Asterochiton rhamnoidis, Martin, 2020

Martin, Nicholas A., 2020, Revision of the whitefly genus, Asterochiton Maskell (Hemiptera: Aleyrodidae) from New Zealand, a study of intraspecific variation, Zootaxa 4859 (3), pp. 301-341 : 330-333

Asterochiton rhamnoidis sp. n.

Figures 11 A–H

Diagnosis. This species is similar to A. foetidissimae . Its ‘larger’ discal setae tend to be larger than those on A. foetidissimae . Caudal setae larger, 50–88 µm.

Puparium ( Figs. 11 A–D). Oval; unpigmented; found on undersurface of leaves; widest at abdominal segments II & III; emarginated at thoracic and caudal tracheal pores; margin separated from leaf by a fringe of wax that may develop into a vertical side wall. Length 1.37 mm, 4 paratypes, 1.14–1.37 mm (mean 1.23); width 1.0 mm, paratypes, 0.82–1.0 mm (mean 0.93). Caudal and thoracic tracheal pores narrowly invaginated with 3–5 teeth ( Figs. 11 F–G). Margin finely crenulated ( Figs. 11 F–G), 9–12 crenulations in 0.1 mm .

Dorsum. Finely sculptured verging to linear markings marginally, submedian area smooth ( Figs. 11 B–C, 11F– G). Submargin area about 75 µm wide. Cephalothoracic (pro-, meso- & metathoracic) and abdominal depressions present. Abdominal segment VII median length 38 µm, paratypes 25–38, about half the median length of abdominal segment VI ( Fig. 11E ). Transverse moulting sutures reaching subdorsal area. Pro-mesothoracic and meso-metathoracic sutures, and abdominal segmentation prominent, reaching subdorsal area. Small pores on disc, a row around the edge of the submargin. Vasiform orifice located anterior of caudal tracheal opening by two times its own length. Caudal furrow present and well defined.

Vasiform orifice ( Fig. 11E ). Subtriangular; length 85 µm, paratypes, 70–85 µm (mean 78), width 58 µm, paratypes 53–62 µm (mean 57), open posteriorly, floor reticulated; operculum sub-trapezoidal, covering nearly half the length of orifice, length 33 µm, paratypes 30–38 µm (mean 34), width 48 µm, paratypes 40–48 µm (mean 45); lingula exposed, not reaching beyond posterior margin of the vasiform orifice, terminal end slightly expanded and rounded, length 38 µm, paratypes 33–42 µm (mean 38), two subapical setae, 23 µm, paratypes 15–25 µm.

Venter. Thoracic tracheal fold with stippling ( Fig. 11G ); caudal tracheal fold unclear. Legs and antennae present, a tiny seta on the basal and terminal segments of legs 2 and 3 ( Fig. 11H ). Ventral setae 25 µm long, paratypes, 20–25 µm, distance apart 73 µm, paratypes 58–83 µm, one quarter distance of vasiform orifice length back from anterior margin of vasiform orifice. Adhesive sacs seen. Anterior spiracles on abdominal segment II, posterior spiracles near vasiform orifice.

Chaetotaxy. First cephalothoracic setae 10 µm, one specimen with the socket of a larger seta; first abdominal setae, 35–113 µm; eighth abdominal setae, 5 µm, paratypes 5–8 µm, setae anteriad of vasiform orifice; 8 pairs of cephalothoracic lateral setae, cephalothoracic lateral setae 6 & 8 on subdorsum, 63–103 µm, cephalothoracic setae 2 either on submargin or on subdorsum, on the subdorsum it may be tiny, 10 µm or larger (based on size of setal socket); cephalothoracic lateral setae 1, 3, 4, 5 & 7, tiny, 10 µm, seventh submarginal, cephalothoracic setae posterior to thoracic pore; abdominal lateral setae, seta 4 60–90 µm, always on subdorsum, seta 5 on subdorsum, mostly tiny, 10 µm or larger, 55 µm, setae 6–8, tiny, may be on lateral edge of subdorsum. Caudal setae mainly large, 50–88 µm, but some 3–5 µm. Anterior marginal setae 10 µm, posterior marginal setae 10–18 µm.

Material examined. Holotype: NEW ZEALAND, AK, Waitakere Ranges , Laingholm Drive, 14 July 2001, NA Martin, Coprosma rhamnoides ( NZAC02015599 slide 01-105). Specimen furthest from data label.

Paratypes: 1 puparium, parasitised and damaged, on slide with Holotype; 3 puparia, one with parasitoid exit hole, ( NZAC02015600 slide 01-106a), same data as Holotype .

Other specimens: 2 puparia, one parasitised (slide NAM1908C), AK, Orewa, Alice Eaves Scenic Reserve, 16 August 2019, NA Martin, Coprosma rhamnoides ; 3 puparia, one parasitised (slide NAM1908D), AK, Orakei, Kepa Bush Reserve, 31 August 2019, NA Martin, Coprosma rhamnoides ; 3 puparia, 2 parasitised (slide NAM1909D), AK, Northcote, Smiths Bush Reserve, 14 September 2019, Coprosma rhamnoides .

All specimens deposited in NZAC (Auckland, New Zealand) .

Host plant. The only known host plant is Coprosma rhamnoides A.Cunn. (Rubiaceae) .

Distribution. The species has been found in native forests in the Auckland Region. The host plant is widespread in the North & South Islands.

Etymology. The new species is named after its host plant.

Remarks. Variation was found between specimens in the presence or absence of cephalothoracic seta 1, and cephalothoracic lateral setae 6 and abdominal lateral seta 5. The caudal setae and some abdominal lateral setae may be large or tiny.

Figures

FIGURE 11. Asterochiton rhamnoidis sp. n. Holotype A–B, E–G. A. Dorsum, line drawing, B. Dorsum. Slide mount, C. Puparium on leaf, note white wax in thoracic folds and eye spots of adult, D. Dorsum, showing variation in setae, E. Abdominal segments VI, VII and vasiform orifice, F. Caudal pore, caudal setae, posterior marginal setae, G. Thoracic tracheal pore and fold with stippling, H. Antenna and legs.