Anchimothon Fennah 1952

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 : 362-363

Genus Anchimothon Fennah 1952

Type species: Phaciocephalus parishi Muir 1918

Amended Diagnosis. Robust, moderate sized (5–7 mm, with wings) cenchreine derbids. Head smoothly rounded in lateral view, slightly projecting beyond eyes, in dorsal view much narrower than pronotum. Vertex roughly trapezoidal in dorsal view, broader at base than along midline, narrowing apically, apex concave (transverse apical carina absent) and posterior margin concave, lateral carinae foliate and raised (vertex medially concave), bearing 2 rows of pits, median carina obsolete. Frons compressed and relatively broad (narrower than Herpis Stål, 1862 and Oropuna Fennah, 1952 ; broader than Agoo , comparable to Omolicna ), narrowest between eyes, broadest slightly above frontoclypeal suture; lateral carinae foliate (contiguous with vertex), bearing a row of pits (with partial second row in widest portions); frons medially concave, median carina absent. Frontoclypeal suture approximately straight, clypeus elongate-triangular, bearing median carinae. Antennae short, scape very short, pedicle spheroid, bearing sensory plaques, flagellum bristle-like with bulbous base. Lateral ocelli distinct, in front of and slightly below antennae.

Pronotum along midline slightly narrower than frons, anterior margin following contours of head, posterior margin broadly concave, in lateral view, pronotum distinctly inclined posteriorly; paranota strongly foliate behind antennae, foliate margins, in frontal view, greatly exceeding antennae. Mesonotum along midline much longer than combined vertex and pronotum, width subequal to pronotum, tricarinate. Tegmina with subcostal cell long (vs. Cenchrea Westwood, 1840 ).

Pygofer narrowly quadrate in lateral view, medioventral process of pygofer large and elongate, longer than broad, apically rounded or truncate. Gonostyli elongate, in ventral view with mesally directed quadrate lobe proximally, apex medially curved and pointed. Aedeagus bilaterally asymmetrical, shaft in lateral view weakly upturned, generally bearing a variably bifid process on right lateral side and simple process on left lateral side and complex apical retrorse endosoma and processes. Anal tube elongate and slender (vs. Omolicna ).

Remarks. There are currently 11 genera represented in New World Cenchreini . Anchimothon can be diagnosed most readily from Herpis and Oropuna by having a narrower and more strongly concave frons (lacking a median carina). The frons of Anchimothon is broader than Agoo , Cenanges Fennah, 1952 and Contigucephalus Caldwell, 1944 . The head of Anchimothon , in lateral view, is smoothly rounded, not projected (as in Persis Stål, 1862 , subgenus Persis ) or obtusely angle (unlike Neocenchrea Metcalf, 1923 and Persis subgenera Anapersis Fennah, 1952 and Eritalaena Fennah, 1952 ), with foliately lateral carinae on the vertex. The genera Cenchrea and Tico are smaller than Anchimothon (~ 3 mm vs ~ 6 mm), have fewer closed cells in the forewing (e.g., cell C3aa is present in Anchimothon , absent in Tico and Cenchrea ) and the medioventral lobe of the pygofer is present in Anchimothon , absent in Tico and Cenchrea . The genus Omolicna is the most similar genus diagnostically and phylogenetically. Omolicna , as currently comprised, varies and may be heterogeneous. Compared with Omolinca proxima Fennah, 1945 , Anchimothon has the anterior margin of the vertex in dorsal view concave with the transverse carinae at the head apex absent (in Omolicna apex of vertex straight, transverse carina present). In Anchimothon , the medioventral lobe of the pygofer is large and apically rounded or truncate, lacking lateral projections, whereas in Omolicna the medioventral process usually has lateral projections (usually near apex, but sometimes near base, but there may be exceptions), gonostyli in ventral view with proximate quadrate median lobe (varied in Omolicna ). The definitive feature is that in Anchimothon the anal tube is relatively slender and elongate (exceeding the gonostyli), versus shorter and stouter in Omolicna and Anchimothon bears a bifid process on the right lateral side of aedeagal shaft. Fennah (1952) noted that the aedeagus of Anchimothon parishi was symmetrical (noted also by Caldwell 1944) and attributed this feature to the genus, but the processes of the endosoma and aedeagal shaft are asymmetrical.

Included species:

Anchimothon dubia ( Caldwell, 1944) — Mexico (Chiapas), Costa Rica

Anchimothon myriei sp. n. — Costa Rica

Anchimothon parishi ( Muir, 1918) — Guyana

Key to species of Anchimothon (males)

1. Dark species, forewing largely fuscous; male terminalia with apex of anal tube elongate, inflected in apical third to form outer concavity, bifid process on right lateral side small, processes asymmetrical, apices blunt ( Fig. 6A , process A1)...................................................................................................... myriei sp. n.

1.- Paler species; male terminalia with apex downcurved, but not greatly elongate.................................... 2

2. Bifid process on right lateral side with processes elongate, pointed caudad ( Fig. 1F )............................. dubia

2.- Bifid process on right lateral side with processes relatively short, angled laterad ( Fig. 1B )....................... parishi

Figures

FIGURE 1. Adult males of Anchimothon; (A) A. parishi, habitus, lateral view, (B) aedeagus right lateral view, (C) aedeagus left lateral view, (D) terminalia in ventral view, (E) A. dubia, habitus, lateral view, (F) aedeagus right lateral view, (G) aedeagus left lateral view, (H) and ventral view of terminalia (H); scale = 1 mm.

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