Oecleus urru Bahder & Bartlett 2023, sp. n.
Creators: name: Zumbado Echavarria, Marco A.
name: Barrantes Barrantes, Edwin A.
name: Bartlett, Charles R.
name: Helmick, Ericka E.
name: Bahder, Brian W.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Cixiidae
Oecleus
Oecleus urru

description: Oecleus urru Bahder & Bartlett sp. n.
(Figures 1–5)
Type locality. Cotinga Biological Station, Puntarenas Province, Costa Rica.
Diagnosis. Moderate-sized (~ 6 mm) species with a golden-brown coloration and five carinae on the mesonotum and head slightly projecting beyond the eyes. Male terminalia with elongate pygofer bearing a broad, rounded medioventral process, apically concave.Aedeagal shaft without processes or lobes near base or midlength, bearing 2 subapical processes (right process much longer than left, exceeding half-length of shaft), endosoma with 2 processes, both less than half length of shaft (proximal process short and straight, distal exceeding endosomal apex). Anal tube, in lateral view much broadened distally, ventrally convex, distally forming large, quadrangular lobes.
Description. Color. General body color in males pale yellow with fuscous wash, darkly infuscated in concavities (Fig. 1). Frons and genae dark brown (carinae pale), clypeus dark brown below antennae, otherwise paler; ocelli reddish. Carinae of mesonotum stramineous, region between lateral carinae strongly infuscate (carinae pale).
Structure. Body length males (n = 4): 6.02–6.05 mm with wings; 4.22–4.25 mm without wings (Table 3). Head. Anterior margin (lateral view, Fig. 2A) of head rounded (with slight keel on fastigium corresponding to transverse carina), weakly projected in front of eyes, vertex and face (below fastigium) weakly convex. Vertex very narrow (dorsal view, Figs 2B, median carina absent), trough-like, broadest at fastigium, narrowed posteriorly, lateral keels foliate, nearly in contact at posterior margin, apex with transverse carinae. Frons in frontal view (Fig. 3A) elongately oval, foliately keeled on lateral margins, median carina distinct, becoming obsolete near fastigium, dorsal margin “U-shaped”, lateral margins sinuate, narrowest between eyes, distinctly expanding to level of antennae, widest just above frontoclypeal suture; median ocellus distinct just above frontoclypeal suture; frontoclypeal suture approximately straight (angled slightly ventrad at lateral margins), clypeus triangular with distinct median carina. Antennae bulbous with scape ring-like and very short (Figs. 2A, C), pedicle rounded (as wide as tall) bearing many sensory plaques, flagellum elongate, bristle-like with bulbous base. Lateral ocelli distinct below compound eye, anterior to antennae.
Thorax. Pronotum short in dorsal view (Fig 2B), anterior margin hidden by head posterior margin concave; disc with median carina nearly obsolete, laterally flanked with serpentine oblique carinae, lateral margins with carinae between tegula and eye; in lateral view (Fig. 2A), paradiscal region broad forming rough parallelogram between ventral margin and lateral carina. Mesonotum longer at midlength than vertex plus pronotum combined (Fig. 2B), disc bearing five carinae, lateral and intermediate carinae subparallel, slightly serpentine.
Wings transparent (Fig. 3), inconspicuous setae-bearing nodes along veins, forewings with a distinct stigma. Forewings elongate-oval, with leading and trailing sides approximately parallel-sided (leading margin arched); apex of clavus exceeding forewing midlength, Pcu+A1 fused before claval midlength, composite vein reaching wing margin well before CuP, combined vein stem ScP+R+MP forming long stem from basal cell, fork of MP from ScP+R at level with fusion of Pcu+A1; fork of RP from ScP+RA near wing midlength; CuA forked close to claval margin distal. Branching pattern RA2 two-branched, RP 3-branched, MP 5-branched of anterior trifid Type (Le Cesne et al., 2021); CuA 2-branched, distally anastamosed after nodal line forming the characterical oecleininian diamond C5 cell (=‘procubital cell’, Emeljanov 1996]); crossveins ir, r-m, im, m-cu and icu present, the later very short joining distal extremity of CuP.
Terminalia. Terminalia approximately bilaterally symmetrical. Pygofer in lateral view broad (Fig. 4A), narrowest at dorsal margin, greatly expanded ventrally, ventral margin irregularly sinuate, with invagination just before medioventral process, posterior margin convex, anterior margin concave, irregularly sinuate. In ventral view (Fig 4B), medioventral process rounded with invagination at apex, slightly wider than long, attached to a trapezoidal base bearing lateral ridges, appearing “crown-like”. Gonostyli in lateral view (Fig 4A) slender, expanded in distal half, dorsal margin bearing two small triangular projections near apex, apex rounded, ventral margin with 1 small rounded projection near apex; in ventral view (Fig. 4B), margins subparallel, curving mesad, forming subtriangular apices, inner margins with bifurcated hooked process curving subapically. Aedeagus slender (Fig. 5), shaft lacking processes or lobes except two slender subapical retrorse processes (A1 & A2) on lateral margins, right lateral process (A2) elongate, reaching just past midpoint, slightly curved distad and ventrad, left lateral process (A1) approximately half the length of A2, curved distad and ventrad. Endosoma with two processes (E1 & E2); E1 proximad, arising on left lateral margin, directed dorsad, short, not reaching base of second process (E2), E2 more distad, arising subapically on left lateroventral margin, elongate and directed dorsoventrad, nearly reaching base of aedeagus, endosoma helical, completing one rotation around axis from base to apex (Fig. 5). Anal tube in lateral view (Fig. 4A) greatly enlarged distally and strongly downcurved (forming pair of quadrangular lateral flanges), basis narrow; in dorsal view (Fig. 4C), obovate, narrowed distally; paraproct elongate lingulate.
Plant associations. Unknown; collected sweeping edge habitat, predominantly grasses.
Distribution. Cotinga Biological Station, Puntarenas Province, Costa Rica (8.621825, -83.478819).
Etymology. The specific epithet is a reference to the aedeagus in a left lateral view resembling the head of the urru from the film “The Dark Crystal”.
Material examined. Holotype male “ Costa Rica, Puntarenas Pr. / Cotinga Biological Station / 16.VII.2021 / Coll.: B.W.Bahder // Holotype / Oecleus urru ♁ ” (FLREC); Paratypes 1 male, 3 females, same data as holotype (FSCA).
Sequence data. For the COI locus, a 700 bp product was generated (GenBank Accession No. OQ749902), for the 18S locus, a 1,399 bp product was generated (GenBank Accession No. OQ745735), and for the H3 locus, a 344 bp product was generated (GenBank Accession No. OQ744000). Based on the phylogenetic analyses of the COI, 18S, and H3 loci and the consensus analysis (Fig. 6), Oecleus urru sp. n. resolves adjacent to O. dormido (Fig. 6D). Based on the consensus tree, Oecleus (assessing the three taxa available here) is monophyletic with strong bootstrap support (99). This is also seen in the 18S phylogeny (91 bootstrap support) (Fig. 6B). Based solely on COI or H3, Oecleus is not monophyletic (Fig. 6A & 6C). Despite this, Oecleus urru sp. n. resolves adjacent to O. dormido for COI, 18S, H3, and in the consensus tree with strong bootstrap support, respectively 97, 91, 99, and 99.
Based on the pairwise comparison of the 18S gene for taxa assessed, the average variability within genus is 0.3% (±0.1), 0.6% (±0.3), 0.5% (±0.1), and 0.8% for Oecleus, Myxia, Haplaxius, and Nymphocixia respectively (Table 4), while the variability among genera is an average of 2.1% (±0.04). Oecleus urru sp. n. differs from O. borealis and O. mackaspringi by 0.1% and 0.5%, respectively. However, Oecleus urru sp. n. is 100% identical to O. dormido at the 18S locus. For the COI gene, Oecleus urru sp. n. differs from O. dormido by 8.2% and approximately 14% compared to O. borealis and O. mackaspringi (Table 5). For the H3 gene, Oecleus urru sp. n. differs by 0.6% to O. dormido and 7.2% and 12.5% to O. borealis and O. mackspringi, respectively (Table 6).
Remarks Oecleus urru sp. n. is placed in Oecleus based on both morphological (lacking spines on hind tibia, trough-like vertex, head slightly projecting, and five longitudinal carinae on mesonotum) and molecular features based on analysis of three independent loci.
Most species of Oecleus are treated (described or redescribed) in Kramer (1977) for forms north of Mexico and Caldwell (1944) for Mesoamerican forms. Caldwell (1944) does not provide a key but does illustrate terminalia. Oecleus urru sp. n. can be separated from the 13 illustrated forms by the shape of the medioventral lobe (most of the forms illustrated by Caldwell, 1944, have elongated, not rounded, medioventral lobes) along with the shape of the anal tube; and from the two species O. seminiger Stål, 1862. O. apicatus Caldwell 1944) by Caldwell’s descriptions (and for O. seminiger the illustration in Fowler, 1904).
Using the key in Kramer (1977), the new species keys most readily to couplet 24, a choice between O. chrisjohni Kramer 1977 (from southcentral US) and O. lineatus Ball, 1902 (from southwestern US). The main diagnostic features used in the key include the aedeagus shaft with 2 subapical processes (right process much longer than left, exceeding half-length of shaft), aedeagal shaft without lobes or projections at midlength or base, endosoma with 2 processes, both less than half length of shaft (proximal process short and straight), anal tube much broadened distally, medioventral lobe of pygofer rounded with apex indented. O. urru sp. n. most strongly resembles O. lineatus in structure, but differs most obviously in the shape of the medioventral lobe (more broadly rounded with an apical concavity in O. urru sp. n.), the lengths of both aedeagal (right about twice length of left in O. urru sp. n., subequal in length in O. lineatus) and endosomal (proximal much shorter than distal in O. urru sp. n., proximal marginally shorter than distal in O. lineatus) processes, and the anal tube more greatly enlarged and projecting in O. urru sp. n.).
Oecleus species not treated in Caldwell 1944 and Kramer 1977 are described in O’Brien (1982), Emeljanov (2007), Bartlett et al. (2018), and Barrantes et al. (2022), but none of these species are closely similar to O. urru sp. n.
While the level of variability between Oecleus urru sp. n. and O. dormido for COI is lower than that observed with other species, it is still within an acceptable level of interspecific variation (i.e. H. pocococo and H. dougwalshi differ by 10.2% according to Barrantes et al. (2021)). The variability between the two species for H3 shows a substantially smaller difference (0.6%) when other species differ by approximately 7%. Finally, the observation that 18S was identical between Oecleus urru sp. n. and O. dormido is interesting. Under most circumstances, there is some measurable level of variability in 18S among species in the same genus but recently it was shown that distinct species can have identical 18S sequences (Myrie et al. 2023) and has also been shown that sister taxa can have extremely limited variation in 18S sequences, as in the case of H. dougwalshi and H. pocococo (Barrantes et al. 2021).
description: Published as part of Zumbado Echavarria, Marco A., Barrantes Barrantes, Edwin A., Bartlett, Charles R., Helmick, Ericka E. & Bahder, Brian W., 2023, A new species of Oecleus (Hemiptera: Auchenorrhyncha: Fulgoromorpha: Cixiidae) from the Osa Peninsula in Costa Rica, pp. 533-546 in Zootaxa 5339 (6) on pages 536-541, DOI: 10.11646/zootaxa.5339.6.3, http://zenodo.org/record/8313741