Myxia baynardi, Zumbado Echavarria & Barrantes Barrantes & Bartlett & Helmick & Bahder, 2021

Zumbado Echavarria, Marco A., Barrantes Barrantes, Edwin A., Bartlett, Charles R., Helmick, Ericka E. & Bahder, Brian W., 2021, A new species of planthopper in the genus Myxia (Hemiptera: Auchenorrhyncha Cixiidae) from the Reserva Privada el Silencio de Los Angeles Cloud Forest in Costa Rica, Zootaxa 4915 (3), pp. 351-363 : 356-359

Myxia baynardi sp. n.

( Figures 4–11 )

Type locality. Costa Rica, Alajuela, Reserva Privada el Silencio de Los Angeles , Hotel Villa Blanca .

Diagnosis. Body color dark fuscous. Basal third of forewing fuscous with conspicuous pterostigma. Vertex bicolored (fuscous anteriorly, pale caudad), relatively broad and flat. Gonostyli in ventral view strongly curved inward. Aedeagal shaft stout, aedeagus plus flagellum curled nearly into complete helix, bearing four processes on left lateral side (last two paired). Periandrium ring-like at base of aedeagus with elongate projection subtending aedeagus bearing two elongate, strongly hooked apical processes.

Description. Color. General body color dark brown. Fore and middle legs light brown and hind legs testaceous ( Fig. 4A & 4B ). Head with vertex bicolored, caudally tan, distally dark brown; frons dark brown, except pale marks above lateral portion of frontoclypeal suture; upper half of clypeus and genae below antennae white, grading to brown below ( Fig. 5 A–5C). Pronotum chestnut-brown. Mesonotum dark brown anteriorly becoming paler posteriorly with scutellum white (except brown adjacent to scutum; Fig. 5A ). Forewings distally clear, proximately darkened in proximal third of forewings plus brown patch along Sc+R vein to pterostigma (veins embrowned to wing midlength); middle of costal cell and basal half of clavus up to CuP light fuscous ( Fig. 6A ). Abdomen dark brown (reddish brown in females).

Structure. Body length males with wings (n = 4): 2.62–2.81 mm; males without wings 1.74–1.75 mm; females with wings (n = 18): 3.33–3.54 mm; females without wings 2.25–2.26 mm. Head. Head in lateral view obtusely rounded ( Fig. 5B ). Vertex (dorsal view) roughly quadrate, length males: 0.22–0.23 mm, females: 0.24–0.25 mm; width at hind margin males: 0.30–0.31 mm; females: 0.33–0.35mm; width at distal margin males: 0.19–0.20 mm; females: 0.22–0.24 mm; median carina nearly obsolete (strongest near posterior margin), broadest caudally, weakly narrowing distally (expanded slightly at apex) to weakly convex apex; fastigium (lateral view), smoothly rounded, bearing weak transverse carina ( Fig. 5A ). Frons broadly ovate, longer than wide, length males: 0.39–0.40 mm, females: 0.41–0.42 mm; dorsal width males: 0.19–0.20 mm, females: 0.21–0.22 mm; width at widest point males: 0.30–0.31 mm, females: 0.32–0.34 mm; frontoclypeal margin width, males: 0.28–0.29 mm; females: 0.30–0.31 mm; sides laterally carinate, convexly arched, narrowest and parallel-sided between eyes, expanding ventrally about to level of antennae, constricting at frontoclypeal suture, median carina evident, median ocellus distinct ( Fig. 5B ). Lateral ocelli conspicuous on genae below eyes at level of top of antennae; antennae bulbous, scape very short, pedicel about as wide as tall bearing conspicuous sensory plaques, flagellum bristle-like with bulbous base. Clypeus roughly triangular, median carina evident, length males: 0.12–0.13 mm; females: 0.14–0.16 mm.

Thorax. Pronotum short, length at midline males: 0.03–0.04 mm; females: 0.04–0.05 mm; convex anteriorly, concave posteriorly, roughly uniform width from midpoint to tegulae ( Fig. 5A ); median carina weak; postocular pronotal carinae almost obsolete, extending to ventral margin, approximate midpoint ( Fig. 7 ). Mesonotum slightly longer than wide; length at midline males: 0.54–0.55 mm; females: 0.55–0.56 mm; width males: 0.57–0.58 mm; females: 0.58–0.59 mm; tricarinate, lateral carinae, diverging posteriorly, reaching posterior margin ( Fig. 5A ).

Forewing ( Fig. 7 ) length males: 2.18–2.19 mm; females: 2.21–2.22 mm; bearing conspicuous pterostigma; veins punctate with setal bases (more conspicuous proximally); clavus reaching midlength, about level of Sc and fork of CA; fork of R proximal to apex of clavus. Branching pattern: RA one-branched, RP three-branched, MP four-branched, CuA two-branched (converging to form small C5 cell); fusion of Pcu and A 1 in clavus near claval midlength.

Terminalia. Pygofer in lateral view roughly triangular, broadest basally, narrowing dorsally; anterior margin concave, posterior margin sinuate, with distinct subbasal concavity ( Fig. 8A ); sides of pygofer with ridge (marking slight inward inflection of pygofer) arising from posterior margin in dorsal fourth, arching ventrad back to posterior margin at top of subbasal concavity, forming an irregular half-circle ( Figs. 8A & 8B ). In ventral view, ventral opening of pygofer with bluntly triangular medioventral lobe, terminating at rounded, knob-like apex ( Fig. 8B ). Gonostyli in lateral view ( Fig. 8A & 9 ) narrow basad, expanding midpoint, constricting with dorsal margin slightly serrate ( Fig. 9 ), apex broadly rounded with an anteriorly angled dorsal process ( Fig. 9 ); in ventral view, widest at base, strongly incurved, constricting distally, bearing subapical inner lateral tooth ( Fig. 8B ). Periandrium basally ring-like, not extending dorsally ( Fig. 10C ) but strongly developed ventrally as a ventral prolongation bearing 2 long acute processes; supporting dorsally an elongated well sclerotized aedeagus (enclosing ductus ejaculatorius). Aedeagal shaft (lateral view) simple, irregularly sinuate on dorsal and ventral margin ( Fig. 10 ), distally downcurved; sclerotized aedeagus plus membranous endosoma collectively arced into sinistral helix; entire structure roughly segregated into three parts, the thicker, sclerotized basal third and second a thinner sclerotized portion (collectively comprising the aedeagus), with a simple distal membranous endosomal apex (forming a membranous tubular sac); the downward directed distal portion of the aedeagus bearing 4 elongate processes ( Fig. 10A ), one arising near flagellar base on left ventro-lateral side (F1), a second arising on the left dorso-lateral margin (F2), and a terminal pair (F3& F4) directed anteriorly from a common base (F3 & F4), both slightly curved, F3 dorsal, F4 ventral ( Fig. 10 & Fig. 11 ). Anal segment (lateral view) short, broad, spatulate with downcurved, broadly rounded apex ( Fig. 8A ); in dorsal view, approximately as long as wide, lateral margins nearly parallel, apex irregularly rounded ( Fig. 8C ); paraproct in dorsal view, short and conical.

Plant associations. Palm ( Geonoma sp.), Arecaceae .

Distribution. Costa Rica (Alajeula).

Etymology. The specific name is given in honor of the senior author’s father, James Herbert Bahder, who was commonly called “Baynard” by friends and family.

Material examined. Holotype male “ Costa Rica, Alajuela / Los Angeles Cloud Forest / Coll.: B.W.Bahder / 16.V.2018 / Host: Geonoma sp. palm // Holotype / Myxia baynardi ” (FSCA) Paratypes, Los Angeles Cloud Forest [16 May 2018] (3 males, 18 females, FLREC) .

Remarks. The morphological features of Myxia baynardi sp. n. that are consistent with the genus Myxia especially include the form of the terminalia—having a short, stout, downward directed anal tube, and the periandrium separated from, and subtending, the aedeagus, in combination with the molecular evidence places this species in Myxia . However, Myxia baynardi sp. n. is dark colored (contrasting with the pale Myxia belinda and Myxia delta ). With a broad, smooth vertex (in contrast to the other two species with a relatively narrow vertex with lateral margins keeled making the vertex disc convex). Furthermore, the form of the aedeagal complex is unusual, having the aedeagus plus endosoma curled into a sinistral helix. Also, the demarcation between the endosoma and aedeagus is not entirely clear—while it is evident that the distal membranous portion is endosoma, it is entirely possible that the preceding sclerotized portion bearing the four processes also is part of the morphological endosoma. We anticipate that additional Myxia will be discovered and described in further survey work in the Caribbean basin and it will be of interest to see how this unusual taxon compares morphologically and molecularly to other Myxia taxa as they are discovered.

Figures

FIGURE 4. Adult habitus Myxia baynardi sp. n.; (A) body dorsal view male, (B) body lateral view male, (C) body dorsal view female, and (D) body lateral view female, scale = 1mm.

FIGURE 5. Adult Myxia baynardi sp. n.; (A) male head, pronotum, and mesonotum dorsal view, (B) male head and pronotum frontal view, and (C) male head, pronotum and mesonotum lateral view, scale = 1 mm.

FIGURE 6. Forewing venation of Myxia baynardi sp. n.

FIGURE 7. Habitus frontal view highlighting presence (white arrow) of carina on prothorax that terminates at midpoint of ventral margin of prothorax; illustration of generalized prothorax in frontal view highlighting the pronotal carinae (PC) orientation in Myxia and Myndus (A) and in Haplaxius (B).

FIGURE 8. Male terminalia of Myxia baynardi sp. n.; (A) lateral view, (B), ventral view, and (C) dorsal view.

FIGURE 9. Caudo-lateral view of male gonostylus for Myxia baynardi sp. n.

FIGURE 10. Aedeagus and periandrium of Myxia baynardi sp. n.: (A) right lateral view, (B), left lateral view, (C) dorsal view, and (D) ventral view.

FIGURE 11. Line art of aedeagus and periandrium of Myxia baynardi sp. n.: (A) right lateral view, (B), left lateral view, (C) dorsal view, and (D) ventral view.