Hister criticus Marseul

Hister criticus Marseul (Figs. 1, 3 A, 4A, 5A, 6A)

Hister criticus Marseul, 1861: 551; lectotype, probably male, hereby designated: “ Mexique, Salle”, MNHN; examined by the author; paralectotype male, hereby designated, same data and repository as type; two BMNH specimens labelled “ Mexico, Salle coll.”/ “Cordova” may also be syntypes, but this cannot be confirmed, and they are not formally recognized.

Diagnosis: Within this species group, Hister criticus is most easily recognized by the relatively sparse punctation of the propygidium and pygidium. Punctures of the propygidium are moderate in size and separated by nearly their widths throughout, while those of the pygidium are smaller and more widely spaced. On both the intervening integument is smooth and shining. In H. laevimargo, H. latimargo and H. foveipygus this punctation is much denser (Figs. 4 B, C, E), and in H. latimargo, the intervening surface is densely alutaceous, while in H. guanacaste, the pygidia are impunctate (Figs. 4 D).

Description: Average length (from anterior pronotal margin to apex of elytral suture): 3.3 mm (range 3.1–3.6); Avg. width (at widest point): 3.2 mm (range 3.0–3.4); body black and shining, elongate oval, its outline not interrupted at the pronotal/elytral junction (Fig. 3 A); frons broad, minutely punctate; frontal stria bisinuate; labrum twice as wide as long; apically truncate; mandibles flat above, notched at anterobasal corner; right mandible with small tooth at base below incisor edge; stipes with 4–6 setae; mentum convex, setose, emarginate at apex; penultimate labial palpomere with a crown of apical setae; apical labial palpomere with short scattered setae.

Pronotum widest at base, sides weakly converging anteriorly, inwardly curved at apex; marginal pronotal stria present from posterior corner to behind eye; outer lateral stria absent; inner lateral stria complete, continuous across anterior pronotal emargination, faintly crenulate; hypomeron bare; prosternal keel bistriate, striae divergent basally, parallel to slightly divergent at anterior apex; prosternal lobe rounded to nearly triangular; protibia tridentate, the apical tooth with two spines, deeply emarginate between marginal teeth, submarginal carina complete, bearing 2–3 small spinules along its length (Fig. 5 A).

Elytra (Fig. 3 A) lacking subhumeral striae; dorsal striae 1 and 2 complete, 3 complete or briefly interrupted at middle, 4th visible as short basal and apical fragments, 5th absent, sutural stria in apical two­thirds or less, nearly absent from some individuals. Mesosternum emarginate anteriorly, with complete marginal stria joining postmesocoxal stria at sides; mesometasternal stria broadly interrupted at middle, nearly absent between mesocoxae, laterally extending to middle of metepisternum; meso­ and metasternal disks smooth at middle, shallowly punctate at sides; 1st 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 faintly depressed on either side, with moderately large, shallow punctures, mostly separated by at least their diameters, punctures smaller and sparser at middle; pygidial punctures smaller, more evenly distributed, separated by about their diameters (Fig. 4 A).

Male (Fig. 6 A): aedeagus with tegmen only slightly expanded apically compared to others in this group.

Female: Only a single female has been seen, the reproductive tract of which did not clear well. Ovipositor shape and coxite/valvifer relative lengths as for H. guanacaste below.

Records (Fig. 1): MEXICO: Veracruz (BMNH); Veracruz, 10 mi W. Alvarado, beach debris – July (FMNH); Puebla, Cholula (FMNH); Cordova (FMNH); GUATEMALA, Cubilguitz, Vera Paz (BMNH); USA: AZ, Pima Co., Green Valley – April, Neotoma nest, (JSHC); AZ, Patagonia – July (CASC); BELIZE: Orange Walk Distr., Rio Bravo Conserv. Area, La Milpa Field Sta., FIT – May (PWKC).

Remarks: The two specimens from southern Arizona differ consistently from the other specimens in the short broadly rounded prosternal lobe, and in the near absence of the sutural elytral stria. However, these differences will likely be bridged by intermediate forms in the large sampling gap between Arizona and Puebla. Specimens have been found both in Neotoma (woodrat) nests, and under beach debris.