Asterochiton asteliae, 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 : 313-315

Asterochiton asteliae sp. n.

Figures 5 A–H.

Diagnosis. The invaginations associated with the thoracic and caudal tracheal pores are relatively shallow. It has the full complement of true discal setae, 3 pairs, tiny; and the highest number of submarginal setae, 15 pairs, plus a pair of caudal setae.

Puparium ( Figs. 5 A–C). Oval; unpigmented to almost completely black; found on undersurface of leaves, usually on the upper third part; 1–3 puparia per leaf; widest at abdominal segment II; emarginated at thoracic and caudal tracheal pores; with thick wax along vertical side walls/margin. Length 1.44 mm, 33 paratypes 1.20–1.70 mm (mean 1.54); width 1.30 mm, paratypes 0.80–1.30 mm (mean 1.12). Caudal and thoracic tracheal pores shallow, invaginated with 2–3 teeth ( Figs. 5 G–H). Margin finely crenulated ( Fig. 5H ), 9–11 crenulations in 0.1 mm.

Dorsum. Finely sculptured verging to linear markings marginally Fig. 5B ). Submarginal area 20–30 µm wide. Cephalothoracic (pro-, meso- & metathoracic) and abdominal depressions conspicuous. Abdominal segment VII median length 52 µm, paratypes 38–63 µm (mean 52), less than half median length of segment VI ( Fig. 5D ). Transverse moulting suture extending to margin. Pro-mesothoracic and meso-metathoracic sutures, and abdominal segmentation prominent, reaching subdorsal area. Vasiform orifice located anterior of caudal tracheal opening by two times of its own length. Caudal furrow present and well defined.

Vasiform orifice ( Fig. 5E ). Elongate subtriangular; length 90 µm, paratypes 65–100 µm (mean 90); width 75 µm, paratypes 53–75 (mean 68); open posteriorly, floor reticulated; operculum sub-trapezoidal; covering nearly half the length of orifice; length 40 µm, paratypes 15–40 µm (mean 37); width 50, paratypes 19–50 (mean 47); lingula exposed, not reaching beyond posterior margin of the vasiform orifice, terminal end slightly expanded and bluntly pointed, length 40 µm, paratypes 20–50 µm (mean 38) long, two short subapical setae 7.5 µm, paratypes 4–15 µm (mean 9.5).

Venter. Thoracic tracheal fold without stippling, caudal tracheal fold not seen. Legs and antennae present, a tiny seta on the basal and terminal segments of legs 2 and 3 ( Fig. 5F ). Ventral setae 25 µm, paratypes 18–30 µm (mean 21), distance apart 95 µm, paratypes 50–78 µm (mean 74); located level with the anterior margin of the vasiform orifice. Adhesive sacs not seen. Spiracles on abdominal segment II and near vasiform orifice.

Chaetotaxy. Cephalic, first and eighth abdominal setae present, tiny, 5–10 µm long; eighth abdominal setae anteriad of vasiform orifice; 15 pairs of lateral setae in submargin, 50–60 µm, 5 pairs anterior to thoracic pore, 3 pairs between thoracic pore and transverse moulting suture, 7 pairs abdominal; caudal setae, 50 µm, paratypes 40–60 µm (mean 51); anterior marginal setae 18 µm, posterior marginal setae 23 µm.

Material examined. Holotype. NEW ZEALAND, AK, Orewa , Alice Eaves Reserve, 22 August 2014, N.A. Martin, ex Astelia trinervia , on underside of leaf near tip ( NZAC02015592 slide NAM1408Ge), the central puparium of three is selected as the holotype.

Paratypes.15 puparia( NZAC 02015593, NZAC 02015694, NZAC 02015695, NZAC 02015696, NZAC 02015697, NAM1408Ga–e), same data as holotype. 12 puparia (8 slides NAM1408Fa–h), AK, Orewa, Alice Eaves Reserve, 5 August 2014, N.A. Martin, Astelia trinervia , underside of leaf near tip; 1 puparium, parasitised, (slide NAM1403L), AK, Orewa, Alice Eaves Reserve, 18 May 2014, N.A. Martin, Astelia trinervia , underside of leaf, near tip; 5 puparia (2 slides NAM1311Ea–b), AK, Orewa, Alice Eaves Reserve, 12 November 2013, N.A. Martin, Astelia trinervia , underside of leaf near tip.

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

Host plant. The only known host plant is Astelia trinervia Kirk (Asteliaceae)

Distribution. The species has been found in Orewa, Auckland.

Etymology. The new species is named after the host plant genus, Astelia .

Remarks. This is the only species of Asterochiton found infesting a monocotyledon.

Figures

FIGURE 5. Asterochiton asteliae n. sp. Holotype puparium, A–B, D–H. A. Dorsum line drawing, B. Dorsum slide mount, C. Puparium, parasitoid exit hole and black parasitoid pupal skin, D. Abdominal segments VI and VII, E. Vasiform orifice, F. Antennae and legs, G. Caudal pore, H. tracheal pore.