Agathidium aristerium Wheeler, 1987

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 : 54-58

Agathidium aristerium Wheeler Figures 25, 26 , 74, 75 , 91

Agathidium aristerium Wheeler, 1987: 399 ; 1990 (description of larva).

TYPE MATERIAL: Holotype, Ƌ in CUIC (see Wheeler, 1987).

TYPE LOCALITY: United States, New York, Tompkins County, Smith Woods, Trumansburg.

DIAGNOSIS: This species is characterized by the dorsally red, shiny coloration without maculae or microreticulation, the anterior clypeal margin strongly excavate (fig. 26), the head narrowed immediately posterad of the compound eye without a posterior ocular rim (fig. 26), the male with a metasternal fovea located medially along the midline of the metasternum, the male mandibular horn, when present, formed by extension of the apex of the mandible in a long, dorsally curved, flattened structure (figs. 25, 26), and the median lobe in lateral aspect slender, evenly and shallowly curved (fig. 75) and in ventral aspect with apex expanded and broadly pointed (fig. 74). Females have 4­4­ 4 tarsi.

DESCRIPTION: Body moderately large (TBL = 2.33–2.68 mm), robust, broadly rounded (PNW/TBL = 0.44–0.46), moderately contractile.

Head dark red; pronotum and elytra red to dark red; venter red­yellow; basal antennomeres red­brown, club antennomeres red­yellow; palpi brown; legs red­yellow.

Head broad (fig. 26) (MDL/OHW = 0.61– 0.64), broadly convex, without transverse, medial crease; temporum short, inconspicuous (fig. 26); head finely and sparsely punctate, surface between punctures shiny; eyes large, rounded, finely faceted; frontoclypeal suture obsolete medially; clypeal margin strongly excavate (fig. 26); anterior margin of labrum slightly concave; antennomere ratios: length I:II:III = 1.4:1.0:1.1, width VII: VIII:IX = 1.1:1.0:2.6. Pronotum broad (PNL/PNW = 0.63–0.72), lateral margin rel­ atively short, not strongly produced, posterolateral angle more angulate than anterolateral angle; punctation similar to that of head. Elytra broad, robust (SEL/ELW = 1.06–1.21); punctation fine and sparse; sutural stria about one­half length of elytron on most specimens. Mesosternum strongly concave posteriorly, without prominent lobe extending ventrally between mesocoxae, anterior portion less than one­half length of posterior portion; medial longitudinal carina absent on anterior portion. Metasternum broad medially (MTL/MTW = 0.20–0.22), slightly convex, setose; oblique carinae absent.

Male tarsi 5­5­4; pro­ and mesobasotarsomeres moderately broad and with moderately large ventral field of spatulate setae; mandibular horn, when fully developed, formed by apex of mandible extending in broad, flat, sweeping curve dorsad and to the right over the right mandible (figs. 25, 26), finely setose but without prominent setose fovea, some specimens with mandible variously thickened, others without modification; metafemur moderately broad, unmodified; metasternal fovea small, round, medial, with small brush of fine, dense setae. Median lobe in lateral aspect slender, slightly curved basally, apical portion short, directed slightly dorsad, narrowly rounded (fig. 75); in ventral aspect slender, lateral margins subparallel, apical portion broad, apex abruptly, but evenly, narrowed to broadly pointed apex (fig. 74); operculum an inconspicuous, broad flat lobe (fig. 74); lateral lobes slender, curved basally, apically narrowly rounded with 2 long setae (figs. 74, 75).

Female tarsi 4­4­4.

DISTRIBUTION: This species is known from northeastern North America (fig. 91).

SPECIMENS EXAMINED: CANADA: Manitoba: Rennie Lily Pond Whiteshell Prov. Park, 6 Jun 1984, maple poplar forest, FIT, S and J Peck (2, CNCI) ; Rennie, Lily Pond Whiteshell Prov. Park, 6 Jun 1984, maple, poplar forest, FIT, S and J Peck (13, PECK). Ontario: Chaffeys Locks QUBS, 21 Sep 1980, malaise­FIT, S Peck (1, CUIC) ; Markham , 24 May 1980, deciduous forest, RS Anderson (1, CNCI) ; 25 km W Ignace, 75 km E Dryden , 5 Jun 1984, fir­maple forest, FIT, S and J Peck (1, CNCI) ; Hackston , 20 km SE Kemptville, 24 Jun 1984, FIT, M Kaulbars (5, PECK) ; Shirleys Bay 15 km W Ottawa, 15 May 1984, M Kaulbars (3, PECK) ; Ottawa, Stittsville, 10 Jul 1977, M Sanbourne (1, CNCI). Quebec: Hull , Gatineau Park nr Pinks Lake , 8 Aug 1979, S Peck, A Davies (1, PECK) ; Hull, Gatineau Park nr Pinks Lake , 13 Apr 1980, malaise (2, CUIC) .

UNITED STATES: Illinois: Union Co.: Pine Hills Field Station, 15 May 1967, rotten log, Berlese, JM Campbell (3, CNCI). Michigan: Kalamazoo Co.: Hickory Corners, Gull Lake, 11 Jun 1981, FIT, RS Anderson (10, CNCI); Hickory Corners, Gull Lake, 11 Jun 1981, FIT, R Anderson (3, CNCI). New Hampshire: Carroll Co.: The Bowl, 2.5 mi NW Wonalancet, 5 Jun 1985, FIT, DS Chandler (5, CNCI); Coos Co.: Norton Pool, 3 mi NE East Inlet Dam, 25 Jul 1986, FIT, DS Chandler (3, CNCI). New York: Tompkins Co.: Trumansburg, Smith Woods, 6 Aug 1986, on Physarum polycephalum plasmodium on Pleurotus fruiting body, QD Wheeler (20, MCZC). Ohio: Fairfield Co.: 13 Sep, DJ and JL Knull (22, OSUC).

DISCUSSION: Agathidium aristerium has been collected from May to September. Specimens have been found in deciduous and fir forests. A single host record is from a Physarum polycephalum plasmodium on Pleurotus fruiting body (see Wheeler, 1987). All instars of the larva were described by Wheeler (1990).

Agathidium atronitens Fall

Figures 27, 28 , 76, 77 , 92 Agathidium atronitens Fall, 1934b: 122 .

TYPE MATERIAL: Holotype, ♀ in MCZC labeled ‘‘ Urbana ILL 4/20/25/ ♀ / TYPE atronitens [name handwritten, red line under ‘‘TYPE’’]/ M.C.Z. Type 24029 [number handwritten, red label]/H.C. FALL COL­ LECTION’’.

TYPE LOCALITY: United States, Illinois, Urbana.

DIAGNOSIS: This species is distinguished from others in the group by the concolorous, dark red dorsal surfaces which lack microreticulation, the head narrowed immediately behind eye and without postocular rim (figs. 27, 28), anterior clypeal margin strongly excavated (fig. 28), the male metasternal fovea located medially along the midline of the metasternum, the male mandibular horn straight, extending from middle of mandible in oblique angle to right over the right mandible (figs. 27, 28), and the median lobe in lateral aspect robust, with large basal portion and submedial constriction and with small apical spine (fig. 77). Females have 4­4­4 tarsi.

DESCRIPTION: Body moderately large (TBL = 3.15–3.21 mm), robust (PNW/TBL = 0.48–0.50), broadly rounded, moderately contractile.

Head dark red; pronotum and elytra red to dark red; venter red to red­yellow; basal antennomeres red­brown, club antennomeres brown; palpi red; legs red to red­yellow.

Head broad (fig. 28) (MDL/OHW = 0.51– 0.60), flattened, often with prominent transverse, medial crease; temporum very short, without rim at posterior margin of eye (fig. 28); head finely punctate, with microsculpture of fine cells on surfaces between punctures; eyes large, rounded, finely faceted; frontoclypeal suture moderately well defined medially; clypeal margin strongly excavate (fig. 28); anterior margin of labrum entire; antennomere ratios: length I:II:III = 1.6:1.0: 1.0, width VII:VIII:IX = 1.0:1.0:1.6. Pronotum broad (PNL/PNW = 0.55–0.61), laterally not strongly produced, anterolateral angle subquadrate, posterolateral angle distinctive, but rounded; punctation and surface microsculpture similar to those of head. Elytra robust (SEL/ELW = 1.00); nearly impunctate to finely and sparsely punctate, surface between punctures shiny and smooth; sutural stria about one­half length of elytron on most specimens. Mesosternum strongly concave posteriorly, without prominent lobe extending ventrally between mesocoxae, anterior portion less than one­half length of posterior portion; medial longitudinal carina absent on anterior portion. Metasternum relatively short medially (MTL/MTW = 0.21– 0.24), slightly convex, setose; oblique carinae absent.

Male tarsi 5­5­4; pro­ and mesobasotarsomeres slightly expanded and with small ventral field of spatulate setae; mandibular horn highly variable in length, straight, extending from middle of mandible in oblique angle to right over right mandible (figs. 27, 28), setose, apically pointed, with small, indistinct setose fovea near pointed apex; metafemur moderately broad, unmodified; metasternal fovea medial, transversely slightly ovoid, with large brush of fine, dense setae. Median lobe in lateral aspect robust, basal portion extremely large and robust, with dis­ tinct submedial constriction, straight and short distad of constriction, apical portion short, stout, directed slightly dorsad, apically narrowly rounded (fig. 77); in ventral aspect robust, lateral margins subparallel, apical portion broad, apex broadly pointed (fig. 76); operculum broad, flat, apically narrowly emarginate, hyaline and indistinct (fig. 76); lateral lobes slender, curved basally, apically narrowly round with 2 long, stout setae (figs. 76, 77).

Female tarsi 4­4­4.

DISTRIBUTION: This species is found in eastern North America from Saskatchewan and New Hampshire south through Oklahoma to Louisiana and Alabama and east to Washington, DC (fig. 92).

SPECIMENS EXAMINED: CANADA: Ontario: Sudbury , Laurentian Univ., 26 May 1982, FIT, R DeClerck (1, CNCI) ; Alfred Bog, Alfred , 13 Aug 1984, M Sanborne (1, CNCI). Saskatchewan: Prince Albert NP 16 km W Christopher, 9 Jun 1984, fir­aspen forest, FIT, S and J Peck (2, CNCI) .

UNITED STATES: Alabama: Monroe Co.: Big Flat Creek 31°36̍30̎N, 87°24̍53̎W, 27 May 1995, upland decid, Berlese , CE Carlton (1, LSAM). District of Columbia: paratype (1, MCZC). Kentucky: 5 mi W Hopkinsville, 22 Sep 1967, deciduous duff, Berlese, JM Campbell (2, CNCI). Louisiana: W Feliciana Co. : 6 mi ESE St Francisville, 17 May 1995, forest litter, D Colby, D Landau (1, LSAM) ; Cabin Area 30°47̍N, 91°15̍W, 1 Dec 2000, fallen logs, FIT, AR Cline (5, LSAM) ; Tunica WMA 30°55̍N, 91°30̍W, 28 Nov 1998, FIT, C Carlton, J Johnson, A Tischechkin (3, LSAM). New Hampshire: Grafton Co.: Hubbard Brook Exp. Sta. , Bear Brook , 6 Jul 1983, rotten wood, DS Chandler (5, DENH) ; Straf. Co.: 1 mi SW Durham, 27 Jun 1987, FIT, DS Chandler (1, CNCI). New York: Westchester Co.: Calder Ecology Center , Armonk , 24 Apr 1979, Berlese, K Schmidt (16, AMNH) ; Calder Ecology Center, Armonk , 24 Apr 1979, Berlese, K Schmidt (4, AMNH). Ohio: Franklin Co.: Columbus , 13 Sep 1975, QD Wheeler (4, QDWC) ; Columbus , 13 Sep 1975, QD Wheeler (2, QDWC). Oklahoma: Latimer Co.: 5 mi W Red Oak, Dec 1980, K Stephan (2, QDWC) ; K Stephan (2, QDWC). Pennsylvania: Lebanon Co.: 1 mi E Indian Town Gap, 13 Jul 1969, Berlese, W Michmore (1, CNCI). Tennessee: Sevier Co. : Appalachian Trail at Beech Gap on Clingmans Dome Rd 83°26̍50̎W, 35°36̍36̎N, 28 Jun 2001, 1750̍, forest litter, Berlese , C Carlton, A Tsichechkin, V Mosely (5, LSAM). Virginia: Alexandria , 4 Apr 1971, on Polyporus versicolor, J Powell (8, EMEC) .

DISCUSSION: This species has been collect­ ed from deciduous and fir forests. A single altitude record is from 1750 ft (Tennessee). A single host record is from Polyporus versicolor .

Figures

Figs. 17–30. Agathidium concinnum­ and A. pulchrum­group species, male heads showing left mandibular horn: 17, 18, A. mollinum: 17, left lateral; 18, dorsal. 19, 20, A. angulare: 19, left lateral; 20, dorsal. 21, 22, A. pulchrum: 21, left lateral; 22, dorsal. 23, 24, A. marae: 23, left lateral; 24, dorsal. 25, 26, A. aristerium: 25, left lateral; 26, dorsal. 27, 28, A. atronitens: 27, left lateral; 28, dorsal. 29, 30, A. picipes: 29, left lateral; 30, dorsal. Bars = 0.5 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. 91. Geographic distribution of Agathidium pulchrum­group species: A. aristerium = ^; A. marae = *; A. rotundulum = •.

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