Hintonelmis guianensis, Polizei & Barclay, 2019

Polizei, Thiago T. S. & Barclay, Maxwell V. L., 2019, The genus Hintonelmis (Coleoptera: Elmidae: Elminae), new species and records, Journal of Natural History (J. Nat. Hist.) 52 (45 - 46), pp. 2949-2959 : 2952-2954

Hintonelmis guianensis sp. nov.

( Figure 1 (a–c))

Type locality

Guyana [ NEW COUNTRY RECORD FOR GENUS]

Male holotype. Labels : [♂], [Holotype], [ GUYANA, Essequibo/Kaieteur Falls/rest house area/ October, 1991], [HOLOTYPE / Hintonelmis guianensis / Polizei & Barclay], [ NHMUK010846331 ] ( BMNH) .

Paratypes. Labels : 1 specimen . [♀], [ BRITISH GUIANA / Ikuribisi / x.1948 – iii 1949 / D.J. Atkinson / At light], [ NHMUK010583992 ], [PARATYPE / Hintonelmis guianensis / Polizei & Barclay]. ( BMNH) . 3 specimens (1♂ and 2 undetermined sex): [ GUYANA, Essequibo / Kaieteur Falls /rest house area/ October, 1991], [PARATYPE / Hintonelmis guianensis / Polizei & Barclay]. (2 in MZSP, 1 in BMNH) . ( MZSP 35133–35134 ) .

Diagnosis

Body elongate, moderately convex, yellowish with dark-brown stripes. Pronotum with one brown stripe on each side of the impression, not reaching the posterior margin, and one transverse stripe near to the anterior margin, reaching the lateral margin. Elytra with stripes. Prosternal process with a transverse carina in the median portion. Aedeagus five times as long as wide, distinctly narrowed at apical portion, with apex slightly rounded.

Description

Body elongate, moderately convex. Yellowish colour with dark-brown stripes. Total length 2.12 mm, greatest width (elytra) 0.67 mm.

Head. Partially retractable without impressions, surface with microgranulation. Eyes black, slightly projecting laterally, separated from each other by one eye-width. Antenna filiform, reaching the base of the elytra, with 11 antennomeres, distal antennomere swollen and longer than the preceding, with an acute apex. Clypeus lightbrown, concave, granulated, with some scattered recumbent hairs. Frontoclypeal suture straight. Labrum rectangular, large and broad, with anterior margin strongly rounded and surface like the clypeus. Maxillary and labial palps short, yellowish. Maxillary palps four segmented; labial palps three segmented, yellowish in colour.

Thorax. Pronotum as long as wide, anterior margin flexed upwards, moderately convex, lateral margin black, moderately sinuous, smooth, anterior angle acute, and posterior margin sinuous, strongly concave near to scutellum. Pronotal surface microgranulated, with a few golden setae on the apical anterior portion of the disc; sinuous sublateral carina present, very short, on the posterior third of pronotum; short and deep longitudinal impression on disc, with one depression on each side of posterior region, one brown stripe on each side of the impression, not reaching the posterior margin, and one transversal stripe near to the anterior margin, reaching the lateral margin. Elytra longer than wide, anterior margin sinuous, lateral margin moderately arcuate, humeral angles broadly rounded and elevated, apex moderately produced and broadly rounded. Median suture elevated. Surface punctured, punctures confluent, forming rows, separated by double rows of long light-coloured setae. Carinae on intervals 3 (on anterior 1/5), 6 (on anterior half) and 8 (on posterior half); surface with three dark-brown stripes, one on intervals 2–3 occupying anterior 1/3 of elytra, other on the median portion of the elytra on the 3–5 intervals, and another one on 2–8 intervals, on the apex of the elytra. Scutellum yellow, long and narrow, without punctures, with double rows of golden setae. Epipleura covered with tomentum. Hind wings macropterous. Prosternum covered by tomentum, forming a belt with the anterior portion of the hypomerum, surface with microgranulations. Prosternal process as long as wide, reaching the coxae, with moderately sinuous posterior margin, surface with microgranulation and a transverse carina in the median portion. Mesoventrite straight, with a shallow depression to receive the prosternal process, surface covered by tomentum. Metaventrite very broad, larger than prosternum and mesosternum combined, lateral margins covered by tomentum and metasternal disc glossy, without punctures, carinae or setae. Legs covered by tomentum. Coxae moderately globular. Femora long with the apex moderately thin. Tibiae long, very thin, with rows of fringes on the distal three quarters. Tarsi long, with a 5–5–5 tarsal formula, without setae, last tarsomere larger than the preceding tarsomeres combined. Claws long, flat, feebly dentate at base, darker than the rest of the leg.

Abdomen. Five ventrites covered by tomentum, absent only in the median portion of the first segment. Margins anterior and posterior moderately arcuate. Lateral margin moderately rounded. Fifth sternite produced apically, with several gold setae and with lateral margin slightly produced posterolaterally.

Genitalia. ( Figure 1 (c)) Without punctures or setae. Phallobase three times as long as wide. Parameres long and narrow, reaching 4/5 of the length of the aedeagus. Aedeagus five times as long as wide, distinctly narrowed in apical part, with apex slightly rounded.

Female

External morphology similar to male.

Etymology

The specific epithet refers to the country where this species was collected. This is the first record of Hintonelmis from Guyana.

Comments. In the key for species of Hintonelmis ( Hinton, 1971) , Hintonelmis guianensis sp. nov. will key to Hintonelmis perfectus ( Grouvelle, 1908) because of the similar carinae on the elytra, tibia with tomentum, trochanters and median portion of the first ventrite without tomentum, but it can be distinguished by the following characteristics: H. guianensis is yellowish with dark-brown stripes; pronotal longitudinal stripe not reaching the posterior margin, and the transversal stripe reaching the lateral margin and reaching the anterior margins of the elytra, the pronotum only has setae in the anterior distal portion, and the tibiae are recumbent with tomentum without hairs. However, Hintonelmis perfectus is brown with dark-brown stripes; the pronotum stripes reach the posterior margin; the antennae extend beyond the anterior margin of the elytra; the pronotum surface is covered with setae, and the tibiae covered with tomentum and long golden hairs.

Figures

Figure 1. Hintonelmis guianensis sp. nov. Male. Holotype. (a) Dorsal view; (b) ventral view. Scale bars = 0.5 mm. (c) Ventral view of genitalia. Scale bar = 0.1 mm.