Agathidium rhamphastes 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 : 99-100

Agathidium rhamphastes Miller and Wheeler , new species Figures 127 , 203–205, 361

TYPE MATERIAL: Holotype, Ƌ in AMNH labeled ‘‘ 14 mi SW El Salto, Dg. MEX. VI.20 ’64 E.E.Lindquist, coll./bunch grass & sod below [handwritten]/ HOLOTYPE Agathidium

rhamphastes Miller and Wheeler, 2003 [red label with black line border]’’. Only the holotype was examined of this species. The specimen is in several pieces glued to a point.

TYPE LOCALITY: Mexico, Durango, 14 mi SW El Salto.

DIAGNOSIS: This species is somewhat similar to A. recurvatum externally but with male pro­ and mesobasotarsomeres somewhat more broadly expanded and with a large, flat, triangular process extending anteriorly from the dorsal surface of the labium. The male genitalia (figs. 203–205) are somewhat similar to A. recurvatum (figs. 267–269) as well but differ somewhat in the shape of the apical portion of the median lobe and the operculum. In addition, this species bears distinct microreticulation on the dorsal surface of the pronotum and elytron consisting of small, isodiametric cells, a condition unique among Mexican Agathidium , but similar to more northern species such as A. exiguum .

DESCRIPTION: Body moderate in size (TBL = 3.88 mm), broad, robust (PNW/TBL = 0.46), strongly contractile.

Head and pronotum red; elytra red, not iridescent; venter yellow­red, antennae, palpi, and legs yellow.

Head broad (MDL/OHW = 0.57), dorsal surface flattened, dorsoventrally compressed; with very fine punctures, each with a short, very fine seta, surface between punctures shiny, with indistinct microreticulation consisting of fine, isodiametric cells; frontoclypeal suture obsolete medially; with prominent, anteriorly directed, flat, triangular process extending from (apparently) labium, process upturned apically; eyes moderately large, not dorsoventrally compressed; gula slightly concave; antennomere ratios: length I:II:III = 1.9:1.0:1.7, width VII:VIII:IX = 1.0:1.0:2.1. Pronotum very large, broad (PNL/PNW = 0.77), 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 shiny, with indistinct microreticulation consisting of fine, isodiametric cells. Elytra broad, lateral margins strongly rounded, apically rounded (SEL/ELW = 1.06); punctation similar to pronotum but with microretic­ ulation much more distinctly evident; sutural stria absent. Flight wings strongly reduced. Mesosternum broad, flattened; medial carina well developed. Metasternum narrow (MTL/ MTW = 0.16), flattened, sloping dorsad anteriorly; oblique femoral carinae moderately prominent laterally, medially meeting in moderately prominent, posteriorly directed lobe.

Male tarsi 5­5­4; pro­ and mesobasotarsomeres slightly laterally expanded, with small field of ventral spatulate setae; mandibles not modified; metafemur moderately broad with broad, moderately large tooth subapically on posterior margin (fig. 127); metasternal fovea moderately large, rounded with moderately large pencil of long, dense, fine setae. Median lobe in lateral aspect slen­ der basally, strongly curved, expanded submedially, with prominent dorsal prominence and lateral carina between which is a sulcus in which fits the lateral lobe, apical portion elongate triangular, slightly sinuate, apex sharply pointed and directed anterad (fig. 204); in ventral aspect slender, long, lateral margins subparallel, apical portion evenly narrowed to slender, sharply pointed apex (fig. 203); operculum moderately long, apex with V­shaped emargination, each ramus triangular in shape, with points directed laterad and ventrad (fig. 203); lateral lobes slender, evenly curved through much of length, apically strongly sinuate and distinctly expand­ ed submedially and apically, apex rounded with 2 stout setae (fig. 205).

Female unknown.

ETYMOLOGY: This species is named from the Greek word rhamphos, meaning ‘‘curving beak’’, for the unusual anteriorly produced structure of the labium.

DISTRIBUTION: This species is known only from the type locality in Durango (fig. 361).

DISCUSSION: The type specimen was collected from ‘‘bunch grass and sod’’.

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 = *.