Agathidium tribulograndum 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 : 109-110

Agathidium tribulograndum Miller and Wheeler , new species Figures 116 , 137 , 236–239 , 364

TYPE MATERIAL: Holotype, Ƌ in FMNH labeled ‘‘ MEXICO: Hidalgo 2.5–3.5 mi N Tlan­chinol, 50–5200 ft. vii.6–11.1973/fungusy wood chips A. Newton/ HOLOTYPE Agathidium tribulograndum Miller and Wheeler, 2003 [red label with black line bor­ der]’’. Only a single specimen is known of this species.

TYPE LOCALITY: Mexico, Hidalgo, 2.5 mi N Tlanchinol.

DIAGNOSIS: Males of this species are immediately recognizable by the combination of the very large, flattened tooth extending from the ventral surface of the procoxa (fig. 116), the characteristic metafemur with two prominent teeth and a relatively strongly concave surface between them (fig. 137), and the relatively broad metasternum with the fovea located anterad of the middle. The male genitalia, while unique in shape (figs. 236– 239), are also similar to many of the other members of the A. aztec subgroup.

DESCRIPTION: Body moderate in size (TBL = 3.44 mm), broad, robust (PNW/TBL = 0.48), strongly contractile.

Head and pronotum red; elytra red, with blue iridescence laterally; venter yellow, dark brown on metasternum; antennae, palpi, and legs yellow.

Head broad (MDL/OHW = 0.54), 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 flat; antennomere ratios: length I:II:III = 1.6:1.0:1.6, width VII:VIII:IX = 1.0:1.0:2.1. Pronotum very large, broad (PNL/PNW = 0.76), 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 = 1.00); punctation similar to pronotum; sutural stria present in apical one­half. Flight wings fully developed. Mesosternum broadly convex; medial carina prominent. Metasternum narrow medially (MTL/MTW = 0.18), slightly sloping dorsad anteriorly, flattened, smooth; oblique femoral carinae low, not strongly developed, especially laterally, medially low and obsolete.

Male tarsi 5­5­4; pro­ and mesobasotarsomeres distinctly laterally expanded, protarsomeres more so and with large field of spatulate setae ventrally; mandibles not modified; metafemur moderately broad, prominent, with distinct tooth about one­third distance from apex, smaller tooth about one­third distance from base, with concave area between, apical margin rounded (fig. 137); metasternal fovea large, anteromedial, transversely oval, with dense brush of long, fine setae; procoxa with large ventral, broad flattened tooth (fig. 116). Median lobe in lateral aspect long, slender, evenly curved, expanded subapically along dorsal margin, apical portion directed dorsad at angle, slender, straight, apically slightly expanded and curved ventrad, apex narrowly rounded (fig. 238); in ventral aspect slender, evenly constricted medially, expand­ ed basal to apical portion with a distinct carina which forms, together with dorsal carina, a sulcus in which fits the lateral lobe, apical portion narrowed to elongate, slender apex (figs. 236, 237); operculum elongate, parallel­sided, slightly expanded apically, apex rounded with small medial emargination (fig. 236); lateral lobes long, slender, subapically expanded, apex evenly expand­ ed, rounded, sinuate apically, apex abruptly narrowed, with a single stout subapical seta (fig. 239).

Female not examined.

ETYMOLOGY: This species is named from the Latin words tribulus, meaning ‘‘thorn’’, and grandis, meaning ‘‘large’’, for the large, thornlike process on the male procoxa.

DISTRIBUTION: This species is known only from the type locality in Hidalgo (fig. 364).

DISCUSSION: The holotype was collected from ‘‘fungusy wood chips’’ at ‘‘5000–5200 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. 232–260. Agathidium oniscoides­group species, aedeagus: 232–235, A. tribulosum: 232, ventral; 233, median lobe, apex, ventral; 234, median lobe, lateral; 235, left lateral lobe, lateral. 236–239, A. tribulograndum: 236, ventral; 237, median lobe, apex, ventral; 238, median lobe, lateral; 239, left lateral lobe, lateral. 240–243, A. invisitatum: 240, ventral; 241, median lobe, apex, ventral; 242, median lobe, lateral; 243, left lateral lobe, lateral. 244–247, A. multidentatum: 244, ventral; 245, median lobe,

Figs. 363, 364. Geographic distribution of Agathidium oniscoides­group species: 363, A. popocatepetlae = -; A. potosii = •; A. stenomma = *; A. tribulosum = ^. 364, A. hyle = *; A. grandidentatum = O; A. multidentatum = •; A. sejunctum = ^; A. tribulograndum = •.