Dysmerus hamaticornis Thomas 2009, new species
Creators: name: Thomas, Michael C.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Laemophloeidae
Dysmerus
Dysmerus hamaticornis

description: Dysmerus hamaticornis Thomas, new species   
Fig. 12, 24, 36, Map 1  
 Diagnosis. Males can be distinguished from other members of the genus by a combination of the following character states: laterally elevated, toothed clypeus (Fig. 24), distinct dorsal pubescence, and strongly curved, acutely pointed male scape (Fig. 12).   
 Description. Holotype, male, in FSCA, with label data as follows: “ MEXICO: Quintana Roo 19km N Carrillo Puerto, 30-VI-1990 M.C. Thomas blacklight trap”.   
 Body elongate, parallel-sided, convex; length, 1.54 mm.   
 Head 2.00X wider than long; punctures longitudinally elliptical, smaller than an eye facet, separated by 1 or more puncture diameters, sparse medially, denser laterally and basally; each subtending a long, pale seta; surface between punctures smooth and shining; clypeus prolonged, comprising 0.25 of total length of head measured along midline from front of eyes to front of head capsule, shallowly emarginate, sides strongly reflexed, laterally acutely toothed (Fig. 24); angle above antennal insertion obtuse, strongly elevated; antennal scape large, length equal to 0.55 length of head; from dorsal view strongly curved medially, apex sharply tapered to a point (Fig. 24), dorsally without a dark tubercle (Fig. 12); pedicel small, quadrate; antennomeres III-VIII quadrate, about equal in length; antennomeres IX-X broader and longer; XI longer than X; eye moderately, evenly convex, about 0.43 length of head.   
 Pronotum as long as wide; surface sculpture and pubescence as head; roughly rectangular in shape, broadest at apex, thence narrowing slightly to base; width across anterior angles 1.16X width across posterior angles; vaguely longitudinally sulcate medially; sides steeply descending from sublateral line to margin; anterior angles right, not produced; posterior angles right, not produced.   
 Elytra 1.87X longer than combined width; parallel-sided for basal half, then gradually converging; all three cells visible, lateral margin of third cell slightly more prominent than others but scarcely carinate; sides laterally perpendicular to margin.   
Male genitalia as in Fig. 37.  
 Type material. Paratypes, 3, with following data: 1, “ COSTA RICA: Limon Reventazon, Hamburg Farm XI:1:1927 leg. F. Nevermann /at light/ FMNH (HD) 27-2/Field Mus. Nat. Hist. 1966 A. Bierig Colln. Acc. Z-13812" (FMNH); 1, “10/2/75 LT” (FSCA); 1, “ Cercis Jr 23+ [illegible] Coll. Chttn Dysmerus basalis Cas. USNM 204872" (USNM).   
The following female specimens are considered to be this species but are excluded from the type series: 1, “ALABAMA: Jefferson Co. Westavia 10-VIII-1980 Coll. T. King ” (FSCA); 3, “ COSTA RICA: Limon Reventazon, Hamburg Farm XI:1:1927 leg. F. Nevermann /at light/ FMNH (HD) 27-2/Field Mus. Nat. Hist. 1966 A. Bierig Colln. Acc. Z-13812" (FMNH).  
 Variation. The paratypes range in length from 1.78 mm to 1.86 mm. Otherwise, they are very similar to the holotype. The females that I have assigned to this species resemble the males in having a shallowly sulcate pronotum and distinct dorsal pubescence but differ in having a globose scape that is somewhat swollen on the apicomedial surface and a laterally toothed clypeus that is not or barely reflexed.   
 Etymology. The specific epithet is derived from the Latin words for “hooked” and “antenna,” referring to the sharply hooked scape.   
 Distribution. Costa Rica, Mexico, USA (Map 1).   
 Discussion. It was surprising to find a second species of Dysmerus occurring in the U.S., but the evidence seems to support its presence in the southeastern states. The male FSCA specimen was received in a batch of specimens from Tim King of Birmingham, AL. The female with full data was from the same collector. I am assuming that “Chttn” on the label of the USNM specimen refers to H. F. Chittenden. As he apparently did not collect outside of the U.S. (Blake 1951 -1952) it is probable that the USNM specimen was also collected in the U.S.
description: Published as part of Thomas, Michael C., 2009, A review of the genus Dysmerus Casey (Coleoptera: Laemophloeidae), pp. 1-30 in Insecta Mundi 2009 (74) on pages 13-15, DOI: 10.5281/zenodo.5405025