Trialeurodes bruneiensis 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 : 4-7

Trialeurodes bruneiensis Martin sp. nov. ( Fig. 1 ­ 3 )

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

PUPARIUM ( Figs 1­2 ). Habitus. Scattered under fronds, not in distinct feeding groups. Appearance in life not noted, but dried body colour of pre­pupal fourth­instar larvae yellowish, with no visible dorsal wax coating. Empty pupal cases silvery, with a transparent, glassy, wax filament issuing from each dorsal (glandular) papilla; filaments from smallest papillae curved, but those from largest papillae straight and very long, some as long as the pupal case.

Margin. Outline rather unevenly elongate­oval, 0.62­0.75 mm long, 0.30­0.40 mm wide, 1.85­2.00 times longer than wide, generally widest at first abdominal segment (n=15). Anterior and posterior marginal setae present, anterior pair fine, about 16 m, and posterior pair almost as stout as caudal setae, up to 40 m long. Margin variably and unevenly crenate; where teeth evident, approximately 15­22 occupy 0.1 mm of margin; margin not modified at thoracic and abdominal tracheal openings, combs of teeth absent.

Dorsum. Chaetotaxy, with typical setal lengths quoted, comprises single pairs of cephalic (22­24 m), 1st abdominal (24­30 m), 8th abdominal (12­16 m) and caudal (60­65 m) setae, these setae stout, usually somewhat curved as shown ( Fig. 1 ) but apically acute; sclerotised setal bases about 8 m in diameter. Longitudinal moulting suture reaches puparial margin; transverse moulting sutures almost reach margin and terminate opposite point of confluence of longitudinal and transverse sutures. Dorsal disc generally smooth but with relatively large, and approximately paired, geminate pore / porettes as shown, and also with an uneven row of simple porettes mesad from the papilla bases. With a submarginal row of uneven­sized glandular papillae which are apically acute; papillae absent elsewhere. Pro­/mesothoracic segmentation often only faintly marked, close to median line; meso­/metathoracic and abdominal segmentation clear only submedially, abdominal segment VII much reduced medially, but pockets not protruding into segment VI. Caudal furrow defined by a shallow ridge to either side of vasiform orifice, the 8th abdominal setae placed mesad from these ridges. Vasiform orifice elongate­cordate, apically notched, the inner edges ridged as shown ( Fig. 2 ), and with a pair of tiny punctae visible when lingula recessed under operculum; operculum occupying about half length of orifice. Lingula head with lobulation much more subtle than in many Trialeurodes species, but with the normal pair of apical setae. Position of lingula very variable between examined specimens, but always included within vasiform orifice; its natural position likely to be as shown in Figs 1 & 2 , with only apex uncovered.

Ven te r. Cuticle diaphanous and smooth; tracheal folds completely unmarked. Ventral abdominal setae underlying operculum, very fine but can exceed opercular length. Middle and hind legs each with a fine, hair­like seta up to 20 m long, and an adjacent minute spine­like seta.

THIRD­INSTAR LARVA ( Fig. 3 ). Elongate­oval, 0.51 mm long, 0.25 mm wide (n=1). Margin crenate, 18 teeth occupying 0.1 mm, anterior and posterior marginal setae present, 12 m and 40 m, respectively. Dorsal chaetotaxy ­ single pairs of cephalic (8 m), 1st abdominal (8 m), 8th abdominal (12 m) and caudal (64 m) setae present. Abdominal segmentation similar to puparia. Dorsum without papillae. Vasiform orifice similar to puparia, but with lingula head a little less developed. A pair of rather large geminate pore / porettes on each cephalothoracic segment, and on abdominal segments I, V, VII & VIII. Ventrally, middle and hind legs appearing 2­segmented, the normal apical pad developed as an acute “joint”, each with only a pair of minute spine­like setae; antennae entirely anterior to fore legs, apically hook­shaped, as shown.

ADULTS. Six slide­mounted adults are available for study. Given that the significance of many adult characters await assessment, it is felt that attempting to describe these would not be beneficial at present. However, R. Gill (personal communication) considers that they closely match a putative character suite for the Trialeurodinae, resulting from his own preliminary studies.

MATERIAL EXAMINED. Holotype puparium, Borneo, BRUNEI, eastern Belait District, near Bukit Bedawan (4° 30' N, 114° 48' E), 200m, on unidentified member of the fern family Thelypteridaceae , growing on fallen tree in deep forested river valley, 30 March 1989 (J.H.Martin #5523) (BMNH) . Paratypes: 33 puparia, 1 third­instar larva, 1 third­instar / puparium intermoult, 5 adult females, 1 adult male, same data as holotype (BMNH, MDB, USNM) . Other material: dry residue of original collection, same data as holotype (BMNH) .

ETYMOLOGY. This species is named for its type locality, the sultanate of Brunei Darussalam, Borneo.

COMMENTS. This species probably does not belong to one of the species­groups that were defined by Russell (1948), in her detailed study of the North American species of Trialeurodes (most Trialeurodes species are natives of the New World), but may be nearest to the pergandei ­group, with fine marginal crenations and abdominal segment VII discernible medially. The puparium quite strongly resembles the pilose­leaf form of T. ricini ( Misra) , an Old World species which is found from the Mediterranean Basin eastwards to the Philippines, including Brunei. However, the puparia of T. bruneiensis bear an unusually long and fine seta at the base of each middle and hind leg, in contrast to the pair of thorn­like spines in the members of the ricini ­group. Also, members of the ricini ­group commonly have gelatinous dorsal secretions, requiring mechanical removal to reveal the cuticle, which are not present in T. bruneiensis . Further, the lingula head in T. bruneiensis is considerably less clearly lobulate than in T. ricini or the North American Trialeurodes species. The Australian fern­feeding species, T. dicksoniae , has papillae of similar form to those of T. bruneiensis , but T. dicksoniae has many fewer papillae, has cephalic and anterior marginal setae wanting, and bears a cluster of minute leg­base setae of which none are hair­like.

Figures

FIGURES 1 ­ 3. Trialeurodes bruneiensis Martin sp. nov. (1) puparium, ventral detail to right of line; (2) vasiform orifice and posterior dorsal detail of puparium; (3) third­instar larva, ventral detail as inset to right.