Macratria tiriyo, Telnov, 2023

Telnov, Dmitry, 2023, New species and records of Macratriinae LeConte, 1862 (Coleoptera: Anthicidae) from the Americas with five new descriptions, Zootaxa 5389 (2), pp. 173-192 : 188-192

Macratria tiriyo sp. nov. ( Figures 11–13 )

https://zoobank.org/ 7AE98739-04A2-440A-AF50-426D19501FF3

Type material designated. Holotype ♂, BMNH: Brit.Mus.1939–370 [printed] // BRITISH GUIANA: New River . 750 ft. 15.iii.1938. C.A.Hudson. [printed]. The antennomeres 10–11 of the left, 5–11 of the right antenna and tarsomeres 3–5 of the right mesothoracic tarsus are missing.

Paratypes 2♂ & 2♀ BMNH: same labels as holotype .

Derivatio nominis. Named after the Tiriyó people, an Amerindian ethnic group of disputed Tigri Area, where the new species was collected. Noun in apposition.

Measurements, holotype male, total body length about 3.4 mm; head length 0.6 mm, head width across compound eyes about 0.65 mm, pronotal length 0.85 mm, maximum pronotal width about 0.6 mm, elytral length 2 mm, combined maximum elytral width 0.8 mm. Female paratype 3.6 mm long.

Description. Male ( Fig. 11A–B ). Dorsum and venter uniformly brown. Mouthparts, anterior frons, antenna and legs with exception of metathoracic femora yellow. Head subopaque dorsally and ventrally, broadly elliptical. Frons broad, about as wide as dorsal eye length.Compound eye large, occupying most of lateral side of head beyond antennal insertion, strongly protruding from lateral outline of head. Interfacetal setae moderately long, moderately dense. Tempus short, rounded towards head base. Head base subtruncate, shortly notched medially. Frontoclypeal suture or impression not observed. Head dorsal punctures small, dense, shallow. Intervening spaces smooth, narrower than to as wide as punctures. Head dorsal setae yellowish, subdecumbent, moderately dense, not concealing dorsal sculpture of head. Tactile setae sparse, erect, slightly longer than ordinary setae. Antenna slender and filiform, thickened distally, extending towards base of pronotum when directed posteriorly. Basal antennomere elongate, about 1.5× as long as antennomere two. Antennomere three about as long as each of antennomeres two and 4–7. Antennomere 8 widened distally, 9–10 enlarged, thickened and widened. Terminal antennomere elongate fusiform, apically pointed, about 1.5× as long as penultimate antennomere, shorter than combined length of antennomeres 9–10. Terminal maxillary palpomere nearly axeform. Pronotum subopaque dorsally and on prothoracic hypomeron, flattened in dorsal aspect, subrectangular, slightly narrower than head across compound eyes. Anterior margin truncate. Lateral margins slightly constricted posteriorly. Dorsal pronotal punctures larger, denser and deeper than those on head. Intervening spaces somewhat raised, distinctly narrower than punctures. Pronotal dorsal setation dirty yellowish, decumbent, dense, effectively concealing dorsal sculpture of pronotum. Base of pronotum without area of dense setae. Tactile setae sparse, erect, not longer than ordinary setae. Scutellar shield small, truncate at posterior margin, densely setose. Elytron elongate, subopaque, hardly narrows posteriorly. Humerus broadly rounded. Postbasal transverse impression not indicated. Punctures on elytron arranged into six flat, poorly defined longitudinal rows. Intervening spaces between rows minutely punctate to microstrigose. Elytral setation dirty yellowish, moderately long, decumbent, dense, directed posteriorly, effectively concealing dorsal sculpture of elytron. Those setae in rows of punctures longer and thinner, directed strongly posteriorly. Lateral humeral stria not shifted dorsad, not visible in dorsal view. Sutural stria complete, moderately broad. Metathoracic wing fully developed. Legs long. Femora clavate. Tibia short, stout, distally widened, densely setose. Prothoracic tarsus elongate, basal and penultimate protarsomeres strongly widened. Tibial terminal spurs paired, serrate, metathoracic tibial spurs long than those of other tibiae. Basal metathoracic tarsomere 1.3× as long as combined length of remaining metathoracic tarsomeres. All pretarsal claws dentate at base. Male tergite VII elongate, broadly emarginate at posterior margin ( Fig. 12A ). Male morphological sternite VII rather short and broad, sinuous and densely setose at posterior margin ( Fig. 12B ). Male tergite VIII broadly, U-shapely emarginate at posterior margin, with narrow lateral arms; morphological sternite VIII deeply, broadly cleft towards base, lobes acute apically ( Fig. 12C ); sternite IX V-shaped. Aedeagus ( Fig. 12D–E ) with basale more than twice as long as apicale. Paramere short, apically asymmetrically produced inwardly. Median lobe apically tripartite, its lateral prongs short and only shortly divided.

Sexual dimorphism. Female ( Figs 11C–D , 13 ) externally close to male, somewhat larger and more stout, terminal antennomere about twice as long as penultimate and slightly shorter than combined length of antennomeres 9–10. Female tergite VII somewhat tripartite at posterior margin ( Fig. 13A ), morphological sternite VII somewhat produced and medially subtruncate at posterior margin ( Fig. 13B ). Female tergite VIII as in Fig. 13C . Ovipositor as in Fig. 13D .

Differential diagnosis. Macratria tiriyo sp. nov. slightly reminds M. basicollis Pic, 1942 (Brazilian Amazon) but differs in the comparatively shorter compound eyes and the shorter tempora, the notched head base (evenly broadly rounded in M. basicollis ), the coarser punctured pronotal dorsum, the comparatively stronger decumbent dorsal vestiture and the more prominent rows of the elytral punctures in anterior half of the elytron (elytral punctures either scattered, not arranged into rows in M. basicollis or the rows indistinct).

Ecology. Currently known from a lowland rainforest area of about 228 m elevation.

Distribution. Tigri Area, Guyana / Suriname. The exact position of the type locality remains unknown (the New River or the Upper Corantyne River forms the Western border of the Tigri Area, a disputed territory that is controlled by Guyana and claimed by Suriname). The first Macratria record for the faunas of both Guyana and Suriname.

Figures

FIGURE 11. Macratria tiriyo sp. nov. A—Holotype ♂, habitus, dorsal view; B—Ditto, forebody, dorsal view; C—Paratype ♀, habitus, dorsal view; D—Ditto, head and antennae, dorsal view [not to scale].

FIGURE 12. Macratria tiriyo sp. nov., holotype ♂. A—Tergite VII, dorsal view; B—Morphological sternite VII, ventral view; C—Tergite VIII and morphological sternite VIII, ventral view; D—Aedeagus; E—Aedeagus, apicale, enlarged [not to scale].

FIGURE 13. Macratria tiriyo sp. nov., paratype ♀. A—Tergite VII, dorsal view; B—Morphological sternite VII, ventral view; C—Tergite VIII, dorsal view; D—Ovipositor [not to scale].