Percyella Bastin, Burckhardt & Ouvrard, 2023

Bastin, Saskia, Burckhardt, Daniel, Reyes-Betancort, Alfredo, Hernández-Suárez, Estrella & Ouvrard, David, 2023, A review of the jumping plant-lice (Hemiptera: Psylloidea) of the Canary Islands, with descriptions of two new genera and sixteen new species, Zootaxa 5313 (1), pp. 1-98 : 52-53

Percyella Bastin, Burckhardt & Ouvrard gen. nov.

( Figs 188–195 , 215–218 , 272, 274 , 297–307 ) urn:lsid:zoobank.org:act:6A3986DE-D53E-4939-943E-D4B46B713C9B

Type species: Percyella guanche sp. nov., by present designation.

Diagnosis. Adult. Genal processes developed, conical, subacute apically, not constricted at base. Thorax, in lateral view, weakly curved dorsally.Anterior margin of mesosternum incised in middle; pleurosternal suture well developed; basisternum triangular; lateral part of katepisternum almost as wide as head; anterior part of katepisternum large, slightly angular. Metacoxa lacking anterior lobe; bearing long horn-shaped meracanthus. Metatibia with 1+2 apical sclerotised spurs. Forewing indistinctly angled or subacute apically; trifurcation of vein R+M+Cu strict; vein Rs short, vein M branching near line connecting apices of veins Rs and Cu 1a. Male subgenital plate, in lateral view, elongate, with short, blunt posterior process. Paramere much shorter than proctiger, with broad basal two thirds and digitiform apical process. Proximal segment of aedeagus straight; distal segment with large, spine-like process basally and irregularly oval apical dilatation. Female terminalia short, cuneate.

Fifth-instar immature. Body oval, flattened, 1.6–1.8 times as long as wide. Body fringed with a single row of very sender, long subacute sectasetae, dorsum lacking sectasetae. Antenna 7 segmented, strongly curved. Tarsal arolium including pedicel and unguitractor modified to a claw-like structure; claws forming small sclerites on either side of claw-like structure. Forewing pad with short humeral lobe ending at hind margin of eye. Anus ventral; outer circumanal ring relatively large, heart-shaped, consisting of a single row of slit-like pores.

Description. Adult ( Figs 272, 274 ). Head slightly narrower than thorax; in lateral view, hardly inclined from longitudinal body axis. Vertex subtrapezoidal, 0.6–1.2 times as long as wide; with a fovea on either side of median suture which is fully developed; irregularly beset with moderately long, fine setae; anteriorly slightly produced and curving down to genae from which it is separated by transverse suture; frons almost completely covered by median ocellus; genal processes ( Fig. 188 ) developed, conical, subacute apically, not constricted at base, 0.2–0.5 times as long as vertex along mid line. Antenna ( Figs 189, 190 ) 10 segmented, 1.9–2.9 times as long as head width; with a subapical rhinarium on each of segments 4, 6, 8 and 9, and a subapical pair of fine setae on segments 3–9. Clypeus ( Fig. 191 ) shortly tubular, with a group of short apical setae; rostrum short, only distal segment visible in lateral view. Thorax, in lateral view, weakly curved dorsally; pronotum curved down and backwards laterally; propleurites with large episternum, small epimeron and oblique suture. Anterior margin of mesosternum incised in middle; pleurosternal suture well developed; basisternum triangular; lateral part of katepisternum almost as wide as head; anterior part of katepisternum large, slightly angular. Metacoxa ( Fig. 192 ) lacking anterior lobe; bearing long, pointed horn-shaped meracanthus. Ventral sense organs of metafemur in median position; apex bearing a few moderately long bristles. Metatibia 0.9–1.1 times as long as head width, distinctly longer than metafemur; weakly swollen basally with several uneven spines; with 1+2 apical sclerotised spurs. Metabasitarsus lacking lateral spurs. Forewing ( Figs 193, 194 ) 2.4–2.8 times as long as broad, 4.3–5.9 times as long as head width; angled or subacute apically; trifurcation of vein R+M+Cu strict; vein Rs short, weakly curved to costal wing margin; vein M branching near line connecting apices of veins Rs and Cu 1a; membrane transparent; radular areas present in cells m 1, m 2 and cu 1; surface spinules absent from distal half of wing. Hindwing ( Fig. 195 ) distinctly shorter than forewing; costal setae grouped; veins R and M with short common petiole. Lateral setae on abdominal tergites usually restricted to the first visible segment. Male proctiger tubular, slightly narrowing apically; in lateral view, anterior margin weakly curved, posterior margin almost straight. Male subgenital plate, in lateral view, elongate, dorsal margins weakly indented with short, blunt posterior process. Paramere much shorter than proctiger, with broad basal two thirds and digitiform apical process. Proximal segment of aedeagus straight, thick at base, irregularly narrowing to apex; distal segment with large, spine-like process basally and irregularly oval apical dilatation; sclerotised end tube of ductus ejaculatorius short, weakly curved. Female terminalia short, cuneate; proctiger blunt, subgenital plate pointed apically.

Fifth-instar immature. Body oval ( Fig. 215 ), flattened, 1.6–1.8 times as long as wide. Body fringed with a single row of very sender long subacute sectasetae, dorsum lacking sectasetae. Antenna 7-segmented, strongly curved. Tarsal arolium ( Figs 216, 217 ) including pedicel and unguitractor modified to a claw-like structure; claws forming small sclerites on either side of this “claw”. Forewing pad with short humeral lobe ending at hind margin of eye. Anus ventral; outer circumanal ring ( Fig. 218 ) relatively large, heart-shaped, consisting of a single row of slit-like pores.

Etymology. Dedicated to Diana M. Percy for her fundamental work on the psyllids from the Canary Islands; gender feminine.

Biology. The immatures induce galls consisting of a roll along the leaf margins ( Figs 297, 300, 302, 303 ) or of the folded apex of the leaf ( Fig. 299 ). The fully developed galls form a closed tube ( Fig. 304 ). Each gall shelters immatures of various stages, skins and globules of honeydew coated with a layer of wax ( Figs 298, 301 ). The fifth instar immatures leave the gall for emergence and the skins can be found exposed on the leaf ( Fig. 305 ). The galls dry and turn black after all the immatures have left ( Fig. 297 ). Sometimes Pseudococcidae ( Fig. 307 ), Coccinellidae , aphids, thrips or psocids are found in the galls. We also observed the presence of larvae and adults of psyllid predators and ectoparasitic mites. In some galls, mummies were found documenting the presence of parasitic wasps.

Comments. Percyella gen. nov. is erected here to contain following four species described below: Percyella benahorita sp. nov., P. canari sp. nov., P. gomerita sp. nov. and P. guanche sp. nov. The genus is endemic to the Canary Islands and the species develop on Convolvulus floridus (Convolvulaceae) .

In the mitogenome analysis by Percy et al. (2018), Percyella gen. nov. was recovered in clade A (represented by Trioza sp. DP3.ca.7180021052875 = P. benahorita sp. nov.) grouped with strong support with Dyspersa , Hemitrioza and Spanioza . Percyella is morphologically well defined and differs from the other three genera in having a basally broad and apically digitiform paramere; a blunt posterior process on the male subgenital plate; a straight proximal segment of the aedeagus; a large, basal spine-like process on the distal segment of the aedeagus; and, in the immature, a modified tarsal arolium and claws. Percyella differs also in its host associations from Dyspersa (mostly on Apiaceae and Asteraceae ), Hemitrioza (on Asteraceae ) and Spanioza (on Rubiaceae ).

Figures

FIGURES 186–195. (186)Heterotrioza chenopodii, male terminalia, lateral view.(187)Lauritrioza laurisilvae, male terminalia, lateral view. (188–195) Percyella spp.; (188) head, dorsal view (P. benahorita); (189) antenna (P. guanche); (190) antenna, showing rhinaria (P. guanche); (191) proboscis (P. gomerita); (192) metacoxa (P. gomerita); (193) forewing (P. gomerita); (194) forewing (P. guanche); (195) hindwing (P. gomerita).

FIGURES 212–218. Fifth-instar immature; (212–214) Lauritrioza laurisilvae: (212) habitus, right half; (213) marginal sectasetae and simple setae on forewing pad; (214) marginal sectasetae and simple setae on caudal plate. (215–218) Percyella species: (215) habitus, right half; (216) modified tarsal arolium and claws, lateral view; (217) modified tarsal arolium and claws, dorsal view; (218) circumanal rings and anus.

FIGURES 269–280. (269–271) Lauritrioza laurisilvae: (269, 270) adult, habitus; (269) lateral view; (270) dorsal view; (271) immature. (272, 273) Percyella canari: adult, habitus; (272) lateral view; (273) dorsal view. (274–276) Percyella gomerita, adult, habitus, dorsal view. (277–280) Percyella guanche: (277) Acari attached to the abdomen; (278) adult, habitus, dorsal view; (279, 280) immature. Photographs 269 and 270 by Alfonso Peña Darias.

FIGURES 297–307. (297–300) Percyella benahorita galls. (301) Percyella canari gall. (302–305) Percyella gomerita galls. (305) Anthocoris salicis. (307) Pseudococcidae sp.