The genus Syzeton Blackburn, 1891 (Coleoptera, Aderidae) in the United States of America
FIGURE 1. Morphological characteristics of the genus Syzeton Blackburn, 1991. a, uniseriate elytral pubescence (example, Syzeton nubifer (LeConte, 1878)). b, bean-shaped transversal head in dorsal view (example Syzeton ouachitanus (Werner, 1990)). c, pronotum shape in dorsal view, with anterior margin made of segments converging toward head in an obtuse angle (example Syzeton floridanus (Werner, 1990)). d, pedicel (antennomere 2) shorter than antennomere 3 (examples, left, Syzeton ouachitanus (Werner, 1990) and right, Syzeton nubifer (LeConte, 1878)). e, last abdominal ventrite of ♀ with a medial pit (ex- ample Syzeton fasciatus (Melsheimer 1846)). f, enlargement of framed region in panel e, arrow pointing to pit. g, right midtarsus with arrowheads pointing to ventral brush (example Syzeton pallidus (Werner, 1990)). h, right hind femora in ventral view, white frame centered on excavation (example Syzeton pallidus (Werner, 1990)). i, enlargement of framed region in panel h, arrow pointing to excavation. scale bars: 100 µm.
FIGURE 2. Habitus of US Syzeton species. a, Syzeton ouachitanus (Werner, 1990) ♂ from Texas. b, S. fasciatus (Melsheimer 1846) ♂ from Wisconsin. c, S. hubbardi (Casey 1895) ♂ from Oklahoma. d, S. nubifer (LeConte, 1878) ♂ from Texas. e, S. ater (LeConte, 1875) ♂ from Arkansas. f, S. gruberi n. sp. ♂ paratype from Arizona. g, S. arizonae n. sp. ♂ holotype from Arizona. h, S. belovi n. sp. ♂ holotype from Texas. i, S. pallidus (Werner, 1990) ♂ from Texas. j, S. subfasciatus (LeConte, 1855) ♂ from Missouri. k, S. floridanus (Werner, 1990) ♂ from Florida. l, S. signatus (Haldeman, 1848) ♂ from South Carolina. m, S. ouachitanus (Werner, 1990), elytral variation. n, S. hubbardi (Casey 1895), elytral variations, the white lines delinate a ~20º angle between the inner oblique markings. o, S. nubifer (LeConte, 1878), elytral variations, the white lines delinate a ~30–40º angle between the inner oblique markings. Scale bars: 1 mm.
FIGURE 3. ♂ genitalia of US Syzeton species in ventral view (left on all panels) and lateral view (right on all panels, ventral facing to the left). a, Syzeton ouachitanus (Werner, 1990) ♂ from Texas. b, S. fasciatus (Melsheimer 1846) ♂ from Wisconsin. c, S. hubbardi (Casey 1895) ♂ from Oklahoma. d, S. nubifer (LeConte, 1878) ♂ from Texas. e, S. ater (LeConte, 1875) ♂ from Texas. f, S. gruberi n. sp. ♂ paratype from Arizona. g, S. arizonae n. sp. ♂ holotype from Arizona. h, S. belovi n. sp. ♂ holotype from Texas. i, S. pallidus (Werner, 1990) ♂ from Texas. j, S. subfasciatus (LeConte, 1855) ♂ from Missouri. k, S. floridanus (Werner, 1990) ♂ from Florida. l, S. signatus (Haldeman, 1848) ♂ from South Carolina. Note the presence of air bubbles in some of the genitalia presented here. Scale bars: 0.1 mm.
FIGURE 5. External morphology of US Syzeton species. a–l, ♂ right foretibia in upper view. a, Syzeton ouachitanus (Werner, 1990) ♂ from Texas. b, S. fasciatus (Melsheimer 1846) ♂ from Wisconsin. c, S. hubbardi (Casey 1895) ♂ from Oklahoma. d, S. nubifer (LeConte, 1878) ♂ from Texas. e, S. ater (LeConte, 1875) ♂ from Texas. f, S. gruberi n. sp. ♂ paratype from Arizona. g, S. arizonae n. sp. ♂ holotype from Arizona. h, S. belovi n. sp. ♂ holotype from Texas. i, S. pallidus (Werner, 1990) ♂ from Texas. j, S. subfasciatus (LeConte, 1855) ♂ from Missouri. k, S. floridanus (Werner, 1990) ♂ from Florida. l, S. signatus (Haldeman, 1848) ♂ from South Carolina.Arrowheads indicate kinks or other modification of the inner side of the tibias; double black arrow denotes the curve of the tibia. m–n, ♀ antennae with details of antennomere 6–8 (inset). m, S. belovi n. sp. ♀ paratype from Texas. n, S. pallidus (Werner, 1990) ♀ from Texas. o, left hind-leg of S. fasciastus (from Wisconsin) in ventral view (arrow indicates the inflated femur). p–q, pubescence on elytral disc. p, S. belovi n. sp. ♂ holotype from Texas. q, S. arizonae n. sp. ♂ holotype from Arizona. Scale bars: 0.1 mm.
Upper Hillsborough Wildlife Management Area