Agathidium bituberculum 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 : 91-94

Agathidium bituberculum Miller and Wheeler , new species Figures 121 , 181–183 , 359

TYPE MATERIAL: Holotype, Ƌ in CMNC labeled ‘‘ MEXICO: Chiapas: Cerro Hultepec ca. 5 km W San Cristobal. R.S.Anderson 92– 101 14­IX­1992 /wet oak forest litter. Elev. 2700 m./ HOLOTYPE Agathidium bituber­

culum Miller and Wheeler, 2003 [red label with black line border]’’.

TYPE LOCALITY: Mexico, Chiapas, Cerro Hultepec, ca. 5 km W San Cristobal, 2700 m.

DIAGNOSIS: Males and females of this species are immediately recognizable by the presence of two prominent processes on the gula medially on each side of the midline. The male metafemur has a very large, curved, apical tooth (fig. 121). The male genitalia are also diagnostic (figs. 181–183). The lateral sulcus on the median lobe for reception of the lateral lobe is less well developed than in many other members of the A. aztec subgroup (fig. 182).

DESCRIPTION: Body moderate in size (TBL = 2.35–2.94 mm), broad, robust (PNW/TBL = 0.46–0.50), strongly contractile.

Head and pronotum dark red; elytra dark red, iridescent on most specimens; venter yellow­brown to red­brown; antennae, palpi, and legs yellow.

Head broad (MDL/OHW = 0.48–0.55), 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 dorsoventrally distinctly compressed; gula with a prominent tubercle or tumidity on each side of midline; antennomere ratios: length I:II:III = 2.1:1.0: 1.2, width VII:VIII:IX = 1.0:1.0:2.2. Pronotum very large, broad (PNL/PNW = 0.76–0.82), 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 = 0.83–1.01); punctation similar to pronotum; sutural stria absent. Flight wings strongly reduced. Mesosternum broad, not declivitous; medial carina well developed, not prominent medially. Metasternum moderately narrowed (MTL/ MTW = 0.14–0.32), anteriorly sloping dorsad, concave medially; oblique femoral carinae well developed, meeting medially in broad, posterior flange.

Male tarsi 5­5­4; pro­ and mesobasotarsomeres only slightly laterally expanded, with small field of ventral spatulate setae; mandibles not modified; metafemur moderately broad, with exceptionally large subapical, curved tooth along posterior margin (fig. 121); metasternal fovea, broadly transverse, with dense series of fine setae. Median lobe in lateral aspect elongate, slender, strongly curved basally, expanded medially on dorsal margin by dorsal carina, with shallow lateral sulcus subtending carina for reception of lateral lobe, apical portion curved dorsad, slender, straight, apex pointed and slightly flexed ventrad (fig. 182); in ventral aspect slender, lateral margins subparallel, apical portion evenly narrowed to broadly triangular and acutely pointed apex (fig. 181); operculum broad, apically slightly expanded and broadly rounded (fig. 181); lateral lobes slender throughout length except medially slightly expanded, distinctly bent medially, apex very narrowly rounded with 2 stout setae (fig. 183).

Female 5­4­4.

ETYMOLOGY: This species is named bituberculum for the two tubercles present on the gula.

DISTRIBUTION: This species is known only from Chiapas in Mexico (fig. 359).

PARATYPES: MEXICO: Chiapas: Yerbabuena Preserve, 2.1 km NW Pueblo Nuevo, Solistahuacan , 21 Sep 1992, cloud forest litter, R Anderson (2, CNCI) ; 15.1 km NW Bochil. , 24 Sep 1992, pine­oak­ Liquidambar litter, R Anderson (1, CNCI) ; 10 km W El Bosque , 15 Sep 1992, 1475 m, pine cloud forest litter, R Anderson (14, CNCI) ; Cerro Hultepec , 5 km W San Cristobal, 14 Sep 1992, 2700 m, wet oak forest litter, R Anderson (17, CNCI) ; 8.9 km E Rayon , 19 Sep 1991, 1500 m, cloud forest litter, R Anderson (7, CNCI) ; 8.9 km E Rayon , 19 Sep 1991, 1500 m, cloud forest litter, R Anderson (9, CNCI) ; 6 km WSW San Cristobal , 24 Sep 1986, 2400 m, litter, pine­oak forest, R Baranowski (7, LUND) ; Jitotol , 20 Sep 1986, 1500 m, leaf litter under Salix (?) shrubs, R Baranowski (6, LUND) ; 8 km SE San Cristobal , 28 Sep 1986, 2400 m, litter at logs, fungus pine­oak forest, R Baranowski (1, LUND) .

DISCUSSION: Agathidium bituberculum has been collected only in September. It has been collected from various habitats including oak, pine, Salix , and Liquidambar forest litter. Elevation records are from 1475 to 2700 m.

Agathidium oedema Miller and Wheeler , new species Figures 122 , 184–187 , 360 TYPE MATERIAL: Holotype, Ƌ in CNCI labeled ‘‘ MEX. Km.10, 10,000̍ V. Popocate­

petl Mex., V­9­1971 J.M. Campbell/HOLO­ TYPE Agathidium oedema Miller and Wheeler, 2003 [red label with black line bor­ der]’’.

TYPE LOCALITY: Mexico, State of Mexico, V. Popocatepetl, 10,000̍.

DIAGNOSIS: Members of this species have moderately large, finely faceted eyes, a small male metafemoral tooth that is located anteapically (fig. 122), and a very distinctive anteromedial prominent line or carina on the metasternum that forms a prominent, posteriorly directed, swollen lobe (as in fig. 113). The species is very similar to A. gomezae and A. hidalgoense since they possess this unusual modification to the metasternum. Agathidium gomezae and A. hidalgoense differ from A. oedema in the shape of the median lobe. The operculum on the first two species is very long, deeply emarginate, and has each ramus apically prominently expanded ventrad (figs. 188, 192), whereas in A. oedema the operculum is only shallowly emarginate apically, not deeply divided (fig. 184). Agathidium hidalgoense differs from A. gomezae in that the male metafemoral tooth is small but distinct and acute (fig. 124), whereas the tooth in A. gomezae is broad and rounded (fig. 123). Also, the apical portion of the median lobe of the aedeagus in A. hidalgoense is broader in lateral aspect (fig. 194) and the operculum is not as strongly expanded (fig. 192) compared with A. gomezae (figs. 184, 186). Finally, the lobe formed by the sinuate line on the metasternum in A. gomezae is swollen, forming a prominent tumidity, whereas in A. hidalgoense this lobe is flat and on approximately the same plane as proximate portions of the metasternum.

DESCRIPTION: Body moderately large (TBL = 3.81–3.88 mm), broad, robust (PNW/TBL = 0.46–0.48), strongly contractile.

Head and pronotum red­brown; elytra redbrown, slightly iridescent laterally; venter light red­brown; antennae and palpi redbrown; legs yellow to yellow­brown.

Head broad (MDL/OHW = 0.57–0.71), 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, moderately finely faceted; gula flat; antennomere ratios: length I:II:III = 1.9: 1.0:2.1, width VII:VIII:IX = 1.0:1.0:2.1. Pronotum very large, broad (PNL/PNW = 0.69–0.77), 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 smooth. Elytra broad, lateral margins strongly rounded, apically rounded (SEL/ELW = 1.02–1.06); punctation similar to pronotum; sutural stria present in apical one­third. Flight wings well developed. Mesosternum broad, rounded medially; medial carina reduced anteriorly. Metasternum narrow (MTL/MTW = 0.16– 0.21), flattened, slightly sloping dorsad anteriorly, with prominent, medial, sinuate line, with lobelike structure medially that may be somewhat swollen (as in fig. 113); oblique femoral carinae present, medially obsolete.

Male tarsi 5­5­4; pro­ and mesobasotarsomeres moderately laterally expanded, with ventral field of spatulate setae; mandibles not modified; metafemur moderately broad, with small subapical tooth along posterior margin (fig. 122); metasternal fovea moderately large, transversely linear, with series of fine, dense setae. Median lobe in lateral aspect slender, evenly curved, expanded along dorsal margin submedially with prominent lateral carinae between which is a sulcus that receives the lateral lobe, apical portion slen­ der, somewhat expanded medially, directed dorsally but evenly curved, apex narrowly pointed (fig. 186); in ventral aspect slender, expanded laterally by carinae at base of apical portion, apical portion broad basally, narrowed medially and slender thereafter, apex slightly expanded and rounded (figs. 184, 185); operculum in lateral aspect long, slen­ der, slightly expanded on ventral margin at apex, ending short of apex of median lobe, in ventral aspect long, with lateral margins subparallel or slightly convergent, apex slightly expanded laterally, apicomedially with short, V­shaped medial emargination (fig. 184); lateral lobes long, slender, apically expanded and strongly sinuate, apices round­ ed, each with 2 subapical setae (fig. 187).

Female tarsi 5­4­4.

ETYMOLOGY: This species is named from the Greek word oedema , meaning ‘‘swell­

ing’’, for the lobe­shaped metasternal swelling.

DISTRIBUTION: This species is known only from the highlands of central Mexico (fig. 360).

PARATYPES: MEXICO: Mexico: Temescaltepec, Real de Arriba , Jul 1934, 6000–7000̍, HE Hinton, RL Usinger (1, BMNH) ; Mex / Pueblo border nr Tiamacas , 23 Aug 1987, 11,400̍, J Doyen (2, EMEC) ; km 10, V Popacatepetl , 9 May 1971, 10,000̍, JM Campbell (1, CNCI) ; 7 air km WSW Juchitepec , 24 Aug 1987, 2750 m, JT Doyen (1, EMEC) .

DISCUSSION: This species has been collect­ ed from 6000 to 11,400 ft in elevation.

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. 173–202. Agathidium oniscoides­group species, aedeagus: 173–176, A. vaderi: 173, ventral; 174, median lobe, apex, ventral; 175, median lobe, lateral; 176, left lateral lobe, lateral. 177–180, A. kimberlae: 177, ventral; 178, median lobe, apex, ventral; 179, median lobe, lateral; 180, left lateral lobe, lateral. 181–183, A. bituberculum: 181, ventral; 182, median lobe, lateral; 183, left lateral lobe, lateral. 184–187, A. oedema: 184, ventral; 185, median lobe, apex, ventral; 186, median lobe, lateral; 187, left lateral lobe, lateral. 188–191, A. gomezae: 188, ventral; 189, median lobe, apex, ventral; 190, median lobe, lateral; 191, left lateral lobe, lateral. 192–195, A. hidalgoense: 192, ventral; 193, median lobe, apex, ventral; 194, median lobe, lateral; 195, left lateral lobe, lateral. 196–198, A. skoliosternum: 196, ventral; 197, median lobe, lateral; 198, left lateral lobe, lateral. 199–202, A. erythromelas: 199, ventral; 200, median lobe, apex, ventral; 201, median lobe, lateral; 202, left lateral lobe, 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 = *.