Perigracilia exigua ( Zayas, 1975 ) Devesa & Santos-Silva, 2021

Devesa, Sergio & Santos-Silva, Antonio, 2021, Transference, descriptions, and notes on Cuban Graciliini (Coleoptera, Cerambycidae, Cerambycinae), Zootaxa 4908 (4), pp. 527-536 : 528-530

Perigracilia exigua ( Zayas, 1975) , comb. nov.

( Figs 1–9 , 16–17 )

Merostenus exiguous Zayas, 1975: 122 ; Chemsak et al., 1992: 54 (cat.).

Merostenus exiguus ; Monné, 1993: 3 (cat.); Monné & Giesbert, 1994: 82 (checklist); Peck, 2005: 171 (distr.).

Caribbomerus exiguus ; Vitali & Rezbanyai-Reser, 2003: 12; Monné, 2005: 48 (cat.); Lingafelter, 2011: 37;

Caribbomerus exiguous ; Devesa et al., 2015: 32, 254.

Merostenus decoratus ; Nearns et al., 2006: 8, fig. 5a. (holotype, error).

Zayas (1975) described M. exiguous as follows (translated from Spanish): “ Merostenus exiguous sp. nov. (Plate 15; fig. c). Unicolorous, very thin, brown and slightly shiny. Head with antennal tubercles wide and elevated, depressed between them. Antennae very thin, more than twice body length; scape cylindrical, thickened and short, antennomere III somewhat arched, as long as IV, the remaining antennomeres longer and more slender. Pronotum is sometimes almost as wide as elytra, subcylindrical, flattened in disc, slightly narrowed laterally from middle, confluently punctate and with thin and short pubescence, tiny, especially toward sides. Elytra about as wide as eyes [width between outer margins of the eyes], short, separately rounded at apex, and with surface similar to that of the pronotum; both as narrowed, it posterior half is entirely flattened. Legs very short, flattened, with the femora thickened. Length 4 mm. Described based on three specimens, collected in Siboney, Oriente, in July 1944; another in Sierra Maestra, in Turquino, in 1964. Species easily separable due to its small size, the almost equal length of the pronotum and elytra, and the shape of them.”

Zayas (1975) did not report the number of antennal segments. Furthermore, the figure on the plate 15 is not the “c,” but “e,” as indicated in Tavakilian & Chevillotte (2020). Lingafelter (2011) correctly reported that the figures of the types of Merostenus exiguus and M. decoratus were inverted in Nearns et al. (2006). However, this correction was not incorporated in Monné (2020) and Tavakilian & Chevillotte (2020). It is important to point out that the drawing in the original description of M. exiguous (Plate 15, fig. e) does not agree with the holotype and paralectotype of the same species. That is because the antennae are much shorter than they really are, and are 11-segmented in the drawing.

It is also important to note that Nearns et al. (2006) reported their figure “5a” as being the holotype of M. decoratus , and the figure “5b” as the holotype of M. exiguus . As M. decoratus ( Figs. 24–26 ) was described from a single specimen, despite the inversion of the figures, it is correct to say that there is a holotype of this species.

However, M. exiguus was described from four specimens (three from “Siboney, Oriente, July 1944 ” and one from “Turquino, Sierra Maestra, June 1964 ”) and, as was not designated a holotype, there are four syntypes (not holotype as in Nearns et al. (2006), Monné (2020), Tavakilian & Chevillotte (2020), and Devesa et al. (2015)). Actually, only three specimens remain in the Zayas collection: two from “Siboney” and one from “Sierra Maestra, Turquino”.

Examination of the three syntypes in Zayas collection allowed us to see that the two specimens from “Siboney” ( Figs. 1–3 , 16–17 ) are really M. exiguus . However, the syntype from “Sierra Maestra, Turquino” (now a paralectotype of M. exiguus and holotype of Caribbomerus zayasi sp. nov.) ( Figs. 18–23 ) belongs to a different species. Fernando de Zayas only added type label (“Typus”) in one of the four specimens used by him to describe M. exiguus . As there are some mistakes and omissions regarding the identity of M. exiguous , we designated a male specimen as lectotype for the nomenclatural stability of this species. The lectotype ( Figs. 1–2 ) has the following labels ( Fig. 3 ):

1. Rectangular, mostly beige, handwritten: Merostenus exiguos / Zayas;

2. Circular, red, printed: Typus;

3. Rectangular, white, printed and handwritten: P. de Siboney Ote [printed] / VII [handwritten] 19 [printed, followed by the handwritten final part of the year, which is unreadable];

4. Rectangular, red, printed [added by us]: LECTOTYPE.

Monné (1993) corrected the species group name from “exiguous” (reported as “exiguos” in the labels, and as “exiguus” in the explanation of the figure 15e), to “exiguus.”

Vitali (2003) replaced Merostenus White, 1855 to Caribbomerus due to the homonymy with Merostenus Walker, 1837 . However, the lectotype, paralectotype from Siboney, as well as all specimens (males and females) of Caribbomerus exiguus examined by us do not belong to Caribbomerus .

Linsley (1942) described Perigracilia as follows: “Male: Form elongate, very slender, subcylindrical. Head nearly one and one-fourth times as wide as pronotum at apex, perceptibly wider than pronotum at base […] antennae twelve-segmented, about two and one-half times as long as body, not ciliate, segments three to six, distinctly swollen at apex […] twelfth segment longest, about one and one-fifth times as long as eleventh […] Thorax elongate; pronotum nearly twice as long as apical width, narrowly constricted at base, broadly and shallowly before apex, base wider than apex, broadly emarginate, sides widest in front of base, thence gradually narrowed to apex, apex truncate […] Elytra nearly three times as long as basal width, a little shorter than the abdomen […[Legs moderately short; femora strongly clavate, subpedunculate […] Abdomen with first sternite at middle not longer than second sternite.” This description agrees well with Caribbomerus exiguus , especially the number of antennal segments, elytra shorter than abdomen, and femora strongly clavate, which are not present in Caribbomerus . Accordingly, we transferred C. exiguus to Perigracilia .

The geographical distribution of Perigracilia becomes so very discontinuous since the other two species ( P. delicata Knull, 1942 (Arizona, USA) and P. tenuis Linsley, 1942 ( Mexico, Baja California Sur )) are known from western North America.

All specimens of Perigracilia exigua examined by us are males, and the antennal length is considerable variable. However, the prothorax length and shape, elytral length and shape, and abdominal shape are noticeably constant.As only males of P. tenuis Linsley, 1942 , and P. delicata Knull, 1942 are also known, it is not possible to know whether females of this genus also have the antennae12-segmented.

Material examined (in addition to the specimens of the type series). CUBA, Sancti Spiritus: Topes de Collantes , mirador , 15.III.2010, 1 male, S. Devesa col. ( SDPC) ; III.2012, 2 males, S. Devesa col. ( SDPC) ; 17.III.2013, 1 male, S. Devesa col. ( SDPC) . Santiago de Cuba: Siboney, reserva Jutici , 15.VII.2009, 1 male, S. Gutiérrez col. ( SDPC) ; 21.II.2011, 11 males, A. Barro, R. Núñez & D. Saladrigas col. ( SDPC) ; Sigua , 19.II.2011, 1 male, A. Barro, R. Núñez & D. Saladrigas col. ( SDPC) .

Figures

FIGURES 1–9. Perigracilia exigua. 1–3) Lectotype male of Merostenus exiguous: 1) Dorsal habitus; 2) Head and pronotum, frontal view; 3) Labels. 4–9) Males: 4) Specimen 1, ventral habitus; 5) Specimen 1, dorsal habitus; 6) Specimen 1, lateral habitus; 7) Specimen 2, dorsal habitus; 8) Specimen 1, head and pronotum; 9) Specimen 3, dorsal habitus.

FIGURES 16–26. 16–17) Paralectotype male of Merostenus exiguous (= Perigracilia exigua), dorsal habitus. 18–23) Caribbomerus zayasi sp. nov. (paralectotype of Merostenus exiguous): 18) Dorsal habitus; 19) Lateral habitus; 20) Lateral habitus showing entire antennae; 21) Pronotum; 22) Upper eye lobes; 23) Original label. 24–26) Merostenus decoratus, holotype male: 24) Dorsal habitus; 25) Lateral habitus; 26) Labels.