Agaporomorphus hamatocoles, Miller, 2020

Miller, Kelly B., 2020, Two new species of Agaporomorphus Guignot from Suriname (Coleoptera, Adephaga, Dytiscidae, Copelatinae), ZooKeys 923, pp. 51-63 : 51

Agaporomorphus hamatocoles sp. nov. Figures 1-3 , 24 , 26

Type locality.

Suriname, Sipaliwini District, Sipaliwini Savannah Nature Reserve, Four Brothers Mountains, 2.005700N, 55.969151W, 337 m.

Diagnosis.

This species does not share many features with other members of the genus and does not have modified antennomeres, modified male mesotarsal claws or a lobe on the apex of mesotarsomere V, it lacks a stridulatory apparatus on the abdomen and metaleg, and lacks a triangular process at the apical margin of visible sternite V of the abdomen. Unique features of A. hamatocoles are the strongly hooked male median lobe (Fig. 1 ) and the elongate curved flagellum on the ventral surface of the male median lobe (Figs 1 , 2 ). These features are diagnostic within Agaporomorphus .

Description.

Measurements (N = 3). TL = 2.8-3.2 mm, GW = 1.4-1.6 mm, PW = 1.2-1.3 mm, HW = 0.8 mm, EW = 0.5-0.6 mm, FL = 0.7-0.8 mm, FW = 0.2-0.3 mm, TL/GW = 1.9-2.0, HW/EW = 1.5-1.6, FL/FW = 2.9-3.4. Body shape elongate oval, evenly and shallowly curved along lateral margins, curvature continuous between pronotum and elytron.

Coloration. Head and pronotum dark orange. Elytron dark orange throughout except transverse basal band light orange. Ventral surface orange, similar in coloration throughout but legs distinctly lighter in color.

Sculpture and structure. Head shiny, very finely microreticulate comprised of small isodiametric cells; eyes small (HW/EW = 1.5-1.6). Pronotum shiny, similar microreticulation to head; lateral margin slightly curved, extremely finely beaded, bead absent at anterior angle. Elytron with lateral margin shallowly curved; surface shiny, microreticulation extremely fine, apical half with numerous extremely fine punctures. Prosternum elongate, carinate, prosternal process short, strongly carinate medially. Metaventer and metaventral wings smooth and shiny, with very dense, extremely fine microreticulation. Metacoxa smooth and shiny, similar in microsculpture to metaventer; metacoxal lines distinct, region between metacoxal lines narrow medially; metafemur not unusually broadened (FL/FW = 2.9-3.4).

Male genitalia. Median lobe exceptionally complex in shape, strongly asymmetrical; in lateral aspect broad basally, irregularly shaped, apically narrowed with apex dramatically hooked, curved anteriorly on dorsal surface with elongate apex directed posteriorly, curved portion elongate, slender and apically narrowly rounded (Fig. 1 ); in ventral aspect very broad, lateral margins broadly curved, with slender, long curved “flagellum” extending from left anteroventral region in broad curve along antero-ventral surface along left side to apex, apically sharply pointed (Fig. 2 ); lateral lobe in lateral aspect robust, apically narrowed, with slender apical lobe, with series of fine setae along apicodorsal margin (Fig. 3 ).

Sexual dimorphism. Males have the pro-mesotarsomeres I-III distinctly broader than in females with enlarged ventral adhesive setae.

Variation. The few specimens are quite similar to each other in coloration and other features.

Distribution.

This species is known only from southern Suriname (Fig. 24 ).

Habitat.

The type series was collected from "detrital pools."

Discussion.

This species is quite unlike other species in the genus. The A. knischi group is characterized by somewhat similarly shaped male median lobes with a fringe of setae along the dorsal margin of each side and many of them have expanded male antennomeres and/or stridulatory devices on the abdomen and metalegs ( Miller 2005; Miller and Wheeler 2008; Hendrich et al. 2015). The A. dolichodactylus group has an elongate process on the dorsal surface of the male median lobe and elongate, sinuate mesotarsal claws ( Miller 2005). The A. pereirai group has none of these features, but the male median lobe has prominent angulate flanges on the ventral side apically and other autapomorphies ( Miller 2005). The new species described here does not share any of these characteristic features and is phylogenetically isolated (Fig. 26 , see below), so it is placed in its own group, the A. hamatocoles species group.

Etymology.

This species is named hamatocoles , from Latin hamatus for hooked and coles for penis for the unique shape of the hooked male median lobe in this species (Fig. 2 ).

Type material.

Holotype in NZCS, male labeled, "SURINAME: Sipaliwini District 2.005700N, 55.969151W, 337m Sipaliwini Savannah Nature Res. Four Brothers Mts, detrital pools, 31.iii.2017 leg. Short. SR17-0331-01D/ Holotype Agaporomorphus hamatocoles Miller, 2020 [red label with double black line border]." 3 paratypes labeled same as holotype except with “… /Paratype Agaporomorphus hamatocoles Miller, 2020 [blue label with black line border]."

Figures

Figure 26. Two equally most parsimonious cladograms of Agaporomorphus species derived from parsimony analysis (L = 17, CI = 82, RI = 92): " alt " = alternative equally parsimonious configuration for A. knischi clade. Numbers above hatch marks refer to characters. Numbers below hatch marks refer to character state transformations. Characters mapped using " fast " or " acctran " optimization in WinClada (Nixon 2002).

Figures 1 - 6. Agaporomorphus species, male genitalia. 1 - 3 A. hamatocoles 1 male median lobe, right lateral aspect 2 male median lobe, ventral aspect 3 male right lateral lobe, right lateral aspect 4 - 6 A. tortus 4 male median lobe, right lateral aspect 5 male median lobe, ventral aspect 6 male right lateral lobe, right lateral aspect.

Figures 24, 25. Known distributions of Agaporomorphus species of northern South America (A. pereirai also known from Brazil, not shown on map).