Asterochiton arboreae, 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 : 307

Asterochiton arboreae sp. n.

Figures 3 A–I.

Diagnosis. The presence of relatively large setae on abdominal segment I, 3–5 large lateral setae on dorsal disc and the presence of large cephalothoracic seta 1 on some specimens are distinctive features of this species.

Puparium ( Figs. 3A, B, C, D ). Oval to sub-circular; unpigmented; submedian area raised up, found on undersurface of leaves; widest at abdominal segments I & II; emarginated at thoracic and caudal tracheal pores ( Fig. 3D ); margin separated from leaf by a thin layer of wax. Length 1.44 mm, 3 paratypes, 1.30–1.50 mm; width 1.12 mm, paratypes, 1.02–1.25 mm. Caudal and thoracic tracheal pores narrowly invaginated with 3–4 teeth ( Figs. 3E, I ). Margin smooth with signs of crenulations ( Fig. 3E, I ), 8 crenulations in 0.1 mm.

Dorsum. Finely sculptured verging to linear markings marginally ( Figs. 3E, I ). Submargin area clearly defined, about 95 µm wide. Cephalothoracic (pro-, meso- & metathoracic) and abdominal depressions faintly indicated. Abdominal segment VII, median length 25 µm, paratypes 25–38 µm, less than half length of segment VI ( Fig. 3F ). Transverse moulting sutures extending into subdorsal area. Pro-mesothoracic and meso-metathoracic sutures, and abdominal segmentation prominent, reaching subdorsal area. Small pores on dorsal disc and submargin. Vasiform orifice located anterior of caudal tracheal opening by two times its own length. Caudal furrow present and well defined.

Vasiform orifice ( Fig. 3H ). Elongate subtriangular; length 88 µm, width 63 µm; open posteriorly; floor reticulated; operculum sub-trapezoidal, covering nearly half the length of orifice, length 38 µm, width 50 µm; lingula exposed, not reaching beyond posterior margin of the vasiform orifice, terminal end slightly expanded and bluntly pointed, length 43 µm, two subapical setae, 20 µm long.

Venter. Thoracic tracheal fold with stippling ( Fig. 3E ). Caudal tracheal fold with indistinct, stippling. Legs and antennae present, tiny seta on the basal and terminal segments of legs 2 and 3 ( Fig. 3G ). Ventral setae 18 µm long, 75 µm apart, near to and posterior to anterior margin of vasiform orifice ( Fig. 3I ). Adhesive sacs not seen. Anterior spiracles on abdominal segment 2 and posterior spiracles near vasiform orifice.

Chaetotaxy. First cephalothoracic seta 5 & 60 µm, paratypes 0 [absent]- 58 µm. First abdominal setae, 55 µm, paratypes 60–70 µm; eighth abdominal setae, 8 µm, paratypes 4–5 µm, setae anteriad of vasiform orifice. Eight pairs of cephalothoracic lateral setae, cephalic lateral setae 6 and 8 on subdorsum, 40–70 µm, cephalothoracic lateral setae 1–5, 7 tiny, submarginal, cephalothoracic lateral setae 1–5 anterior to thoracic pore, cephalothoracic lateral setae 7 posterior to thoracic pore; abdominal lateral setae, 4–7, on subdorsum, some 40–70 µm, others may be tiny, on Holotype abdominal lateral setae 4 and 6 are large on right and not seen on the left, a tiny seta is present on some specimens in these positions, abdominal lateral seta 8, tiny, near caudal setae. Caudal setae mainly tiny, variable between sides, up to 25 µm. Anterior marginal setae 10 µm, posterior marginal setae 15–18 µm.

Material examined. Holotype: NEW ZEALAND, AK, Flat Bush , Murphys Bush Reserve, 24 August 2019, NA Martin, Coprosma arborea , ( NZAC02015588 slide NAM1908B).

Paratypes. 3 puparia, parasitised ( NZAC02015589 slide 05-020), AK, S. Auckland, Murphys Bush , 27 December 2004, NA Martin, Coprosma arborea leaves .

Other specimens: 1 puparium, parasitised (slide NAM1908A), AK, Maraetai, Omana Regional Park, 20 August 2019, NA Martin, Coprosma arborea ; 3 puparia, (2 adults emerged, 1 parasitised) (slide NAM1909B), AK, Maraetai, Dr. Adah Platt-Mills Reserve, 15 September 2019, NA Martin, Coprosma arborea .

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

Host plant. The only known host plant is Coprosma arborea Kirk (Rubiaceae) .

Distribution. The species has been found in several native reserves in Auckland. Its host plant is widespread in New Zealand, and the whitefly species could be equally widespread.

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

Remarks. Caudal setae; on some specimens both are of similar size and in similar positions, but in the Holotype and another specimen, one caudal seta is more marginal and in one paratype, one seta is longer than the other and those of the Holotype.

Figures

FIGURE 3A. Asterochiton arboreae n. sp. Holotype puparium, A–B, E–I; Paratype puparia, C–D. A. Dorsum line drawing, B. Dorsum slide mount, C. Puparium on leaf, adult emerged, D. Dorsum of puparium from which adult parasitoid has emerged. E. Thoracic tracheal pore and tracheal fold with stippling, F. Vasiform orifice and abdominal segments VI–VIII. G. Antenna and legs, H. Vasiform orifice, I. Vasiform orifice, caudal pore, ventral setae, posterior spiracles and caudal trachea with stippling.