Aleurocanthus callistemonus, Gillespie, Peter S., 2012

Gillespie, Peter S., 2012, A review of the whitefly genus Aleurocanthus Quaintance & Baker (Hemiptera: Aleyrodidae) in Australia, Zootaxa 3252, pp. 1-42 : 9-12

Aleurocanthus callistemonus sp. n. ( Figs 7–18 )

Puparium. Pigmented brownish black ( Fig. 7 ), requiring bleaching for microscopic observation, found on both surfaces of the lamina. Peripuparial wax absent except occasionally small white wax tufts at cephalothoracic and caudal openings. White wax usually conspicuous on dorsum but unevenly distributed, usually on margin and on raised parts of puparium such as rhachis arms. Puparium oval-shaped, abdomen rounded giving puparium distinctive pear shape. Abdomen rhachisiform with lateral arms reaching outer submargin. Sexually dimorphic: male 621–683 μm long, 497–538 μm wide; female 745–828 μm long, 621–662 μm wide. Margin finely toothed 6– 7 teeth per 0.1 mm, teeth often slightly exaggerated at thoracic and caudal openings.

Dorsum ( Figs 9–11 ). Margin narrow and pale, not distinctly separated from subdorsum. Well defined submedial folds present in cephalothorax. Submargin and subdorsum with linear markings in radial pattern becoming darker and more pit-like near rhachis and submedial folds. Longitudinal moulting suture present and reaching margin. Transverse moulting suture characteristic of the ‘ banksiae-valenciae’ group, smoothly curving posteriad from confluence with longitudinal suture, then abruptly curved anterolaterad and terminating in subdorsum. Scattered simple pores found on dorsum. Abdominal segment VII width more or less equal to preceding segments. Vasiform orifice sub-circular to chordate in shape, not elevated above dorsum ( Fig. 11 ). Vasiform orifice distant from margin a distance of two vasiform orifice widths. Operculum rounded, chordate and in life conspicuously pink in colour, completely filling vasiform orifice and obscuring lingula. Conspicuous posterior marginal hump or dome present between vasiform orifice and posterior margin adjacent to posterior margin, appearing pink and non waxy in live specimens. Caudal furrow absent. Scattered simple pores present in submargin.

Chaetotaxy ( Figs 9–12 ). Anterior marginal setae present. Cephalothoracic and first abdominal setae short (<50 μm). Eighth abdominal setae short (length about half vasiform orifice width), situated laterad of vasiform orifice. Caudal setae long (length twice vasiform orifice width) and situated about three setal base widths from posterior margin. Posterior marginal setae present. Marginal glandular spines long, tapered (110–160 μm) with expanded laciniate tips ( Fig. 12 ), typically with 3–7 cephalothoracic marginal pairs and 7–8 abdominal marginal pairs but see comments below. Glandular spines lacking basal pore. Frequently none, one, two or three cephalothoracic subdorsal glandular setal pairs may also be present. Abdominal subdorsal glandular spines sometimes present. 4–6 pairs of minute setae irregularly distributed in the outer margin distal to the glandular spines.

Venter ( Fig. 10 ). Caudal and thoracic tracheal folds visible. Tracheal folds and submedian area lacking stippling except for a few minute stipples beneath the vasiform orifice and medially on each abdominal segment and two small lines of stipples on base of each leg. Mid and hind legs each with small seta at base. Antenna short (shorter than length of fore leg) and situated immediately anterior of fore leg. Abdominal ventral setae short (about 50 μm) situated anterior to vasiform orifice.

3rd instar nymph. shape similar to puparium; with 10 pairs of long glandular spines with slightly expanded, laciniate apices, the anterior 2 pairs submarginal the remainder subdorsal with 5 abdominal (III–VIII) and 3 cephalothoracic pairs, the vasiform orifice similar to puparium and posterior hump or ridge visible posteriorly of vasiform orifice.

Adult female. Head, pronotum and abdominal segment VIII entirely dark chocolate brown; thorax, meso- and metanotum bicoloured dark chocolate brown and bright yellow. Remainder of venter, pleurotergites and abdominal segments bright yellow in colour. Legs dark chocolate brown with paler yellowish patches at joints. Wing length 1140 μm. Wings uniform pale dusky colour with no patches, venation typical for subfamily. Antenna seven segmented ca 370 μm long, each segment with numerous rings of sparse small spinules. Ragged crown-like sensory seta one found subterminally on each of segments V and VII and two subterminally on III ( Figs 15, 16 ). Seta-like sensoria found terminally on VII and subterminally on VI. Eye halves separated by two facets ( Fig. 14 ). Two pairs of wax plates.

Adult male. similar to female, four pairs of wax plates and genitalia as figured in Fig. 18 .

Egg. ( Fig. 17 ) Glossy brownish black, smooth and kidney shaped with one end slightly pointed and subterminal pedicel. Length ca 180 μm, width ca 70 μm.

Distribution. SA, NSW, Qld.

Hosts. MYRTACEAE : Callistemon spp., C. salignus , C. sieberi , C. viminalis .

Material examined. Holotype puparium slide: ex Callistemon sp. Elephant Park, Orange, NSW, 7.ix.2003, P.S. Gillespie ( ASCT 00024788)( ASCU). Paratypes: [Qld] ex Callistemon sp, Paddington, Brisbane, 26.ii.1997, P.J. DeBarro, 5 x puparia on one slide (AN20.10729)( ANIC); [ NSW] ex Callistemon sp., Adelong Motel, Narrabri, 5.vi.2001, P.J. DeBarro, 5 x puparia on a slide, ( ANIC); ex Callistemon viminalis, Wellington Caves , 6.x.2001, P.S. Gillespie, 9 x puparia on three slides, ( ASCT 00027545-47)( ASCU); reared ex puparium on Callistemon, Orange , 22.ii.2005, P.S. Gillespie, 1 x adult male slide ( ASCT 00131860)( ASCU); same data as holotype, 2 x puparia on two slides ( ASCT 00024786-87)( ASCU); ex Callistemon viminalis , street tree, Orange, 5 September 1999, P.S. Gillespie, 3 x puparia on one slide ( ASCT 0000478627)( ASCU), 14 x puparia on 4 dry leaves ( ASCT 00027530)( ASCU); ex Callistemon sieberi , ‘Cumboogle’ 4th crossing Summer Hill Creek, near Orange NSW, 14.vii.2008, P.S. Gillespie, 4 x puparia on four slides ( ASCT 00025265-68)( ASCU), 56 puparia on 8 dry leaves ( ASCT 00025269)( ASCU); ex Callistemon sp. Orange, 27.viii.2004, B.C. McNeil, 23 x puparia on 23 slides ( ANIC); ex Callistemon sp. park in Bletchington, Orange NSW, April 2002. P.S. Gillespie ~80 puparia on dry leaves ( ASCT 00025286)( ASCU); ex Callistemon sp., Burrendong S.R.A. kiosk, near Wellington, 19.ix.2004, P.S. Gillespie, 16 x puparia on 9 dry leaves ( ASCT 00131940)( ASCU); ex Callistemon sp., Cotton C.R.C., near Narrabri, NSW, 13.x.2005, P.S. Gillespie, ~60 puparia on dry leaves ( ASCT 00131965)( ASCU); [South Australia] ex Callistemon salignus, Morialta Falls , 28.ii.1976, M. Carver, 6 x puparia on one slide ( ANIC).

Etymology. Named after the only known host genus for this species.

Comments. This species usually prefers drier habitats. The number and distribution of glandular spines in this species is always quite variable, both within and between populations (cephalothoracic marginal glandular setal counts Variance = 1.3, n = 51). This species is superficially similar to A. valenciae , but A. valenciae has a more regular spine count (cephalothoracic marginal glandular setal counts Variance = 0, n = 40). A. valenciae always has 5 pairs of marginal setae and one submarginal pair in the cephalothorax whereas A. callistemonus has between 3 and 7 pairs of marginal and between 0 and 3 submarginal pairs of glandular spines in the cephalothorax. A. callistemonus can be readily separated from A. valenciae by its more rounded pear-shaped appearance, the presence of the posterior dome and its restricted host preference. A number of abdominal subdorsal glandular spines may sometimes be found on specimens of A. callistemonus , which is never the case for A. valenciae . This species will likely be collected in Victoria on suitable Callistemon hosts. A remarkable illustration of this species was figured in Insects of Australia ( Carver, et al., 1991). The abundance of Callistemon hybrids used as ornamental plants in urban areas has undoubtedly encouraged the spread of this species. Although populations will be found selectively on one hybrid but not another, the host records from C. salignus and C. sieberi represent two genuine native hosts for this species. Previously known as “ Aleurocanthus undescribed sp. 1” ( Martin 1999) and “ Aleurocanthus undescribed sp. 1” ( Carver and Reid 1996). A small series of similar looking puparia from near 40 Mile Scrub in North Queensland represent a closely related species ( Aleurocanthus sp. 10 of Carver - ANIC). This undescribed species is larger and lacks submarginal setae. A. papuanus Martin from PNG shares with A. callistemonus a similar shape and spine count but is nearly twice its size with far longer spines. A single specimen collected from Pittosporum from central Qld (BMNH – J. Martin pers comm.) may represent A. papuanus or another, undescribed species in the banksiae-valenciae -group.

Figures

FIGURES 7 – 10. A. callistemonus sp. nov. puparia: 7, habitus (1 mm); 8, slide (500 µm); 9 – 10, illustrations (500 µm) (cutaway venter).

FIGURES 11 – 17. A. callistemonus sp. nov.: 11, puparium vasiform orifice detail; 12, puparium glandular spine (50 µm); 13, adult male habitus (500 µm); 14, adult eye - detail (100 µm); 15, adult male antenna (100 µm); 16, adult male antenna - detail (100 µm); 17, egg (50 µm).

FIGURES 18 – 21. A. callistemonus sp. nov. 18, adult male terminalia (100 µm); A. ceracroceus puparia 19 – 21: 19, habitus (pale form) (1 mm); 20, slide (dark form) (500 µm); 21, illustration (A) vasiform orifice (B) glandular seta (C) margin detail (modified from Martin 1999).