Dineutus productus Roberts, 1895

Gustafson, Grey T., Maier, Crystal A., Baca, Stephen M. & Faris, Christina K., 2014, Rediscovery ofLutrochus laticepsCasey, 1893 (Coleoptera: Lutrochidae) and the Discovery ofDineutus productusRoberts, 1895 andDineutus serrulatus analisRégimbart, 1882 (Coleoptera: Gyrinidae) in Kansas, USA, with Notes on Habitat Preference, The Coleopterists Bulletin 68 (4), pp. 713-718 : 715-717

Dineutus productus Roberts, 1895

Dineutus productus has been an enigmatic taxon due to mistaken identity and the limited number of specimens available for study. Roberts (1895) described the species from four specimens (2 ♀, 2 ♂), provided no habitat information, and reported the locality as simply “Texas”. Dineutus productus has been reported from Carolina (without specification as to which one) ( Régimbart 1907), Illinois at the Sangamon River near Decatur (without details of how many specimens were collected) ( Hatch 1925), and in Texas a single specimen from Dallas and a “small series” from Clifton ( Ochs 1929). Ochs (1929) reported that all specimens seen by him identified as D. productus from outside Texas were incorrectly identified. Later, Ochs (1949) reported three specimens collected from Nuevo León, Mexico. Young (1954) mentioned having seen specimens of D. productus from the Apalachicola River in Florida. Despite this, Wood (1962) and Epler (2010) doubt any records of the species from outside of Texas and Mexico. Here, we report definitively identified D. productus specimens collected from Kansas and provide detailed descriptions of the habitat from which it was recollected.

Eight specimens of D. productus were collected from four localities in southeastern Kansas during the KBS in the 1970s (CReAC 2014), and the identity of the specimens was confirmed. Dineutus productus was recollected 22 June 2014 at two localities ( Fig. 1 ) along the Elk River: 1) just south of Longton (N 37.36960°, W 96.078735°); and 2) at Elk Falls (see above for description, Fig. 2 ). At the first locality, the Elk River ( Fig. 3A ) is large (ca. 20 m in width, over 1.7 m in depth near the center), fairly slow moving, and with cool water (≈ 20°C) and a mud

THE COLEOPTERISTS BULLETIN 68(4), 2014 717

and sand/gravel bottom. The water is brown and turbid. The river flows over a small artificial wall, creating a waterfall with a deep pool beneath ( Fig. 3 ). Six specimens (4 ♀, 2 ♂) of D. productus were collected from the deep pool under the falls, but the species was absent above the falls and further downstream (ca. 40 m extent). Dineutus serrulatus analis Régimbart, 1882 (see below) was abundant here, similarly not found in the immediate area above the falls, but was found further downstream. In the pool, D. serrulatus analis frequently moved close to shore and upon being startled moved back to deeper water. Dineutus productus was present in much lower numbers and tended to be more cautious, stayed far away from the stream banks, and remained in deeper water where it was more difficult to catch. In the water, D. productus could be distinguished from D. serrulatus analis by its smaller size, narrower body form, and avoidance of the banks. At the second site, Elk Falls, the Elk River was clearer but still had cool water temperature and a mud-sand/gravel bottom, with fairly murky brown water in areas away from the falls. Five female specimens were collected under shade a short distance upstream of the waterfall. Dineutus productus also co-occurred with D. serrulatus analis at this site.

Figures

Fig. 1. Map of Kansas with collection sites. Black circle = locality on Elk River South of Longton; gray circle = Elk Falls; white circles = additional localities sampled.

Fig. 2. Elk Falls, habitat. A) Pointer indicates area of falls where Lutrochus laticeps was found, B) Pointer indicates microhabitat of L. laticeps, C) Pointer indicates L. laticeps in moist moss, D) G. Gustafson and C. Faris collecting L. laticeps from falls.

Fig. 3. Elk River just south of Longton, habitat. A) Pool beneath falls and river downstream, B) The falls.