Crucisternum sinuatus , Giron, Jennifer C. & Short, Andrew Edward Z., 2018

Giron, Jennifer C. & Short, Andrew Edward Z., 2018, Three new genera of acidocerine water scavenger beetles from tropical South America (Coleoptera, Hydrophilidae, Acidocerinae), ZooKeys 768, pp. 113-158: 120

publication ID

http://dx.doi.org/10.3897/zookeys.768.24423

publication LSID

lsid:zoobank.org:pub:399BCC3E-9D6F-4231-870E-05C79B9FD4B0

persistent identifier

http://treatment.plazi.org/id/BD20616D-2360-4509-84FE-210B65E9D54E

taxon LSID

lsid:zoobank.org:act:BD20616D-2360-4509-84FE-210B65E9D54E

treatment provided by

ZooKeys by Pensoft

scientific name

Crucisternum sinuatus
status

sp. n.

Crucisternum sinuatus  sp. n. Figs 3 A–D; 6G, H; 7

Type material examined.

Holotype (male): BRAZIL: Minas Gerais: Lassance, -17.83384, -44.50515, 568 m, Cachoeira da Palmeira, flotation of root mats and moss from side of waterfall and seepage, 2.iii.2018, leg. Benetti & team; BR18-0302-04A ( INPA). Paratypes (10): BRAZIL: Pará: Rio Xingu Camp 52°22'W, 3°39'S, Altamira, ca 60km S., 3.x.1986, leg. P. Spangler & O. Flint, Colln. #6, 1st jungle stream on trail 1 (1, USNM); same, except 14.x.1986, Colln. #23, stream on left branch of trail 1 (3; SEMC, USNM); Minas Gerais: same data as holotype (2 INPA, 4 SEMC).

Differential diagnosis.

Crucisternum sinuatus  is very similar to C. escalera  and C. xingu  in the shallowness of the punctation. In addition, it can be distinguished from C. xingu  by the aedeagus with median lobe constricted at midlength, continuing as a narrow and roundly pointed bar (see Fig. 6G, H; as opposed to gradually narrowing towards the apex, see Fig. 6E, F), and the outer margins of the parameres, which are strongly constricted at apical third, continuing nearly parallel (as opposed to nearly straight to sinuate).

Description.

Body length 2.0-2.4 mm, width 1.1-1.4 mm. General coloration variable, either orange brown or uniformly dark brown (Fig. 3 A–D). Elytra with punctures shallowly marked. Aedeagus with outer margins of parameres strongly constricted at apical third, continuing nearly parallel towards apex; inner margins of parameres slightly concave only along apical sixth; median lobe constricted at midlength, continuing as a narrow and roundly pointed bar (Fig. 6G, H).

Etymology.

Named in reference to the abrupt constriction of the outer margins of the parameres at their apical third, with the Latin word sinuatus meaning bent, curved.

Distribution.

Brazil (Minas Gerais, Pará). See Fig. 7.

Biology.

The series from Lassance was collected by floating root mats and detritus that were on rock at the margin of a river and waterfall. The specimens from Altamira were collected in streams.