Petascelis Signoret

Brailovsky, Harry, 2008, Notes on the genus Petascelis Signoret and description of one new species (Hemiptera: Heteroptera: Coreidae: Coreinae: Petascelini), Zootaxa 1749, pp. 18-26 : 18-19

Petascelis Signoret

Petascelis Signoret, 1847: 302 .

Redescription. Body large, over 28.00 mm, broad, not depressed. Head. Subquadrate, short, wider than long, apex strongly bending downward at level of antenniferous tubercles, and clothed with dense golden pilosity; antenniferous tubercles protruding forward, unarmed, almost filling intertubercle space; tylus not protracted; jugum anteriorly not expanded; posttylar sulcus deeply cleft medially; antennae shorter than body length; antennal segment I stouter than other segments; antennal segment II cylindrical, robust, segment III slightly flattened, IV fusiform, its apical third slender or gently clavate, and apex acute or weakly rounded ( Fig. 1 ); eyes protuberant; postocular tubercle not visible, forming contiguous curve with eyes; buccula uniformly rounded, short, raised, not projecting beyond antenniferous tubercles; rostrum short, not extending beyond anterior margin of mesosternum. Thorax. Pronotum. Declivent, wider than long, narrowed anteriorly, diverging posteriorly; collar clearly demarcated; anterior border entire, straight; anterolateral borders nodulose to crenate; humeral angles rounded, weakly expanded; posterolateral borders sinuate, smooth; posterior border slightly convex, smooth; callar region flat, not clearly demarcated; posterior lobe glabrous, finely punctate. Prosternum deeply concave; mesosternum flat, nonsulcate, anteriorly tuberculate between fore coxae; metasternum variable through the species ( Figs. 2–11 ); anterior lobe of metathoracic peritreme elongate, slender, half-moon shaped, and posterior lobe small, subacute. Legs. Fore coxae placed somewhat closely together; hind coxae widely separated; fore and middle femora robust, ventrally armed with two broad subapical spines, and dorsally smooth, undulate; hind femora incrassate, much more so in males, ventrally armed with two broad subapical spines and two rows of strong denticles, and dorsally smooth, undulate; fore and middle tibiae unarmed, dilated, outer dilation wide expanded, lanceolate, rounded, occupying 100% of total length of tibia, and inner dilation straight, weakly expanded; hind tibia unarmed, remarkably expanded, outer dilation lanceolate, rounded, very long, occupying 100 % of total length, and inner dilation much shorter occupying 55– 65 % length of outer dilation with at least two deep emarginations. Scutellum.- Wider than long, triangular, flat, apically subacute; basal third transversely elevated. Hemelytra.- Macropterous, reaching or extending beyond apex of last abdominal segment; costal margin emarginated, apical margin sinuate. Abdomen.- Broad, conspicuously dilated, widest point at segments IV–V, much wider than hemelytra; connexivum raised above tergum, posterior angles of connexival segments IV to VI exposed, subacute; posterior third of abdominal segment VII laterally expanded, much more so in males; abdominal spiracle large, transversely oblongate-oval, closer to anterior edge and far from lateral edge of the sternite. Integument.- Antennal segments I to III densely clothed with large, decumbent, setae-like hairs, forming a silver pubescence; antennal segment IV intermixed short, erect and decumbent, setae-like hairs, forming a silver pubescence; calli clothed with dense decumbent golden pubescence; pro-, meso, and metapleura clothed with longitudinal stripes of erect to decumbent golden pubescence; pro-, meso- and metasternum clothed with short erect to decumbent silver pubescence; legs intermixed short erect and decumbent golden and silver pubescence. Male genital capsule.- Simple; posteroventral edge straight, or slightly exposed. Female genital plates.- Abdominal sternite VII with plica and fissura; plica subtriangular, covering ¾ of sternite; gonocoxae I enlarged anteroposteriorly, subtriangular, in caudal view closed, upper margin rounded and weakly protracted, outer margin straight; paratergite VIII triangular, spiracle visible; paratergite IX squarish, subequal to VIII.

Comments. The general body plan of Petascelis Signoret (1847) resembles Petascelisca Distant (1881) . In the latter the middle tibiae are not dilated at the outer and inner margins; the outer dilation of the hind tibiae is barely expanded, occupying less than 60 % of the total length, and the inner dilation is shorter than outer dilation, and expanded as an acute spine like projection; the metasterum of both sexes is unarmed, the anterior lobe of the metathoracic peritreme is black, and the posterior angles of connexival segments IV to VI are unarmed. In Petascelis the middle tibiae are conspicuously dilated at their outer margins, and eventually at the inner margins; the hind tibiae of both sexes have outer margins remarkably expanded, occupying 100 % of the total length, and a much shorter inner dilation, occupying 55–65 % of the total length of the outer dilation; the metasternum of both sexes is armed; the anterior lobe of the metathoracic peritreme is not entirely black; and the posterior angles of connexival segments IV to VI are exposed and subacute.

Figures

FIGURE 1 – 6. Petascelis spp. 1. Antennae of P. inconditus n. sp. 2 – 6. Mesothorax, metathorax and abdominal sterna in lateral view. 2. Petascelis affinis Dallas. 3. Petascelis remipes Signoret. 4. Petascelis inconditus n. sp. 5. Petascelis foliaceipes Distant. 6. Petascelis laminipes Fairmaire.

FIGURE 7 – 11. Mesosternum, metasternum and abdominal sterna of Petascelis spp. 7. Petascelis affinis Dallas. 8. Petascelis remipes Signoret. 9. Petascelis foliaceipes Distant. 10. Petascelis inconditus n. sp. 11. Petascelis laminipes Fairmaire.