Research Article |
Corresponding author: J. Adilson Pinedo-Escatel ( adilson1030@gmail.com ) Academic editor: Christopher H. Dietrich
© 2019 J. Adilson Pinedo-Escatel, Dmitry Dmitriev.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Pinedo-Escatel JA, Dmitriev D (2019) Redescription of the Dikraneurini leafhopper Dikrella mella Ruppel & DeLong, 1952 (Hemiptera, Cicadellidae) with a synoptic checklist of leafhoppers on avocado trees in Mexico. ZooKeys 857: 17-27. https://doi.org/10.3897/zookeys.857.33910
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Among leafhoppers (Hemiptera, Cicadellidae), only Typhlocybinae are known in Mexico to inhabit avocado, an important horticultural crop. In this paper, a potential avocado pest, Dikrella mella Ruppel & DeLong, 1952, is redescribed and illustrated. Additionally, a detailed checklist and a key for all known species of Typhlocybinae associated with avocado trees in Mexico are provided.
Alconeura, Auchenorrhyncha, Empoasca, Empoascini, Idona, Joruma, Typhlocybinae
Herbivorous sap-sucking insects are potentially devastating agricultural pests because they not only injure plants directly but may also transmit plant pathogens (Bosco and Marzachi 2016). Most such pests belong to the order Hemiptera (
Avocado is one of the most important horticultural crops worldwide and Mexico is the main exporter (
The genus Dikrella Oman, 1949 was described based on type-species Dikraneura cockerellii Gillette, 1895. Oman (1949) also moved 14 species previously placed in Dikraneura Hardy, 1850 to Dikrella. Today, the genus includes two subgenera: Readionia Young, 1952 with four species and Dikrella Oman, 1949 with 37 well-defined species and three subspecies. The genus is restricted to the New World. Only one species of the genus is known so far to be a potential vector of diseases of avocado crops.
Dikrella mella Ruppel & DeLong, 1952 was described from four localities in Mexico based on two males and four females. The original description and illustrations lack important details useful for distinguishing the species. Since then, no further information was published on its distribution or host plants. Here we provide a redescription and diagnostic illustrations of this important avocado leafhopper. We also provide a detailed checklist and a key to all known species recorded from avocado trees in Mexico.
All specimens identified in this study are housed at the Colección Nacional de Insectos, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico (
Taxonomic criteria and terminology follows mainly
Dikrella (Dikrella) Oman, 1949
Dikrella (Dikrella) Oman, 1949: 83.
Dikraneura cockerellii Gillette, 1895
Slender leafhoppers, overall body coloration usually white to yellowish. Head as wide as pronotum, produced, crown convex. Forewing fourth apical cell short and third narrow. Hind wing submarginal vein complete, three apical cells. Pygofer with process. Aedeagus body elongate or robust usually with a pair of basal process.
Dikrella differs from Kunzeana Oman, 1940 by the distinctly widened basal part of the forewing inner apical cell.
Confined to the New World, recorded from: United States, Mexico, Costa Rica, Cuba, Puerto Rico, Panama, Canada, Ecuador, Colombia, Bolivia, and Brazil.
Dikrella (Dikrella) mella Ruppel & DeLong, 1952: 90
Small, delicate. Body slender. Texture of head, pronotum, and mesonotum uniform. General coloration yellowish with orange-gold infusions on pronotum and ventral view, forewing with two black spots on first and fourth apical cell, spots of same diameter but one in fourth cell lighter (Figs
Same as male but color somewhat paler overall.
Pygofer conical, narrowing caudally, longer than wide, with notch on dorsal margin, dorsal process slender curved dorsad arising beyond midlength of pygofer near dorsal notch; ventral process short, straight subapical (Fig.
VII sternite quadrate, ovipositor large, pointed.
Unknown
Body size 3.0–3.5 mm
Avocado (Persea americana)
Cuernavaca, Morelos state (Mexico)
Mexico: Guerrero (Iguala), Michoacán (Uruapan), Oaxaca (Rancho Monter), Morelos (Cuernavaca; Tetela del Volcán), and Chiapas (Vergel)
Holotype ♂ (OSUC), MEXICO: Cuernavaca Mor. \ X-21-41. \ K. 57 \ DeLong, Good, Caldwell and Plummer \ D. M. DeLong collection; 2♂ Paratypes (OSUC), MEXICO: Iguala, Guerrero \ IX-11 39 \ D. M. DeLong collection; 1♂, 2♂ (CEAM), MEXICO: Morelos, Tetela del Volcán, San Miguel \ 1,962m \ 18°50'27.204"N, 98°44'46.895"W \ 30–Ene–2014 \ ex: Persea americana \ sweep net \ R.M. Quezada-Daniel; 1♀, 1♂ (CEAM), MEXICO, Morelos, Tetela del Volcán, Huerta El Calabazo \ 2,195m \ 18°52'3.252"N, 98°44'5.2"W \ 19–Oct–2014 \ ex: Persea americana \ sweep net. \ R. M. Quezada-Daniel; 9♂, 11♀ (CAJAPE), MEXICO: Morelos, Tetela del Volcán, San Miguel \ 1,962m \ 18°50'27.204"N, 98°44'46.895"W \ 30–Ene–2014 \ ex: Persea americana \ sweep net \ R.M. Quezada-Daniel; 1♂, 1♀ (CNIN), MEXICO: Morelos, Tetela del Volcán, San Miguel \ 1,962m \ 18°50'27.204"N, 98°44'46.895"W \ 30–Ene–2014 \ ex: Persea americana \ sweep net \ R.M. Quezada-Daniel; 1♂ (CEAM), MEXICO: Morelos, Tetela del Volcán, San Miguel \ 1,962m \ 18°50'27.204"N, 98°44'46.895"W \ 30–Ene–2014 \ ex: Persea americana \ sweep net \ R.M. Quezada-Daniel
1 | Submarginal vein of hind wing extended along apex and connected to vein R2+3 (Fig. |
2 |
– | Submarginal vein of hind wing not extended along apex, not connected to R2+3 or absent | 3 |
2 | Forewing with fourth apical cell long, slender, and parallel. Head produced and sharply angled, in lateral view, face long and strongly convex. Pronotum, mesonotum, and forewings with many tiny red spots. Aedeagus with posterior preapical processes (Fig. |
Alconeura candida |
– | Forewing with fourth apical cell distinctly tapered distally. Head sometimes produced and angled, in lateral view, face short. Crown, pronotum, mesonotum, and forewings sometimes with orange, black or yellow marks but not red. Aedeagus with processes, if present, arising near base of shaft | 5 |
3 | Hind wing with apex of vein RP free, connected by crossvein to MA (Fig. |
Joruma krausi |
– | Hind wing with RP confluent to MA, r-m crossvein absent. Crown shorter than distance between eyes | 4 |
4 | Pygofer with suture close to sternite VIII (Fig. |
Empoasca angustella |
– | Pygofer without suture close to sternite VIII. Aedeagus with pair of basal processes | Empoasca deskina |
5 | Inner apical cell of forewing broader basally than apically. Hind wing with three apical cells | Dikrella mella |
– | Inner apical cell of forewing parallel sided. Hind wing with two apical cells | 6 |
6 | Pygofer process black (Fig. |
7 |
– | Pygofer process pale (Fig. |
Idona minuenda |
7 | Pygofer process extended beyond pygofer apex (Fig. |
8 |
– | Pygofer process not extended beyond pygofer, visible above dorsal margin (Fig. |
Idona gonzalezae |
8 | Clavus with small spot, not reaching margin and veins (Fig. |
Idona floresi |
– | Clavus with large spot, reaching margin and veins (Fig. |
Idona dmitrievi |
Morphological structures of microleafhopper (Typhlocybinae) species associated to avocado trees in Mexico 9 forewing of Idona dmitrievi 10 hind wing of Idona dmitrievi 11 forewing of Idona floresi 12 hind wing of Joruma krausi 13 aedeagus of Alconeura candida 14 pygofer of Empoasca angustella, lateral view 15 pygofer of Idona dmitrievi, lateral view 16 pygofer of Idona gonzalezae, lateral view 17 pygofer of Idona minuenda, lateral view.
Material examined. 25♀, 2♂ (CEAM), MEXICO, Morelos, Tetela del Volcán, Huerta El Calabazo \ 2,195m \ 18°52'3.252"N, 98°44'5.2"W \ 19–Oct–2014 \ ex: Persea americana \ sweep net \ R. M. Quezada-Daniel.
Material examined. 1♂, 2♂ (CEAM), MEXICO: Morelos, Tetela del Volcán, San Miguel \ 1,962m \ 18°50'27.204"N, 98°44'46.895"W \ 30–Ene–2014 \ ex: Persea americana \ sweep net \ R.M. Quezada-Daniel; 1♀, 1♂ (CEAM), MEXICO, Morelos, Tetela del Volcán, Huerta El Calabazo \ 2,195m \ 18°52'3.252"N, 98°44'5.2"W \ 19–Oct–2014 \ ex: Persea americana \ sweep net. \ R. M. Quezada-Daniel; 9♂, 11♀ (CAJAPE), MEXICO: Morelos, Tetela del Volcán, San Miguel \ 1,962m \ 18°50'27.204"N, 98°44'46.895"W \ 30–Ene–2014 \ ex: Persea americana \ sweep net \ R.M. Quezada-Daniel; 1♂, 1♀ (CNIN), MEXICO: Morelos, Tetela del Volcán, San Miguel \ 1,962m \ 18°50'27.204"N, 98°44'46.895"W \ 30–Ene–2014 \ ex: Persea americana \ sweep net \ R.M. Quezada-Daniel; 1♂ (CEAM), MEXICO: Morelos, Tetela del Volcán, San Miguel \ 1,962m \ 18°50'27.204"N, 98°44'46.895"W \ 30–Ene–2014 \ ex: Persea americana \ sweep net \ R.M. Quezada-Daniel
Material examined. 25♀, 16♂ (CEAM), MEXICO, Morelos, Tetela del Volcán, Huerta El Calabazo \ 2,195m \ 18°52'3.252"N, 98°44'5.2"W \ 19–Oct–2014 \ ex: Persea americana \ sweep net \ R. M. Quezada-Daniel; 1♂ (CAJAPE), MEXICO, Morelos, Tetela del Volcán, Huerta El Calabazo \ 2,195m \ 18°52'3.252"N, 98°44'5.2"W \ 19–Oct–2014 \ ex: Persea americana \ sweep net \ R. M. Quezada-Daniel.
Material examined. 13♀, 16♂ (CEAM), MEXICO, Morelos, Tetela del Volcán, Huerta El Calabazo \ 2,195m \ 18°52'3.252"N, 98°44'5.2"W \ 19–Oct–2014 \ ex: Persea americana \ sweep net \ R. M. Quezada-Daniel.
Material examined. 1♀, 1♂ (OSUC), MEXICO, Michoacán, Salvador Escalante, 03–Aug–2012 \ ex: Aguacate \ Graciela Gonzales Col.
Material examined. 1♀, 1♂ (OSUC), MEXICO, Michoacán, Salvador Escalante, 03–Aug–2012 \ ex: Aguacate \ Graciela Gonzales Col.
Material type examined. Holotype ♂ (OSUC), MEXICO: Cuernavaca Mor. \ Mexico III-1945 \ N. L. H. Krause \ D. M. DeLong collection
Additional material reviewed. 12♀, 25♂ (CEAM), MEXICO, Morelos, Tetela del Volcán, Huerta El Calabazo \ 2,195m \ 18°52'3.252"N, 98°44'5.2"W \ 19–Oct–2014 \ ex: Persea americana \ sweep net \ R. M. Quezada-Daniel.
Material examined. 3♀, 9♂ (CEAM), MEXICO, Morelos, Tetela del Volcán, Huerta El Calabazo \ 2,195m \ 18°52'3.252"N, 98°44'5.2"W \ 19–Oct–2014 \ ex: Persea americana \ sweep net \ R. M. Quezada-Daniel.
Material examined. 6♀, 12♂ (CEAM), MEXICO, Morelos, Tetela del Volcán, Huerta El Calabazo \ 2,195m \ 18°52'3.252"N, 98°44'5.2"W \ 19–Oct–2014 \ ex: Persea americana \ sweep net \ R. M. Quezada-Daniel.
Nine species in five genera of typhlocybine leafhoppers are reported from avocado trees in Mexico. None of these species have been tested or confirmed to transmit any disease so far. Species are recorded from Mexican states (Table
Geographical occurrence of known leafhoppers of the subfamily Typhlocybinae inhabiting avocado trees.
Leafhoppers | Distribution | ||
Genus | Subgenus | Species | Country: state (known localities) |
Alconeura | Hyloidea | candida | Mexico: Morelos (Cuernavaca; Tetela del Volcán) |
Dikrella | Dikrella | mella | Mexico: Morelos (Cuernavaca; Tetela del Volcán), Guerrero (Iguala), Oaxaca (Rancho Monter), and Chiapas (Vergel) |
Idona | dmitrievi | Mexico: Morelos (Tetela del Volcán) | |
minuenda | Mexico: Morelos (Tetela del Volcán), and Tamaulipas (Ciudad Victoria) | ||
floresi | Mexico: Michoacán (Uruapan) | ||
gonzalezae | Mexico: Michoacán (Uruapan) | ||
Joruma | Joruma | krausi | Mexico: Morelos (Cuernavaca; Tetela del Volcán), Veracruz (Córdoba), and Oaxaca (Chiltepec) |
Empoasca | Empoasca | deskina | Mexico: Morelos (Cuernavaca; Tetela del Volcán), Hidalgo (Jacala), Estado de México (Distrito Federal), and Veracruz (Orizaba) |
angustella | Mexico: Morelos (Laguna de Zempoala; Tetela del Volcán) |
The first author is very grateful to Axel Cristobal P. E. for comments during development of manuscript. We kindly were helped by Christopher Dietrich (Illinois Natural History Survey. USA) and Maria I. Catalano (Centro de Bioinvestigaciones de la Universidad Nacional del Noroeste de la provincia de Buenos Aires) with helpful comments to improve the manuscript. Edith Blanco-Rodríguez helped corroborate identification of the specimens. We also thank curators of collections, Luciana Musetti (OSUC), Harry Brailovsky and M. Cristina Mayorga-Martínez (CNIN), Jose Luis Navarrete-Heredia (CZUG), and Jesus Romero-Nápoles (CEAM) for access to types and other specimens. J.A. Pinedo-Escatel is supported by CONACyT [CVU: 705854] and BEMARENA Ph.D. program of the Universidad de Guadalajara at Centro Universitario de Ciencias Biológicas y Agropecuarias, Zapopan, Jalisco, Mexico. Dmitry Dmitriev is supported by National Science Foundation [NSF 16-39601].