Research Article |
Corresponding author: Stuart H. McKamey ( stuart.mckamey@usda.gov ) Academic editor: Mick Webb
© 2020 Stuart H. McKamey.
This is an open access article distributed under the terms of the CC0 Public Domain Dedication.
Citation:
McKamey SH (2020) Description of a new, unusual species of Diestostemma Amyot & Serville (Hemiptera, Cicadellidae) from Ecuador. ZooKeys 908: 31-37. https://doi.org/10.3897/zookeys.908.38477
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Diestostemma bicristata sp. nov., is described from Napo Province, Ecuador. It is unusual for the genus in lacking a visible white powdery covering, having raised, weakly reticulate veins on the forewing, a short metathoracic femur (half length of the metathoracic tibia), and is the only species with a double-crested pronotum.
Auchenorrhyncha, Neotropical, new species, Proconiini, sharpshooter, taxonomy
Sharpshooters are members of the cosmopolitan Cicadellinae, the third largest leafhopper subfamily, with over 2200 valid species among 327 genera. Sixty-two of these genera, and 425 species, belong to the New World tribe Proconiini (
Species of the genus Diestostemma occur from Mexico to Argentina and are distinguished by an apical scar at the apex of the head (also present in Proconia Le Peletier & Serville) and a digitate posterior process on the pronotal lateral lobe (the portion behind the eye), both of which are present in the new species described here.
In providing distribution data of the holotype, quotation marks separate labels and a vertical line separates lines on a label.
Terminology for general morphology was based on
A Leica MZ12 stereomicroscope, with an ocular micrometer, was used to examine structures and to determine ratios between smaller distances. The larger dimensions of the head and pronotum were measured with a manual 5mm micrometer and body length was measured using a digital micrometer.
The abdomen was detached, macerated in a warmed, 10% KOH solution for 24 hours at room temperature, bathed in water, then acetic acid to stop the reaction. After dissection, structures were stored in a glass microvial containing glycerin and pinned beneath the specimen.
Images were taken with a Canon EOS 5Dsr camera with an adjustable Canon MP-E 65 mm lens. Photos were taken using Capture One Pro version 10.1.2, 64 bit, build 10.1.2.23 imaging software, aided by CamLift version 2.9.7.1. The specimen was lighted using two adjustable Dynalite MH2050 RoadMax flash heads, each attached to a Manfrotto 244 arm. The light was diffused using a simple, lampshade-style cone of translucent paper between the specimen and light sources. After individual “slices” were photographed, they were compiled into a single, composite image using Zerene Stacker - USDA SI-SEL Lab Bk imaging system, version 1.04, build T201706041920. Stacked images were enhanced and edited in Adobe Photoshop CSS Extended version 12.0. The scale bar (in Fig.
A small narrow species with a long head, pronotum with two long, weakly converging raised ridges, forewing with extra crossveins but only weakly reticulate. Aedeagus of male in lateral view with gradually recurved basiventral process.
Holotype male. “Ecuador. Napo. Km23, | Via Sta. Barbara-La | Bonita. 2400m. | 7–9 April 1986”, “collected by | S.H. McKamey”, and a red “HOLOTYPE | Diestostemma | bicristata | McKamey” (USNM). The left forewing and hind wing are damaged.
Total length (from anterior of head to tip of forewings in repose) 13.8; crown length 2.6; transocular distance 2.8; interocular distance 2.0; distance between compound eye and mesal line 1.0; distance between ocellus and mesal line 0.5; pronotal disc maximum width 3.4; pronotal disc maximum length 3.0; forewing length 9.5; length of metathoracic femur 2.4; metathoracic tibia 4.8.
Body (Figs
Thorax (Figs
Diestostemma spp. 5 Diestostemma sp., nymph, from Mérida, Venezuela (courtesy of D. Takiya) 6–12 Diestostemma bicristata, sp. nov., holotype 6 head and partial thorax, ventroanterior view 7 head and pronotum, dorsoanterior view 8 connective and styles, dorsal view 9 pygofer base and subgenital plates, ventral view 10 pygofer and subgenital plate, lateral view 11, 12 aedeagus and basiventral process in lateral and posterior views, respectively (left ramus broken).
Coloration. Head and thorax including legs pale brown except median of frons orange and forewings dark brown and hind wings smoky translucent. Abdomen dark brown.
Male terminalia. Pygofer (Fig.
Female unknown.
Known only from the type locality at the Kilometer 23 post along the road between Santa Barbara and La Bonita, at 2400 m elevation, in Napo Province, Ecuador. Biology and ecology unknown.
The specific name is feminine and based on the Latin “crista,” for crest, in reference to its unique double-crested pronotum.
The new species is externally most similar to D. truncatipenne Schmidt, which also has an extended vertex and strongly raised forewing veins that are not very reticulate compared to most species of the genus; D. truncatipenne has been recorded only from Peru. The aedeagus is most similar to D. bituberculatum, which has more abruptly curved basiventral processes; D. bituberculatum is recorded from Brazil, French Guiana, and Guyana.
I thank Alyssa Seemann for taking and processing photographs, Daniela Takiya for use of her photograph, and Gabriel Mejdalani for comments on an earlier draft. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply endorsement by the USDA. The USDA is an equal opportunity provider and employer.