Description of the Aguatala compsa young (Hemiptera: Cicadellidae: Cicadellinae) female

Descrição da fêmea de Aguatala compsa young (Hemiptera: Cicadellidae: Cicadellinae)

SYSTEMATICS, MORPHOLOGY AND PHYSIOLOGY

Description of the Aguatala compsa young (Hemiptera: Cicadellidae: Cicadellinae) female

Descrição da fêmea de Aguatala compsa young (Hemiptera: Cicadellidae: Cicadellinae)

Luiz G N Rodrigues; Gabriel Mejdalani

Depto. de Entomologia, Museu Nacional, Univ. Federal do Rio de Janeiro, Quinta da Boa Vista, São Cristóvão, 20940-040, Rio de Janeiro, RJ; [e-mail]

ABSTRACT

The female of Aguatala compsa Young is for the first time described and illustrated based on specimens from Colombia. This consists also on a new distribution record for the monotypic genus Aguatala Young. The female genitalia of A. compsa are described in detail and compared with those of supposedly related genera belonging to the Erythrogonia generic group (sensu Young).

Key words: Leafhopper, morphology, Membracoidea, Cicadellini

RESUMO

A fêmea de Aguatala compsa Young é descrita e ilustrada pela primeira vez com base em espécimes provenientes da Colômbia, consistindo em novo registro de distribuição para o gênero monotípico Aguatala Young. A genitália feminina de A. compsa é detalhadamente descrita e comparada com aquelas de gêneros supostamente próximos, pertencentes ao grupo genérico Erythrogonia (sensu Young).

Palavras-chave: Cigarrinha, morfologia, Membracoidea, Cicadellini

The subfamily Cicadellinae is composed of leafhoppers that feed on the xylem of vascular plants. Most genera of this economically important subfamily (all species being potential vectors of xylem-borne phytopathogenic bacteria) are still in need of taxonomic studies (Takiya & Mejdalani 2004). According to Young (1968), the subfamily is divided into two tribes: a cosmopolitan Cicadellini and a New World Proconiini. The Cicadellini, which includes the genus herein studied, currently comprises 266 genera and 1,886 species (McKamey 2007).

The genus Aguatala Young comprises a single species, A. compsa Young, which is uncertainly recorded from Venezuela (Young 1977, McKamey 2007). The species was so far known only from two males. Young (1977) included Aguatala in his Erythrogonia generic group and observed that Aguatala is similar to Erythrogonia Melichar. Aguatala can be distinguished from Erythrogonia, as well as from other Neotropical Cicadellini, by the following combination of characters (see Young 1977): (1) clypeus with contour of its lower portion more horizontal than profile of frons (continuing the profile in Erythrogonia), (2) pronotal width much greater than transocular width of head (shorter in Erythrogonia) (Fig 1), (3) lateral margins of pronotum strongly convergent anteriorly (parallel in Erythrogonia) (Fig 1), (4) male pygofer with macrosetae located on posterior half of disk (often covering a considerable portion of disk in Erythrogonia), (5) aedeagus with a pair of dorsoapical processes, and (6) paraphyses with short stalk and narrow elongate rami.

 

In the present paper, the genus Aguatala is for the first time recorded from Colombia and the previously unknown female of A. compsa is described and illustrated. The female genitalia of Aguatala are compared to those of supposedly related genera in the Erythrogonia generic group.

Material and Methods

The studied specimens are deposited in the collection of the Departamento de Entomologia, Museu Nacional (MNRJ), Universidade Federal do Rio de Janeiro. Label data are given inside quotations with a reversed virgule (\) separating lines. Morphological terminology follows mainly Young (1977), except for the head (Mejdalani 1998) and for the female genitalia (Nielson 1965, Hill 1970, Davis 1975). The use of the term gonoplac (= third ovipositor valvula) follows Mejdalani (1998). Techniques for preparation of male and female genital structures follow, respectively, Oman (1949) and Mejdalani (1998). The dissected parts are stored in microvials with glycerin.

Results

Aguatala compsa Young (Figs 1-12)

 

Description of the female. Length, 11.6 mm. Head (Fig 1), in dorsal view, deltoid, well produced, with anterior margin rounded; median length of crown approximately one-half interocular width and three-tenths transocular width; without carina at transition from crown to frons; slight carina on posterolateral margins of crown behind compound eyes, in lateral view. Surface of crown, in lateral view, with more elevated area behind ocelli, forming angle with more anterior portion; in dorsal view smooth, without sculpturing or setae. Frontogenal sutures, in dorsal view, extending onto crown and attaining ocelli; the latter located slightly before imaginary line between anterior eye angles; each ocellus closer to adjacent eye angle than to median line of crown. Antennal ledges, in dorsal view, not protuberant. Frons (Fig 2), in frontal view, slightly flattened medially; muscle impressions distinct. Epistomal suture incomplete medially. Clypeus (Fig 2), in frontal view, strongly swollen on superior portion, swollen area narrowing toward apex; in lateral view, continuing profile of frons on superior portion, inferior portion nearly horizontal.

Thorax (Fig 1), in dorsal view, with pronotal width distinctly greater than transocular width of head. Pronotum with lateral margins convergent anteriorly; dorsopleural carinae incomplete; pronotal surface with some punctures on median portion; posterior margin almost rectilinear. Scutellum (= scutellum behind transverse sulcus sensu Young), in lateral view, slightly swollen. Forewings (Fig 3), in rest position, extending well beyond apex of ovipositor; without plexus of veins on apical portion; with three closed anteapical cells; base of fourth apical cell more proximal than base of third; corium with coriaceous texture; membrane distinct, restricted mostly to apical cells. Hindlegs with femoral setal formula 2:1:1; first tarsomere with two parallel rows of small setae on plantar surface, its length greater than combined length of two more distal tarsomeres.

Color. Crown and pronotum (Fig 1) yellow; inner margins of eyes outlined by black maculae; eyes black; pronotum with broad, transverse brown band between humeral angles, anterior margin of band expanded on median portion, anterolateral pronotal margins with inconspicuous brown marks. Mesonotum (Fig 1) mostly reddish-brown with brown apex. Forewings (Fig 3) dark red with conspicuous, irregular pale yellow maculae as follows: large basal one on corium and clavus extending nearly from costal margin to inner claval margin, one on basal half of corium adjacent to claval sulcus, one group of maculae on posterior portion of corium, some of them forming transverse stripe from outer wing margin to inner apical cell, other smaller spots also present; membrane with dark brown area. Face (Fig 2) yellow; inferior half of frons with somewhat V-shaped brown macula; this macula continuous with brown areas on genae, lora, and upper and lateral portions of clypeus. Abdomen, in ventral view, chiefly red; sternite VII and pygofer mostly black, the former with red lateral marks.

Female genitalia. Sternite VII (Fig 4), in ventral view, with posterior margin approximately transverse, rounded laterally, forming short projection medially; median portion of sternite with sulcus extending approximately from posterior half to apex of projection, lateral borders of sulcus slightly carinate. Internal sternite VIII membranous, not forming sclerites. Pygofer (Fig 5), in lateral view, well produced posteriorly; posterior margin narrowly rounded; surface with macrosetae on posterior portion and extending anteriorly along ventral margin; with few small microsetae mostly on basal portion. Valvifers I (Fig 6), in lateral view, with elongate, rectangular associated sclerite on superior portion, slightly expanded posteriorly. Valvulae I of ovipositor (Fig 7), in lateral view, with dorsal margin of shaft approximately rectilinear behind basal curvature; dorsal sculptured area (Fig 8) formed by diagonally arranged rows of scale-like processes extending from basal portion of shaft to apex; ventral sculptured area (Fig 8) formed by scale-like processes restricted to apical portion of shaft; ventral interlocking device distinct on basal half of shaft; apex of shaft acute; base of valvulae I (Fig 9), in ventral view, expanded, with pair of digitiform processes directed inwardly. Valvulae II (Fig 10), in lateral view, expanded behind basal curvature; dorsal margin of shaft moderately convex, covered by round or subtriangular, contiguous teeth from basal portion to apex; teeth (Fig 11) and ventroapical portion of shaft (Fig 12) bearing denticles; shaft with inconspicuous preapical prominence; apex acute. Gonoplacs, in lateral view, expanded at apical half; apex obtuse; shaft narrowing slightly on apical half toward apex; surface with few small setae and many minute spines on apical portion and extending anteriorly along ventral margin.

Material examined. Colombia. One female, "X/94 \ Casobuy [Casabuy Corregimiento, Nariño Department] \ Hoja \ Acosta-Rojas" (MNRJ). One male, "Sandona [Sandoná Municipality, Nariño Department]", plus other illegible data (MNRJ).

Discussion

The specimens of A. compsa herein studied were identified using the original description and illustrations of Young (1977). The male genitalia agree perfectly well with those of the holotype. However, our specimens are distinctly larger (male, 11.9 mm, female, 11.6 mm) than the holotype (8.4 mm) and have a more deltoid head. The median length of crown corresponds to approximately one-half of interocular width and three-tenths of transocular width in our specimens, whereas in the holotype these ratios are slightly different (six-tenths and four-tenths, respectively). Although our female is slightly smaller than the male, the former could be associated with the latter due to their remarkably similar color patterns. The species is newly recorded from Colombia. The specimens were collected in two localities in Nariño Department that are close to each other (less than 30 km apart). Aguatala compsa was previously known only from Venezuela, although it is important to mention that Young (1977) considered the latter country record as uncertain.

The female genitalia have yielded useful characters for the taxonomy of sharpshooters, as demonstrated by several authors (e.g., Nielson 1965, Young 1977, Mejdalani 1995, 1998, Takiya & Mejdalani 2004). However, the morphological diversity found in the female genitalia is still poorly known when compared to our current knowledge of the male genitalia. The present study revealed the occurrence of peculiar features in the female genitalia of Aguatala, such as a pair of digitiform processes on the basal portion of valvulae I (Fig 9) and a distinct sclerite on the superior portion of valvifers I (Fig 6), which can be added to the combination of features that distinguish the genus.

As pointed out in the introduction, Young (1977) treated Aguatala in the Erythrogonia generic group. In this group, he placed Aguatala near Erythrogonia Melichar, Inuyana Young, and Tettisama Young. Among the latter three genera, the female genitalia of Tettisama [based on T. quinquemaculata (Germar)] were described in detail by Mejdalani (1998). Hence, we concentrate our discussion in the comparison between Aguatala and Tettisama, with the goal of pointing out potentially useful taxonomic features in the female genitalia. The sternite VII in Tettisama has the posterior margin distinctly concave, whereas in Aguatala it is approximately transverse (Fig 4); in addition, the sternite VII of Aguatala has on posterior portion a peculiar sulcus with carinate margins. In Tettisama, the internal sternite VIII is conspicuously developed, being formed by a large semicircular ventral sclerite and three smaller dorsal sclerites, whereas in Aguatala the sternite VIII is membranous, without sclerites. The valvifers I in Tettisama do not have the associated dorsal sclerite observed in Aguatala (Fig 6), and the valvulae I in the former genus do not have basal digitiform processes like those of the latter (Fig 9). The valvulae II are also distinct in the two genera; in Tettisama, the dorsal margin of the shaft is distinctly and regularly convex, whereas in Aguatala the dorsal margin is more rectilinear, only moderately convex (Fig 10).

A study of the female genitalia in Erythrogonia is currently underway (Carvalho & Mejdalani, unpublished data) and has already revealed a series of peculiar characters, such as a large spiniform process in the valvifer I of E. phoenicea (Signoret), a feature that is not present in Aguatala. The internal sternite VIII in Inuyana (based on I. ucaya Young) has distinct sclerites (Young 1977, sclerites of the "genital chamber"), whereas in Aguatala it is membranous. The preliminary results herein discussed indicate that the female genitalia may provide useful features for the taxonomy of members of the Erythrogonia generic group.

Acknowledgements

Dr. Tito Bacca (Facultad de Ciencias Agrícolas, Universidad de Nariño) has kindly sent us to study a small collection of Colombian sharpshooters. The manuscript benefited from the useful comments of Alcimar Carvalho and Rachel Carvalho (Museu Nacional, Universidade Federal do Rio de Janeiro), as well as two anonymous reviewers. This research was supported in part by Fundação Universitária José Bonifácio (FUJB). A PIBIC fellowship from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) to LGNR is acknowledged.

Received 30/V/08.

Accepted 25/XII/08.

Edited by Takumasa Kondo - CORPOICA

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Publication Dates

• Publication in this collection
  14 Sept 2009
• Date of issue
  Aug 2009

History

• Accepted
  25 Dec 2008
• Received
  30 May 2008