Proarna gianucai Sanborn, 2008

Sanborn, Allen F., 2008, New Records of Brazilian Cicadas Including the Description of a New Species (Hemiptera: Cicadoidea, Cicadidae), Neotropical Entomology 37 (6), pp. 685-690 : 686-688

Proarna gianucai Sanborn , sp. nov. ( Figs. 1-6 )

Type material. HOLOTYPE: male ( FSCA), “ BRAZIL, 28 km South of Cassino Beach, 20-XI-1992, N.M. Gianuca coll., ex. Panicum racemosum (P. Beauv.) Spreng. ” PARATYPES: four males ( AFSC) same data as holotype, three males ( AFSC) same data as holotype except 11-XII-1991.

Type locality. The type series was collected Brazil, Rio Grande do Sul, 28 km South of Cassino Beach in December 1991 and November 1992.

Etymology. The new species is described in honor of Prof. Dr. Norton Gianuca (Secretary for Environmental Affairs, Rio Grande, RS) who collected the type series and provided information on the biology of the species.

Description. Description is based on a series of males. The female is unknown.

Coloration. Ground color of head and thorax ochraceous marked with fuscus, abdomen castaneousmarked with tawny and fuscus ( Fig. 1 ).

Head ( Fig. 2 ). Fuscus except for transverse band between lateral portions of supra-antennal plates along frontoclypeal suture to anterior median ocellus, a spot between the transverse band and compound eye on anterior head, triangular spot medial to compound eye on posterior head in which there isa small fuscusspot, small spot anterior-lateral tolateral ocelli, smallspot on posteriorepicranial suture, gena posterior to level of antennae, and anterior third of lorum all ochraceous. Long silver pile on head, very thick posterior to eye. Postclypeus fuscus within transverse grooves and mediallyexcept for ochraceous medial stripe dorsally which extendslaterally alongfrontoclypeal suture.Anteclypeus with medial castaneous stripe on anterior two thirds, along entire length in some paratypes and other paratypes with central ochraceous line in posterior third of complete castaneous stripe. Rostrum ochraceous with fuscus tip. Long white pile on lorum, gena, anteclypeus and ventral to eye. Short whitepile medially, laterally and withing transverse grooves of postclypeus. Scape and proximal pedicel castaneous, remaining antenna fuscus.

Thorax ( Fig. 2 ). Pronotum ochraceous with fuscusmarks in ambient fissure, lateral fissure and anterior half of paramedian fissure. Mark in paramedian fissure extends posteriorly and terminates in a lateral curve anterior to ambient fissure. Fuscus mark on either side of midline which expands medially anteriorly before curving laterally posterior to anterior margin and curving back to midline parallel to paramedian fissure. Medial mark expandsposteriorly forming a roughly triangular mark on ambient fissure expanding onto pronotal collar and to level of hooked mark from paramedical fissure meeting medially in ambient fissure. Small fuscus spots on plates between fissures, variable in size and number in paratypes. Lateral margin of pronotal collar fuscus. Castaneousspot on medial half of paramedian fissure betweenmedial fuscus markand hooked mark. Sparse white pile medially, in posterior ambient fissure and lateral margin of pronotal collar. Mesothorax with four obconical spots and two lateral fasciae fuscus. Lateral obconical spots and lateral fasciae fuse in some paratypes. Medial obconical spot covers most of submedian sigilla, lateral obconical spot half the length of medial spot, lateral fasciae extend to level of scutal depression. Medial triangular castaneous spot beginning between medial obconical spots, expanding anterior to anterior arms of cruciformelevation. Fuscus band on posterior mesothorax extending medially across anterior arms of cruciform elevation to medial castaneous mark. Transverse fuscus mark with anterior depression posterior to medial obconical spot connecting medially to castaneous line, connecting anteriorly to medial obconical spots in some paratype and posteriorly to transverse band on cruciform elevation in another paratype. Scutal depression fuscus. Metanotum ochraceous. Fuscusmarks on posterior trochantin 2, medial meron 2, and medial epimeron 2. Central portion of basisternum 2 and 3 fuscus.

Legs. Ochraceous marked with fuscus. Fore coxae striped with fuscus, distal fuscus mark medially. Fore trochanters tawny laterally, fuscus medially. Fore femora ochraceous striped with fuscus, medial half mainly testaceouss, dark fuscus mark distally. Primary and secondary spines upright, testaceous with fuscus tips. Fore tibia testaceous, lighter at ends. Fore tarsi testaceous. Middle and hind coxae with testaceous lateral mark proximally, middle coxae with distal fuscus spot. Middle and hind femora and tibiae striped with fuscus, anterior side testaceous. Middle tarsitawny, hind tarsi ochraceous. Pretarsal claws with fuscus tips. Tibial spurs fuscus. Legs with erect white pile.

Tegmina andwings ( Fig. 1 ). Hyaline with light infuscation. Tegmina with eight apical cells. Fuscus spot on basal membrane. Anterior half of basal cell ochraceous, fuscus mark along anterior margin expanding to fuscus spot in anterior distalportion of basal cell. Basal venationochraceous except testaceous distalmedian vein along proximal ulnarcell 2, distal two-thirds of radius posterior, radius anterior, radius anterior 1, radius anterior 2, radial crossvein, radiomedial crossvein, median vein 1, distal two-thirds of median veins 2 and 3, distal half of median vein 4 and ambient vein from two-thirds distal apical cell 3 to junction with radius anterior 1. Light infuscation on proximal radius anterior 2, radial, radiomedial, medial and mediocubital crossveins, and ambient vein inapex of apical cell 1, middle distal portion of apical cells 3-7 and distal portion of apical cell 8. Venation of wings ochraceous except testaceousradius anterior, radius posterior, distal median vein 1 and ambient vein between radius anterior and median vein 2. Fuscus spot at base. All butapex of analcell 3, analcell 2 along analvein 3 andalong the sides of proximal half of anal vein 2 ochraceous.

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Operculum ( Fig. 4 ). Ochraceous not reaching to sternite II. Fuscus mark on anterior quarter of lateral margin and base of meracanthus. Fine white pile on surface, longer and more dense next to lateral fuscus mark. Sinuate lateral margin, smoothly curved, not meeting along midline.

Abdomen ( Figs. 1, 3 ). Dorsal abdomen castaneous, anterior margin fuscus, posterior margin testaceous except fuscus tergite 2. Testaceous band expands laterally on tergite 2, and increasingly on middle lateral tergites from tergite 4-8 so most of tergite 8 becomes testaceous. Fine silvery pile on tergites, dense on posterior borders of tergites 3-6. Timbal cover small, triangular, edged with fuscus, castaneous spot in testaceous background in some paratypes. Timbal white, semitransparent with four long and one short testaceous ribs and a testaceous spot between posterior pair of long ribs which fuse dorsally. Sternites tawny except for fuscus mark on lateral half of anterior border of sternite 2, fuscus region between sternites II and III and ochraceous posterior of sternites III-VII. Sternite VIII ochraceous.

Male genitalia ( Figs. 5, 6 ). Pygofer ochraceous, lateral surfaces fuscus. Fuscus markdorsally on eachside of midline connecting posteriorly across midline forming a U-shape. Uncus ochraceous with lateral fuscus mark, mostly fuscus laterally in some paratypes. Median uncus lobe recurved dorsally. Lateral uncus lobes bent at right angle with sinuate lateral border.

Measurements (in mm). N = 8 males, mean (range). Length of body: 19.6 (17.2-22.2); length of tegmina: 26.2 (22.8- 30.2); width of tegmina: 9.0 (7.5-10.7); length of head: 2.7 (2.5-3.0); width of head including eyes: 7.1 (6.5-7.9); width of pronotum including suprahumeral plates: 8.1 (7.2-8.9); width of mesonotum: 7.2 (6.5-8.0).

Taxonomic notes. The species is distinguished from other members of Proarna by the coloration pattern and structure of the genitalia. The most similar species is Proarna uruguayensis Berg . The author received specimens of P. uruguayensis collected at Cassino Beach, 10 km south of Cassino Beach and 15 km south of Cassino Beach from Panicum racemosum (P. Beauv.) Spreng. , the proposed host of Proarna gianucai (see below). However, in P. uruguayensis the ground coloration is castaneous rather than ochraceous, the prothoracic markings are reduced, the abdomen is completely castaneous, the timbal cover has a more oblique angle anteriorly, and the infuscation in the wings is lighter and reduced in number. The genitalia also differ significantly in that the lateral lobes of the pygofer of P. uruguayensis diverge and the termini are angled laterally rather than arching smoothly parallel to the midline as in P. gianucai .

Biological notes. The biological notes were compiled from the field notes of Norton M. Gianuca (pers. comm.). The southernmost part of the Brazilian littoral zone is characterized by extensive coastal dunes above exposed sandy beaches. The dunes are stabilized partially by autochthonous herbaceous vegetation which acts as a host plant for P. gianucai . Both nymphs and adults of P. gianucai were associatedwith P. racemosum , anative perennial, dunebuilding rhyzomatosus grass which is the dominant plant species of the foredune habitat. Nymphs were found between 0.2-1 m depthsthroughout theyear, adults and nymphal skins were found between December and March 0.3-0.5 m above the ground on P. racemosum .

Sedentary P. gianucai were preyed uponby the Sand Toad ( Bufo arenarum Hensell ) and the Common Miner ( Geositta cunicularia [Vieillot]) from the sand surface as well as vegetation. Cicadas in flight were preyed upon by the robber fly Eccritosia rubreventris (Macquart) and the Gray-breasted Martin ( Progne chalybea [Gmelin]).

The encroachment of cattle pasture on the sand grass is a potential threat to the survival of P. gianucai . Expansion of pastureland into the foredune zone reduces the plant cover and height and thus substrate stability resulting in erosion and sand transport by the wind.

Figures

Figs. 1-6. Proarna gianuca sp. n. 1. Dorsal view of holotype male; bar = 2 cm; 2. Holotype dorsum illustrating head and thoracic markings; 3. Holotype male timbal cover; 4. Holotype male operculum; 5. Lateral view of holotype male genitalia; 6. Posterior view of holotype male genitalia