Enchenopa gennyae, Rueda-Rodríguez & Montalvo-Salazar, 2024

Rueda-Rodríguez, María P. & Montalvo-Salazar, Jorge L., 2024, Two new species of the treehopper genus Enchenopa Amyot & Serville, 1843 (Hemiptera, Membracidae) from northwest Ecuador, ZooKeys 1216, pp. 43-62 : 43-62

Enchenopa gennyae sp. nov.

Figs 1 , 2 , 3 , 4

Material examined.

Holotype: Ecuador • 1 ♀; Santo Domingo de los Tsáchilas, Santo Domingo, Río Baba -0.30295, -79.15211, 480 m; 12 May 2023; Montalvo, J. & Rueda, M. P. leg.; Ex. Manual ZSFQ -i12112 . Paratypes: Ecuador • 2 ♂; same labels as for holotype; ZSFQ -i12110 , ZSFQ -i12111 • 2 ♀, 1 ♂ Santo Domingo de los Tsáchilas, Santo Domingo, Quebrada del Río Pove -0.25237, -79.156668, 570 m; 14 Aug. 2023; Rueda, M. P. & Montalvo, J. leg.; Ex. Manual; ZSFQ -i17766 : 17768 • 3 ♀, 1 ♂ same locality as paratypes; 20 Apr. 2024; Rueda, M. P. leg.; Ex. Manual; ZSFQ -i18855 : 18858 .

Notes on the type series.

All specimens are minuten-mounted. Dissected abdomens of the holotype and two female and two male paratypes were placed in vials with glycerol pinned beneath the specimens. Some paratypes are in poor condition, with legs or wings lost.

Additional material.

Ecuador • 3 5 th instars; same data as paratypes; ZSFQ -i17925 , 17926 .

Diagnosis.

Overall color black with whitish dorsal spot and subapical band; metopidium straight, two to four sub-equal accessory carinae. Sexually dimorphic: female with obtuse projection instead of horn, short lateral carina not surpassing humeral angles, dorsal spot 2 × longer than subapical band, and longer than male in size; male with narrow horn slightly curved forwards, lateral carinae almost touching lateral margin of pronotum and dorsal spot subequal in length to subapical band.

Description.

Female holotype ( ZSFQ -i12112 ). Measurements (mm): Length from head to wings at rest: 5.7; Total length: 6.3; Head to apex of posterior process: 4.6; Pronotal length: 4.4; Head to horn apex: 2.4; Forewing length: 4.9; Body width: 1.9; Vertex width on ocellar line: 1; Head length: 1.2; Frontoclypeus length: 0.8; Frontoclypeus width: 0.7; Prothoracic tibia length: 0.9; Metathoracic tibia length: 1.4; Metathoracic tibia width: 0.3; Prothoracic tibia width: 0.3.

Color. Overall black with whitish dorsal spot and subapical band on dorsum. Dorsal spot 2 × longer than subapical band. Eyes black with dark brown margins, ocelli golden. Forewings opaque dull black, hind wings hyaline, veins black. Tarsi golden.

Surface. Head, pronotum, ventral sclerites of thorax, legs, and abdomen with dense golden pubescence; subcostal cell and veins of forewings with short, dispersed, almost indistinguishable golden pubescence. Pronotum (except metopidium) strongly punctured. Head, metopidium, forewings, and legs rough.

Head. Triangular, longer than wide (avoiding eyes); ocelli closer to eyes than each other; supra-antennal ledges arranged above clypeus; clypeus broad, longer than wide, anterior margin rounded; rostrum reaching hind coxae (Fig. 1 A ).

Thorax. Pronotum somewhat compressed, in lateral view, triangular, dorsal contour arched; metopidium straight, inclined anteriorly; horn reduced to an obtuse projection, obliquely directed dorso-anteriorly, wider than long, apex broadly rounded; median carina laminated and somewhat foliaceous, especially on dorsum; lateral carina short, not extending beyond humeral angles (Fig. 1 C ); three parallel accessory carinae, almost as long as lateral carina extending ventroposteriorly from projection apex; posterior apex of pronotum acuminate almost reaching the apex of first apical cell (Fig. 1 D ); humeral angles slightly produced (Fig. 1 B ). Forewings with five apical cells, one discoidal cell, and one vein in the clavus, one r-m crossvein, two m-cu crossveins, and without s crossvein; apical limbus broad. Hind wings with four apical cells and one r-m crossvein. Anterior and middle tibiae foliaceous; posterior femur with apical, ventral and middle cucullate setae, metathoracic tibia compressed with spine-like cucullate setae on rows I and II, row III absent.

Abdomen. Sternum III with a transverse keel extending along the sternite and slightly projected ventrally. Dorsum of tergites VII and VIII with medial tuberosities, tergites IV – VI with reduced medial tuberosities (Fig. 2 A ). Genitalia. Gonoplac ventrally with few setae and more sclerotized, apex rounded (Fig. 2 B ). First valvula blade shaped, apex ventrally rounded, dorsally acuminate extending beyond ventral margin (Fig. 2 C ). Second valvula broad throughout, dorsally rounded, ventrally weakly serrated with a ventral apical tooth directed upwards (Fig. 2 D, E ).

Male paratype (ZSFQi- 17766). Similar to female except dorsal spot as long as subapical band, pronotal horn narrow and curved forwards, lateral carina almost touching lateral margin of pronotum, metopidium with three accessory carinae at each side. Genitalia. Subgenital plate, in lateral view, 3 × longer than wide, lobes diverging in first 1 / 4, dorsal margin concave, distally expanded (Fig. 2 F ). Styles 5 × as long as wide, anterior projection subequal to posterior projection; shank with notch at middle of ventral margin, distally recurved and apically truncate, slightly expanded with posterior end longer and narrower than anterior end (Fig. 2 G ). Aedeagus U-shaped with anterior arm smaller than posterior arm and rounded; posterior arm lanceolate and abruptly narrowed at 1 / 3 length, anterior surface smooth, without serrations (Fig. 2 H ).

Variation.

Measurements. Male / Female (mm): Length from head to wings: 4.4–5.1 / 5.3–5.8; Total length: 4.9–5.6 / 6.2–6.3; Head to apex of posterior process: 3.8–4.5 / 4.58–5; Pronotal length: 3.8–5.5 / 4.4–5.3; Head to horn apex: 2.2–2.7 / 2.4–2.9; Forewing length: 3.7–4.2 / 4.5–5.1; Body width: 1.6–1.7 / 1.9–2; Vertex width on ocellar line: 0.9–1 / 1.0–1.1; Head length: 1.1–1.2 / 1–1.2; Frontoclypeus length: 0.7–0.8 / 0.7–0.8; Frontolypeus width: 0.7 / 0.7–0.8; Metathoracic tibia length: 0.8–1 / 0.9–1; Prothoracic tibia length: 1.2–1.4 / 1.4–1.8; Metathoracic tibia width: 0.2–0.3 / 0.3–0.5; Prothoracic tibia width: 0.3–0.4 / 0.3.

Females longer than males, with obtuse projection instead of horn, dorsal spot 2 × longer than subapical band, lateral carina not surpassing humeral angles and, in some individuals, weakly produced; two to four secondary carinae almost as long as lateral carina. Male with horn narrow and curved forwards, dorsal spot <2 × subapical band length (Fig. 3 A – C ), lateral carina almost attaining lateral margin of pronotum and metopidum with three accessory carinae on each side (Fig. 3 D ). Independent of gender, dorsal contour of pronotum is more or less arched.

Fifth-instar nymph description.

Overall color mostly white with black tarsi and scoli (Fig. 3 E ). One pair of abdominal scoli on each segment from III to VII; scoli length 5–6 × basal width. Pronotum anteriorly with nascent horn not extended beyond head and posteriorly extended to abdominal segment III; anterior apex rounded and directed forward; posterior apex acute, dorsal margin convex in middle. Needle-like setae on chalazae distributed over whole body.

Distribution and natural history.

Specimens of Enchenopa gennyae sp. nov. were found in two secondary forest remnants of the Western Foothills Forest from the urban area of Santo Domingo (Fig. 9 ): on the banks of the Baba River (Fig. 4 C ) and Pove River’s ravine (Fig. 4 D ). Adult and nymph congregations were found on several occasions cohabiting together and perched on the underside of leaves and stems of an unidentified species of the genus Piper L. between 100 and 150 cm above the ground (Fig. 4 A ). Females were always more abundant than males in these congregations. Nymphs were attended by fire ants of the species Wasmannia auropunctata (Roger) (Fig. 4 B ).

Etymology.

The species is dedicated to the mother of the first author, Genny Elizabeth Rodríguez Cueva, who helped to find the specimens of this species and has been a great support and inspiration throughout her life.

Remarks.

Females of Enchenopa gennyae sp. nov. have a short lateral carina that does not extend beyond the humeral angles, while males have a long lateral carina that almost reaches the lateral margin of pronotum. In the tribe Membracini , the length of the lateral carina has not been previously reported as sexually dimorphic in any species. However, in some species of Membracis , it has been noted that the lateral carina may or may not be present among individuals ( Richter 1947). Likewise, Richter (1954) argued the lateral carina of some species of Enchophyllum and Enchenopa can vary in length within the same population. This species is the first known in the Enchenopa biplaga species group to exhibit sexual dimorphism in pronotum shape and lateral carina length. Like Enchenopa gennyae sp. nov., E. longimaculata Strümpel & Strümpel, 2014 has remarkable sexual dimorphism of the dorsal spot. However, in Enchenopa longimaculata the females the spot is 4 × the length of the subapical band and in males 2 × while in E. gennyae sp. nov. the spot is 2 × as long in females but subequal in males.

Sexual dimorphism in the shape of the pronotal horn is characteristic of the Enchenopa minuta species group. However, Enchenopa gennyae sp. nov. does not belong to that group, given its coloration, the shape of the second valvula and, more importantly, the female’s lack of a pronotal horn; in the E. minuta species group, males lack the horn and females generally have a developed horn.

Enchenopa gennyae sp. nov. belongs to the E. biplaga species group due to the presence of bands on dorsum of the pronotum, the second valvula with a ventral apical tooth, and forewings with one discoidal cell. Enchenopa gennyae sp. nov. differs from E. ignidorsum ( Walker, 1858) and E. vittifera ( Stål, 1869) by the two white lateral bands instead of just one yellow or white one, respectively. Enchenopa gennyae sp. nov. differs from E. dubia ( Fowler, 1894) , E. lanceolata , E. reticornuta Strümpel & Strümpel, 2014 , and E. richteri Strümpel & Strümpel, 2014 by a horn shorter than the distance between the tips of humeral angles rather than longer. Enchenopa singularis Strümpel & Strümpel, 2014 and E. longimaculata have two accessory carinae with the posterior one ~ 1 / 2 or almost the total length, respectively, of the lateral carina, while E. gennyae sp. nov. has from two to four somewhat subequal accessory carinae. E. gennyae sp. nov. is distinguished from E. melaleuca Walker, 1858 by the shorter horn that is not curved forward. The new species closely resembles Enchenopa biplaga Walker, 1858 due to the shape of the pronotal horn, pronotum coloration, and the disposition of the accessory carinae. However, Enchenopa gennyae sp. nov. has a straight metopidium, less produced horn, and sexual dimorphism. In contrast, in E. biplaga the metopidium is convex, the horn is large and strongly produced, and without sexual dimorphism. The females of E. gennyae sp. nov. have a short and straight horn while E. biplaga females have the horn longer than wide and curved forward. In males of E. gennyae sp. nov. the posterior arm of the aedeagus, in lateral view, is abruptly narrowed at one-third of its length, and the apical hook of the styles has the posterior tooth longer and narrower than the anterior tooth. In contrast, in the male of E. biplaga the width of the posterior arm of the aedeagus, in lateral view, slightly decreases at half of its length, and the apical hook of the styles has the posterior tooth similar in size to the anterior tooth.

McKamey (2022) reinstated Enchenopa melaleuca from the genus Enchophyllum and suggested it shares morphological similarities with some species of the E. biplaga species group. However, the holotype of this species has yet to be reviewed to confirm these affinities. Therefore, excluded E. melaleuca from the key to E. biplaga group species but compared it with E. gennyae sp. nov. in the above discussion.

In the E. biplaga species group, nymphs of E. reticornuta and E. vittifera are known ( Strümpel and Strümpel 2014). They share with the nymph of E. gennyae sp. nov. the body covered with white wax-like material, black tarsi, and the presence of scoli on abdominal tergites III – VIII. However, we found the nymphs of E. gennyae sp. nov. differ from them mainly in the shape of the pronotum and scoli. The nymphs of Enchenopa vittifera have a longer horn directed forward with the posterior apex of the pronotum reaching the abdominal tergite III and have shorter scoli. While the nymphs of Enchenopa reticornuta have a straight horn with the posterior apex of the pronotum not touching the abdomen and longer scoli widened at the base.

Figures

Figure 1. Enchenopa gennyae sp. nov. holotype female A – C habitus in frontal, dorsal view, and lateral views respectively D illustration of pronotum showing the carination. Scale bars: 1 mm (A); 2 mm (B, C).

Figure 2. Abdomen and terminalia of Enchenopa gennyae sp. nov. A undissected female abdomen in lateral view B gonoplac in lateral view C first valvula in lateral view D second valvula in lateral view E close-up apex of second valvula F undissected male pygofer in lateral view G styles in dorsal view H aedeagus in lateral view. Scale bars: 1 mm (A); 0.1 mm (B – D); 0.01 mm (E); 0.2 mm (F); 0.05 mm (G, H).

Figure 3. Enchenopa gennyae sp. nov. paratype male and nymph A – C male habitus in frontal, dorsal view, and lateral views respectively D illustration of male pronotum showing the carination E nymph habitus in lateral view. Scale bars: 1 mm (A); 2 mm (B, C, E).

Figure 4. Enchenopa gennyae sp. nov. in its natural environment and habitat A male paratype perched on a stem of its host plant B nymphs attended by Wasmannia auropunctata (Roger) C shore of Baba River D ravine of Pove River.

Figure 9. Distribution of the new species in Ecuador. Red stars = records of Enchenopa gennyae sp. nov.; blue stars = records of Enchenopa chocoandina sp. nov.