Cobacella palmensis Bahder & Bartlett, 2023

Zumbado Echavarria, Marco A., Barrantes Barrantes, Edwin A., Helmic, Ericka E., Bartlett, Charles R. & Bahder, Brian W., 2023, A newspecies ofplanthopper in thegenus Cobacella (Hemiptera: Auchenorrhyncha Derbidae) from oil palm (Elaeis guineensis) in Costa Rica, Zootaxa 5351 (1), pp. 107-121 : 111-119

Cobacella palmensis Bahder & Bartlett sp. n.

( Figures 2–6 )

Type locality. Costa Rica, Puntarenas Province, Costa Rica.

Diagnosis. Description. Color. General body color yellow, darker in males, paler ventrad ( Fig. 2 ). Head in lateral view dark orange, yellow around eyes and antennae, antennae concolorous with body. Mesonotum with six black spots, three each side of midline, anterior-most rounded adjacent to tegulae, second pair crescent-shaped at lateral extreme of scutum,third pair circular, near caudal extreme of lateral carinae ( Fig. 2 ). Wings fuscous with red veins, darker in males ( Fig. 2 ). Legs pale yellow, with variable reddish wash, especially proximad, male with reddist tarsi. Dorsum of abdomen brown.

Structure. Body length (including wings) males: 7.0 mm (n = 1) and females: 7.8 mm (n =2). Head. Strongly compressed, projecting beyond eyes for distance about equal to greatest width of eye, in lateral view, head rounded, vertex declinate smoothly rounded at fastigium.Vertex in dorsal view narrowly triangular, approximately twice as long as wide at base, disc strongly concave, posterior margin strongly concave, lateral margins converging anteriorly (nearly meeting at apex), strongly carinate and thickened bearing row of pits ( Fig. 3A ), continued in reduced form on lateral margins of frons ( Fig. 3B ). In frontal view, frons greatly compressed, lateral margins strongly carinate, closely approximate ( Fig. 3C ). Antennae cylindrical and tubular, scape ring-like, pedicle approximately four times as long as wide ( Fig. 3 ). Eyes roughly oval, emarginated above antennae, lateral ocelli faintly indicated anterior to antennae.

Thorax. Prothorax steeply inclined in lateral view ( Fig. 3B ), narrow in dorsal view, strongly convex at anterior margin, strongly concave at posterior margin, expanding slightly at lateral margins ( Fig. 3B ); tricarinate, median carina strong, lateral carinae weak, arising from median carina near midlength, becoming obsolete laterad ( Fig. 3A,B ). Mesonotum large, scutum convex in lateral view with concave inflection at leading margin of scutellum, in dorsal view posterior margin of mesoscutellum truncate; in dorsal view with tricarinate, median carina extending from anterior margin to posterior margin, inner lateral carinae sinuate, curved distad at anterior margin ( Fig. 3A ), lateral margin of mesothorax carinate, arising near midpoint, forming posterior lip of the mesothorax ( Fig. 3B ). Spinulation of hind tibiae 5-5-4.

Forewings broad and spatulate, narrowest basally, widest near midlength, costal margin weakly convex, broadly rounded, trailing margin broadly convex except for concave expansion in jugal region. Clavus open, composite vein Pcu+A1 projecting anteriorly to encompass CuP and branches of CuA before arched to wing margin past midlength; 22 vein branches reaching wing margin between ScP and A1+Pcu+Cu inclusive; marginal cells longer than wide. MP branching from ScP+R in base of wing just beyond basal cell, with fork of RP from Sc+RA shortly beyond fork of MP; ScP reaching wing margin just before wing midlength. Branching pattern RA 8-branched, RP 2-branched, MP 10-branched, CuA 2-branched (anastomosed to form closed procubital cell ( Emeljanov 1996).

Terminalia. Pygofer in lateral view narrow, irregular, strongly narrowed at dorsal margin, strongly sinuate on anterior margins, posterior margin bearing large rounded lobe in dorsal half, ( Fig. 5A ); medioventral process absent ( Fig. 5B ). Gonostyli in lateral view spatulate, medially cupped, irregularly sinuate on dorsal and ventral margins, inner dorsal margin with elongate process with sclerotized hooked apex ( Figs 5A–C ); in ventral view, gonostyli narrow basally, expanding greatly at midpoint, truncate at apex with slight invagination near inner margin ( Fig. 5B ). Aedeagal shaft tubular, simple, slightly upcurved, spinose flange on dorsal margin near midpoint (A1) and process arising subapically on left, dorso-lateral margin (A2), angled dorsad, curving slightly ventrad, nearly reaching apex of flagellum, reaching anterior margin of A1 ( Fig. 6 ), and serrulations on right lateral margin, from midlength to near apex ( Fig. 6A, 6D ). Flagellum bilaterally asymmetrical, two large processes on left lateral side along dorsal margin (F1 & F2), process F1 on outer lateral margin, generally uniform in width, apex slightly constricted, inner and outer margins sinuate, apex curved slightly mesad; F2 more constricted at apex and curved mesad, F1 and F2 curved ventrad, approximately equal length ( Fig. 6A & 6B ). Anal tube in lateral view slender, dorsal margin straight, ventral margin sinuate, apex angled ventrad, almost reaching apex of gonostyli ( Fig. 6A ); in dorsal view, apex appears strongly forked and pointed ( Fig. 6B ).

Plant associations. African oil palm, Elaeis guineensis Jacq. (Arecaceae) .

Distribution. Puntarenas Province, Costa Rica.

Etymology. The specific epithet is in reference to the town where specimens were collected “La Palma”, formed by the trucation of the town name as “ palm- “ with the suffex “- ensis ”, meaning from a place or location. The specific name is intended as feminine to agree with the genus, although the spelling would be the same in either feminine or masculine form.

Material examined. Holotype male “ Costa Rica, Puntarenas Pr. / Finca La Palma / 6.VI.2021, sweeping palms / Coll.: B.W.Bahder // Holotype / Cobacella palmensis ♂ /” ( FLREC) ; Paratypes same as holotype (2 females, FLREC) .

Sequence Data. For the barcoding region of COI, a 584 bp product was generated, for the 18S gene, a 1,305 bp sequence was generated, and for the D9-D10 region of the 28S gene, a 776 bp sequence was generated. The phylogeny generated based on the available data and taxa showed low bootstrap support for most clades for COI, except for the genus Patara , which had moderate support (83) ( Fig. 7A ). However, the phylogeny based on 18S showed strong bootstrap support (97) for C. palmensis sp. n. resolving adjacent to Sayiana sayi ( Fig. 7B ). The phylogeny generated based on 28S showed moderate support (69) for placement of C. palmensis sp. n. adjacent to Anotia , however strong bootstrap support (100) for Anotia as a distinct clade from Cobacella ( Fig. 7C ). Both the 18S and 28S derived phylogenies showed strong bootstrap support (100 and 99 respectively) for a clade comprised of Anotia , Cobacella , and Sayiana . The consensus tree based on all three loci also shows strong bootstrap support (87) for the placement of C. palmensis sp. n. adjacent to Sayiana sayi and also showed strong support (100) for the clade comprised of Anotia , Cobacella , and Sayiana ( Fig. 7D ).

Based on the pairwise comparison for the 18S gene, the average intrageneric variability is 1.8% (±0.2) while the average intergeneric variability is 11.7% (±0.5) ( Table 4 ). Cobacella palmensis sp. n. differs on average by 12.3% (±1.3) from all other genera included in this analysis with the lowest level of variation occurring when compared to Sayiana sayi where it differs by 5.3% and the highest level of variance (excluding cenchreine outgroup) occurring with S. ballii and P. vanduzei , varying by 14.9% ( Table 4 ). Based on the pairwise comparison for 28S, the average intrageneric variability is 3.9% (±0.1) whereas the average intergeneric variability is 16% (±0.7) ( Table 5 ). Based on 28S, C. palmensis sp. n. differs on average by 15.3% (±0.2) from the other genera analyzed, with the lowest level of variability observed with Sayiana sayi (7.7%) and the highest level of variability observed with Mula resonans (23.2%) ( Table 5 ).

Remarks. The placement of C. palmensis sp. n. in Cobacella is supported by morphological characters observed and compared to both C. rubescens and C. sexguttata . However, a paucity of specimens from institutional collections, and limited observations on citizen science forums like iNaturalist, make it difficult to ascertain the extent of intraspecific variation or sexual dimorphism within species. In this manuscript we are annotating all the specimens or observations of which we are aware.

Cobacella palmensis sp. n. differs from C. sexguttata in both the structure of aedeagus and wing coloration. Fennah (1952: 163, figs 34H, 34I) illustrated the aedeagus of C. sexguttata , which he described as “… asymmetrical, sinuately tubular; flagellum with a single spinose process at its base, and a flattened plate acute at tip on left· on right two sclerties distally acute, supporting membranous portion”. Fennah’s (1952) illustrations are imprecise, but it is evident that the aedeagus of C. sexguttata is more strongly asymmetrical, lacks the spinose flange on dorsal margin (found in C. palmensis sp. n., A 1 in Fig. 6 ) near midpoint, and has a different arragements of sclerotized spines of the flagellum. With respect to wing coloration, C. sexguttata has a more fuscous patch at the apex of the forewing with basal portion less fuscous while C. palmensis sp. n. has a uniform tint to the forewing.

Concerning C. rubescens , it appears that the wing membrane is uniformly fuscous in C. palmensis sp. n. and more clearly hyaline in C. rubescens . In addition, C. palmensis sp. n. differs from C. rubescens in the size and shape of black spots on the mesothorax. Unfortunately, the male terminalia of C. rubescens has not been described and the syntypes are female.

Aside from type material, the only other available specimen of Cobacella is a pallid female from La Selva research station in Costa Rica ( Fig. 11 ) with the mesothoracic spots reduced to one on each side. This specimen likely represents an additional species. On iNaturalist there are four additional records of Cobacella . Two are from Puntarenas, Costa Rica (#151547369, 146292818) that appear to represent C. palmensis sp. n., one from San José, Costa Rica (#88345785) that may be C. rubescens , and one from S„o Paulo State, Brazil (#146995673) that we are reluctant to speculate on because it is geographically distant from the other observations.

Other material examined. Cobacella rubescens ( BMNH, female syntypes, Figs 9B, C ) Teapa, Mexico, H.H. Smith; ( NHMW, female, Fig. 10 ) “[Dominik] Bilimek / Mexico / 1871 / Orizaba // Juni [Duch for June] // rubescens / det. Fowler // Otiocerus ? rubescens Fowler / Type” (in Mus. Vind. Caes. = in Museo Vindobonense Caesarei = Imperial Museum Vienna) .

Cobacella sexguttata (BMNH, male); Amazonas, Fonteboa, Broomfield (det: Broomfield); and male holotype and female paratype ( BMNH, in alcohol) “Cobaccella / sexguttata / Fenn. Type / 1949 / Trinidad B.W.I.” reported as La Reunion, Carapo , 14.ix.1949, R. G. Fennah .

Cobacella sp. (UDCC, female): Costa Rica, Heredia nr Puerto Viejo , La Selva Biol Sta. (at station) 179ft, N10 25’, W84 00, 24 Feb. 2004, light, CR Bartlett, J. Cryan & J. Urban.

iNaturalist records: Costa Rica (observations #146292818, 151547369, 88345785); Brazil (S„o Paulo) (observation #146995673).

Figures

FIGURE 2. Adult habitus of Cobacella palmensis sp. n.; (A) adult male lateral view, (B) adult male dorsal view, (C) adult female lateral view, and (D) adult female dorsal view.

FIGURE 3. Adult male of Cobacella palmensis sp. n.; (A) head, pronotum, and mesonotum in dorsal view, (B) lateral view, and (C) head and pronotum in frontal view; scale bar = 1 mm.

FIGURE 4. Adult male forewing of Cobacella palmensis sp. n.; black = vein, italics = crossvein, green = cell.

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

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

FIGURE 7. Maximum Likelihood trees (1,000 replicates) showing the relationship of Cobacella palmensis sp. n. relative to other available species of Otiocerinae; (A) COI, (B)18S, (C) 28S and (D) consensus tree based on concatenated COI and 18S sequence data, scale bar = percent nucleotide difference.

FIGURE 9. Habitus of Cobacella specimens from the Natural History Museum, London (BMNH); (A) Cobacella sexguttata Fennah (Amazonas, Brazil, Det. P.S. Broomfield), (B–C) Cobacella rubescens (Fowler), syntype female (B) lateral and (C) dorsal view.

FIGURE 10. Habitus of Cobacella rubescens syntype female from Orizaba, Veracruz, Mexico (image credit Harald Bruckner, Hemiptera Image Collection, Natural History Museum Vienna); (A) lateral view, (B) dorsal view (C) ventral view, and (C) labels.

FIGURE 11. Habitus of a female Cobacella specimen from La Selva, Costa Rica (University of Delaware Insect Research Collection, UDCC), (A) lateral habitus view, (B) dorsal habitus view, (C) ventrofrontal view, and (D) label.

Tables

TABLE 4. Pairwise comparison based on the 18S rRNA locus to demonstrate intra (orange) and inter (blue) generic variability by percent nucleotide difference (bottom left) and standard error (top right).

		1234567891011	1234567891011	1234567891011	1234567891011	1234567891011	1234567891011	1234567891011	1234567891011	1234567891011	1234567891011	1234567891011
1	Cobacella palmensis sp. n.		0.008	0.008	0.007	0.011	0.011	0.011	0.011	0.010	0.010	0.011
2	Anotia firebugia	0.071		0.004	0.008	0.010	0.010	0.010	0.010	0.010	0.010	0.011
3	Anotia sp.	0.075	0.018		0.008	0.010	0.011	0.011	0.011	0.010	0.010	0.011
4	Sayiana sayi	0.053	0.068	0.074		0.011	0.011	0.011	0.011	0.011	0.011	0.011
5	Mula resonans	0.137	0.134	0.135	0.138		0.010	0.010	0.010	0.010	0.010	0.010
6	Shellenius serratus	0.147	0.138	0.136	0.141	0.133		0.005	0.004	0.006	0.006	0.008
7	Shellenius schellenbergii	0.148	0.137	0.138	0.142	0.132	0.022		0.005	0.007	0.007	0.009
8	Shellenius ballii	0.149	0.140	0.138	0.146	0.132	0.013	0.026		0.006	0.006	0.008
9	Patara vanduzei	0.149	0.143	0.140	0.148	0.129	0.051	0.058	0.053		0.003	0.007
10	Patara cooki	0.148	0.140	0.137	0.149	0.131	0.048	0.055	0.051	0.012		0.007
11	Agoo xavieri	0.155	0.146	0.147	0.161	0.140	0.080	0.090	0.079	0.068	0.062

TABLE 5. Pairwise comparison based on the 28S rRNA locus (D9-D10 region) to demonstrate intra (orange) and inter (blue) generic variability by percent nucleotide difference (bottom left) and standard error (top right).

		1	2	3	4	5	6	7	8	9	1011	1011
1	Cobacella palmensis sp. n.		0.010	0.010	0.011	0.016	0.014	0.014	0.014	0.014	0.014	0.014
2	Sayiana sayi	0.077		0.010	0.010	0.015	0.013	0.014	0.013	0.014	0.014	0.013
3	Anotia firebugia	0.090	0.096		0.004	0.016	0.014	0.014	0.014	0.015	0.014	0.014
4	Anotia sp.	0.101	0.104	0.016		0.016	0.014	0.014	0.014	0.015	0.014	0.015
5	Mula resonans	0.232	0.228	0.216	0.225		0.015	0.015	0.015	0.015	0.015	0.015
6	Shellenius ballii	0.167	0.160	0.183	0.178	0.220		0.009	0.006	0.010	0.010	0.010
7	Shellenius schellenbergii	0.172	0.173	0.185	0.180	0.217	0.072		0.009	0.011	0.011	0.011
8	Shellenius serratus	0.167	0.163	0.179	0.178	0.213	0.024	0.064		0.011	0.010	0.009
9	Patara vanduzei	0.176	0.175	0.194	0.194	0.229	0.090	0.107	0.086		0.005	0.011
10	Patara cooki	0.179	0.176	0.192	0.191	0.225	0.087	0.105	0.086	0.018		0.011
11	Agoo xavieri	0.173	0.169	0.192	0.192	0.220	0.080	0.090	0.071	0.101	0.093