Philagra Stål, 1863

Liang, Ai-Ping, 2022, Three new species of the genus Philagra Stål (Hemiptera: Cercopidea: Aphrophoridae) from China and Bangladesh, Zootaxa 5200 (2), pp. 169-180 : 170-171

Genus Philagra Stål, 1863

Chalepus Walker, 1851: 731 .

Type species: Chalepus hastatus Walker, 1851 , by subsequent designation of Distant, 1908: 107. Preoccupied by Chalepus Thunberg, 1805 .

Philagra Stål, 1863: 593 ; Distant, 1908: 107; Metcalf & Horton, 1934: 399; Metcalf, 1962: 571.

Type species: Philagra douglasi Stål, 1863 , designated by Metcalf and Horton, 1934: 399.

Diagnosis. Species of Philagra Stål can be distinguished by the following combination of characters: body relatively slender and elongate, medium to large-sized, covered with fine, short, silvery setae ( Figs 1 , 2 , 5 ); head relatively narrow, conically produced in front of eyes into a cephalic process as long as or longer than pronotum and scutellum combined, usually curving dorsad ( Figs 1 , 2 , 4A–C , 5 , 7A,B ); pronotum wider than head; scutellum relatively large, usually about half as long as pronotum; antennae with expanded flagellar base ( Figs 3A–E ) hidden in apical cavity of pedicel and not visible in lateral aspect, bearing two peg-like basiconic sensilla and a few coeloconic sensilla on surface ( Figs 3A–E ); rostrum short, not passing trochanters of middle legs; forewings usually large, coriaceous, with venation indistinct, costal margin usually strong convex, widest about level of apex of scutellum, with apical angle acuminate; venation inconspicuous, M and Cu fused basally, with 3 preapical cells of similar width; legs relatively robust and short, posterior tibia short and stout, with two stout spines on lateral edge, the distal larger than the proximal, second segment of hind tarsus bilobed with median lobe usually longer than lateral lobe; male pygofer in lateral view short, cylindrical ( Figs 4D , 6A–D , 7C ); anal segments and anal style elongate ( Figs 4D , 6A–D , 7C ); subgenital plates relatively large, narrow, acuminate, and elongate, base fully fused with pygofer, tapering from base to dorsally recurved apex, fully covering genital styles and aedeagus in ventral view, with a strong recurved process at apical margin ( Figs 4D,E , 6A–D , 7C,D ); genital style elongate, usually forked or excavated apically, with upper edge subapically strongly excavated in lateral view ( Figs 4D,F , 6A,E–G , 7C,E ); aedeagal shaft slender, tubular, moderately long, nearly perpendicular, apex usually with two spinose processes directed postero-ventrad; gonopore subapical dorsally ( Figs 4G,H , 6E–G , 7F,G ) ( Metcalf & Horton 1934; Liang & Fletcher 2003).

Biology. In common with most spittlebug groups, currently no biological data are available for Philagra species. The nymphs of Philagra species produce conspicuous masses of cuckoo-spit on shrubs and small trees ( Liang & Fletcher 2003).

Distribution. India, China, Japan, Cambodia, Vietnam, Laos, Indonesia (Batjan, Halmahera), and Australia ( Metcalf 1962; Liang & Fletcher 2003).

Notes on the type species of the genus. Metcalf and Horton (1934) discussed the question of a type species for Philagra . They regarded Stål's (1863: 593) description of Philagra as the creation of a new genus rather than a replacement name for Chalepus Walker , which was preoccupied. Stål (1863) appeared to have been unaware of Walker's genus Chalepus and described Philagra as a new genus with two new species, P. douglasi and P. scotti , neither of which was designated as type species. Metcalf and Horton (1934) rightly pointed out that a type species for such a new genus needed to be designated from those species placed in the genus by the original author. As Stål (1863) had failed to designate a type species, Metcalf and Horton (1934) selected the first of the two species included in the genus by Stål (1863) as the type. Other authors have followed Distant (1908) who selected Chalepus hastatus Walker as the type on the assumption that Stål's name simply replaced Walker's preoccupied name but, as pointed out by Metcalf and Horton, this was not the case and C. hastata cannot be considered available for designation as type species of Philagra ( Liang & Fletcher 2003) .

Schmidt (1920) established the tribe Philagrini to accommodate Philagra . Three genera, Philagra , Interocrea Walker, 1870 and Grellaphia Schmidt, 1920 were included in the world catalogue of the family Aphrophoridae ( Metcalf, 1962) . Philagrini is obviously not a monophyletic group and the phylogenetic position of the tribe needs to be investigated cladistically.

Figures

FIGURE 1. Dorsal habitus of Philagra species. A. Philagra bimaculata sp. nov., paratype male (China: Tibet). B. Philagra fuscofasciata sp. nov., female (China: Sichuan). C. Philagra straminea sp. nov., paratype male (China: Sichuan). Scale bar = 1 cm.

FIGURE 2. Philagra bimaculata sp. nov., adult habitus (China: Tibet). A, B. Dark form, male. C, D. Pale form, female.

FIGURE 3. Scanning electron micrographs of antennal sensilla and rostral structure. A–C. Philagra bimaculata sp. nov. Expanded flagellar base, top view, showing two peg-like basiconic sensilla and some coeloconic sensilla on surface. D, E. Philagra straminea sp. nov. D. Antenna, ventrolateral view, showing the segmented flagellum with scar-shaped rings and the expanded, bulbous flagellar base bearing peg-like basiconic sensilla and some coeloconic sensilla on surface. E. Two peg-like basiconic sensilla and some coeloconic sensilla on surface of expanded flagellar base. F–H. Philagra bimaculata sp. nov. F. Maxillar stylet. G, H. Ten sensilla of two types (b1 and b2) of basiconic sensillum on lateral lobe of rostral apex. Abbreviations: b1 = type I basiconic sensillum with distinct longitudinal grooved surface; b2 = type II basiconic sensillum with smooth surface and the fine pits on surface; ba = basiconic sensillum; co = coeloconic sensillum; fb = expanded flagellar base; fl = flagellum; pe = pedicel; sc = scape.

FIGURE 4. Philagra bimaculata sp. nov. A. Head, pronotum and scutellum, dorsal view. B. Head, ventral view. C. Head, pronotum and scutellum, lateral view. D. Genital capsule, lateral view. E. Subgenital plates, ventral view. F. Left genital style, ventrolateral view. G. Aedeagal shaft, lateral view. H. Aedeagal shaft, posterior view. Scale bar =1.0 mm in A–C and 0.5 mm in D–H.

FIGURE 5. Philagra fuscofasciata sp. nov. Habitus.A. Holotype male, dorsal view. B. Paratype female, dorsal view. C. Paratype female, lateral view. Scale bar = 1 mm.

FIGURE 6. Philagra fuscofasciata sp. nov. Male genitalia.A. Genital capsule, lateral view. B. Genital capsule, ventral view. C. Genital capsule, dorsolateral view. D. Genital capsule, right lateroventral view. E. Genital styles and aedeagal shaft, left lateral view. F. Genital styles and aedeagal shaft, right lateral view. G. Aedeagal shaft and genital styles, posterior view. Scale bar = 1 mm.

FIGURE 7. Philagra straminea sp. nov. A. Head, pronotum and scutellum, lateral view. B. Head, ventral view. C. Genital capsule, lateral view. D. Subgenital plates, ventral view. E. Left genital style, ventrolateral view. F. Aedeagal shaft, lateral view. G. Aedeagal shaft, posterior view. Scale bar = 1 mm in A, B, 0.5 mm in C, D and 0.25 mm in E–G.