Aleurocybotus cereus, Martin, 2005

Martin, Jon H., 2005, Whiteflies of Belize (Hemiptera: Aleyrodidae) Part 2 - a review of the subfamily Aleyrodinae Westwood, Zootaxa 1098 (1), pp. 1-116 : 11-12

Aleurocybotus cereus sp. nov.

( Figs 1–8 , 86)

PUPARIUM ( Figs 7–8 , 86). Habitus. The immature stages of this species occur singly or in aggregations under the blades of the host grass, smaller groups most usually occurring near the blade’s base. A dense and finely flocculent white secretion completely obscures the insects themselves, and there is little indication of ant­attendance. Whitefly­infested blades were found only in deep shade. Margin. Outline elongate­oval, often slightly asymmetric, 0.57–0.78 mm long, 0.27–0.39 mm wide, generally widest at metathorax/ abdominal segment I (n=15). Margin often appearing irregular but crenulate when viewed in relief ( Fig. 8 ), around 16–18 rounded teeth occupying 0.1 mm of lateral margin, not modified at tracheal openings. Dorsum. Longitudinal moulting suture reaches puparial margin; transverse moulting sutures also reaching margin posterior to meso­metathoracic division, allowing cephalothoracic plates to detatch as adult emerges (Fig. 86). Submedian/subdorsal area of dorsal disc smooth to slightly uneven, with abdominal segmentation and meso­metathoracic division well marked, but remainder of cephalothoracic divisions hardly evident ( Fig. 8 ); abdominal segment VII not significantly reduced in length medially; submedian abdominal depressions rather subtly indicated. Entire submarginal zone obviously glandular in nature, punctuated by subcircular glands ( Fig. 7 ) and darker inter­glandular divisions, the whole zone appearing reticulate (Fig. 86). Vasiform orifice ( Fig. 7 ) rounded­cordate, internally smooth, inset from puparial margin by approximately its own length; operculum laterally­rounded trapezoidal, occupying a little over half of vasiform orifice, its posterior margin finely setose and with a pair of fine setae; lingula head only slightly expanded, rounded, bearing a single pair of posteriorlydirected setae and included within vasiform orifice. Caudal furrow little­defined. Chaetotaxy. Anterior and posterior marginal setae present, hair­like, a little shorter than dorsal setae. Normal dorsal disc chaetotaxy comprises single submedian pairs of cephalic and eighth abdominal setae, single subdorsal pairs of pro­, meso­ and metathoracic ( Fig. 8 ), and first abdominal setae; pair of submarginally­placed caudal setae, plus two pairs of submarginal setae placed anterior to caudal setae and lateral/posterolateral to vasiform orifice ( Fig. 7 ); occasionally subdorsum of abdominal segment V or VI with a seta on one or both sides of body; eighth abdominal setae placed opposite anterior edge of operculum ( Fig. 7 ); all dorsal setae similar to each other, long and fine, the shortest pair usually the eighth abdominals which are about as long as the vasiform orifice. Pores. A small number of rather large simple pores present, inconsistently paired on either side of puparium—usually 1 lateral to the submedian abdominal depression on each of segments I and III–VIII, 1–2 on each side of each thoracic segment, and 2–3 on each side of cephalic segment; the simple pores not evidently of the geminate pore/porette type. Venter. Cuticle smooth, diaphanous. Ventral abdominal setae very fine, underlying vasiform orifice. Legs bisegmental and with apical adhesion pads directed anteriorly on the fore legs, and posteriorly on the middle and hind legs (Fig. 86) which also each have one or two minute basal setae. Antennal bases anterolateral to fore legs. Slightly sexually dimorphic, with puparial antennae of females reaching middle of middle legs, and those of males reaching base of hind legs. Tracheal folds absent.

ADULT ( Fig 1–6 .). Adult females were observed feeding solitarily, each within an annulus of mealy wax, somewhat reminiscent of species of Paraleyrodes (Aleurodicinae) . A small number of adults were also reared from puparia in culture. These display the curious generic characteristic of having only one smooth tarsal claw on each leg, the other “claw” being a more fleshy and minutely spinulose structure ( Figs 5–6 ), possibly the modified paronychium ( Russell, 2000). Further, the antennae of males end in two long filaments, usually fused together ( Fig. 1 ), while those of females have a similar but single filament ( Fig. 2 ). These claw and antennal characters are diagnostic for adults of Aleurocybotus , species of which only occur in the New World. Other major characters include: antennal segment II approximately 3X segment I; body length 1.08–1.18 mm (male, n=4) and 1.21–1.30 mm (female, n=5), females with 7 antennal segments, males with 6 or 7 recognisable segments (some fusion seems common), abdomen of female with two pairs of ventral wax plates ( Fig. 3 ) but of male with four pairs ( Fig. 4 ); abdominal dorsum of female with a broad band of thick­rimmed simple pores on each of abdominal segments II–VII ( Fig. 3 ), such pores absent in males. Males with aedeagus simple, curved upward and apically acute ( Fig. 4 ).

MATERIAL EXAMINED. Holotype puparium, BELIZE, CFR, site of Millionario camp, on Lasiacis ? rugelii ( Poaceae ), 24.vi.2002 (J.H.Martin #7707) ( BMNH). Paratypes (all Martin coll.): 85 puparia, 1 third­instar larva, 15 first­instar larvae, 4 adult males, 15 adult females, same data as holotype ( BMNH, USNM); 1 puparium, 1 adult female, same host and locality, 26.iii.2003 ( BMNH); 34 puparia, 22 third­instar larvae, 2 second­instar larvae, 5 first­instar larvae, same host and locality, 03.vi.2004; 4 puparia, CFR, San Pastor track, on Lasiacis sp. (possibly a different species), 22.iii.2003 ( BMNH); numerous puparia and larvae dry on leaves, same host and locality as holotype ( BMNH).

ETYMOLOGY. The species name is the latin cereus (meaning waxen), alluding to the large amount of secreted wax in the immature stages.

COMMENTS. The immature stages of A. cereus are rendered highly visible because of the white­coloured and rather fibrous nature of their secretions. In complete contrast, those of all species of Aleurocybotus previously described, including those Old World species transferred to the new genus Vasdavidius by Russell (2000), only secrete limited amounts of clear or translucent material, frequently rendering them very cryptic when feeding. Certainly, therefore, the absence of visible secretions in a colony of Aleurocybotus should indicate that it cannot be cereus .

See also COMMENTS on Aleurotulus laneus , here described (p. 26).

Figures

FIGURES 1–8. Aleurocybotus cereus sp. nov. 1, adult male, antennal apex; 2, adult female, antennal apex; 3, adult female, abdomen, lateral; 4, adult male, abdomen, lateral; 5, adult male, single claw and claw­like?paronychium; 6, adult female, single claw and claw­like?paronychium; 7, puparium, posterior dorsal detail (see Fig. 86 for photograph); 8, puparium, cephalothoracic plate with inner margin of glandular zone indicated by dashed line, and one glandular cluster shown.