Hister latimargo Schmidt

Caterino, Michael S., 2004, Taxonomy of the Hister criticus group, with description of a new species (Coleoptera: Histeridae), Zootaxa 601, pp. 1-16 : 10-11

Hister latimargo Schmidt ( Figs. 1 , 3 C, 4C, 5B)

Hister latimargo Schmidt, 1893: 14 ; type locality: “ Mexico ”. The type of H. latimargo is lost. An empty card with Schmidt's type label bearing an appropriate locality label is present in ZMHB, but no loose specimens remotely matching Schmidt's description have been found. The identity of the species, however, is in little question. Several very distinctive characters are adequately described by Schmidt. In particular, the 'fronte biimpressa ', 'mandibulis concavis', 'thorace lateribus rotundatim angustato, angulis anticis impressis, stria laterali unica integra, a margine valde distante', 'propygidio densissime punctato, margine subelevato angusto laevi', and 'prosterno angustissimo pone coxas triangulari bistriato'. Furthermore, Lewis, who likely either had specimens identified by Schmidt, or actually saw his type, identified several specimens as this species, now at BMNH.

Diagnosis: This species is among the most easily recognized New World Hister . The single lateral pronotal stria very distant from the margin, with the intervening area strongly convex, is not seen elsewhere in the group. The combination of this with the compressed (nearly triangular in cross section), bistriate prosternum, and the depressed frons provide an unambiguous diagnosis.

Description: Average length: 4.1 mm (range 3.6–4.7); Avg. width: 4.0 mm (range 3.6– 4.5); body black and shining, broadly oval, the outline interrupted at the pronotal/elytral junction, both separately outwardly arcuate, with the apex of the mesepimeron prominent between; frons depressed behind carinate frontal stria, most strongly on either side of middle, with conspicuous, though minute punctures; frontal stria bisinuate; supraorbital stria absent; labrum transversely convex, about 1.5x as wide as long; mandibles flattened above, curving slightly upward at apices, notched at upper basal corners, right incisor with prominent tooth at base, left edentate.

Pronotal sides strongly rounded, widest about one­fourth from base; marginal pronotal stria hidden beneath sides in basal three­fourths, ascending abruptly near apex, thence following anterior margin, ending behind eye; outer lateral pronotal stria absent, inner complete, distant from margin, intervening space convex; inner lateral stria continuous with anterior marginal stria along anterior pronotal emargination; posterior edge of pronotum with irregular marginal punctures, disk otherwise impunctate; hypomeron somewhat excavate; prosternal keel laterally compressed, with two striae parallel, approximate in apical two­thirds (rarely obsolete anteriorly), divergent at base; lateral striae of prosternal keel deeply impressed, recurving inwardly behind presternal suture; prosternal lobe subtriangular, broad, reaching hypomera; incomplete outer, and complete inner, marginal striae deeply impressed at their bases; protibia tridenate, the apical tooth bispinose, with complete submarginal carina bearing 2–3 small spinules near its base ( Fig. 5 B).

Elytron short, wider at maximum width than length along suture; elytral sides arcuate, widest behind middle, their lateral curvature discontinuous from that of pronotum; inner and outer subhumeral striae absent, dorsal striae 1–3 complete, stria 4 slightly abbreviated from base, stria 5 present in apical one­fourth or less, sutural stria present in apical onehalf or less. Mesosternum shallowly emarginate, with complete marginal stria joining postmesocoxal stria at sides; mesepimeron prominent between bases of pronotum and anterior elytral corners; mesometasternal stria broadly interrupted at middle, laterally extending straight back to near metacoxae, abruptly bent forward (often interrupted) at this point, extending to middle of metepisternum; meso­ and metasternal disks smooth at middle, shallowly punctate at sides; first abdominal ventrite with two oblique striae along inner edge of each metacoxa; mesotibia weakly arcuate, metatibia nearly straight, both with two rows of marginal spines.

Propygidium and pygidium both with densely alutaceous ground sculpture extending not quite to edges; propygidium shallowly but conspicuously depressed on each side, with evenly spaced medium sized punctures separated by about their widths; pygidium similarly punctate, with punctures not confined to the alutaceous area ( Fig. 4 C).

Male: aedeagus very similar to that figured for H. criticus ( Fig. 6 A); tegmen only very slightly expanded to apex; probably not diagnostic.

Female: Ovipositor not obviously different from that of H. foveipygus , described below ( Fig. 8 B).

Records ( Fig. 1 ): Hister latimargo is rather widely distributed, from central Mexico into Costa Rica. The species occurs primarily, and probably exclusively, in the refuse deposits of leaf cutting ants. Records: MEXICO: (country label only) (BMNH); San Luis Potosí, 14 mi N. Tamazunchale, 300', refuse deposit Atta mexicana , June (FMNH); San Luis Potosí, El Naranjo (3 mi W), 1100 ft., 22°31'N 99°21'W, June, refuse deposit Atta mexicana (FMNH); Jalisco, Autlán (9.5 mi SW), Puerto Los Mazos, 4400 ft, 19°42'N 104°23'W, September, refuse deposit Atta mexicana (FMNH); Jalisco, Chapala, San Juan Cosalá, 1500m, ex. Atta mexicana , July (CZUG); Jalisco, Chapala Ajijic, 1475–1600m, July, (CZUG); Jalisco, Tala, Ahuisculco, 1350m, ex. Atta mexicana , November, (CZUG); Jalisco, Tlaquepaque, Parque Montenegro, 1600m, detrito de Atta mexicana , October, (CZUG); Jalisco, 5 mi W Guadalajara, June (UCRC); Colima, Carrizalillo, ex. Atta mexicana , December (CZUG); Hidalgo, Chapulhuacán (8.7 mi SW), 4300 ft, 21°08'N 98°59'W, June, refuse deposit Atta mexicana (FMNH); Veracruz, Fortin, Canyon SW of R. Metlac, 3200–3400', refuse deposit Atta mexicana , July (FMNH); Morelos, Tlayacapan, detrito Atta mexicana , November (CZUG); Distrito Federal, Tejupilco, 3960', July (BMNH); Puebla, Atlisco (BMNH); Oaxaca, 9 mi NE Oaxaca on Mex. 175, 6000 ft., 17°08'N 96°37'W, refuse deposit Atta mexicana , July, August (FMNH); Oaxaca, Huajuapan de León (6 mi NW), 6400 ft, 17°52'N 97°49'W, September, refuse deposit Atta mexicana (FMNH); Chiapas, Mpio. Cintalapa, 5 mi N Nve. Tenochtitlan, July (PWKC); COSTA RICA, Guanacaste , Est. Palo Verde, Ref. Nac. Fauna Silv. R. L. Rodriguez, 10m, June (INBI); EL SALVADOR, San Salvador, June (USNM).

Figures

FIGURE 1. Map of specimen records for Hister criticus, H. laevimargo, and H. latimargo.

FIGURE 3. Dorsal habitus photographs of Hister spp. A. Hister criticus; B. H. laevimargo; C. H. latimargo.

FIGURE 4. Photographs of propygidium and pygidium of Hister spp. A. Hister criticus; B. H. laevimargo; C. H. latimargo; D. H. guanacaste; E. H. foveipygus.

FIGURE 5. Posterior view of protibiae of Hister spp. A. Hister criticus; B. H. latimargo; C. H. guanacaste; D. H. foveipygus.

FIGURE 6. Dorsal view of components of aedeagus of Hister spp. A. Tegmen of Hister criticus; B. Tegmen of H. guanacaste; C. Tegmen of H. foveipygus; D. Median lobe of H. foveipygus.

FIGURE 8. Lateral view of valvifer and coxite (ovipositor) of Hister spp. A. Hister guanacaste; B. H. foveipygus.