Agathidium bistriatum Horn, 1880

WHEELER, QUENTIN D. & MILLER, KELLY B., 2005, Slime-Mold Beetles Of The Genus Agathidium Panzer In North And Central America, Part I. Coleoptera: Leiodidae, Bulletin of the American Museum of Natural History 2005 (290), pp. 1-95 : 41-48

Agathidium bistriatum Horn Figures 53–62

Agathidium bistriatum Horn, 1880: 304 ; Leng, 1920; Fall, 1934; Hlisnikovsky´, 1964.

TYPE MATERIAL: Lectotype (designated here to clarify association of this name with the species), Ƌ in MCZC (G.H. Horn Collection) labeled ‘‘Nev [with red line on left edge of ‘N’]/ LectoTYPE 3021 [red label]/ A. bistriatum Horn / LECTOTYPE, Agathidium bistriatum Horn , des. Q.D. Wheeler & K.B. Miller, 2001 [red label with black line border]’’.

TYPE LOCALITY: United States, western Nevada.

DIAGNOSIS: This species can be distinguished from other members of the group by the presence of only 2–3 evident series of punctures medially on elytron, punctures more confused laterally, punctures moderately large and dense (fig. 56); head and elytron dark reddish­brown, pronotum more pale red; and aedeagus with median lobe attenuated apically (fig. 61).

DESCRIPTION: Body broadly round, globose, noncontractile (figs. 58, 59); TBL = 3.2 mm. Clypeal region, pronotum, and appendages pale reddish; head, elytra dark reddish­brown.

Head narrow (fig. 58); OHW/MDL = 1.4; dorsal surface with moderately dense punctures (about 10 per 0.01 mm 2) (fig. 54); postocular temporum short, head narrowed behind eyes; frontoclypeal suture present, fine; clypeus with sparse punctures, half as dense as on head (ca. 5 per 0.01 mm 2); antenna short with 3­segmented club; length ratio of antennomere II:III = 1:1.4; width ratio of antennomeres VII:VIII:IX = 0.8:1:1.3; labrum similar in form to that of A. sexstriatum . Pronotum short, not convex; PNW/PNL = 2.1; PNL/PNH = 1.3; PNW/PNH = 2.9; dorsal surface with irregularly distributed, sparse and very poorly defined punctures, generally smaller than those of head and much less distinct (fig. 55). Elytra convex, wider than long; ELW/SEL = 1.2, SEL/ELH = 1.3, ELW/ELH = 1.5; dorsal surface with about 2 or 3 poorly defined series of punctures near midline, punctation becoming increasingly confused laterally; punctures larg­ er than those of head, surface between punctures with minute, almost imperceptible punctules; punctures moderately dense and large (ca. 4 punctures per 0.01 mm 2, puncture ca. 0.04 mm diameter) (fig. 56). Mesosternum subhorizontal anteriorly; narrow anteri­ or area set off; carinate posteriorly only; vertical between mesocoxae; surface alutaceous; about half length of metasternum. Metasternum with impunctate areas both in front of and behind center, punctures through middle and laterally, and alutaceous pattern laterally. MTL/MTW = 0.2.

Male tarsi 5–5–4; pro­ and mesobasotarsomeres slightly expanded; metasternal fo­

56, elytron. 57. Male metasternal fovea. Figs. 58, 59 , habitus: 58, dorsal; 59, lateral. Bars = 0.5 mm.

veae paired, large, circular, with pencil of fine golden setae (fig. 57), MFD = 0.06 mm; metafemur not modified; left mandible not modified. Aedeagus elongate, narrow; medi­ an lobe attenuated apically (fig. 61); apex recurved (figs. 60, 61); operculum platelike, divided (fig. 61); lateral lobes with two subapical setae nearly equal in length (figs. 60, 61).

Female tarsi 4–4–4. Spermatheca bulb small; neck very long, strongly curved and attenuated to fine point apically (fig. 62).

DISTRIBUTION: Specimens were examined from California and Nevada (fig. 53).

SPECIMENS EXAMINED: UNITED STATES: California: Lassen Co.: 4 Jun 1913, paralectotypes (2, MCZC). Nevada: paralectotypes (11, MCZC).

DISCUSSION: This species has been relatively rarely collected, and we did not examine any recently collected specimens. Thus, its status is unknown and nothing is known of its biology.

Agathidium sexstriatum Horn

Figures 52 , 53 , 63–71

Agathidium sexstriatum Horn, 1880: 303 ; Leng, 1920; Fall, 1934; Hlisnikovsky´, 1964.

TYPE MATERIAL: Lectotype (designated here to clarify association of this name to the species), Ƌ in MCZC (G. H. Horn Collection) labeled ‘‘Nev [with red line on left edge of N]/ Lectotype 3025 [red label]/ A. sexstriatum Horn / LECTOTYPE, Agathidium sexstriatum Horn , des. Q. D. Wheeler & K.B. Miller, 2001 [red label with black line bor­ der]’’.

TYPE LOCALITY: United States, western Nevada.

DIAGNOSIS: This species can be distinguished from A. sextriatum group members by the body being elongate oval (figs. 52, 67) and dorsoventrally compressed (fig. 68) relative to body form of other known species of the group, the head and pronotum generally distinctly red in color, contrasted with black elytra, the elytra with more than 6 distinct rows of serial punctures, coarse and deeply impressed, and the aedeagus with median lobe broadly truncate (fig. 70).

DESCRIPTION: Body elongate oval, not contractile, only little convex (fig. 68); TBL = 2.3–2.5 mm. Color of head, prothorax, and appendages pale red; of elytra dark reddishbrown; head sometimes darker than pronotum.

Head narrow, more strongly narrowed behind eyes (fig. 67); OHW/MDL = 1.3; dorsal surface with moderately dense (ca. 10 per 0.01 mm 2), small, irregularly distributed punctules (fig. 63); postocular temporum short; frontoclypeal suture nearly absent; surface of clypeal region paler in color than rest of dorsum and nearly impunctate; antenna short, not reaching posterior margin of pronotum; length ratio of antennomeres II:III = 1:1.5; width ratio of antennomeres VII:VIII: IX = 0.7:1:1.4; labrum narrowed apically (length/width at base = 0.55; at apex = 0.9); apex shallowly emarginate medially; with fine pubescence. Pronotum short and wide, not strongly convex; PNW/PNL = 2.0; PNL/ PNH = 1.2; PNW/PNH = 2.26; dorsal surface similar to head with dense, small punctures (ca. 10 punctures per 0.01 mm 2) (fig. 64); surface shiny. Elytra broad, about as wide as long; ELW/SEL = 1.0; dorsal surface with about six serial rows of punctures set in shallow longitudinal impressions; intervals with dense punctures nearly equal to those of series; series obscure laterally, punctation confused (about 6 punctures per 0.01 mm 2), punctures larger than those of pronotum and head (fig. 65). Mesosternum vertical between mesocoxae; almost indistinct, weak carina medially; length about 0.2 mm; surface minutely alutaceous; with narrow anterior area set off by suture. Metasternum surface smooth, shiny, with dense, irregularly distributed punctures; MTL/MTW = 0.4.

Male tarsi 5–5–4; pro­ and mesobasotarsomeres moderately expanded; metasternal foveae comprised of paired shallow depressions with dense pencils of setae (fig. 66); MFD = max. about 0.07 mm; metafemur unmodified; left mandible unmodified. Aedeagus with median lobe broad, slightly recurved distally in lateral view (fig. 69); broadly truncate (fig. 70); apical pores fanning out from wide central area (fig. 70); operculum divided, each part narrow, truncate (fig. 70); lateral lobes shorter than median lobe, terminating just beyond operculum (figs. 69, 70).

Female tarsi 4–4–4. Spermatheca bulb narrow and neck subapically widened (fig. 71).

DISTRIBUTION: Specimens were examined from Nevada, several sites in California, and southwestern British Columbia (fig. 53).

SPECIMENS EXAMINED: CANADA: British Columbia: Squamish, 25 Jul 1980, FIT, SA Marshall, RS Anderson (1, CNCI).

UNITED STATES: California: state only (5, MCZC) ; Yosemite Valley , 26 May 1928, FE Blaisdell (1, CASC) ; Yosemite Valley , 8 Jun 1930 (4, CASC) ; Marin Co.: SP Taylor State Park entrance, 9 Mar 1963 (2, EMEC) ; Tehama Co.: 2 mi SW Lassen Lodge, Paynes Ck , 6 Dec 1986, 3700′, Douglas fir leaf litter, DS Chandler (3, CASC) ; 6 mi W Log Springs Mendocino Natl Forest , 29 Nov 1986, 5200′, oak leaf litter, DS Chandler (1, CASC). Nevada: state only, paralectotypes (3, MCZC) .

DISCUSSION: This species has been collect­ ed from oak and Douglas fir forest litter. Elevation records are from 3700 to 5200 ft.

Agathidium estriatum Horn

Figures 53 , 72–79

Agathidium estriatum Horn, 1880: 304 ; Leng, 1920; Fall, 1934; Hlisnikovsky´, 1964.

TYPE MATERIAL: Holotype, Ƌ in MCZC (G. H. Horn Collection) labeled ‘‘Garland Col 30.6 [‘30.6’ handwritten]/ HoloTYPE 3023 [red label, ‘3023’ handwritten]/ A. estriatum [handwritten]/ HOLOTYPE, Agathidium sexstriatum Horn, 1880 [red label with black line border]’’. Because only a single specimen was available to Horn (1880), it is a holotype by monotypy.

TYPE LOCALITY: United States, Colorado, Garland (probably Fort Garland, Costilla Co.).

DIAGNOSIS: This species is distinguishable by the elytron with confused punctures, only inconspicuously arranged into series, the confused elytral punctation consists of two kinds of punctures, small, dense punctures and minute punctules on integument between (fig. 74), the elytral integument with weak alutaceous pattern, the male metasternum with single, small, round anteromedian fovea (fig. 75), and the aedeagus elongate, median lobe gradually narrowed apically in ventral view (fig. 79).

DESCRIPTION: Body broadly rounded, convex, not contractile (figs. 76, 77); TBL = 2.2 mm. Color dark reddish­brown, pronotum, clypeus, labrum, and appendages, except antennal club, paler reddish.

Head narrow, narrowed behind (fig. 76); dorsal surface with moderately dense punctures (ca. 20 per 0.01 mm 2); punctures larger than those of pronotum, smaller than those of elytra; with minute secondary punctules irregularly distributed between punctures (fig. 72); punctures smaller and less dense on clypeus; postocular temporum indistinct; frontoclypeal suture distinct; length ratio of antennomere II:III = 1.3:1; width ratio of an­ tennomeres VII:VIII:IX = 0.9:1:1.1; labrum separated by broad membrane; subquadrate, apically emarginate; with very sparse, fine pubescence; punctures smaller and less dense on clypeus. Pronotum short, wide, and not very convex (PNW/PNH = 2.2; PNL/PNH = 1.6); dorsal surface with moderately dense punctures, with minute secondary punctules (fig. 73). Elytra very broad and convex; ELW/SEL = 1.0, SEL/ELH = 2.0, ELW/ ELH = 1.9; dorsal surface with dense irregular punctures larger than those of head; areas between punctures with minute irregularly distributed punctules; punctures dense (ca. 9 per 1 mm 2) (fig. 74). Mesosternum flat, nearly vertical between mesocoxae; weak, indistinct carina medially; anterior part set off by distinct suture; surface densely and minutely alutaceous. Metasternum large, MTL/MTW = 0.8; punctures indistinct to absent anteriorly, moderately dense posteriorly and laterally; impunctate anteromedial region with dense, poorly defined alutaceous pattern.

Male tarsi 5–5–4; pro­ and mesobasotarsomeres moderately expanded; metasternal fovea small, single, round, anteromedial in position, with short tuft of setae (fig. 75); MFD = 0.03 mm; metafemur not modified; left mandible not modified. Aedeagus elongate and subparallel­sided (figs. 79); median lobe narrowed apically, with slight subapical constriction (fig. 79); operculum consisting of two small plates (fig. 79); lateral lobes short, with unequal pair of subapical setae (figs. 78, 79).

Female tarsi 4–4–4.

DISTRIBUTION: This is the most broadly distributed member of the group. Specimens were examined from British Columbia, Saskatchewan, Arizona, California, Colorado, Montana, New Mexico, Oregon, and Washington (fig. 53).

SPECIMENS EXAMINED: CANADA: British Columbia: 2 mi E Squamish (1, CNCI) ; Midday Valley, Merritt , 18 May 1925, J Stanley (1, CASC) ; Manning Pk E Gate , 2 Jun 1984, lodgepole pine forest, FIT, D Miller (1, CNCI) ; Vancouver, B Stephens (1, CASC). Saskatchewan: Cedar Hills Prov. Park (1, CNCI) .

UNITED STATES: Arizona: Barfoot Park, Chiricahuas, 18 Jul 1963, PSB (1, CASC); Barfoot Park, Chiracahuas, 18 Jul 1963, PSB (4, CASC); Barfoot Park, Chiricahuas, 18 Jul 1963, PSB (1, CASC); Cochise Co.: Rustler Park, 7 Sep 1976, FG Andrews (9, FGAC); Graham Co.: Hospital Flat Pinaleno Mts, 2 Aug 1965, 8950′, on Daldinia ­like fungus, HB Leech (6, CASC). California: Amador Co.: 1 mi W Pine Grove, 24 Jun 1975, leaf litter mixed hardwood conifer forest, A Newton, M Thayer (1, MCZC); Calaveras Co.: 2.7 mi N Camp Connell, 4 May 1976, litter, berlese, SC Kuba (1, FGAC); Eldor Co.: 2 mi E Lake Edson Dam, 12 Jul 1971, Ponderosa pine duff, DS Chandler (1, CASC); Lassen Co.: Norval Flats, 13 May 1920, 5500′, JO Martin (2, CASC); Mono Co.: White Mts S Fk Cottonwood Crk, 18 Jun 1987, 9200′, pitfall, D Giuliani (1, FGAC); Shasta Co.: Buckhorn Summit, 15 Feb 1983, oak duff, TR Haig (1, FGAC); Trinity Co.: Junction City, 12 Mar 1981, TR Haig (2, FGAC); Douglas City, 23 Jan 1980, oak duff, berlese, TR Haig (1, FGAC); Douglas City, 6 Mar 1975, TR Haig (1, FGAC); Tulare Co.: Sequoia Natl Park, Mineral King, 25 May 1984, 7700′, R Baranwoski (4, LUND); Kaweah, 10 Apr 1907 (1, CASC); Sequoia Natl Park, Halstead Crk, 23 May 1984,

74, elytron. 75. Male metasternal fovea. Figs. 76, 77 , habitus: 76, dorsal; 77, lateral. Bars = 0.5 mm.

7000′, R Baranwoski (1, LUND); Tuolene Co.: 5 mi W Dardanelle, 18 Aug 1953, white fir and cedar, GA Marsh (1, CASC). Colorado: Garland, 30 Jun, Hubbard and Schwarz (3, USNM); Garland, 30 Jun (5, MCZC); Ouray, 1 Jul 1897, 8000′, HF Wickham (2, USNM); Ouray, 1 Jul 1897, 8000′ (1, MCZC). Montana: Madison Co., Hidden Lake Ranch (1, USNM). New Mexico: Torrance Co.: 6 mi SW Manzano, Red Can. Camp, 17 Jun 1979, 9000′, spruce­fir litter, S and J Peck (3, PECK). Oregon: Lake Co.: Quarts Mt, 14 Jun 1984, 1600 m, R Danielsson (1, LUND); Wasco Co.: Wapinitia Pass, 11 Jul 1975, 4000′, on Fuligo septica , A Newton, M Thayer (1, MCZC). Washington: Pierce Co.: Mt Rainier Natl Park, 4.7 mi W Longmire, 20 Jul 1975, 2200′, on Fuligo septica , A Newton, M Thayer (3, MCZC); Skaminia Co.: Gifford Pinchot Natl Forest, 20 Jul 1984, old growth, D Thomas (1, PECK); Yakima Co.: 8 mi SW Tieton RS Snoqualmie NF Bear Crk, 11 Jun 1973, WJ Turner (1, WSUC).

DISCUSSION: Depending upon variation among individuals and the angle of light un­ der which specimens are examined, evidence of serial punctation is variable. Whereas series are not as prominent as in A. sexstriatum and A. bistriatum , given proper illumination six or more serial rows of punctures can generally be seen among the dense and slightly smaller punctures present between them. Some specimens, possibly teneral ones, have the head and especially pronotum reddish in contrast to distinctly darker reddish elytra. In some of these bicolored specimens (e.g., Ouray, Colorado; Norval Flats, California) the apex of the median lobe is more gradually narrowed than in most other specimens and the ventral operculum is slightly more elongate. In the most extreme cases, specimens from Cochise Co., Arizona, have the pronotum rather brightly orange­red in sharp contrast to the dark head and elytra. Another specimen, from Douglas City, Trinity Co., California, is similar, but with reddish clypeus and labrum also. The latter material is so brilliantly bicolored as to be confused with A. sexstriatum initially. The dense elytral punctation, smaller serial punctures, and less parallel­sided elytra distinguish such specimens from A. sexstriatum . Unfortunately, all these specimens are females so that their conspecificity with other A. estriatum rests on these external features alone. Considering this structural variation, the broad geographic distribution of the species, and the paucity of existing specimens, infraspecific variation and the possibility of more than one species here should be reconsidered when sufficient numbers of specimens have accumulated. Other specimens, however, are more uniformly darkly colored, aside from pale markings of the pronotum.

A series of specimens from Arizona (Hospital Flat) are labeled as having been collected from a ‘‘daldinia­like fungus’’, which could easily describe Lycoperdales slimemolds. The species has also been reported from the myxomycete, Fuligo septica ( Lawrence and Newton, 1980) . Specimens have been collected from a variety of forest litter types, including ponderosa pine, white fir, cedar, spruce, lodgepole pine, and others. Elevation records are from 2200 to 9200 ft.

AGATHIDIUM BREVISTERNUM SPECIES

Figures

Fig. 53. Agathidium sexstriatum species group geographic distribution: A. bistriatum = ^ (Δ = state record only); A. estriatum = - A. sexstriatum = · (Z = state record only).

Figs. 54–59. Agathidium bistriatum Horn: Figs. 54–56, punctation detail: 54, head; 55, pronotum;

Figs. 60–62. Agathidium bistriatum Horn, genitalia: Figs. 60, 61, aedeagus: 60, lateral; 61, ventral. 62. Spermatheca.

Fig. 52. Agathidium sexstriatum Horn, habitus, dorsal (note: differences in angle of observation result in differences in shape and proportion of structures in this image and that in fig. 67).

Figs. 63–68. Agathidium sexstriatum Horn: Figs. 63–65, punctation detail: 63, head; 64, pronotum; 65, elytron. Fig. 66, male metasternal fovea. Figs. 67, 68, body form: 67, dorsal; 68, lateral. bars = 0.5 mm.

Figs. 69–71. Agathidium sexstriatum Horn: Figs. 69, 70, aedeagus: 69, lateral; 70, ventral. 71. Spermatheca.

Figs. 72–77. Agathidium estriatum Horn: Figs. 72–74, punctation detail: 72, head; 73, pronotum;

Figs. 78, 79. Agathidium estriatum Horn, aedeagus: 78, lateral; 79, ventral.