Agathidium microphthalmum 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 : 147-148

Agathidium microphthalmum Miller and Wheeler , new species Figures 110 , 167 , 338–340 , 376

TYPE MATERIAL: Holotype, Ƌ in CMNC labeled ‘‘ MEXICO: Chiapas: Volcan Tacana , lower slopes, ca. 4 km N Union Juarez, 19­ IX­1992. R. S. Anderson 92­110/ HOLO­ TYPE Agathidium microphthalmum Miller and Wheeler, 2003 [red label with black line border]’’.

TYPE LOCALITY: Mexico, Chiapas, Volcan Tacana, lower slopes, ca. 4 km N Union Juarez.

DIAGNOSIS: Males of this species may be distinguished from most species by the strongly reduced eyes consisting of minute, slightly elongate triangles (fig. 110), the large metafemoral tooth (fig. 167), and distinctive male genitalia with the median lobe moderately slender and with the apex hooked and slightly expanded in lateral aspect (fig. 339). The species is most similar to A. chauliodoum and A. nimbosilva , from which it may be distinguished by smaller eyes, less laterally expanded male probasotarsomeres (to distinguish it from A. chauliodoum ), and differences in the shape of the median lobe (figs. 338, 339).

DESCRIPTION: Body small (TBL = 2.39 mm), broad, robust (PNW/TBL = 0.48), rounded, strongly contractile.

Head dark red­brown; pronotum dark redbrown medially, red along margins; elytra dark red­brown medially, red along margins, not iridescent; venter, antennae, palpi, and legs yellow.

Head broad (MDL/OHW = 0.53–0.55), dorsal surface flattened, dorsoventrally compressed; with very fine punctures, each with a short, very fine seta, surface between punctures shiny, very lightly microreticulate; frontoclypeal suture obsolete medially; eyes strongly reduced to small triangles, only a few facets present (fig. 110); gula flattened, unmodified; antennomere ratios: length I:II: III = 2.0:1.0:1.4, width VII:VIII:IX = 1.0: 1.0:1.9. Pronotum very large (PNL/PNW = 0.71–0.72), broad, strongly convex, anterolateral lobes strongly produced, lateral margin broadly curved, not angulate; with fine, sparse punctures, each with a short, very fine seta, surface between punctures shiny, smooth. Elytra broad, lateral margins strongly rounded, apically rounded (SEL/ELW = 1.00–1.12); punctation and surface similar to pronotum; sutural stria absent. Flight wings strongly reduced. Mesosternum moderately broad, not declivitous; medial carina well developed. Metasternum narrow (MTL/MTW = 0.12–0.15), flat medially, distinctly dorsally sloped anteriorly; oblique femoral carinae well developed, meeting medially in low, but prominent carina.

Male tarsi 5­5­4; pro­ and mesobasotarsomeres distinctly laterally expanded, about equally so, each with moderate field of ventral spatulate setae; mandibles not modified; metafemur moderately broad, with very large, flat, triangular tooth subapically on posterior margin (fig. 167); metasternal fovea minute with small pencil of fine setae. Median lobe in lateral aspect stout, strongly curved basally, straight in medial portion apically flexed dorsad, apical portion slender, straight, apex abruptly expanded with dorsal and ventral points (fig. 339); in ventral aspect parallel­sided for most of length, apex evenly tapered to narrowly rounded apex (fig. 338); operculum broad, flat, apically broadly rounded (fig. 338); lateral lobes long, slender, strongly curved basally, apically with 2 stout setae (fig. 340).

Female tarsi 5­4­4.

ETYMOLOGY: This species is named from the Greek words micro, meaning ‘‘small’’, and ophthalmos, meaning ‘‘eye’’, in reference to the very reduced eyes in this species.

DISTRIBUTION: This species is known only from the type locality in Chiapas (fig. 376).

PARATYPES: MEXICO: Chiapas: Volcan Tacana, lower slopes, 4 km N Union Juarez, 19 Sep 1992, 2000 m, cloud forest litter, RS Anderson (5, CNCI).

DISCUSSION: The type specimens were collected from cloud forest litter at 2000 m.

Figures

Figs. 106–112. Agathidium oniscoides­group species, heads, left lateral aspect: 106, A. vaderi. 107, A. kimberlae. 108, A. oculeum. 109, A. stenomma. 110, A. microphthalmum. 111, A. nimbosilva. 112, A. chauliodoum. Bars = 0.5 mm.

Figs. 145–172. Agathidium oniscoides­group species, left male metafemur, ventral aspect: 145, A. oculeum. 146, A. recurvatum. 147, A. impensum. 148, A. cheneyi. 149, A. tenangoense. 150, A. rumsfeldi. 151, A. hirsutum. 152, A. cortezi. 153, A. tumidiventre. 154, A. aztec. 155, A. iridescens. 156, A. dentigerum. 157, A. stephani. 158, A. akrogeneios. 159, A. appalachium. 160, A. pocahontasae. 161, A. carolinense. 162, A. gallititillo. 163, A. divaricatum. 164, A. bushi. 165, A. georgiaense. 166, A. chauliodoum. 167, A. microphthalmum. 168, A. nimbosilva. 169, A. oniscoides. 170, A. rubellum. 171, A.

Figs. 329–356. Agathidium oniscoides­group species, aedeagus: 329–313, A. bushi: 329, ventral; 330, median lobe, lateral; 331, left lateral lobe, lateral. 332–334, A. georgiaense: 332, ventral; 333, median lobe, lateral; 334, left lateral lobe, lateral. 335–337, A. chauliodoum: 335, ventral; 336, median lobe, lateral; 337, left lateral lobe, lateral. 338–340, A. microphthalmum: 338, ventral; 339, median lobe, lateral; 340, left lateral lobe, lateral. 341–343, A. nimbosilva: 341, ventral; 342, median lobe, lateral; 343, left lateral lobe, lateral. 344–347, A. oniscoides: 344, ventral; 345, apex of median lobe, ventral, specimen from Macon City, NC; 346, median lobe, lateral; 347, left lateral lobe, lateral. 348–350, A. rubellum: 348, ventral; 349, median lobe, lateral; 350, left lateral lobe, lateral. 351–353, A. exiguum: 351, ventral; 352, median lobe, lateral; 353, left lateral lobe, lateral. 354–356, A. fawcettae: 354, ventral; 355, median lobe, lateral; 356, left lateral lobe, lateral.

Fig. 376. Geographic distribution of Agathidium oniscoides­group species: A. chauliodoum = -; A. microphthalmum = •; A. nimbosilva = *.