Diestostemma gervasioi, Pinto & Mejdalani & Takiya, 2017

Pinto, Ângelo Parise, Mejdalani, Gabriel & Takiya, Daniela Maeda, 2017, Unraveling the white-clothed Diestostemma Amyot & Serville: a taxonomic revision of the American sharpshooters of the D. bituberculatum complex (Hemiptera: Cicadellidae), Zootaxa 4281 (1), pp. 135-164 : 148-152

publication ID

https://doi.org/10.11646/zootaxa.4281.1.14

publication LSID

lsid:zoobank.org:pub:DE0BD9D9-B661-43DF-90BA-4F31C4B3ADC9

DOI

https://doi.org/10.5281/zenodo.6032980

persistent identifier

https://treatment.plazi.org/id/03D787EF-0804-FFF7-86DA-FE14FCC9F852

treatment provided by

Plazi

scientific name

Diestostemma gervasioi
status

sp. nov.

Diestostemma gervasioi sp. nov.

LSID http://zoobank.org/urn:lsid:zoobank.org:act:07E791B4-52BA-45BC-B74B-C7AE92F71F5A ( Figures 7–8 View FIGURES 1 – 12 , 21–22 View FIGURES 15 – 24 , 31–32 View FIGURES 31 – 36 , 43–44 View FIGURES 37 – 45 , 50–51 View FIGURES 46 – 55 , 66–68 View FIGURES 56 – 71 , 81–83 View FIGURES 81 – 86 , 90 View FIGURES 87 – 92 , 93 View FIGURE 93 )

Material examined (1 ♂, 1 ♀). Holotype ♂. ECUADOR. Orellana [ Province : Francisco de Orellana Canton], Reserva Étnica Waorani, Transect Ent., 1 km S. Onkone Gare Camp., Fogging terre [sic, terra] firme forest, lot#1039 (00°39’10”S, 076°26’00”W, 248 m a.s.l.), 12.II.1995, T.L. Erwin et al. leg. ( EPNC) GoogleMaps ; 1 ♀ paratype, same data as the holotype but ( USNM) GoogleMaps .

Measurements of the male holotype (mm). Total length (from anterior of head to tip of forewings) 19.4; crown length 2.3; transocular distance 3.6; interocular distance 2.4; distance between compound eye and mesal line 1.2; distance between ocellus and mesal line 0.8; pronotal disc maximum width 4.4; pronotal disc maximum length 3.5; forewing length 13.8; metathoracic femur length 3.4; metathoracic tibia length 6.1.

Description of the male holotype. Head ( Figs. 7 View FIGURES 1 – 12 , 21–22 View FIGURES 15 – 24 ). Crown maximum length 0.65 of transocular distance and about same length of interocular distance (ratio of 0.98) in dorsal view; anterior margin rounded with small concavity at insertion of nymphal blade-like frontal process; epicranial suture slightly distinct; posterior portion with barely distinct M-shaped elevation from ocellar base to posterior margin, connected laterally to strong ridge posterior to ocular suture; lateral portions of frons with deep muscle impressions and median portion flattened, dorsal surface convex; frontogenal suture extending onto crown to ocellar level. Ocellus located at level of anterior limit of compound eye, distinctly closer to eye than mesal line (ratio of distances between ocellus and eye with eye to mesal line of 0.35). Epistomal suture indistinct. Clypeus anterior margin at level of profile of frons in lateral view.

Thorax ( Figs. 7 View FIGURES 1 – 12 , 21–22 View FIGURES 15 – 24 ). Pronotum maximum width at posterolateral angles 1.3 times wider than transocular distance; maximum length (at level of humps) 1.5 times longer than crown length; lateral margins convergent anteriorly; disc sculptured dorsally by punctures and callosities, punctures numerous and closer to each other at posterior 0.66; pair of small bean-shaped anterolateral pits posterior to anterior margin, followed by smooth polished elevated area; anteromesal area depressed into rhombus shape bordered by elevated polished areas (callosities); posterior 0.33 dorsally projected into two rounded humps; V-shaped mesal callosity bordering rhombus depressed anterior area; small mesal callus at posterior margin; posterior margin sinuous with widened Wshaped outline; dorsolateral carina (dorsopleural carina sensu Young 1968) ill-defined anteriorly, rounded; lateral lobe of pronotum punctured, with median rounded ridge, posterior margin projected into short triangular process (genus thumb-like process). Mesonotum not punctate; pairs of rounded pits at scutum and rounded processes at division between scutum and scutellum; scutellum with longitudinal carina at about posterior 0.5 up to apex. Forewing coriaceous (tegmen appearance); surface strongly punctured, punctures minute at distal area; venation sclerotized and moderately elevated at posterior 0.5 of corium, reticulate, except area from brachial cell to anal margin of wing, including first apical cell; three distinct sclerotized dark vein areas (SDV): (1) a small rounded area at proximal edge of first discal cell, (2) a larger oval area at claval sulcus, adjacent and posterior to first one, and (3) a large H-shaped area located at about proximal 0.25 of wing, between ScP&RA&M and claval sulcus. Hind wings membranous and densely coated by brochosomes. Metathoracic leg with femoral chaetotaxy with setal formula 2:1:0:0 (AD1 and PD1 + AD2); tibia with anteroventral row of flattened and same size setae along entire length, posteroventral row dimorphic, with hair-like longer setae at about proximal 0.66 and with shorter flattened setae at distal 0.33; ratio of length of each individual tarsomere by total tarsus length (excluding pretarsus) equal to 0.41, 0.29 and 0.29, respectively.

Coloration. Head and thorax ground color whitish-yellow to ochre with few light brown to brown irregular areas. Crown with pair of light brown spots over M-shaped elevation adjacent to posterior margin, larger than ocelli. Pronotal disc orange-yellow over V-shaped mesal anterior callosity; lateral and ventral surfaces of thorax similar in color to dorsal surface, legs whitish-yellow ochre to dark yellow, darker at tibiotarsal articulations, tibial carinae and over dorsal surface of tarsus. Forewing with three SDVs, two small rounded basal spots and a large typical H-shaped marking at anterior 0.25 of wing; entire anal margin of clavus, continuing over inner margin of apical cell, light brown to brown. Hind wings translucent white. Abdomen largely yellowish-white except for yellow genital capsule and dark brown aedeagus.

Male terminalia (based on the holotype). Pygofer ( Fig. 66 View FIGURES 56 – 71 ) dorsal margin slightly concave at middle; posterior margin rounded, dorsoposterior margin with wide concavity; long microsetae distributed throughout lobe, numerous near posterior margin. Valve, in ventral view, transverse, subrectangular; fused laterally to pygofer lobe; articulated to subgenital plate. Subgenital plate ( Fig. 67 View FIGURES 56 – 71 ) 1.1 times longer than wide at base in ventral view; posterior and internal margin forming acute angle; dorsal surface with strong tooth-like process near outer margin, associated with style apex; microsetae distributed throughout ventral surface, tuft of longer setae at dorsoposterior angle. Style ( Fig. 68 View FIGURES 56 – 71 ) with apex long and narrow, with pair of lateral minute spine-like processes at lateral margin. Connective ( Fig. 68 View FIGURES 56 – 71 ) 2.2 times longer than maximum width; arms joined anteriorly in dorsal view. Aedeagus ( Figs. 81–83 View FIGURES 81 – 86 ) strongly sclerotized; shaft broad at base, gradually narrowing distally into cylindrical, curved, sickleshaped shaft in lateral view, anterior margin with basal hump in lateral view; shaft posterodistal portion membranous; basiventral process cylindrical up to about proximal 0.6, bulbous with a minute knob process basally, slightly constricted before bifurcating into pair of blade-like strongly flattened rami; rami of basiventral processes with their tips distinctly surpassing shaft apex, distally gradually divergent in posterior view, with flattened surface undulate (somewhat plicate) and laterally faced.

Female terminalia. Sternite VII ( Fig. 90 View FIGURES 87 – 92 ) with maximum width about 1.5 of mesal length in ventral view; posterior margin sinuous, with three convex lobes, mesal lobe slightly projected into rounded triangular plate, not extending distally as far as lateral ones, lateral lobes strongly projected into two broad blades.

Variation of paratypes. The female paratype is very similar to the holotype; minor differences are here described. Crown maximum length 0.54 of transocular distance; anterior margin distinctly more rounded; Mshaped elevation more projected. Ratio of distances between ocellus and eye with eye to mesal line 0.17. Scutellar longitudinal carina ill-defined. Forewing with the large H-shaped sclerotized dark vein area (SDV) lacking a central portion (stem), resulting in two separate spots ( Figs. 32 View FIGURES 31 – 36 , 51 View FIGURES 46 – 55 ). Metathoracic leg with femoral chaetotaxy with setal formula 2:0:0:0.

Measurements (mm, n = 1). Female larger than male. Total length (from anterior of head to tip of forewings) 21.5; crown length 2.4; interocular distance 2.7; transocular distance 4.1; distance between compound eyes and mesal line 1.3; distance between ocellus and mesal line 1.1; pronotal disc maximum width 4.8; pronotal disc maximum length 4.0; forewing length 15.9; metathoracic femur length 4.0; metathoracic tibia length 7.5.

Diagnosis. A large, dorsolaterally white and ventrally yellowish-white Diestostemma with two pronotal humps and small dark areas on the forewing. Males and females of D. gervasioi sp. nov. are amongst the palest specimens with few dark areas on the crown and pronotum, being similar in this regard to D. bituberculatum , D. cavichiolii sp. nov., and D. rubriventris , all virtually without dark areas on the pronotal disc. The H-shaped distal SDV on forewing ( Figs. 50–51 View FIGURES 46 – 55 ) will separate it from D. rubriventris ( Figs. 54–55 View FIGURES 46 – 55 ); the yellowish-brown abdomen ( Figs. 43–44 View FIGURES 37 – 45 ) from the ventrally realgar colored D. bituberculatum ( Figs. 39–40 View FIGURES 37 – 45 ) and the strongly projected pronotal humps ( Figs. 7–8 View FIGURES 1 – 12 , 22 View FIGURES 15 – 24 ) separate it from the less humped D. cavichiolii sp. nov. ( Figs. 5–6 View FIGURES 1 – 12 , 19 View FIGURES 15 – 24 ).

Males can be distinguished from all known males of the D. bituberculatum complex, except D. cavichiolii sp. nov. and D. olivia sp. nov., by the rami of the aedeagal basiventral process obtusely curved anteriorly and gradually tapering to apex in lateral view ( Fig. 81 View FIGURES 81 – 86 ; abruptly curved in D. bituberculatum and preapically expanded in D. albinoi sp. nov., Figs. 72, 75 View FIGURES 72 – 80 ). The proximal portion of the basiventral process without median process and flattened rami allow its distinction from D. cavichiolii sp. nov. ( Figs. 81–83 View FIGURES 81 – 86 ; basiventral process with median spine-like process and rami preapically biconical in posterior view in D. cavichiolii sp. nov., Figs. 78–80 View FIGURES 72 – 80 ). Finally, the aedeagus of D. gervasioi sp. nov. is similar to that of D. olivia sp. nov., from which it can be separated by the basiventral process bifurcated proximally at about 0.60 of length ( Fig. 82 View FIGURES 81 – 86 ; distally at about 0.75 in D. olivia sp. nov., Fig. 84 View FIGURES 81 – 86 ), not strongly curved anteriorly ( Fig. 81 View FIGURES 81 – 86 ; distinctly curved over aedeagus shaft in D. olivia sp. nov., Fig. 84 View FIGURES 81 – 86 ), and somewhat plicate in posterior view ( Figs. 82–84 View FIGURES 81 – 86 ; with single large preapical concavity in D. olivia sp. nov., Figs. 85–86 View FIGURES 81 – 86 ).

Females with the posterior margin of sternite VII bilobed (mesal margin slightly projected) and with lateral lobes extending distally beyond mesal margin will separate D. gervasioi sp. nov. from the trilobed sternite VII of other species ( Fig. 90 View FIGURES 87 – 92 ; D. albinoi sp. nov., D. bituberculatum , and D. olivia sp. nov., Figs. 87–88, 91 View FIGURES 87 – 92 ). The new species can be distinguished from other species with bilobed sternite VII ( D. cavichiolii sp. nov. and D. rubriventris ) by the lateral lobes uncarinated and tips almost parallel in ventral view ( Fig. 90 View FIGURES 87 – 92 ; lateral lobes carinated and tips divergent in D. cavichiolii sp. nov., Fig. 89 View FIGURES 87 – 92 ) and shorter sternite VII with ratio between maximum width and mesal length 1.5 ( Fig. 90 View FIGURES 87 – 92 ; ratio 1.3 in D. rubriventris , Fig. 92 View FIGURES 87 – 92 ).

Distribution. Known only from the type locality at Reserva Étnica Waorani, Orellana Province, in the Amazonian Forest of Ecuador ( Fig. 93 View FIGURE 93 ).

Biological and ecological data. Similarly to D. albinoi sp. nov., probably a canopy dweller species (see data on that species).

Etymology. Specific name based on the given name in genitive singular after the eminent spittlebug specialist Gervásio da Silva Carvalho (Pontifícia Universidade Católica do Rio Grande do Sul), a former student of Dr. A.M. Sakakibara and former advisor of the first author, in honor of his contribution to our knowledge of that group of insects.

Remarks. The distinction between D. gervasioi sp. nov. and D. olivia sp. nov. proved to be difficult. Our hypothesis that they are distinct is based on the smaller size of D. gervasioi sp. nov. and largely on the association between male and female. Male terminalia are very similar, in spite of the significant differences observed, which were provided in the key and in the diagnosis, while the female sternite VII shape provides additional support for recognizing two distinct taxonomic entities. Considering the available specimens, we are confident about treating them as two distinct species. On the other hand, the large concavities on the rami of basiventral process of aedeagus of D. gervasioi sp. nov. are similar to those observed in D. cavichiolii sp. nov., and it has a very small basal knob at the same position of the spine-like process observed in D. cavichiolii sp. nov. Further investigations should be undertaken to study the relationships among these species.

USNM

Smithsonian Institution, National Museum of Natural History

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hemiptera

Family

Cicadellidae

Genus

Diestostemma