Agathidium oregonense Miller and Wheeler, 2005

MILLER, KELLY B. & WHEELER, QUENTIN D., 2005, Slime-Mold Beetles Of The Genus Agathidium Panzer In North And Central America, Part Ii. Coleoptera: Leiodidae, Bulletin of the American Museum of Natural History 2005 (291), pp. 1-167 : 58-59

Agathidium oregonense Miller and Wheeler , new species Figures 13 , 78, 79 , 92

TYPE MATERIAL: Holotype, Ƌ in CMNC labeled ‘‘ORE: Clackamas Co. 8500̍,10 miN, 10 mi E Govt. Camp, Mt. Hood rd. 5– 31, 30.viii.72 [handwritten]/ E. Benedict EB­ 789 hemlock litter [handwritten]/ HOLO­ TYPE Agathidium oregonense Miller and Wheeler, 2003 [red label with black line bor­ der]’’. Only a single specimen of this species was examined.

TYPE LOCALITY: United States, Oregon, Clakamas County, 10 mi north, 10 mi east of Government Camp, Mt Hood Road.

DIAGNOSIS: This species differs from other members of the group by the concolorous elytra, the lack of microreticulation on the dorsal surfaces, the moderately excavated anterior clypeal margin (fig. 13), the head narrowed immediately posterad of eyes and without a prominent postocular rim (fig. 13), the male metasternal fovea located distinctly anterad of the middle of the metasternum, and the male lateral lobe apically abruptly expanded and obliquely truncate (fig. 79). The median lobe of the aedeagus in lateral aspect is robust with the apex slender, straight, and sharply pointed (fig. 79). The single male specimen examined lacks a mandibular horn.

DESCRIPTION: Body moderately large (TBL = 2.39 mm), rotund (PNW/TBL = 0.46), laterally broadly rounded, strongly contractile.

Head yellow­red with indistinct paler medial macula; pronotum and elytra yellow­red; sterna red­yellow; antennae, palpi, and legs yellow­red; legs yellow­red.

Head moderately broad (fig. 13) (MDL/ OHW = 0.67), dorsally flat, without transverse, medial crease; temporum short, forming rim at posterior margin of eye (fig. 13); head finely and moderately coarsely punctate, surfaces shiny and smooth between punctures; eyes large, rounded, finely facet­ ed; frontoclypeal suture obsolete medially; clypeal margin moderately excavate (fig. 13); labrum anteromedially entire; antennomere ratios: length I:II:III = 2.2:1.0:1.8, width VII:VIII:IX = 1.0:1.0:1.4. Pronotum broad (PNL/PNW = 0.58), laterally not strongly produced, lateral margins moderately broad, anterolateral angle subquadrate, posterolateral angle distinctive, but more rounded than anterolateral angle; punctation similar to that of head, more sparse. Elytra moderately elongate, lateral margins broadly rounded (SEL/ELW = 1.09); punctation somewhat coarser than pronotum, surface between punctures shiny and smooth, some punctures in vague series; sutural stria about one­half length of elytron. Mesosternum strongly concave posteriorly, with prominent lobe extending ventrally between mesocoxae, anterior portion much less than one­half length of posterior portion; medial longitudinal carina obsolete on anterior portion. Metasternum broad medially (MTL/MTW = 0.32), slightly convex, setose; oblique carinae absent.

Male tarsi 5­5­4; pro­ and mesobasotarsomeres moderately broad and with large ventral field of spatulate setae; mandibular horn absent in single specimen examined; metafemur slender, unmodified; metasternal fovea anterior, minute, with small pencil of fine, dense setae. Median lobe in lateral aspect with relatively robust basal portion and submedial constriction, curved, robust distal to constriction, apical portion directed somewhat dorsad, straight, tapered to long, slender point (fig. 79); in ventral aspect moderately broad, lateral margins subparallel, with moderately distinct constriction near base of apical portion which is broadly triangular, apex pointed, orifice large (fig. 78); operculum a broad, rounded, flat lobe (fig. 78); lateral lobes moderately long, slender to apex which is broadly expanded and obliquely truncate, spatulate, with two long, stout setae (figs. 78, 79).

Female unknown.

ETYMOLOGY: This species is named for the state in which the type specimen was collected.

DISTRIBUTION: This species is known only from the type locality in Oregon (fig. 92).

DISCUSSION: The holotype specimen was collected from hemlock litter at 6500 ft elevation.

Figures

Figs. 3–16. Agathidium concinnum­ and A. pulchrum­group species. 3–15. Heads, dorsal aspect: 3, A. akallebregma. 4, A. hatchi. 5, A. concinnum. 6, A. laetum. 7, A. athabascanum. 8, A. columbianum. 9, A. rusticum. 10, A. repentinum. 11, A. rotundulum. 12, A. atronitens. 13, A. oregonense. 14, A. hamulum. 15, A. politum. 16, A. rusticum, left antenna, dorsal aspect. Bars = 0.5 mm, except fig. 16 bar = 0.25 mm.

Figs. 70–85. Agathidium pulchrum­group species, aedeagus: 70, 71, A. marae: 70, ventral; 71, lateral. 72, 73, A. rotundulum: 72, ventral; 73, lateral. 74, 75, A. aristerium: 74, ventral; 75, lateral. 76, 77, A. atronitens: 76, ventral; 77, lateral. 78, 79, A. oregonense: 78, ventral; 79, lateral. 80, 81, A. picipes: 80, ventral; 81, lateral. 82, 83, A. hamulum: 82, ventral; 83, lateral. 84, 85, A. politum: 84, ventral; 85, lateral.

Fig. 92. Geographic distribution of Agathidium pulchrum­group species: A. atronitens = •; A. oregonense = -; A. politum = *.