Dineutus serrulatus analis Regimbart , 1883

Gustafson, Grey T. & Miller, Kelly B., 2015, The New World whirligig beetles of the genus Dineutus Macleay, 1825 (Coleoptera, Gyrinidae, Gyrininae, Dineutini), ZooKeys 476, pp. 1-135 : 68

Dineutus serrulatus analis Regimbart, 1883 Figures 37, 38, 39, 51, 53

Dineutes analis Régimbart 1883: 416, Dineutus (Cyclinus) analis : Ochs 1926: 1377, Dineutus serrulatus analis : Wood 1968: 4, Dineutus analis : Ciegler et al. 2003: 14.

Type locality.

U.S.A., Texas

Specimens examined.

41

Type material examined.

Lectotype, here designated (1 ♂ pinned, missing right arm) "Texas [white label, handwritten in black ink, handwriting unknown]// MUSEUM PARIS/ COLL MAURICE REGIMBART/ 1908 [blue label with thin black border, typed black ink]// LECTOTYPUS/ P. Brinck designavit 1955. [white label, typed black ink]// TYPE [red label, typed black ink]// LECTOTYPE [red label, typed black ink]//" deposited in the MNHN. Paralectotype (1 ♂ pinned, missing right mesothoracic leg) "Louisiana [white label, typed black ink]// MUSEUM PARIS/ COLL MAURICE REGIMBART/ 1908 [blue label with thin black border, typed black ink]// PARALECTOTYPE [red label, typed black ink]//" (1 ex. MNHN).

Material examined.

U.S.A.: Arkansas: Washington Co., Lake Sequoyah, 7.x.1992, leg. S. Garner (1 ex. MTEC); Florida: Bradford Co., 3.ii.1949, leg. B.W. Cooper (1 ex. FSCA); Highlands Co., Highlands Hammock State. Prk., 15.iii.1974, leg. R.E. Beer (1 ex. KSEM); Liberty Co., Yellow Creek SE of Telogia, 7.x.1992, leg. F.N. Young, #3503 (12 ex. FSCA); Suwannee Co., Branford, 31.vii.1930, leg. P.W. Oman (1 ex. KSEM); Kansas: Elk Co., Longton, 1 mi S, 1 mi E, Elk River, “T31S”, 2.viii.1977, leg. S. Hamilton, SEMC 1057036 (1 ex. KSEM); Labette Co., Altamont, 5 mi E, Labette Creek, 22.vi.1974, SEMC 1056921, 1056919 (2 ex. KSEM); Montgomery Co., Caney, 25.vi.1991, leg. D. Miller, (1 ex. MTEC); Montgomery Co., Havana, ca. 2 mi N, Coon Creek, 24.vii.1974, leg. T. Edmonds, SEMC 1057032 (1 ex. KSEM); Montgomery Co., Drum Creek, US-160, 23.vii1974, leg. T. Edmonds, SEMC 1057034 (1 ex. KSEM) Sedwick Co., Goddard, 2.5 mi N, 5 mi E, creek, 17.vii.1975, leg. S. Matthies, SEMC 1057030 (1 ex. KSEM); Wilson Co., Altoon, 3.4 mi S, 3.5 mi E Chetopa Creek, "T29S R17E sec 31 NW 1/4", 5.viii.1977, leg. S. Hamilton, T. Oldham, SEMC 1057019-1057020 (2 ex. KSEM); Wilson Co., Roper, 0.25 mi W, Buffalo Creek, "T27S R15E sec 35, 5.viii.1977, leg. S. Hamilton, T. Oldham, SEMC 1056998 (1 ex. KSEM); Mississippi: Hancock Co., Devil’s Swamp, 7.v.1965, leg. H.R. Hepburn (3 ex. KSEM); Hancock Co., Asley, 8.iii.1966, leg. H.R. Hepburn, (1 ex. KSEM); Tennessee: McNairy Co., 8 mi S.W. Ramer, 6.viii.1975 (4 ex. FSCA); Texas: Montgomery Co., The Woodlands, 10-18.vi.1977, leg. J.E. Wappes (1 ex. FSCA); Victoria Co., Victoria, Musang Creek, 8.ii.1932, leg. L.D. Tuthill (4 ex. KSEM).

Diagnosis.

Male (Fig. 37C-D): Size: 9.9-11.4 mm. Body form elongate oval; elytral apices flatly rounded, often with sutural angle produced to a point, apicolateral sinuation present, with sinuation shallow, serration and irregularities present apically near sutural production, elytral apices weakly deflexed, reticulation of pronotal and elytral discs strongly impressed, producing a bronzy appearance; elytral striae faintly evident, most evident on the medial portion of the elytral disc; profemora with sub-apicoventral tooth; protibiae subsinuate; mesotarsal claws (Fig. 38F) small and of similar size, with ventral margin with a more or less developed smooth denticle; venter lightly or darkly colored, coloration usually red but ranging to very dark red or black, with the mesothoracic and metathoracic legs usually lighter in coloration, as well as apex of abdomen; Aedeagus (Fig. 38A-C, D, E, G, H-J) with median lobe in dorsal view as long as parameres, highly parallel sided, narrowed in apical 1/4, apex flatly to regularly rounded, in lateral view median lobe weakly curved dorsally after basal 1/3, parameres in apical 1/3 weakly laterally expanded, apically obliquely flatly rounded to truncate.

Female (Fig. 37A-B): Size: 10.0-11.4 mm. Body form elongate oval; elytral apices flatly rounded, sutural angle often produced to a point, apicolateral sinuation shallow, serration present apically near sutural production, elytral apices weakly deflexed, reticulation of pronotal and elytral discs strongly impressed, producing a bronzy appearance; elytral striae faintly evident, most evident on the medial portion of the elytral disc; profemora without sub-apicoventral tooth; protibiae club shaped, with lateral margin flatly round; venter lightly or darkly colored, coloration usually red but ranging to very dark red or black, with the mesothoracic and metathoracic legs usually lighter in coloration, as well as apex of abdomen.

Differential diagnosis.

Dineutus serrulatus analis is unique among all other North American Dineutus species in belong elongate oval and attenuated anteriorly, with elytral apices having apicolateral sinuations in both sexes, flatly rounded elytral apices, often with the sutural angle produced to a point, and with serration present, males with the profemora with a sub-apicoventral tooth, and in the form of the male aedeagus. The species most similar to Dineutus serrulatus analis is Dineutus productus . Dineutus serrulatus analis can be separated from Dineutus productus by the differential diagnosis given for Dineutus productus .

Distinguishing between Dineutus serrulatus analis and Dineutus serrulatus serrulatus can primarily be done using the differences in the key listed above.

Distribution

(Fig. 53C). Southeastern United States ( Ciegler et al. 2003; Epler 2010; Régimbart 1882; Roberts 1895; Wood 1962; 1968).

Habitat.

Lotic species found in small streams usually below 500 feet in elevation ( Wood 1968). For a more in depth description of habitat see ( Gustafson et al. 2014).

Discussion.

Of the two subspecies Dineutus serrulatus analis has the wider of the two ranges ( Wood 1968). Dineutus serrulatus serrulatus is primarily distributed in Florida and to the east in the Carolinas ( Young 1954; Sanderson 1982). In northern Florida where the two subspecies meet specimens show intermediate morphology. Specimens examined in this study from Liberty County, Florida, (Fig. 39D [FSCA]) showed intermediate dorsal coloration being polished black medially, but laterally bronzy green and the sperm-groove of the aedeagus (Fig. 38B) is intermediate between the narrowed sperm-groove of northern populations of Dineutus serrulatus analis and the more broad sperm-groove of Dineutus serrulatus serrulatus from southern Florida. These specimens from Liberty County (FSCA) also show unique variation in the parameres (Fig. 38A), in that they are much more narrow and parallel sided in their apical half, not exhibiting the lateral expansions and arc seen in the parameres of other populations. However, the median lobe is identical in shape to that of Dineutus serrulatus serrulatus . While this variation in the past may have been enough to qualify as sub-specific differences, given how highly variable this species is (Fig. 39), no formal name will be applied at this time. Making the situation even more difficult, Dineutus serrulatus analis from Texas (Fig. 38D, E [KSEM]) have the aedeagus and sperm-groove identical to those of Dineutus serrulatus serrulatus (Fig. 41A, B). Specimens from southeastern Kansas (KSEM) were notable for having a bronzy dorsal surface, but a very dark reddish brown venter (Fig. 39J, K). The profemoral subapicoventral tooth is also quite large for a member of Dineutus serrulatus analis . Future genetic work may shed better light on the significance of this variation.

Type designation.

Régimbart (1882) in the original description describes the species from both Louisiana and Texas. In the MNHN there are two specimens from the Régimbart Collection, one from Texas and one from Louisiana. Here we formerly designate the specimen from Texas (Fig. 51A) as the lectotype and the specimen from Louisiana as the paralectotype.