Himalayaleyrodes sarcococcae Dubey

Dubey, Anil Kumar & Singh, Sudhir, 2017, A new whitefly genus and species, Himalayaleyrodes sarcococcae Dubey (Hemiptera: Aleyrodidae) infesting Christmas box (Buxaceae) in Western Himalaya, India, Zootaxa 4269 (4), pp. 531-544 : 533-541

Himalayaleyrodes sarcococcae Dubey sp. nov.

( Figs 1–59 )

Puparium. In life, covered with long filaments of white wax, forming dome-shaped periphery around puparium ( Figs 2 & 6 ); 1–7 puparia occur per leaf, mostly on lower surface of leaves and 1–12 puparia occur on stems; feeding sites on leaf and stem turn yellow; raised waxy palisade around lateral margin of puparia ( Figs 1–5 ); broadly oval in shape; fresh puparia light pale, empty puparia white; parasitized puparia brown to smoky black; puparia narrowest at prothoracic region ( Fig. 13 ) and broadest at abdominal segment II–III ( Fig. 14 ); clearly dimorphic, ♀ 1275–1325 µm long, 100–1050 µm wide; ♂ 825–1125 µm long, 700–800 µm wide.

Margin: Crenulate, 17–19 crenulations in 0.1 mm ( Fig. 10 ). Caudal tracheal pore area modified into a comb ( Fig. 18 ) and thoracic tracheal pore areas slightly indicated by indented apex of the marginal teeth ( Figs 17 & 26 ).

Dorsum: Submargin not differentiated from dorsal disc by a furrow or fold ( Figs 9 & 23 ), with a row of nine pairs of marginal setae (four pairs on cephalothorax and five pairs on abdomen) ( Figs 15 & 24 ) and 37–39 pairs of geminate pores. Submarginal lines evident. Thoracic tracheal furrows absent. Caudal furrow 115–152 µm long in female and 90–117 µm long in male. Subdorsal area raised in live puparia, formed by a narrow band (30 µm wide) of wax secreting glands ( Figs 11 & 28 ), wax glands mostly pentagonal or hexagonal in shape ( Fig. 20 ), and with randomly placed 130–135 simple pores. Longitudinal moulting suture reaching margin. Transverse moulting suture reaching outer subdorsum on metathoracic region. Cephalothoracic and abdominal segment sutures prominent, reaching submedian area. Submedian pockets present on segment sutures but submedian depressions prominently visible on inter-segmental region. Median length of cephalothorax (561–571 µm long) shorter than abdomen (729– 745 µm long). Median length of meso- and metathorax almost equal. Median length of abdominal segments I–VIII measured: ♀ I 70, II 55, III 70, IV 75, V 65 –67, VI 53, VII 37 –40, VIII 5 7–60 µm long, ♂ I 62 –67, II 40 –50, III 45 –57, IV 45 –62, V 42 –57, VI 32 – 50, VII 22–27, VIII 45 –52 µm long (I>II<III<IV>V>VI>VII<VIII). The longest median length of abdominal segment was of IV and shortest of VII in both male and female puparia (IV>I=III>V>VIII>II>VI>VII). Geminate pores present ( Fig. 27 ), the space between large pore and associated porettes measured 2–5 µm long.

Vasiform orifice ( Figs 12 , 19 , 29 ): situated in a trilobed area of abdominal segment VIII, placed somewhat in a pit ( Fig. 25 ); triangular, longer than wide, posterior margin formed by transverse plates, ♀ 85–88 µm long and 72– 75 µm wide, ♂ 67–78 µm long, 60–65 µm wide; operculum sub-rectangular, covering nearly 50% of the orifice, ♀ 35–43 µm long and 52–55 µm wide, ♂ 32–35 µm long, 42–53 µm wide. Lingula triangular, exposed, not reaching beyond posterior margin of the orifice, 17–18 µm long; a pair of long setae subapically, tip reaching beyond posterior margin of the orifice.

Chaetotaxy. Anterior marginal setae 13–20 µm and 25–35 µm long and posterior marginal setae 23 µm long and 35–45 µm long in male and female, respectively. First abdominal setae absent. Cephalic, eighth abdominal and caudal setae pointed, 15–30, 50 and 23–35 µm long, respectively. Caudal setae nearly equal to the length of vasiform orifice, 22–35 µm long. Submarginal setae 8–13 µm long. Ventral setae 50–65 µm and 25–40 µm long in female and male, respectively, 53–63 µm apart.

Venter ( Figs 30–35 ). A submarginal ventral fold demarcating narrow submarginal area ( Fig. 30 ). Antennae inside prothoracic legs, reaching near base of prothoracic legs, 80–83 µm (including keel, 10–20 µm long) ( Fig. 22 ). Caudal and thoracic tracheal folds with stipples ( Figs 31, 34 & 35 ). A pair of rostral setae 15–20 µm wide ( Fig. 21 ). Microsetae present at base of pro- and mesothorax, each 3 µm long and metathorax 5 µm long. Spiracles visible ( Fig. 35 ).

Third instar ( Fig. 37 ). Puparium elongate oval, 796 µm long, 602 µm wide. Margin crenulate, 12–17 crenulations in 0.1 mm. Caudal and thoracic tracheal combs present. Anterior and posterior marginal setae 13 µm long. First abdominal setae absent. Cephalic setae present. Eighth abdominal and caudal setae 20 µm and 28 µm long, respectively. Longitudinal moulting suture faintly indicated, reaching margin and transverse moulting suture reaching submedian area. Vasiform orifice triangular, posterior end marked with transverse plates ( Fig. 40 ), 55 µm long, 50 µm wide; operculum subrectangular, widest in middle and notched posteriorly, 33 µm long, 38 µm wide. Caudal furrow faintly indicated, 72 µm long.

Second instar ( Fig. 38 ). Oval; dimorphic, ♀ 479 µm long, 321–337 µm wide; ♂ 397 µm long, 194 µm wide. Margin faintly crenulate, 16–18 crenulations in 0.1 mm. Caudal and thoracic tracheal combs indicated. Subdorsal area with wax glands ( Fig. 41 ). Anterior and posterior marginal setae 5–7 µm and 15–17 µm long, respectively. Nine pairs of marginal setae, of which four pairs on cephalothorax and five pairs on abdomen. Cephalic and eighth abdominal setae each 3 µm long and caudal setae 55 µm long. Vasiform orifice elongate triangular, posteriorly truncate ( Fig. 44 ), ♀ 43–48 µm long, 38 µm wide; ♂ 40 µm long, 33 µm wide; operculum subcordate, widest at middle, posteriorly truncate, ♀ 23–33 µm long, 28–30 µm wide; ♂ 40 µm long, 33 µm wide. Caudal furrow ♀ 25– 30 µm long, ♂ 18 µm long. Longitudinal moulting suture faintly indicated, reaching margin and transverse moulting suture reaching submedian area. The median length of meso- and metathorax was equal in male (25 µm long) and female (28 µm long). The median length of abdominal segment I–VIII measured: ♀ 25, 20, 20–23, 23, 20, 20–25, 7–10, 25 µm long, respectively; ♂ 23, 15, 18, 18, 15, 13, 10, 23 µm, respectively. Antennae narrow elongate, located anterior of prothoracic legs ( Fig. 45 ), ♀ 21–23 µm long, ♂ 18 µm long. Ventral setae 13 µm wide, 30 µm apart.

First instar ( Fig. 39 ). Elongate oval; 316–337 µm long, 183–215 µm wide. Margin smooth or faintly crenulate, 28–32 crenulations in 0.1 mm. Anterior and posterior marginal setae 10 µm and 25 µm long, respectively. Margin with nine pairs of setae (four cephalic and five abdominal) in addition to anterior marginal, posterior marginal and caudal setae. Cephalic setae present. First abdominal setae absent. Eighth abdominal and caudal setae 3 µm and 42–55 µm long, respectively. Caudal setae 12–15 times longer than the eighth abdominal setae. Submargin not differentiated from the dorsal disc. Vasiform orifice elongate triangular ( Fig. 43 ), 22–25 µm long, 25–28 µm wide; operculum subrectangular, 15–18 µm long, 20 µm wide. Lingula exposed, triangular, tip of lingula not reaching beyond posterior end of the orifice, with a pair of long setae. The distance between posterior end of vasiform orifice and caudal tracheal comb opening measured 7–10 µm long. Ventral setae 7–13 µm long, 23 µm apart. Antennae located anterior to prothoracic legs ( Fig. 46 ), 72–78 µm long.

Adult male ( Figs 47–51, 59 ). Body 1650–1925 µm long. Each wing with three ashy black mottlings. Antenna seven segmented ( Fig. 47 ), 546 µm long, the length of antennal segments measured: I 30 µm, II 78 µm, III 208 µm, IV 38 µm, V 78 µm, VI 45 µm, VII 53 µm long, segment VII with an apical seta, 13 µm long. Four primary sensoria, 2 on segment III and one each on segment V and VII. Three sensorial cones, located sub-apically one each on segment III, VI and VII. Eighth abdominal segment 130 µm long, four long setae located on each side of vasiform orifice. Vasiform orifice subcordate ( Fig. 50 ); operculum subrectangular, concave in middle, 30 µm long, 35 µm wide; lingula 25 µm long. Claspers elongate ( Fig. 48 ), 175 µm long, apical tooth present ( Fig. 36 ); middorsal surface with 6–8 setae and 3 setae on outer surface near apical tooth, often two setae found constant; aedeagus curved dorsally, broadest at base, then constricted in middle, again broadened and then constricted before opening of the gonopore ( Fig. 49 ), 133 µm long. The upper and lower compound eyes connected with three ommatidia ( Fig. 51 ). Metatibial comb and brush made up of 18 setae and two setae, respectively. Four pairs of wax plates, each wax plate with one microseta near its outer margin and two microsetae near inner margin. Wax plate: I 213 µm wide, II 208 µm wide, III 198 µm wide, IV 163 µm wide.

Adult female ( Figs 7 & 8 , 52–58 ). Body 1650–1925 µm long. Each wing with three ashy black mottlings. Antenna seven segmented ( Fig. 52 ), 666 µm long, the length of antennal segments measured: I 28 µm, II 128 µm, III 240 µm, IV 50 µm, V 95 µm, VI 68 µm, VII 63 µm long, segment VII with an apical seta, 13 µm long. Four primary sensoria, two on segment III and one each on segment V and VII. Three sensorial cones, located subapically one each on segment III, VI and VII ( Fig. 52 ). Sensorial cone on segment VII located anterior to primary sensoria. Vasiform orifice subcordate ( Fig. 55 ), 63 µm long, 89 µm wide; operculum sub-rectangular, concave in middle of posterior end, 52 µm long, 47 µm wide; lingula 37 µm long, each posterior lateral margin with one seta. The distance from posterior end of vasiform orifice to the base of genitalia measured 153 µm long. Genitalia ( Fig. 54 ) 266 µm long, paired gonopophysis with two pairs of setae and unpaired gonopophysis with four pairs of setae, of which two pairs located near apex and two pairs near the base. Cement gland with 4–5 constrictions ( Fig. 57 ). The upper and lower compound eyes connected with four ommatidia ( Fig. 53 ). Metatibia 623 µm long, metatibial comb and brush made up of 24 setae and two setae, respectively. Two pairs of wax plates ( Fig. 56 ), each wax plate with one microseta near its outer margin and two microsetae near inner margin. Wax plate: I 219 µm long, 343 µm wide, II 182 µm long, 359 µm wide.

Host plant. Sarcococca saligna (D. Don) Muell. Arg. (Buxaceae) .

Material examined. Holotype, India: Uttarakhand, Dhanaulti , 30.45°N 78.25°E., 7500 ft msl, first from right of three puparia on a slide under one cover slip, on Sarcococca saligna , 5.viii.2015. K. Dubey. Deposited in NFIC- FRI.

Paratypes. Data same as holotype, 67 female puparia, 42 male puparia, 5 third instars, 6 second instars, 3 first instars, 8 females, and 10 males on 23 slides ; Himachal Pradesh, Mundaghat , 31.10°N 77.25°E., 7510 ft msl, 48 female puparia, 31 male puparia, 1 adult female on 14 slides, on Sarcococca saligna , 25.xii.2014, A. K. Dubey (NFIC-FRI). Several puparia, immatures and adults in 95% ethanol in A.K. Dubey collection.

Etymology. The species is named after its host plant genus “ Sarcococca ”.

Remarks. The origin of wax filaments in live puparia corresponds to a band of wax glands on submedian/ subdorsum areas, seen in mounted puparia. The number of submarginal setae was constant during development of immatures from first to fourth instar.

Biology. This new whitefly species occurs only in the high altitude ranges of the Western Himalaya in India. The host plant, Sarcococca saligna is commonly known as Christmas box, an evergreen shrub that has the ability to flourish in deep shade. It has green, soft stem-skin on which heavy infestations of puparia of this new species were noticed in Western Himalaya in India, and studied since the original find in 2013. Leaf areas infested with puparia (including extended wax filaments) turn yellow, these cholorotic spots were visible from upper surface of leaves, and taken as primary indicators of puparial infestation. Adults found active and flying when disturbed. The puparia and adults population of this species increases during winter (December to February), when there is snow fall, and reaches high levels during spring (March to April), then declines from May to November. During three years of survey (2013–2015) in the Himalayan states in India, Himachal Pradesh and Uttarakhand, the new whitefly species was observed to be exclusively feeding on a single host plant, Sarcococca saligna . In Himachal Pradesh (Chail, Kufri, Mundagaht), it was found feeding alone, but in one locality in Uttarakhand (Dhanaulti) it was found intermingled with a Dialeurodes unidentified species. The live puparia of this Dialeurodes species were flat, transparent, without wax secretion and barely visible on leaf surface until given gentle pressure on ventral surface of leaf to assure its presence through appearance of faded puparial shape, and thus, easily distinguishable from puparia of the new species. Chlorotic spots were not seen at the feeding site of the Dialeurodes species. Parasitoids of the family Aphelinidae and Platygastridae were recovered from H. sarcococcae sp. n.

Figures

FIGURES 1 – 8. Himalayaleyrodes sarcococcae Dubey sp. nov., puparium, habitus, 1, on stem, dorsal view; 2, on leaf, dorsal view; 3, same; 4, lateral view, wax palisade; 5, on stem, lateral view; 6, ventral view, showing wax secretion pattern; 7, adult female; 8, fore wing, three mottlings.

FIGURES 9 – 12. Himalayaleyrodes sarcococcae Dubey sp. nov., camera lucida drawings, 9, puparium, dorsal and ventral views; 10, margin; 11, submedian band of wax glands; 12, posterior abdominal area, vasiform orifice.

FIGURES 13 – 22. Himalayaleyrodes sarcococcae Dubey sp. nov., holotype puparium, 13, anterior area; 14, posterior area; 15, submarginal seta; 16, first abdominal segment, arrows indicate two pairs of geminate pores; 17, thoracic tracheal pore area; 18, caudal pore; 19, vasiform orifice; 20, submedian band of wax glands; 21, rostral setae; 22, legs, antenna and adhesive sacs.

FIGURES 23 – 29. Himalayaleyrodes sarcococcae Dubey sp. nov., SEM photomicrographs, puparium, 23, dorsal view; 24, marginal and submargin setae; 25, posterior abdominal area; 26, thoracic tracheal pore area; 27, geminate pore; 28, subdorsal band of wax gland, simple pores on band; 29, vasiform orifice.

FIGURES 30 – 36. Himalayaleyrodes sarcococcae Dubey sp. nov., SEM photomicrographs, puparium and adult male, 30, puparium, ventral view; 31, caudal tracheal fold, stipples; 32, microseta at leg base; 33, thoracic legs; 34, thoracic tracheal fold; 35, spiracle, stipples; 36, adult male genitalia.

FIGURES 37 – 46. Himalayaleyrodes sarcococcae Dubey sp. nov., Photomicrographs, immatures, 37, third instar, dorsal view; 38, second instar; 39, first instar; 40, vasiform orifice, third instar; 41, second instar, subdorsal wax glands; 42, second instar, submarginal pores; 43, first instar, posterior abdominal area, vasiform orifice; 44, vasiform orifice, second instar; 45, thoracic legs, second instar; 46, thoracic legs, first instar.

FIGURES 47 – 59. Himalayaleyrodes sarcococcae Dubey sp. nov., Photomicrographs, adult male (47 – 51, 59) and female (52 – 58), 47, antenna, enlarged view of segment III, VI and VII; 48, genitalia, dorsal view; 49, same, gonopore; 50, vasiform orifice; 51, compound eye; 52, antenna, enlarged view of segment III, VI and VII; 53, compound eye; 54, genitalia; 55, vasiform orifice; 56, abdominal wax plates; 57, cement gland; 58, tarsal claw (female); 59, tarsal claw (male).