Agathidium megoniscoides 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 : 100-101

Agathidium megoniscoides Miller and Wheeler , new species Figures 128 , 206–209, 362

TYPE MATERIAL: Holotype, Ƌ in AMNH labeled ‘‘ MEX.:Mor. 7 mi S Tres Cumbres VII­7­1975 /QDWheeler colr./ HOLOTYPE Agathidium megoniscoides Miller and

Wheeler, 2003 [red label with black line bor­ der]’’.

TYPE LOCALITY: Mexico, Morelos, 7 mi S Tres Cumbres.

DIAGNOSIS: This species is among the largest of Nearctic Agathidium and is about the size of many A. oniscoides . The male metafemoral tooth is subapical and relatively small (fig. 128). The male genitalia are diagnostic with the median lobe long, the apical portion very short and stout, and with weakly developed lateral sulci for reception of the lateral lobes (fig. 208).

DESCRIPTION: Body large (TBL = 4.17– 4.69 mm), broad, robust (PNW/TBL = 0.44– 0.50), strongly contractile.

Head and pronotum dark red; elytra dark red to testaceous, not iridescent; venter yellow, red­brown on metasternum; antennae, palpi, and legs yellow to yellow­red.

Head broad (MDL/OHW = 0.62–0.70), dorsal surface flattened, dorsoventrally compressed; with very fine punctures, surface between punctures shiny, smooth; frontoclypeal suture obsolete medially; eyes slightly compressed, but protuberant and conspicuous; gula convex; antennomere ratios: length I:II: III = 2.2:1.0:2.3, width VII:VIII:IX = 1.0: 1.0:2.1. Pronotum very large, broad (PNL/ PNW = 0.76–0.79), 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 round­ ed, apically rounded (SEL/ELW = 0.81– 1.13); punctation similar to pronotum; sutural stria extending from apex to about half elytral length. Flight wings strongly reduced. Mesosternum with surface convex, broad, anterior margin broadly curved; medial carina obscured anteriorly. Metasternum moderately narrow (MTL/MTW = 0.12–0.18), flattened, slightly sloping dorsad anteriorly; oblique femoral carinae low, not strongly developed, especially laterally, medially low and obsolete.

Male tarsi 5­5­4; pro­ and mesobasotarsomeres distinctly laterally expanded, with large field of ventral spatulate setae; mandibles not modified; metafemur broad, with relatively small curved subapical tooth on posterior margin (fig. 128); metasternal fovea large, transversely oval, with large, dense brush of fine setae. Median lobe in lateral aspect long, moderately straight throughout length, subapically broad, expanded along dorsal margin, apical portion short, robust, hooked dorsad (fig. 208); in ventral aspect long, straight and parallel­sided, slender, subapically expanded laterally, apical portion short and broadly triangular, apex pointed (figs. 206, 207); operculum in lateral aspect straight, slender, in dorsal aspect very broad, robust, apically truncate with prominent, robust lateral teeth (fig. 207); lateral lobes long, slender, evenly curved through most of length, apex expanded and sinuate, apex pointed, without stout setae (fig. 209).

Female tarsi 5­4­4.

ETYMOLOGY: This species is named from the Greek word mega, meaning ‘‘large’’, and the name oniscoides , a common eastern North American species for which this entire species group is named, in reference to the large size of this species and its placement in this group.

DISTRIBUTION: This species is known only from the type series from Morelos, Mexico (fig. 362).

PARATYPES: MEXICO: Morelos: 7 mi S Tres Cumbres, 7 Jul 1975, QD Wheeler (4, QDWC).

Figures

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