Diaphorina caliginosa, Malenovský & Burckhardt, 2014

Malenovský, Igor & Burckhardt, Daniel, 2014, Jumping plant-lice of Socotra Island (Hemiptera: Psylloidea), Acta Entomologica Musei Nationalis Pragae 54, pp. 23-61 : 31-37

Diaphorina caliginosa sp. nov.

( Figs 18–22 , 27–38 )

Type locality. Yemen, central Socotra, Hagher mountains, Mt.Skand environs, 12°34′36″N 54°01′30″E, 1450 m a.s.l. ( Fig. 23 ).

Type material. HOLOTYPE: ♂ ( MMBC, dry-mounted), ‘ YEMEN, SOCOTRA Island / Hagher Mts. , Scand Mt. env. / 12°34.6′N, 54°01.5′E, 1450 m / montane evergreen woodland / 16.-18.vi.2012 // on Carissa spinarum / I. Malenovský leg.’. PARATYPES: 12 ♂♂ 9 ♀♀, 1 skin of fifth instar immature, same data as the holotype ( MMBC, NHMB, NMPC, dry- and slide-mounted and preserved in alcohol).

Description. Adult. Coloration ( Figs 18, 19 ). Body partly covered with grey waxy secretions. Head including genal processes and thorax dark brown, pronotum medially and mesoscutellum slightly lighter brown, mesoscutum dorsally with blackish brown longitudinal stripes, lateral sclerites of thorax partly red. Eyes dark brown, ocelli red. Antenna dirty yellow, segments 1 and 2 brown, segment 8 fumous, segments 9 and 10 entirely dark brown to black. Legs with tarsi dirty yellow, apical tarsal segments slightly infuscate, tibiae largely dirty yellow, dark brown basally, femora and coxae dark brown. Forewing membrane opaque, off-white, covered from base to apex with many sharply contrasting dark brown irregular patches, fusing into a narrow continuous dark brown band at outer-posterior wing margin, extending from apical tip of r 1 to apex of cu 2 cells and leaving small light semioval patches medially in cells r 2, m 1, m 2 and cu 1 at wing margin ( Fig. 20 ); veins light brown, short basal portions of M+Cu, M, R 1, R S and Cu 1a dark brown, wing margin with several short dark brown sections at apices of R 1 and Cu 1b and in apical wing quarter. Hind wing hyaline, C+Sc vein entirely and apical veins basally dark brown. Abdomen including terminalia dark brown.

Structure. Integument with coarse microsculpture, matt, covered with short greyish setae. Head slightly inclined from longitudinal body axis. Vertex flat with one distinct fovea on each side of median suture; lateral ocelli lying in plane of vertex, frontal ocellus clearly visible in dorsal view. Genal processes approximately as long as vertex along midline, with straight inner margins contiguous basally and strongly diverging in apical two thirds, lateral margins convex, and apex subacute ( Fig. 22 ). Eyes subglobular. Antenna ( Fig. 32 ) relatively long, about 0.9 as long as head width, with 10 segments; segments 3–7 nearly cylindrical, segment 8 strongly widening to apex; segment 3 longest, segments 4–6 each subequal in length, segments 7 and 8 each shorter than more proximal flagellar segments but each slightly longer than segment 9; single circular rhinarium subapically on segments 4, 6, 8 and 9; rhinaria on segments 4 and 6 each associated with simple seta; segment 10 with terminal setae greatly differing in length: one short (ca. 0.02 mm), stout, and truncate, the other long (ca. 0.06 mm) and slender ( Fig. 33 ). Clypeus nearly flat, basally with few short inconspicuous setae; rostrum short, apical segment with two long setae. Metacoxa with relatively long, pointed meracanthus. Metatibia elongate, rugged basally but lacking genual spine, slightly widening to apex, with a crown of 7 or 8 dark sclerotised spurs apically. Metabasitarsus laterally bearing two dark sclerotised apical spurs. Forewing ( Fig. 20 ) elongate, relatively narrow, broadest in apical quarter, broadly and almost symmetrically rounded apically, with apex lying in cell r 2 close to R S vein apex; R S vein sinuate in apical half; membrane densely covered in large, star-shaped surface spinules which are irregularly arranged ca. 7 (6–11) μm apart in middle of cells ( Fig. 21 ) and becoming smaller, simply radular and more densely arranged near veins and along apical wing margin; fore wing veins associated with many short setae inserted into membrane close to veins ( Fig. 21 ). Hind wing costal margin with 2 + 8 ungrouped setae basally and 1 seta apically. Male subgenital plate with slightly sinuate dorsal margin and few sparse short setae postero-ventrally ( Fig. 27 ). Male proctiger relatively broad, with large, apically broadly rounded posterior lobes ( Fig. 27 ). Paramere, in lateral view, nearly parallel-sided, straight; apical part slightly asymmetrical with anterior margin more strongly narrowing to apex than posterior margin; apex narrowly rounded, bearing a small tooth on inner side; inner face covered with numerous long unsclerotised setae ( Fig. 28 ). Distal segment of aedeagus with a simple, obovate apical dilatation, ductus ejaculatorius short and sinuate ( Fig. 29 ). Female terminalia with proctiger, in lateral view, with dorsal margin slightly concave, apex narrowly rounded; circumanal pore ring elliptic with two contiguous rows of pores; subgenital plate, in lateral view, with distinct ventral hump medially, in apical half straight and narrowing to pointed apex ( Fig. 30 ); dorsal and ventral valvulae slightly curved ventrally, smooth, lacking any teeth ( Fig. 31 ).

Measurements (in mm). Males (n = 2): HW 0.59, AL 0.52–0.57, WL 2.21–2.25, WW 0.85–0.89, TL 0.57, MPL 0.31–0.33, PL 0.24–0.25, AEL 0.17–0.18. Females (n = 2): HW 0.60–0.62, AL 0.51–0.54, WL 2.37–2.40, WW 0.94–0.95, TL 0.58, FPL 0.62–0.63, SL 0.47–0.48. Ratios: AL/HW 0.85–0.97, WL/HW 3.75–4.00, WL/WW 2.47–2.60, TL/HW 0.94–0.97, MPL/HW 0.53–0.56, FPL/HW 1.02–1.03, FPL/SL 1.29–1.34.

Fifth instar immature ( Fig. 34 ). Body brownish, broad, flat. Margins of head and wing pads lacking any visible setae, caudal plate margin with 120 densely arranged, relatively long, pointed lanceolate setae ( Fig. 35 ). Antenna with 3 segments; apical segment posteriorly with three pointed lanceolate setae and four rhinaria ( Fig. 36 ). Forewing pad with broadly rounded humeral lobe. Tarsal arolium broadly triangular ( Fig. 37 ). Anus ventral, outer circumanal ring elongate with lateral sides slightly bent forwards, consisting of single row of pores ( Fig. 38 ).

Measurements (n = 1; in mm). BL 1.67, BW 1.66, AL 0.35, FL 1.04, TL 0.34, CPL 0.50, CPW 0.82, CRW 0.18. Ratios: BL/BW 1.01, AL/FL 0.34, CL/CW 0.61, CRW/CPW 0.22.

Differential diagnosis. Diaphorina is a large genus with some 80 species described from tropical and subtropical regions of the Old World ( LOGINOVA 1978, OUVRARD 2014). Only one of them, Diaphorina carissae ( Pettey, 1924) from South Africa, has been reported from Carissa sp. , i.e. the same or related host plant as D. caliginosa sp. nov. According to the published description, D. carissae is generally smaller (HW = 0.4 mm, WL = 1.65 mm, WW = 0.7 mm for female), with lighter head and abdomen (pale yellowish brown to yellow), and shorter genal processes (only a little more than half as long as vertex) than D. caliginosa sp. nov. ( PETTEY 1924, 1925). Both species, however, share a similar forewing shape and maculation (the dark pattern is perhaps more expanded in D. carissae ) and may be closely related. A similar forewing shape and pattern is also present in D. petteyi Capener, 1970 from South Africa which is, however, slightly larger compared to D. caliginosa sp. nov., paler in general coloration, and its immatures have circumanal pore ring composed of four rows of pores and are associated with a different plant ( Polygala myrtifolia L., Polygalaceae ) ( CAPENER 1970). The coarse surface spinulation of the forewing membrane of D. caliginosa sp. nov. is similar to D. citri Kuwayama, 1907 and D. communis Mathur, 1975 which are associated with Murraya and Citrus spp. (Rutaceae) and differ, besides other characters, in a more angulate apical portion of anterior forewing margin ( MATHUR 1975, LOGINOVA 1978), which is regularly rounded in D. caliginosa sp. nov. From other three Diaphorina spp. currently known from Socotra, D. caliginosa sp. nov. differs in characters given in the key below.

Etymology. Derived from the Latin adjective caliginosus (= covered with mist, foggy, cloudy, dark, gloomy), referring to the weather conditions under which the type series was collected and the generally dark coloration of the species.

Host plant. Carissa spinarum L. ( Apocynaceae ) ( Figs 23–24 ).

Biology. Adults and one skin of a fifth instar immature were found close to the central vein on lower surface of leaves of the host plant. Adults, often immerged in water drops from condensed fog, were attached to the leaf only with their fore body, with abdomen oriented almost vertically towards the ground. No deformations of the host plant could be observed. Occurrence in Socotra. Found only in one small area in the highest part of the Hagher mountains, in a dense montane evergreen woodland belonging to the Leucas hagghierensis- - Pittosporum viridiflorum community ( KÜRSCHNER et al. 2006, BROWN & MIES 2012; Fig. 23 ).

Distribution. So far only known from the Socotra Island. The host plant, Carissa spinarum , in its currently accepted taxonomic definition, is very widely distributed throughout Africa, Madagascar, Seychelles, Mascarenes, Arabia, India, China, South East Asia, Australia and New Guinea ( HASSLER 2014).

Figures

Figs 18–22.Diaphorina caliginosa sp. nov., adult. 18 – habitus, lateral view; 19 – habitus, dorsal view; 20 – forewing; 21 – detail of forewing membrane in cell m1 at M-fork; 22 – head, dorsal view.

Figs 27–33. Diaphorina caliginosa sp. nov., adult. 27 – male terminalia, outer lateral view; 28 – paramere, lateral view, inner face; 29 – distal segment of aedeagus, lateral view; 30 – female terminalia, lateral view, with detail of circumanal ring structure; 31 – detail of dorsal and apex of ventral valvulae, lateral view; 32 – antenna; 33 – antennal segments 9 and 10.

Figs 34–38. Diaphorina caliginosa sp. nov., fifth instar immature.34 – body, dorsal view (left side only, with position and relative size of ventral circumanal pore ring indicated on right side of midline); 35 – detail of lanceolate setae on caudal plate margin; 36 – antenna; 37 – detail of tibiotarsus apex; 38 – detail of circumanal pore ring (right side only).

Figs 23–26. Habitats of Diaphorina spp. in Socotra. 23 – montane evergreen woodland in Skand area, Hagher Mts., with a Carissa spinarum tree in foreground (centre): type locality of D. caliginosa sp. nov. 24 – detail of a Carissa spinarum twig, host plant of D. caliginosa sp. nov. 25 – montane shrubland with open grassland patches in wadi Madar, Hagher Mts.: type locality of D. hagherensis sp. nov. 26 – open dry woodland on limestone plateau near Firmihin with a Lycium sokotranum shrub in foreground:habitat and host plant of D. elegans Burckhardt & Mifsud, 1998. Photographs by I. Malenovský (23, 24) and P. Kment (25, 26).