Agathidium iota 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 : 69-70

Agathidium iota Miller and Wheeler ,

new species Figures 102, 103 , 359

TYPE MATERIAL: Holotype, Ƌ in AMNH labeled ‘‘ MEXICO: S.L.P. 14 mi. W Xilitla, 4800 ft., Liq. for. VI.29.73 A.Newton/leaf & log litter/ HOLOTYPE Agathidium iota Mill­ er and Wheeler, 2003 [red label with black line border]’’.

TYPE LOCALITY: Mexico, San Luis Potosi, 14 mi W Xilitla, 4800̍.

DIAGNOSIS: This is the only species in the group and has the diagnostic characters of the group (see above).

DESCRIPTION: Body minute (TBL = 1.15– 1.51 mm), rounded (PNW/TBL = 0.43– 0.53), strongly contractile.

Head, pronotum, and elytra red­brown, not iridescent; venter, antennae, palpi, and legs yellow­brown.

Head broad (MDL/OHW = 0.40–0.72), dorsal surface flattened, dorsoventrally com­

pressed; temporum reduced, not prominent, supraocular carina extending posteriorly to margin of head; surface of head with extremely fine punctures, surface between punctures shiny, smooth; frontoclypeal suture obsolete medially; eyes somewhat reduced, dorsoventrally compressed, relatively large­faceted; gula unmodified; clypeus moderately excavate; antennae relatively short (ratios: length I:II:III = 1.8:1.0:1.0, width VII:VIII:IX = 1.0:1.0:1.9). Pronotum very large, broad (PNL/PNW = 0.69 –0.80), strongly convex, anterolateral lobes strongly produced, lateral margin broadly curved, not angulate; with minute, sparse punctures, each with a short, very fine seta, surface between punctures smooth. Elytra broad, lateral margins strongly rounded, slightly elongate, but not apically acuminate (SEL/ELW = 0.73– 1.47); punctation similar to pronotum; sutural stria indistinctly present apically. Flight wings absent or present, long, narrow, fringed with fine setae. Anterior portion of mesosternum very broad, convex, medial carina prominent anteriorly, obscured posteriorly; posterior portion very short, not concave. Metasternum very short (MTL/MTW = 0.09–0.14), flattened, medially slightly sloped dorsad anteriorly; oblique femoral carinae absent.

Male tarsi 4­4­3; pro­ and mesobasotarsomeres not laterally expanded, with few or no ventral spatulate setae; mandibles not modified; metafemur relatively slender, unmodified; metasternal fovea absent. Median lobe in lateral aspect very broad and robust basally, with subbasal constriction, curved, short, and moderately slender distad of constriction, apical portion narrowed, tapering to long, sharp point (fig. 103); in ventral aspect very broad, lateral margins broadly curved, apical portion broadly triangular, apex broadly pointed (fig. 102); operculum absent (fig. 102); lateral lobes short, slender, glabrous (figs. 102, 103).

Female tarsi 4­4­3.

ETYMOLOGY: This species is named after the smallest Greek letter iota , for the extremely small size of members of this species.

DISTRIBUTION: This species is known from southern Mexico and Guatemala (fig. 359).

PARATYPES: MEXICO: Guerrero: 10.3 km SW Filo de Caballo , 17 Jul 1992, 2700 m, oak­pinefir forest, leaf log litter, Berlese, R Anderson (1, CNCI) ; 10.3 km SW Filo de Caballo, 17 Jul 1992, 2700 m, oak­pine­fir forest (wet), leaf­log litter, Berlese , RS Anderson (5, MCZC). Michoacan: 18 Sep 1973, 9400̍, oak­pine litter, A Newton (2, CNCI). Oaxaca: S. Suchixtepec, 24 Jul 1992, wet riparian alder forest, leaf litter, Berlese, RS Anderson (12, MCZC). Verapaz: 14.5 km S Purulha, 26 May 1991, 1600 m, riparian bottomland, oak forest litter, RS Anderson (2, MCZC) .

DISCUSSION: Agathidium iota has been collected from leaf litter in a variety of habitats including pine, oak, and fir mixed forests and wet alder riparian forests. All known specimens were collected from sifting or Berlese samples. Elevation records are from 1600 to 2700 m. This is the smallest species of Agathidiini known.

Figures

Figs. 94–103. Agathidium compressidens­ and A. iota­group species, aedeagus: 94, 95, A. fenderi: 94, ventral; 95, lateral. 96–98, A. vesperpressidens: 96, ventral; 97, median lobe, lateral; 98, left lateral lobe, lateral. 99–101, A. compressidens: 99, ventral; 100, median lobe, lateral; 101, left lateral lobe, lateral. 102, 103, A. iota: 102, ventral; 103, 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 = *.