Plistonax rafaeli Martins et al. (2006) : 270

Silva Júnior, José O., Haseyama, Kirstern L. F. & Souza, Diego de S., 2021, Phylogenetic approach redefines Plistonax (Coleoptera, Cerambycidae, Lamiinae) with new combinations and a new genus of flat-faced long-horned beetles, Organisms Diversity & Evolution (New York, N. Y.) 21 (2), pp. 491-520 : 513-514

Plistonax rafaeli Martins et al. (2006): 270 , fig. 5; Monné et al. (2017 a): 351 (type); Monné (2021) (cat).

Type locality: holotype (male) – Brazil, Amazonas , Manaus ( INPA) ( Fig. 15h ) .

Diagnosis. Antennomere III–V each with two dark-brown stains ( Fig. 2f ). Humerus and anterior elytral margin with distinct black stain ( Fig. 5c ). Elytra with one pair of small median-longidudinal white stains, and one pair of post-median black Y-shaped stains ( Fig. 5c ).

Redescription. Male (♂) ( Fig. 15h–i ). General surface covered with decumbent light-brown setae, merged with grayish and yellowish setae. Head. Large punctures. Gena of shorter in length than lower ocular lobe. Frons and margin of eyes with yellowish setae. Antenna. Pedicel about 1/4 length of scape; antennomere III slightly longer than scape; antennomere IV slightly smaller than scape; following antennomeres gradually decreasing in length. Antennomere V with two dark-brown stains, one near base and other subapical; antennomeres VI–XI each with only one dark-brown stain subapical; dark-brown stains intercalated by yellowish stains. Inner surface with distinct erect setae on antennomeres I–VII. Antenna reaching elytral apex at antennomere VIII. Prothorax. Pronotum with short lateral tubercle, covered by yellowish setae; median tubercle slightly elevated; one pair of median-longitudinal black bands at level of median tubercles. Prosternal process with lateral margin straight.

Mesothorax. Scutellum mostly covered by black setae, with distinct median-longitudinal yellowish band. Mesoventral process width smaller than diameter of mesocoxa; one pair of antero-lateral tubercles slightly elevated. Elytra. Median-basal crest starting from base, reaching post-median region, curved and with small ridges on anterior region. Tranversal black stains anteriorly, located between crests and elytral suture; small black stains on elytral slope; margin with yellowish stain. Internal semierect seta in punctures white, long and slim, tapered at apex, with near sulci each other ( Fig. 15l ). Elytral apex truncate. Legs. Femora with yellowish setae forming small clusters. Tibiae slightly expanded towards apex, with two dark-brown stains, intercalated by yellowish stains. Tarsomerus I covered with white setae, tarsomeres II–V mainly with dark-brown setae.

Abdomen. Segments I–IV entirely covered with yellowish setae, sparser at median region; segment V with sparse small setae. Male terminalia ( Fig. 16g, h, i, j, k, l ). Tegmen ( Fig. 16g ). Ringed part slightly convex, with anterior region strongly sclerotized, especially in margins; remaining surface membranous, apex rounded, without reentrance. Paramere narrowed towards apex, strongly sclerotized, with distinct weaker band at apex; basal region expanded laterally, with row of short setae; apex entirely covered by long setae; remaining surface with short and sparse setae. Endophallus ( Fig. 16h–i ). Median lobe strongly curved in lateral view, with dorsal lobe indistinguishable; ventral lobe entirely sclerotized, stronger at apex and lateral margins; apex slightly narrowed, with median deep invagination. Median strut membranous, smooth, with apex rounded. Internal sac with one pair of curved sclerotized structures anteriorly; three distinct sclerotized areas before half; one elongated sclerotized structure posteriorly, bifurcated in two rounded parts. Ventral arc ( Fig. 16j ). Membranous, with stem curved at apex; width subequal in stem and lateral projections. Tergites ( Fig. 16k–l ). Tergites VII and VIII both entirely and strongly sclerotized. Tergites VII and VIII longer than wider, entirely sclerotized. Tergite VII with posterior region covered with short setae, longer at apex, with base and apex rounded. Tergite VIII covered with short setae posteriorly and in center-median row, with base and apex truncate; anterior region with membranous apophysis.

Variation. Tranversal black stains on mid-basal region of elytra may be absent; internal semierect seta in elytral punctures may be dark-brown at central area of elytra; mesoventral process may be subequal in width to diameter of mesocoxa.

Measurements (mm). Total length (12.3–13.1); elytral length (8.4–9.1); pronotum length (2.6–2.9); humeral width (5–5.5); pronotum width (4.5–5).

Distribution. Brazil [Amazonas, Rondônia n.rec.] (Fig. S4c).

Remarks. We examined a specimen from the state of Rondônia ( Brazil) that is peculiar in having semierect seta in the elytral punctures that vary in color (white and dark-brown), a feature also present only in P. antonkozlovi within the genus. This species is very similar to P. ariasi and P. bialbomaculatus but has a distinct elytral pattern, especially in the presence of one pair of Y-shaped post-median dark stains. Apparently, the ratio of length of the scape compared to antennomeres II–IV is greater than in P. ariasi and P. bialbomaculatus , but more specimens are necessary to ascertain if this feature is constant. The male terminalia also differs from P. ariasi , most remarkably in the tegmen, which has parameres less sclerotized at apex and apex of ringed part without reentrance in P. rafaeli . On the other hand, the tegmen of P. ariasi has parameres with uniform sclerotization and a slight reentrance at apex of the ringed part.

Figures

Fig. 15 Plistonax inopinatus (a– g): a male’s dorsal habitus; b male’s ventral habitus; c female’s dorsal habitus (paratype); d fe- male’s ventral habitus (paratype); e lateral habitus; f head (anterior view); g semierect seta of the elytral punctures, character state 28:0 (thick), micrograph (from left to right, base and apex; zoom 1500×). P. rafaeli (holotype) (h– l): h male’s dorsal habitus; i male’s ventral habitus; j lateral habitus; k head (anterior view); l semierect seta of the elytral punc- tures, character state 28:1 (slen- der), micrograph (from left to right, base and apex; zoom 900×). Scale bars: 5 mm, except figures f, k (1 mm), g, and l (25 μm)

Fig. 2 Character photographs: a 2:0 frons with small punctures (anterior view, Aegomorphus jaspideus). b 2:1 frons with large punctures (anterior view, A. travassosi). c 21:0 mesoventral process with antero-lateral tuber- cles slightly elevated (lateral view, Plistonax albolinitus). d 21:1 mesoventral process with antero-lateral tubercles very ele- vated (lateral view, Acanthoderes (Acanthoderes) daviesii). e 4:1 male’s antennomeres VI–XI with tubercles in the inner surface and 11:1 male’s antennomeres IX–XI with black setae in the inner sur- face (lateral view, male of P. albolinitus). f 6:1 antennomere III with darker stain near apex, 7:1 antennomere III with darker stain near base, 8:1 antennomere IV with darker stain near base, 9:0 antennomeres IV–XI with darker stain near apex in subapical posi- tion, and 10:1 antennomeres III– VII with erect setae in the inner surface (dorsal view, P. rafaeli). g 9:1 antennomeres IV–XI with darker stain near apex in apical position (dorsal view, P. insolitus). White dashed lines highlight the character states 2:0 and 2:1; blue arrows highlight the character states 6:1, 7:1, 8:1, 9:0, and 9:1; red arrows highlight the character state 10:1. Scale bars: 1 mm

Fig. 5 Character photographs: a 22:0 elytron with sparse punctures (dorsal view, Aegomorphus travassosi). b 23:0 elytron with punctures mainly in the anterior half and 24:0 elytron with small punctures (dorsal view, Acanthoderes (Acanthoderes) daviesii). c 22:1 elytron with clustered punctures, 23:1 elytron with punctures occurring in all surface, and 24:1 elytron with large punctures (dorsal view, Plistonax rafaeli). d 27:1 elytral punctures with internal semierect seta (dorsal view, P. rafaeli). e 29:1 elytral punctures with decumbent seta inserted in the antero-upper re- gion. Scale bars: 1 mm, except figures d and e (0.5 mm)

Fig. 16 Male terminalia: Plistonax inopinatus (a–f): a tegmen (ventral view); b endophallus (ventral view); c endophallus (lateral view); d ventral arc (ventral view); e tergite VII (dorsal view); f tergite VIII (dorsal view). P. rafaeli (g–l): g tegmen (ventral view); h endophallus (ventral view); i endophallus (lateral view); j ventral arc (ventral view); k tergite VII (dorsal view); l tergite VIII (dorsal view). Points and gray shapes represent sclerotized structures. Scale bars: 0.5 mm