Pleocoma, Le Conte, 1856

Marshall, Christopher J., 2018, Two new species of rain beetle (Coleoptera: Pleocomidae: Pleocoma Le Conte, 1856) in the Pacific Northwest of the United State of America, Zootaxa 4471 (2), pp. 387-395 : 395

Key to male rain beetles, Pleocoma , of Oregon and Washington

The author hopes the following key will assist others in identifying rain beetles in the Pacific Northwest. If the key below is used to identify specimens involved in published research (print or online), please cite this work and include the full citation in the list of references.

1. Antenna with 7 lamellae................................................................................ 2

- Antenna with 4 or 5 lamellae............................................................................ 7

2. Medial longitudinal groove of pronotum with dense setation.................................................... 3

- Medial longitudinal groove of pronotum lacking setae, or with only a few scattered setae............................. 6

3. Pronotum entirely setose;(from Hood River , Oregon and vicinity)...................... P. callisto Marshall , new species

- Lateral areas of pronotum lacking or with only a few elongate setae.............................................. 4

4. Entire length of median longitudinal groove of pronotum setose; pronotum and elytra monochromatic, rufus-brown, not dark brown; body length 25–28 mm (from south central Washington, west of Klickitat river )............ P. crinita Linsley, 1938

- Median longitudinal groove of pronotum lacking setae anteriorly or posteriorly; pronotum and elytra either monochromatic dark brown or bicolored, with dark elytra and lighter pronotum................................................. 5

5. Median longitudinal groove of pronotum lacking setae anteriorly; pronotum and elytra monochromatic dark brown (vicinity of Goldendale, Washington; east of Klicktitat River).................................... P. laker Marshall , new species

- Median longitudinal groove of pronotum lacking setae posteriorly; body dark brown, some individuals with slightly lighter colored pronotum; body length 23–25 mm (from Hood River , Oregon and vicinity)................ P. minor Linsley, 1938

6. Pronotum and elytra monochromatic dark-brown, some individuals nearly black (from Oregon Willamette Valley region; Linn and Marion Counties)..................................................... P. dubitabilis dubitabilis Davis, 1935

- Pronotum and elytra distinctly bicolored, pronotum dark brown with caramel colored elytra (from Oregon: Willamette Valley)......................................................................... P. dubitabilis leachi Linsley, 1938

7. Elytra dark brown, nearly black........................................................ P. carinata Davis, 1935

- Elytra rufus to light brown.............................................................................. 8

8. Dorsal surface strongly and distinctly bicolored, with dark pronotum and light brown elytra, pronotum lacking setae, most individuals with 5 antennal lamellae (from Oregon, Wasco, Sherman, and Jefferson counties).... P. oregonensis Leach, 1933

- Dorsal surface monochromatic, not distinctly bicolored, pronotum often with setae in posteromedial region, most individuals with 4 antennal lamellae (Oregon: Lane, Douglas, Coos, Josephine, and Jackson counties)............. P. simi Davis, 1935