Anchimothon myriei Bahder & Bartlett, 2022

Bahder, Brian W., Barrantes, Edwin A., Zumbado Echavarria, Marco A., Helmick, Ericka E. & Bartlett, Charles R., 2022, A new species of planthopper in the genus Anchimothon (Hemiptera: Auchenorrhyncha: Derbidae) on palms from Costa Rica, Zootaxa 5169 (4), pp. 359-370 : 363-368

Anchimothon myriei Bahder & Bartlett sp. n.

( Figures 2–6 )

Type locality. La Selva Biological Station , Heredia, Costa Rica .

Diagnosis. A dark species (vs. congeners) with head and prothorax light orange, washed fuscous posterior, legs nearly white, wings nearly black. Medioventral process of pygofer broad, apically truncate. Gonostyli (ventral view) with proximal medial lobes in form of broad hooks. Bifid process on aedeagus shaft on right lateral side (near midlength) with obtusely rounded apex of ventral process, single, small process on left lateral side. Anal tube (in lateral view) with lobe on ventral margin, apex (formed by distal lateral margins) elongate and strongly downcurved with distinctive anterior inflection in apical third.

Description. Color. General body color fuscous, head bright yellow-orange, frons medially darker orange with lateral carinae brown, prothorax yellow-orange, washed with fuscous medially on pronotum; mesonotum brownish orange with reddish hints, especially along carinae. Wings, dark fuscous to black, paler along margins and clavus, veins at apex red, distal portion of costal cell and subcostal cell yellow, A1 vein and anal cells yellow, becoming red distally.

Structure. Body length (with wings), male 5.01–5.02 mm (n=9; Table 1 ). Head. In dorsal view, head much narrower than pronotum, vertex trapezoidal, narrowing distally concave at anterior and posterior margins basal width about 2x as wide as distal margin, wider than long at midline, lateral carinae foliate, bearing two rows of large pits, disc of vertex concave ( Fig. 3A ). In frontal view, transverse carina lacking at fastigium, frons laterally keeled (keels contiguous with vertex), narrowest at fastigium, slightly expanding ventrally, widest a little above frontoclypeal suture, then narrowed to frontoclypeal suture; median carina absent, lateral margin bearing irregular sized row of pits (plus partial second row) along entire length of lateral margins ( Fig. 3B ). Head in lateral view, rounded, somewhat projecting in front of eyes ( Fig. 3C ). Compound eyes ventrocaudally emarginated for antennae. Antennae short, scape ring-like, pedicle spheroid bearing irregularly arranged sensory plaques, flagellum elongate, bristle-like with bulbous base. Lateral ocelli distinct, located slightly in front of and below antennae.

Thorax. In dorsal view, pronotum about twice as wide as head (subequal to mesonotum), at midline about ¾ length of vertex; anterior margin of prothorax moderately convex (following contours of posterior margin of head), posterior margin concave ( Fig. 3A ); in lateral view, paranota of prothorax greatly foliate forming cup-like structures behind antennae ( Fig. 3C ); in frontal view, foliate expansions greatly exceeding antennae, apex nearly quadrate ( Fig. 3B ). Mesonotum in dorsal view about as wide as long (subequal in width to pronotum), tricarinate, lateral carinae subparallel, sinuate, all carinae extending nearly to posteriorly margin, becoming obsolete posteriorly; two indistinct spurious carinae extending from near midlength of lateral carinae to lateral corners of mesonotal margin (evident also in lateral view), in lateral view, mesonotum arched ( Fig. 3C ). Tegulae large and conspicuous ( Fig. 3A ). Spinulation of hind tibia, basitarsus, and second tarsomere 5-6-6.

Forewing ( Fig. 4 ) with tubercles along composite vein Sc+R(+M) and A1 veins (and faintly along portion of costal near apex of Sc). Apex of clavus near wing midlength (about at level of Sc apex). Fork of Sc+RA from RP in basal quarter of wing, creating a very long C1 cell. Sc reaching wing margin just past wing midlength creating a relatively short cell between apices of Sc and RA (the ‘subcostal cell’ of Fennah 1952). Vein branching pattern RA 1-branched, RP 3-branched, MP 5-branched, CuA 2-branched. In clavus, CuP fused with Pcu near claval midlength with A1 joining composite vein much closer to claval apex, composite vein intercepting icu near wing apex (as similar claval vein arrangement is seen in Omolicna mariajosae Bahder and Bartlett, 2021 , in Echavarria et al. 2021).

Terminalia. Pygofer in lateral view roughly elongate-quadrate, narrowest dorsad, expanding ventrad, anterior and posterior margins irregularly sinuate ( Fig. 5A ). In ventral view, medioventral process large, longer than wide at base, nearly quadrate, apex nearly truncate with rounded corners, slightly invaginated at midpoint ( Fig. 5B ). Gonostyli, in lateral view, broad, ventral margin with a broad rounded lobe proximally, distally broadly rounded to apex; dorsal margin with a complex process proximally (bearing a rounded distal projection and a biramous curved process)broadly angled distally, apex dorsal acuminate projection ( Fig.5B ); in ventral view, narrow and parallel-sided curved mesad, bearing a proximate, quadrate a process (apex rounded, proximal apex hooked cephalad, appearing avicephaliform) on inner margins at approximately 1/4 length from base, ( Fig. 5B ); apex sharply pointed, angled mesad ( Fig. 5B ). Aedeagus robust, asymmetrical, shaft angled slightly upward, bearing three processes: a bifurcated process near midlength on right lateral side (A1), ventral bifurcation longer, truncate (A1a), dorsal bifurcation shorter, pointed (A1b, Fig. 6A ), second process arising on left lateral side on dorsal margin, strongly curved caudad (A2, Fig. 6B ) and third process arising basally, extending to left lateral side (A3). Endosoma complex, bearing 5 sclerotized retrorse apical processes: including a pair (E1 & E2) of long, relatively narrow, heavily sclerotized, reaching midpoint of shaft, apices twisted, E1 slightly longer than E2 ( Fig. 6C ), a second pair (E3 & E4, subtending E1 & E2) more robust and similar in length (E4 just exceeding E3), exceeding E3, membranous proximally, more sclerotized distally, apex of E3 greatly constricted to acute process, E4 apex curved mesad with blunt apex ( Fig. 6 ), final single process narrow arising on left lateral side (E5), sclerotized, similar in length to E3( Fig. 6 ). Anal tube very elongate and slender, in lateral view sinuate on dorsal margin, ventral margin with broad, rounded lobe in distal third; apex bifurcated, elongate and strongly curved ventrad, abruptly angled near midlength bearing small knob on distal margin, outer surface concave after knob ( Fig. 5A ), in ventral view, bifurcations of apex crossed ( Fig. 5B ).

Plant associations. Geonoma sp. (Arecaceae) , a palm.

Distribution. Limón Province, Costa Rica.

Etymology. The specific name is given in honor of Dr. Wayne Myrie, whose collaboration has been critical in the discovery of new planthoppers.

Material examined. Holotype male “ Costa Rica, Heredia / La Selva Biological Station / 15.V.2018 / Coll.: B.W. Bahder, sweeping palms / Holotype Anchimothon myriei ♂ ” ( FLREC); paratypes same as holotype (3 males, 6 females, FLREC and FSCA).

Sequence Data. For COI, a 707 bp product was generated (GenBank Accession No. ON231398 ) and for 18S, a 1,431 bp product was generated (GenBank Accession No. ON230027 ). The Maximum Likelihood analysis for COI placed A. myriei sp. n. in a clade adjacent to Omolicna with weak bootstrap support (70), however it did not resolve adjacent to A. dubia , which was placed within Omolicna ( Fig. 7A ). Statistical support for relationships based on COI were weak (mostly <70). For 18S, Anchimothon resolved as a clade with good bootstrap support (90). The consensus analysis of concatenated COI and 18S data also show good bootstrap support (85) for placing A. myriei sp. n. adjacent to A. dubia , supporting placement of the novel taxon in Anchimothon . However, the placement of Anchimothon adjacent to Omolicna had weak bootstrap support (53).

Remarks. The novel taxon conforms to Anchimothon based on morphology as the genus is currently understood. A synoptic genus diagnosis, compared with other New World cenchreines, would be vertex trapezoidal with apex concave (in dorsal view), apical transverse carina absent, medioventral process of pygofer large and apically rounded (or truncate, without lateral projections), gonostyli in ventral view elongate, proximal median margin bearing a quadrate lobe, anal tube narrow and greatly elongate. Anchimothon dubia , A. myriei sp. n. and A. parishi all have a bifurcated process on the right side of the aedeagus and simple process on the left which appears to be a genus-level feature. The form of the medioventral process of the pygofer and shape of the parameres, are similar in form among the species currently in Anchimothon .

The monophyly of Anchimothon is generally supported (despite the absence of molecular data for A. parishi ) by the combined COI and 18S molecular data. While COI generally is not a reliable phylogenetic marker in derbids, it is helpful for delineating closely related species; the data generated for 18S is far more useful for constructing phylogenies among genera of Cenchreini .

Figures

FIGURE 2. Adult male habitus of Anchimothon myriei sp. n.; (A) lateral view and (B) dorsal view; scale = 1 mm.

FIGURE 3. Adult Anchimothon myriei sp. n.; (A) head, pronotum and mesonotum dorsal view, (B) head, pronotum, and mesonotum frontal view, and (C) head and pronotum lateral view; scale = 1 mm.

FIGURE 4. Forewing venation of Anchimothon myriei sp. n.; black = vein, italics = crossvein, green = cell.

FIGURE 5. Male Anchimothon myriei sp. n. terminalia; (A) lateral view, (B) ventral view, and (C) dorsal view.

FIGURE 6. Aedeagus of Anchimothon myriei sp. n.; (A) left lateral view, (B) right lateral view, (C) dorsal view, and (D) ventral view.

FIGURE 7. Maximum likelihood phylogenetic tree based on 1,000 replicates; (A) COI gene, (B) 18S rRNA gene, and (C) consensus tree of concatenated COI and 18S sequences; scale bar = percent nucleotide difference.