Sternidius micromaculatus, Bezark & Santos-Silva & Botero, 2023

Sternidius micromaculatus sp. nov.

( Fig. 1 -5 View Figures 1-6 )

ZooBank:http://zoobank.org/ F1090A7F-B1E3-44E2-A25E-7CC02EA9A22A

Holotype, ♀, BELIZE, Belize: La Democracia – TEC (Tropical Educ. Center) , N17.35777 W88.54227, 26 m, M/V blacklight, 6-9.VI.2016, L.G. Bezark leg. ( CASC, formerly LGBC). GoogleMaps

Paratypes, ♀, BELIZE, Cayo: 5 mi. N San Ignacio, 22-30.XI.1988, F.D. Parker leg. ( LGBC) .

Description of the holotype ( Fig. 1- 4 View Figures 1-6 )

Coloration. – Integument mostly dark brown; ventral mouthparts mostly reddish brown except yellowish-brown palpomeres; anteclypeus fulvous anteriorly; labrum yellowish anteriorly; antennomere III brown with irregular light brown areas interspersed, except dark brown apex; antennomere IV light brown on basal fifth, brown on remaining surface, except dark brown apex; antennomeres V-VII brown basally, light brown on remaining basal third, brown on apical half, except dark brown apex; antennomeres VIII - X light brown except dark brown apex; antennomere XI light brown. Central area of prosternum, prosternal process, and mesoventral process dark reddish brown. Tarsomeres III– V mostly dark reddish brown.

Head. – Frons densely, finely, shallowly punctate; with abundant pubescence partially obscuring integument, pubescence yellowish-white close to eyes, appearing whiter depending on light intensity, yellowish-white with yellowish-brown pubescence interspersed on inferior half, light yellowish brown with white pubescence interspersed on superior half; with one long, erect dark brown seta close to each eye. Area between antennal tubercles with dense yellowish-brown pubescence, except glabrous median groove. Area between antennal tubercles and upper eye lobes with dense pale yellow pubescence with whitish pubescence interspersed except glabrous median groove. Area between upper eye lobes with dense brownish pubescence laterally and pale yellow pubescence close to glabrous median groove. Remaining surface of vertex with sparse pale yellow pubescence toward eye lobes, pubescence almost absent on triangular central region, glabrous close to prothorax. Area behind upper eye lobes with dense brownish pubescence close to eye, pubescence brownish close to vertex and centrally, yellowish-white between brownish areas, pale yellow toward lower eye lobes, glabrous close to prothorax. Area behind lower eye lobes with dense pale yellow pubescence close to eye, this area distinctly narrowed centrally and abruptly widened inferiorly, glabrous close to prothorax. Genae finely rugose-punctate except smooth apex; with abundant pale yellow pubescence not obscuring integument, appearing whiter depending on light intensity, except glabrous smooth area, and a few long, erect dark setae interspersed. Antennal tubercles with abundant brown pubescence with yellowish-brown pubescence interspersed, except whitish pubescence inferiorly on frontal region. Wide central area of postclypeus with moderately abundant yellowish-white pubescence not obscuring integument, long, erect dark brown setae interspersed, some setae yellowish-brown apically, and long, erect fulvous setae on each side. Sides of postclypeus glabrous. Labrum with yellowish-white pubescence not obscuring integument close to anteclypeus, pubescence appearing white depending on light intensity, with transverse row of long, erect, thick blackish setae on posterior third; long, erect yellowish-brown setae on sides of anterior 2/3 and centrally close to pubescent posterior region, glabrous on remaining surface, except anterior margin with short fringe of yellowish-brown setae. Distance between upper eye lobes 0.23 times distance between outer margins of eyes; in frontal view, distance between lower eye lobes 0.49 times distance between outer margins of eyes. Antennae 2.1 times elytral length, reaching elytral apex at middle of antennomere VII. Scape sinuous on inner region, with apex slightly projected inward; with abundant whitish pubescence not obscuring integument ventrally, pubescence distinctly sparse apically, and with irregular, transverse, both whitish and yellowish-brown pubescent bands dorsally and laterally. Pedicel with sparse brownish pubescence posteriorly, almost glabrous anteriorly. Antennomere III with abundant brownish pubescence not obscuring integument, abundant, irregular yellowish-white pubescent maculae interspersed, and short, erect, sparse yellowish-white setae interspersed; apex with a few long dark setae directed backward. Antennomeres IV-X with dense whitish pubescence basally, this area shorter from VI, except base with brownish pubescence not obscuring integument, this area larger from IX, and light yellowish-white pubescence not obscuring integument on remaining surface; with short, erect, somewhat abundant yellowish-white setae interspersed throughout; ventral apex with a few long, erect dark setae. Antennomere XI with light yellowish-brown pubescence not obscuring integument, and short, erect yellowish-white setae interspersed.

Antennal formula based on length of antennomere III:

– Scape = 0.97.– Pedicel = 0.17.– IV = 0.87. – V =0.73.– VI = 0.67.– VII = 0.63. – VIII = 0.57. – IX = 0.53. – X = 0.53. – XI = 0.50.

Thorax. – Prothorax wider than long; with narrow anterior constriction; sides gradually, distinctly divergent from anterior constriction to lateral tubercles, then abruptly narrowed, subparallel-sided toward posterolateral angles; lateral tubercles large, as a continuation of sides, with their apex located on posterior third. Pronotum abundantly, coarsely punctate, punctures absent close to anterior and posterior margins, sparser centrally, slightly coarser after lateral tubercles of prothorax; with large, oblique, slightly elevated gibbosity on each side, from anterior quarter to after middle, and slightly distinct carina-shaped gibbosity centrally, from about middle to posterior quarter; with abundant yellowish-brown pubescence not obscuring integument, and irregular, white pubescent maculae interspersed, except anterolateral region with dense yellowish pubescence; with a few long, erect dark setae close to posterior region of lateral tubercles of prothorax. Sides of prothorax with abundant yellowish pubescence not obscuring integument, except glabrous narrow area close to anterior margin. Prosternum with dense yellowish pubescence laterally, sparser, yellowish-white centrally, except glabrous anterior sulcus. Prosternal process with abundant yellowish-white pubescence not obscuring integument; narrowest area 0.3 times procoxal width. Ventral surface of mesothorax with dense yellowish pubescence laterally; sides of superior region of mesoventrite with abundant whitish pubescence not obscuring integument; remaining surface of mesoventrite with sparse whitish pubescence, except arched glabrous central band, and yellowish-brown pubescence close to mesoventral process. Mesoventral process gradually narrowed toward posterior fifth, then distinctly widened; narrowest area 0.63 times mesocoxal width; apical width 0.84 times mesocoxal width; with abundant whitish pubescence not obscuring integument. Sides of ventral surface of metathorax with dense yellowish-white pubescence with subcircular areas with sparse pubescence interspersed; central area of metaventrite with abundant whitish pubescence not obscuring integument, except glabrous metathoracic discrimen. Scutellum with yellowish-brown pubescence not obscuring integument laterally and dense, longitudinal white pubescence band centrally.

Elytra. – Somewhat abundantly, coarsely punctate on anterior third, punctures gradually finer and sparser toward apex; area of centrobasal crest slightly tumid; dorsal surface with three slightly distinct longitudinal carinae, innermost starting on apex of tumid area of centrobasal crest, central one startingonbase, bothgraduallydisappearing from posterior third, outermostis the least distinct, starting about middle, gradually disappearing from posterior third, all carinae with short, irregular areas slightly tumid; humeral carina vaguely indicated; apex obliquely truncate, with rounded outer angle; with abundant pale yellowish-brown pubescence not obscuring integument, except row of white pubescence spots along dorsal carinae, innermost carina with larger white pubescent spot after middle, row of dark brown pubescent spots also along dorsal and humeral carinae, oblique white pubescent band from base to tumid area of centrobasal crest, sparse white pubescence close to suture on anterior third, and white pubescent spots close to suture on posterior 2/3, and sides with whitish pubescence not obscuring integument, pubescence denser on anterior half, and irregular light yellowish-brown areas interspersed. Legs. – Femora with abundant whitish pubescence not obscuring integument and irregular areas with sparse yellowish pubescence on femoral clubs. Tibiae with three irregular white pubescent rings, one near base, one about middle, another apically not reaching ventral surface, somewhat abundant yellowish-brown pubescence between them, except dorsal surface of mesotibiae with row of short, erect, thick black setae from sulcus to apex; ventral third of protibiae and apical quarter of meso- and metatibiae with dense, bristly yellowish-brown pubescence; posterior half of dorsal surface of metatibiae with sparse, short, erect, thick black setae interspersed. Tarsomere I mostly with white pubescence dorsally; II with yellowish-brown pubescence and white pubescence interspersed; III - V with yellowish-brown pubescence not obscuring integument; metatarsomere I about as long as II-III together.

Abdomen. – Ventrites with abundant whitish pubescence not obscuring integument; ventrite 5 with a few long, erect dark setae posteriorly; apex of ventrite 5 slightly concave centrally.

Variation. – Area between antennal tubercles with dense yellowish-white pubescence; white pubescent maculae on pronotum more abundant and larger; anterolateral region of pronotum with dense white pubescence; circum-scutellar region with somewhat abundant white pubescence and posterior third of elytra with abundant whitish pubescence interspersed.

Dimensions (mm) (holotype ♀ / paratype ♀).

– Total length, 6.10 / 6.60;

– Prothoracic length, 1.25/ 1.30;

– Anterior prothoracic width, 1.25 / 1.30;

– Posterior prothoracic width, 1.45 / 1.55;

– Maximum prothoracic width, 1.80 / 1.95;

– Humeral width, 2.15 / 2.35;

– Elytral length, 4.40/ 4.75.

Etymology. – The specific epithet “micromaculatus ” (Latin, micro = small; maculatus = spotted) refers to the multiple small light colored pubescent spots on the elytra.

Remarks.

Sternidius micromaculatus sp. nov. is similar to S. punctatus (Haldeman, 1847) (see photographs on Bezark 2022a), but differs by:

– the distance between upper eye lobes equal to apical diameter of the scape (distinctly wider than apical diameter of the scape in females of S. punctatus );

– lateral tubercles of the prothorax larger (smaller in S.punctatus ),

– theelytralapex subrounded (truncate,concave centrallywithouter andsutural angles slightly projected in S. punctatus ;

– sometimes not different slightly oblique, not differing to that in the new species);

– elytra without transverse white band on posterior half (with irregular, fragmented white pubescent band in S. punctatus , sometimes reduced to a series of maculae).

The new species also resembles S. naeviicornis (Bates, 1885) ( Fig. 6 View Figures 1-6 ) but differs from:

– it by the pronotum without one oblique blackish area on each side of anterior half (present in S. naeviicornis ;

– elytra without oblique dark pubescent band (inverted V-shaped) on posterior half, withgrayish-white pubescenceborderingitsanterior region (present in S. naeviicornis ).

Sternidius micromaculatus sp. nov. is also similar to S.chemsaki Lewis, 1977 (see photographs on Bezark 2022a and in the original description), but differs by:

– the body stouter (slender in S. chemsaki );

– lateral tubercles of the prothorax larger and not acute apically (smaller, acute apically in S. chemsaki );

– elytra without black pubescent maculae distinctly contrasting with remaining pubescence (present in S. chemsaki ).