Hister laevimargo Lewis

Caterino, Michael S., 2004, Taxonomy of the Hister criticus group, with description of a new species (Coleoptera: Histeridae), Zootaxa 601, pp. 1-16 : 7-9

Hister laevimargo Lewis ( Figs. 1 , 3 B, 4B)

Hister laevimargo Lewis, 1900: 246 ; lectotype female, hereby designated: “ Costa Rica, P. Biolley”/ “G.Lewis Coll., B.M.1926­369.”/ “ Hister laevimargo Lewis Co­type”/ “Barba. Esmeralda, V.90, Troncs.”, BMNH; examined by the author.

Hister planimargo Lewis, 1900: 247 ; lectotype, hereby designated: “ Costa Rica, (Donckier).”/ “G.Lewis Coll., B.M.1926­369.”/ “ Hister planimargo Lewis Type ”, MNHN; examined by the author; Syn. nov.

Diagnosis: This species shares with H. criticus the relatively narrow lateral pronotal marginal bead (between the single lateral stria and the margin), and the presence of prosternal striae. However, elytral stria 4, interrupted or absent in H. criticus , is complete in H. laevimargo . The propygidial and pygidial punctation also differs substantially, with H. laevimargo having relatively small, and very densely set punctures, most separated by one­third their diameters or less ( Fig. 4 B).

Description: Average length: 3.5 mm (range 3.2–3.8); Avg. width: 3.3 mm (range 3.0– 3.6). This species is extremely similar to H. criticus , externally differing only in those characters given in the diagnosis. The aedeagus has not been examined because the species is only known from types in marginal condition.

Records ( Fig. 1 ): This species is known only from the types. The type locality, Barba Esmeralda, apparently refers to a site on the slope of Volcán Barva in Heredia, about 20 km north of San José, Costa Rica.

Remarks: There is some discrepancy between the published data and those on the the three ‘type’ specimens of these two species. First, Lewis does not report numbers of specimens for either species. The BMNH presently has two specimens labelled, apparently by Lewis himself, as Hister laevimargo , one collected by Donckier, labelled the ‘Type’, and one by P. Biolley, from Barba Esmeralda, as the ‘Co­type’. Only the latter data is cited in the original description for that species. The one specimen of H. planimargo bears a “ Costa Rica, (Donckier)” label, as cited. It seems that Lewis confused these specimens in the labelling, and that the specimen of H. laevimargo labelled Co­type (with the correct label data) should be considered the primary type of the species, and it is designated as such. The other two specimens, both collected by Donckier, are considered syntypes of H. planimargo , despite the fact that only one bears Lewis’ H. planimargo label. This latter specimen is designated the lectotype, and the other is not specifically designated.

Describing H. planimargo, Lewis notes only that it is related to H. laevimargo (and H. latimargo ), but does not specify characters by which they differ. The most obvious difference in their descriptions is how Lewis describes the frontal stria, "sinuous behind the mandibles, angulate above the eyes" in H. laevimargo , and "nearly straight anteriorly" in H. planimargo . However, elsewhere in their descriptions different language is used to describe apparently similar conditions, making it difficult to determine what he considered significant. In any case, in none of these characters can I detect any clear differences.

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.