Aleuroplatus biluminoporus, Martin, J. H. & Malumphy, C. P., 2002

Martin, J. H. & Malumphy, C. P., 2002, A new species of South American whitefly (Sternorrhyncha: Aleyrodidae) colonising cultivated bay laurel, Zootaxa 83, pp. 1-10 : 2-8

Aleuroplatus biluminoporus sp. nov.

( Figs 1 ­ 5 )

PUPARIUM ( Figs 1­ 3 , 5 ) [Many of the microscopic characters are difficult to discern in mature specimens, even when partially bleached, and recently­moulted individuals are to be preferred for accurate diagnosis.]

Habitus. Scattered under leaves, not in distinct feeding groups. Newly moulted puparial stage rapidly becomes completely black, shiny. With increasing maturity, a wide peripheral waxy fringe develops, along with a submedian tuft of similar, pure white, wax ( Fig. 5 A) but subdorsum remains exposed, black.

Margin. Outline ( Fig. 2 ) ovoid, distinctly widest opposite transverse moulting sutures, characteristically indented between caudal and posterior marginal setae; 0.93 ­ 1.15 mm long, 0.72 ­ 0.90 mm wide, 1.25 ­ 1.34 times longer than wide (n=20). Anterior and posterior marginal setae present, fine, posterior pair the longer. Margin evenly crenate, 11­15 (typically 12­13) rounded teeth occupying 0.1 mm of margin; marginal teeth with glandular bases whose precise appearance is dependent on maturity; margin not modified at thoracic and abdominal tracheal openings, but tooth­base glands more elongate between caudal setal bases ( Fig. 1 C).

Dorsum ( Fig. 1 ). Chaetotaxy comprises paired 8th abdominal and caudal setae only, fairly stout but acute, caudal pair up to 0.10 mm long, 8th abdominals slightly shorter than vasiform orifice. Longitudinal moulting suture almost smooth, not keeled, reaching puparial margin; transverse moulting sutures very shallowly “W”­shaped, terminating slightly over half way to puparial margin. Dorsal disc generally smooth, with paired finely granular patches in positions of submedian abdominal and thoracic depressions. A pair of clearly­defined pale, ovoid, cephalic “eyespots” each have a distinct thickened rim mesally; subdorsum with a small number of pale thick­rimmed “bright” pores, distributed as shown ( Fig. 1 D), always 2 present on each side abdominally; although “eyespots” and bright pores are pale, they may still be difficult to see in mature specimens with very dark venters (see Ve nt er, below). Submedian zone punctuated by close­set pore / porette geminate pairs distributed as shown ( Fig. 1 E); inner submargin with an uneven single row of characteristic pores ( Fig. 1 A) which are probably atypical geminate pore / porette pairs, 60 & 62 on each side in holotype, the pores placed within a narrow band of poorly­formed reticulate markings; between these reticulations and marginal teeth, a row of subrectangular markings is sometimes distinct ( Fig. 1 A). Meso­/metathoracic division very distinct; abdominal segmentation rather faintly marked, submedially only; abdominal segment VII not reduced in length medially, pockets indistinct. Vasiform orifice cordate, approximately 0.05 mm long and wide, inset from posterior puparial margin by about its own length, fully occupied by the operculum which obscures lingula unless operculum raised as in ( Fig. 5 B).

Ven te r ( Fig. 3 ). Cuticle of mature individuals heavily sclerotised and sculptured, completely opaque, black ­ a characteristic that leads to difficulties in examining dorsal features in slide­mounted complete specimens. A wide subdorsal band, anterior to mouthparts, lateral to legs and on either side of the submedian zone is coarsely punctate; the wide submarginal band with irregular folds and slightly darker rounded markings; the median band rather granular and corrugate. Thoracic and caudal tracheal folds indicated only by faint pairs of boundary lines, but not otherwise differentiated. Each leg with an apical pad; antennal bases placed antero­mesal to fore legs. A narrow, pale, inverted “V”­ shaped band is present, running from foreleg apices anteromesally, skirting the mouthparts.

THIRD­INSTAR LARVA ( Fig. 4 ). Cuticle pale, with staining required for microscopical study on slides, not visibly waxy in life. Outline ovoid, marginal indentation between posterior marginal and caudal setae very slightly indicated; individuals 0.66 ­ 0.70 mm long, 0.49 ­ 0.50 mm wide, widest opposite hind leg bases (n=3). Margin evenly crenulate, 16­17 teeth per 0.1 mm. Anterior and posterior marginal setal pairs present, fine, acute.

Dorsal chaetotaxy comprises paired cephalic (45 m, apically blunt), mesothoracic (20 m, apically blunt), metathoracic (30 m, apically blunt), 8th abdominal (35 m, apically blunt) and caudal (70 m, apically acute) setae (n=1). Meso­/metathoracic and abdominal segmentation pronounced. An inner submarginal row of about 12 pairs of geminate pore/ porettes present, with others scattered subdorsally; a single bright pore (sometimes a pair) present on each side, close to foreleg and on abdominal segment III. Vasiform orifice cordate, posteriorly elevated, 0.04 mm long and wide; trapezoidal operculum fully occupies orifice, but spinulose lingula visible through operculum. Ventrally with legs triangular, apices directed laterad, each with a subcircular apical pad; antennae small and thornshaped with their apices directed mesad; ventral abdominal setae situated anterior to vasiform orifice; ventral cuticle very fine, diaphanous.

SECOND­INSTAR LARVA. Specimens were in poor condition; they were slidemounted in Heinz mountant for study. Pale, outline ovoid; individuals 0.43 ­ 0.44 mm long, 0.28 – 0.30 mm wide, widest opposite hind leg bases (n=5). Margin relatively smooth. Anterior and posterior marginal setal pairs present, fine, acute. Dorsal chaetotaxy comprises paired cephalic (19­32 m, apically blunt), mesothoracic (17­34 m, apically blunt), metathoracic (17­36 m, apically blunt), 8th abdominal (23­32 m, apically blunt) and caudal (46­51 m, apically acute) setae (n=5). Head with a small, bulbous central projection. Abdominal segmentation pronounced. An inner submarginal row of about 8­10 pairs of geminate pore/porettes present; a single bright pore present on each side, close to mesothoracic setal­base. Vasiform orifice cordate, posteriorly elevated, 0.03 mm long and wide; trapezoidal operculum fully occupies orifice; lingula spinulose. Ventrally, similar to third instar; direction of antennae unclear on study material.

FIRST­INSTAR LARVA ( Fig. 5 C – F). Pale brown, with distinct marginal white­wax pallisade layer. Outline ovoid, lozenge­shaped ( Fig. 5 C); body length 0.31 ­ 0.32 mm long, 0.16 ­ 0.17 mm wide (n=2). Margin finely crenulate; with 9 pairs of setae (including caudal pair). Dorsal chaetotaxy comprises paired cephalic, mesothoracic, metathoracic and 8th abdominal setae (all apically blunt). Head with a dorsal, bulbous, finely spiculate projection; paired, spiculate marginal flanges extending from head and thoracic segments ( Fig. 5 D), and triangular spiculate lateral projections from abdominal segments ( Fig. 5 E). Vasiform orifice cordate, posteriorly elevated; trapezoidal operculum fully occupies orifice ( Fig. 5 F).

OVUM. Habitus ( Fig. 5 G). Golden brown. Scattered, or in small groups, on the undersurface of the foliage. Elliptical, usually laid almost horizontally. The lower surface is strongly convex and the upper surface slightly concave, resembling a short ‘banana’. The chorion is smooth and shiny with little wax evident. Each egg is firmly attached to the leaf surface by a slender pedicel extending from the lower surface, near the base of the egg, inserted into the leaf via a stoma ( Fig. 5 G). Egg length 0.21 mm, width 0.12 mm (n=2); pedicel length 0.07 mm.

KEY

A FOR

LABELS

B C

D E

F G MATERIAL EXAMINED. HOLOTYPE, puparium, ex ­ Colombia at England, Hereford and Worcester, Evesham, Blackminster, on Laurus nobilis ‘Kiska’, 30 July 2001, A. Kirby, CSL reference 2001/3620 (BMNH). PARATYPES, 39 puparia, 2 third­instar larvae, 1 second/third instar intermoult, same data as holotype (BMNH, CSL, USNM).

ADDITIONAL MATERIAL: many older puparia, dry and still attached to leaf tissue, part of the original and subsequent quarantine interceptions (BMNH, CSL).

ETYMOLOGY. The name is derived from the presence of 2 pairs of abdominal subdorsal bright pores on each side, which are diagnostic.

COMMENTS. Aleuroplatus biluminiporus clearly belongs to a group of New World Aleuroplatus species which includes A. oculiminutus and A. oculireniformis (both Quaintance & Baker, 1917), A. vinsonioides ( Cockerell, 1898) , and A. perseaphagus Martin et al. (1996) , as well as undescribed taxa from Central America in the BMNH collection. Of all the species discussed here, A. vinsonioides is considered the most likely to be confused with A. biluminiporus , but differs in the puparial margin not being emarginate between posterior marginal and caudal setae, and in possessing typically 5 pairs of abdominal subdorsal bright pores (only 2 pairs in biluminiporus ). It is important to note that, amongst all the five described species discussed here, A. biluminiporus has only 2 abdominal subdorsal bright pores on each side of the insect, compared with typically 5 on each side in all the others.

The characteristic indentation of the puparial outline on each side, between posterior marginal and caudal setae, is a character only shared by biluminiporus and perseaphagus . However, puparia of A. perseaphagus are considerably smaller (maximally 0.72 mm) than those of biluminiporus (minimally 0.93 mm), and this difference is considered beyond normal inter­population variation. Further puparial differences are: venter of perseaphagus with median area clearly separated from the remainder by a suture­like fold leading from posterior abdominal spiracles and skirting the legs and antennae ( Fig. 3 of Martin et al., 1996) [in biluminiporus , the venter not so divided ( Fig. 3 , here)]; undamaged eighth abdominal setae are lanceolate in perseaphagus , placed very close to segment VII/VIII boundary [in biluminiporus , eighth abdominal setae are curved but similar to caudal setae, placed midway between vasiform orifice and suture VII/VIII]; secreted wax in perseaphagus is in the form of a neat, narrow marginal fringe and a discrete submedian dorsal agglomeration, leaving the submargin uncovered (Figs 7 & 8 of Martin et al., 1996) [in biluminiporus , the marginal fringe is much broader and the dorsal agglomeration is less neatly defined, comprising longer filaments ( Fig. 5 A, here)].

A. oculireniformis has its eighth abdominal setae placed close to the segment VII/VIII boundary and has kidney­shaped “eyespots” (this latter character possibly not very stable within a species); A. oculiminutus has its eighth abdominal setae placed closer to vasiform orifice, but has almost undetectable “eyespots” (again, the eyespot character of questionable stability), and its submargin bears much more extensive polygonal reticulation than seen in any of the other described species discussed here.

Figures

FIGURE 1. Aleuroplatus biluminiporus sp. nov. Puparium with expanded detail of (A) margin & submargin, (B) vasiform orifice region, (C) caudal margin and setae, (D) subdorsal thick­rimmed “ bright ” pores, (E) submedian geminate pore / porettes.

FIGURES 2 ­ 3. Aleuroplatus biluminiporus sp. nov. (2) Outlines of two puparia, with cephalic “ eyespots ”, moulting sutures, vasiform orifice and caudal setae marked; (3) Detail of puparial venter.

FIGURE 4. Aleuroplatus biluminiporus sp. nov. Third­instar larva with expanded detail of (top to bottom) cephalic seta, mesothoracic seta, abdominal margin, geminate pore / porette and vasiform orifice / eighth abdominal seta.

FIGURE 5 (A-G). Aleuroplatus biluminiporus sp. nov. A. Habitus photograph of puparium. B. Scanning electron micrograph (SEM) of puparial vasiform orifice, with operculum raised. C. SEM of first-instar larva, habitus position. D. SEM of first-instar larva, thoracic marginal flanges. E. SEM of first-instar larva, abdominal marginal projections. F. SEM of first-instar larva, vasiform orifice. G. SEM of a group of eggs.