Agathidium skoliosternum 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 : 96-99

Agathidium skoliosternum Miller and Wheeler , new species Figures 114 , 125 , 196–198 , 360

TYPE MATERIAL: Holotype, Ƌ in CMNC labeled ‘‘ MEX:Ver ; 7 km E Huatusco 22. VI.83,1040 m Anderson & Peck cloud forest litter/ HOLOTYPE Agathidium skoliosternum Miller and Wheeler, 2003 [red label with black line border]’’ .

TYPE LOCALITY: Mexico, Veracruz, 7 km E Huatusco, 1040 m.

DIAGNOSIS: This species is immediately distinguishable from all A. oniscoides group species by the modified anterior margin of the mesosternum which is deeply excavated on each side of the midline, making the anterior margin strongly sinuate (fig. 114). This occurs in both males and females, although in females the excavations are not as deep. In other respects this species strongly resembles A. aztec .

DESCRIPTION: Body moderately large (TBL = 2.93–3.22 mm), broad, robust (PNW/TBL = 0.48–0.49), strongly contractile.

Head and pronotum testaceous; elytra testaceous, not iridescent; venter yellow­brown, antennae, palpi, and legs yellow to yellowbrown.

Head broad (MDL/OHW = 0.59–0.60), dorsal surface flattened, dorsoventrally compressed; with very fine punctures, each with a short, very fine seta, surface between punctures shiny, smooth; frontoclypeal suture obsolete medially; eyes prominent, not strongly compressed; gula slightly concave; antennomere ratios: length I:II:III = 1.6:1.0:1.6, width VII:VIII:IX = 1.0:1.0:1.6. Pronotum very large, broad (PNL/PNW = 0.73–0.78), strongly convex, anterolateral lobes strongly produced, lateral margin broadly curved, not angulate; with very fine, sparse punctures, each with a short, very fine seta, surface between punctures smooth. Elytra broad, lateral margins strongly rounded, apically rounded (SEL/ELW = 0.87–0.99); punctation similar to pronotum; sutural stria present only at apex of elytron. Flight wings strongly reduced. Mesosternum moderately broad, not declivitous, anterior margin strongly excavated on each side, medially with anteriorly directed prominence that is apically truncate (fig. 114); with longitudinal carina present only posteriorly. Metasternum moderately narrow (MTL/MTW = 0.13), flattened, sloping slightly dorsad anteriorly; oblique femoral carinae well developed, meeting medially in low, posteriorly directed lobe.

Male tarsi 5­5­4; pro­ and mesobasotarsomeres somewhat laterally expanded, with small ventral field of spatulate setae; mandibles not modified; metafemur relatively narrow, with small subapical tooth along posterior margin, apical margin rounded (fig. 125); metasternal fovea transversely linear, broad, with dense line of fine setae. Median lobe in lateral aspect robust, medially expanded, dorsal margin sinuate, apex slender, slightly curved dorsally, slightly expanded medially along ventral margin, apex slender and pointed (fig. 197); in ventral aspect slen­ der, moderately elongate, medially expanded laterally, apex slender to relatively broadly expanded, arrowhead­shaped apex (fig. 196); operculum long and broad, not extending to apex of median lobe, lateral margins slightly curved, apex bifid, each ramus triangularly pointed, medial emargination narrow (fig. 196); lateral lobe in lateral aspect long, slen­ der, medially slightly expanded and sinuate (fig. 198).

Female tarsi 5­4­4; sinuation of anterior margin of mesosternum less strongly pronounced than in male.

ETYMOLOGY: This species is named from the Greek words skolios, meaning ‘‘curved’’, and sternum, meaning ‘‘chest’’, for the strongly excavated and bisinuate anterior margin of the mesosternum in this species.

DISTRIBUTION: This species is known from Puebla and Vera Cruz (fig. 360).

PARATYPES: MEXICO: Puebla: 24 km N Xicotepec de Juarez , 17 Jun 1983, oak forest litter, R Anderson (4, PECK) ; 4.4 mi SW Huachinango , 25 Jul 1969, 1700 m, moist ravine oak forest, malt traps, S and J Peck (1, PECK) .

DISCUSSION: This species has been collect­ ed from oak forest litter, cloud forest litter, and moist ravine oak forest. Elevation records are from 1040 to 1700 m.

Agathidium erythromelas Miller and Wheeler , new species Figures 126 , 199–202 , 361 TYPE MATERIAL: Holotype, Ƌ in EMEC labeled ‘‘ Morelia , 34 mi E., Michoacan,

Mex.VII­2­63/J.Doyen Collector/HOLO­ TYPE Agathidium erythromelas Miller and Wheeler, 2003 [red label with black line bor­ der]’’.

TYPE LOCALITY: Mexico, Michoacan, 34 mi E Morelia.

DIAGNOSIS: This species is relatively large and rather conspicuously reddish on the head and pronotum with contrasting black on the elytra. The eyes are relatively large and finely faceted. The metasternum is moderately broad and the oblique metasternal carinae are poorly developed. The male metafemoral tooth is small and anteapical (fig. 126). The male genitalia are distinct with the median lobe slender and strongly curved medially and strongly expanded along dorsal and ventral margins at the base of the apical portion in lateral aspect (fig. 201).

DESCRIPTION: Body large (TBL = 3.47– 3.86 mm), broad, robust (PNW/TBL = 0.47– 0.48), strongly contractile.

Head and pronotum red; elytra piceous, red apically and along lateral margin, slightly blue­iridescent laterally; venter red, testaceous on metasternum; antennae, palpi, and legs yellow­red.

Head broad (MDL/OHW = 0.58–0.67), dorsal surface flattened, dorsoventrally compressed; impunctate, smooth, shiny; frontoclypeal suture obsolete medially; eyes prominent, not compressed; gula slightly concave; antennomere ratios: length I:II:III = 2.6:1.0: 2.3, width VII:VIII:IX = 1.0:1.0:2.2. Pronotum very large, broad (PNL/PNW = 0.66– 0.71), strongly convex, anterolateral lobes strongly produced, lateral margin broadly curved, not angulate; with very fine, sparse punctures, each with a short, very fine seta, surface between punctures smooth. Elytra broad, lateral margins strongly rounded, apically rounded (SEL/ELW = 1.05–1.06); punctation similar to pronotum; sutural stria present in apical one­third. Flight wings fully developed. Mesosternum broad, somewhat convex; medial carina prominent. Metasternum narrow (MTL/MTW = 0.16–0.17), flattened, evenly sloping dorsad anteriorly; oblique femoral carinae not prominent, obsolete medially.

Male tarsi 5­5­4; pro­ and mesobasotarsomeres distinctly laterally expanded, protarsomeres more so and with large ventral field of spatulate setae; mandibles not modified; metafemur broad, with small tooth about one­third length from apex (fig. 126); metasternal fovea small, medial, transversely oval, with dense pencil of fine setae. Median lobe in lateral aspect slender in basal half, strongly curved, broadly expanded along dorsal and ventral margins submedially, with prominent lateral sulcus and associated carinae for reception of lateral lobe, apical portion of median lobe slender, evenly curved ventrally, apex pointed (fig. 201); in ventral aspect slender basally, broadly laterally expanded medially, apical portion evenly narrowed basally, then abruptly narrowed, apex a long slender process (figs. 199, 200); operculum in lateral aspect very slender, apically narrowly rounded, in ventral aspect long, slen­ der, lateral margins gently curved, apex narrowly emarginate (fig. 199); lateral lobes very slender, strongly curved, expanded submedially and slightly subapically, broadly sinuate in apical half each with 2 stout subapical setae (fig. 202).

Female not examined.

ETYMOLOGY: This species is named from the Greek words erythro, meaning ‘‘red’’, and melas, meaning ‘‘black’’, for the red head and pronotum and contrasting black elytron in this species.

DISTRIBUTION: This species is known only from southern Mexico (fig. 361).

PARATYPES: MEXICO: Mexico: Temascaltepec, Real de Arriba, Jul 1934, 6000–7000̍ (2, BMNH); 7 air km WSW Juchitepec, 24 Aug 1987, 2750 m, JT Doyen (3, EMEC). Michoacan: 34 mi E Morelia, 2 Jul 1963, J Doyen (2, EMEC); 34 mi E Morelia, 2 Jul 1963, J Doyen (9, EMEC). Vera Cruz : 10 mi S Las Vigas, 15 Jul 1971, 10,000̍, under bark of Pinus, A Newton (1, FMNH).

DISCUSSION: Agathidium erythromelas has been collected from under pine bark from 6000 to 10,000 ft.

Figures

Figs. 113–117. Agathidium oniscoides­group species, sterna and legs: 113, A. gomezae, metasternum, arrow indicating medial metasternal lobe. 114, A. skoliosternum, mesosternum, arrow indicating anterior excavation of mesosternal margin. 115, A. tribulosum, Ƌ left proleg, arrow indicating spine on Ƌ left protrochanter. 116, A. tribulograndum, Ƌ left proleg, arrow indicating spine on Ƌ left procoxa. 117, A. framea, Ƌ left metaleg, arrow indicating broad lobe along anterior margin of Ƌ left metacoxa.

Figs. 118–144. Agathidium concinnum­ and A. oniscoides­group species, left male metafemur, ventral aspect: 118, A. concinnum. 119, A. kimberlae. 120, A. vaderi. 121, A. bituberculum. 122, A. oedema. 123, A. gomezae. 124, A. hidalgoense. 125, A. skoliosternum. 126, A. erythromelas. 127, A. rhamphastes. 128, A. megoniscoides. 129, A. grumum. 130, A. triangularum. 131, A. lobosternum. 132, A. potosii. 133, A. popocatepetlae. 134, A. hyle. 135, A. stenomma. 136, A. tribulosum. 137, A. tribulograndum. 138, A. invisitatum. 139, A. multidentatum. 140, A. sejunctum. 141, A. grandidentatum. 142, A. andersoni. 143, A. disgregum. 144, A. oaxacaense. Bars = 0.5 mm.

Figs. 173–202. Agathidium oniscoides­group species, aedeagus: 173–176, A. vaderi: 173, ventral; 174, median lobe, apex, ventral; 175, median lobe, lateral; 176, left lateral lobe, lateral. 177–180, A. kimberlae: 177, ventral; 178, median lobe, apex, ventral; 179, median lobe, lateral; 180, left lateral lobe, lateral. 181–183, A. bituberculum: 181, ventral; 182, median lobe, lateral; 183, left lateral lobe, lateral. 184–187, A. oedema: 184, ventral; 185, median lobe, apex, ventral; 186, median lobe, lateral; 187, left lateral lobe, lateral. 188–191, A. gomezae: 188, ventral; 189, median lobe, apex, ventral; 190, median lobe, lateral; 191, left lateral lobe, lateral. 192–195, A. hidalgoense: 192, ventral; 193, median lobe, apex, ventral; 194, median lobe, lateral; 195, left lateral lobe, lateral. 196–198, A. skoliosternum: 196, ventral; 197, median lobe, lateral; 198, left lateral lobe, lateral. 199–202, A. erythromelas: 199, ventral; 200, median lobe, apex, ventral; 201, median lobe, lateral; 202, left lateral lobe, lateral.

Figs. 359, 360. Geographic distribution of Agathidium iota­ and A. oniscoides­group species: 359, A. bituberculum = ^; A. iota = •. 360, A. gomezae = ^; A. hidalgoense = •; A. oedema = -; A. skoliosternum = *.

Figs. 361, 362. Geographic distribution of Agathidium oniscoides­group species: 361, A. erythromelas = •; A. rhamphastes = -; A. triangularum = ^. 362, A. grumum = -; A. lobosternum = ^; A. megoniscoides = *.