antennomere 3 small, somewhat bulbed apically; 4 crescent shape; and 5–9 compact. Labrum (
Figure 4
) transverse, moderately large, rounded; apical margin weakly serrate, slightly emarginate medially; strongly microreticulate. Mandibles (
Figure 5
) almost symmetrical, triangular; apex acute, with roughly serrated large retinaculum; mola with grinding region; lateral margin with one long seta and some short setae; hidden under labrum. Maxillary palpomere 3 longest, thick, weakly or clearly imbricate (Figures 12–14); and 4 small, slender, apex with some extremely short setae. Galea (
Figure 6
) slender; apex with some long and short setae. Lacinia with some large spines and long setae along inner margin; apex acute. Labial palpi very slender, indistinct. Mentum hexagonal; narrowed basally; apical margin broadly emarginate; some long flexible setae present on each antero-lateral region; somewhat microreticulate. Pronotum (
Figures 19–21
) about as wide as or slightly wider than long; widest in front of middle; moderately narrowed apically, strongly narrowed basally; three distinct or indistinct longitudinal impressions and fine lateral impression present; strongly microreticulate and granular. Elytra (
Figures 1–2
and
19–21
) longer than wide; 10 indistinct rows of punctures present, each with a distinct white seta; surface uneven. Hind wings absent. Scutellum small, transverse, pentagonal (visible as triangular); most hidden under pronotum; basal margin broadly emarginate; strongly imbricate. Prosternum (
Figures 22–23
) weakly convex; procoxae almost contiguous; procoxal cavities open; strongly imbricate. Mesoventrite (
Figures 22–23
) not carinate; mesocoxae narrowly separated; apex of mesocoxal process acute and reached to metacoxal process, isthmus absent; strongly imbricate. Metaventrite (
Figures 24–25
) relatively short; metacoxae almost contiguous; strongly imbricate. Legs slender. Femur normal, transverse; clearly imbricate; profemur with a series of fine setae dorsally. Tibia slender, some fine sparse spines present, microreticulate; metatibia slightly outcurved. Tarsal formula 5–5–5, tarsomeres 1–4 small; and 5 long, as long as 1–4 combined. Abdomen (
Figures 24–25
) strongly imbricate; last abdominal segment of female with a row of some large spines apically (
Figures 17–18
). Aedeagus slender; apex with a large distal lobe on left side in dorsal aspect, distal lobe sinuate; with some relatively long setae near apex ventrally in lateral aspect; moderately curved in lateral aspect. Parameres thin; moderately expanded at apex; apex with very short setae ventrally.
Key to the species of the genus
Neochthebius
1. Mesoventrite as in
Figure 23
, mesoventral process blunt apically; metaventrite and abdominal sternites relatively weakly setose (
Figure 25
); elytra weakly uneven (
Figure 21
)..........
Neochthebius vandykei
(Knisch)
– Mesoventrite as in
Figure 22
, mesoventral process sharply pointed apically; metaventrite and abdominal sternites strongly setose (
Figure 24
); elytra strongly uneven (
Figures 19–20
).....................................................
N. granulosus
(Satô)