Trialeurodes rex Martin, 2001

Martin, Jon H. & Camus, Josephine M., 2001, Whiteflies (Sternorrhyncha, Aleyrodidae) colonising ferns (Pteridophyta: Filicopsida), with descriptions of two new Trialeurodes and one new Metabemisia species from south­east Asia, Zootaxa 2, pp. 1-19 : 7-8

Trialeurodes rex Martin sp. nov. ( Fig. 4­5 )

Trialeurodes sp. Martin, 1988: 82 ; Mound et al., 1994: 1405; Martin, 1999: 110.

PUPARIUM. Habitus. No duplicate dry material available for study, but a field note recorded that puparia bore "sparse mealy­wax", with fine wax “rods” (filaments). They were collected from the lower surfaces of the fronds.

Margin. Outline elongate­oval, 0.50­0.63 mm long, 0.27­0.34 mm wide, 1.8­2.0 times longer than wide, usually widest at transverse moulting sutures (n=8). Anterior marginal setae absent; posterior marginal setae long, fine, 48­ 60 m. Margin variably uneven to finely crenate, with more than 25 crenations occupying 0.1 mm of margin; margin not modified at tracheal openings.

Dorsum. Chaetotaxy, with typical setal lengths quoted, comprises single pairs of cephalic (44­52 m), 1st abdominal (36­52 m), 8th abdominal (48­56 m) and caudal (52­68 m) setae, these setae fine and hair­like; sclerotised setal bases about 8 m in diameter. Longitudinal moulting suture reaches puparial margin; transverse moulting sutures terminate in subdorsum. Dorsal disc generally smooth but punctuated by scattered porettes (not geminate pore / porettes), as shown ( Fig. 4 ). With a submarginal row of uneven­sized glandular papillae which are apically acute, sometimes smaller papillae present mesad of larger ones, in a partial second rank; papillae absent elsewhere. Pro­/ mesothoracic and meso­/metathoracic divisions, transverse moulting sutures, and abdominal division I/II marked rather faintly; remaining abdominal segmentation very clearly marked submedially, occasionally appearing almost rhachisform; abdominal segment VII reduced medially, but distinct. Vasiform orifice cordate, smoothly rounded apically, internally smooth; operculum occupying about two­thirds of orifice. Lingula head with a pair of stout setae, markedly lobulate, reaching or slightly overlapping vasiform orifice boundary, only the basal pair of lobes normally covered by operculum. Surrounding vasiform orifice posterolaterally is a large, U­shaped, structure which comprises poorly defined glandular facets, the caudal setae marking the postero­lateral corners; caudal furrow absent.

Ven te r. Cuticle diaphanous and smooth; tracheal folds completely unmarked. Ventral abdominal setae underlying operculum, very fine and hair­like. Base of each middle and hind leg each with a minute seta and sometimes also one or two apparent setal bases.

OTHER INSTARS. Other larval instars are unknown. A single adult female is present on one slide ­ see discussion of adults of T. bruneiensis .

MATERIAL EXAMINED. Holotype puparium, Indonesia, SULAWESI UTARA, Dumoga ­ Bone NP, forested ridge 10km NW of Toraut, 0° 37' 30"N, 123° 51' 00"E, 1140m, on unidentified fern, 18 April 1985 (J.H. Martin #4879 ) ( BMNH) . Paratypes: 12 puparia, same data as holotype ; 11 puparia, 1 adult female, same data as holotype but different individual fern ( JHM #4869 ) ( BMNH, MZB, USNM) .

ETYMOLOGY. The ornate glandular patch surrounding the puparial vasiform orifice at once sets this species apart from all other known species of this large whitefly genus, and the name rex (Latin, king) is appropriate.

COMMENTS. With the presence of an extraordinary U­shaped glandular patch encompassing all but the anterior edge of the vasiform orifice, this remarkable species is quite unlike any other described, or known undescribed, species of Trialeurodes . However, all other characters clearly indicate that Trialeurodes is the correct generic placement. The absence of leg­base spines, and absence of gelatinous dorsal secretions exclude T. rex from the ricini species­group. It is probable that T. rex belongs to the same group as do T. bruneiensis and T. dicksoniae , the only other known Australasian / Asian fern­feeding species, but the significance of the posterior glandular patch is unknown.

Figures

FIGURES 4 ­ 5. Trialeurodes rex Martin sp. nov. (4) puparium, ventral detail to left of line; (5) vasiform orifice and posterior dorsal detail of puparium.