Metabemisia palawana 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 : 10-12

Metabemisia palawana Martin sp. nov. ( Figs 6­7 )

PUPARIUM ( Figs 6­7 ). Habitus. The few vacated pupal cases were found under the fronds; appearance not noted, but significant waxy secretion would have attracted comment in field notes.

Margin. Outline elongate­oval, 0.74­0.78 mm long, 0.39­0.41 mm wide, 1.80­1.95 times longer than wide, generally widest at abdominal segment I/II (n=6). Anterior and posterior marginal setae present, hair­like, posterior pair a little longer than adjacent submarginal setae, anterior pair finer and shorter. Margin variably and unevenly crenulate as shown, modified at thoracic tracheal openings as a shallowly “W”­shaped notch, and also indented between caudal setae.

Dorsum. Subdorsal chaetotaxy comprises single pairs of cephalic, 1st and 8th abdominal setae, blunt to faintly capitate, around 8 m long; submarginal chaetotaxy comprises 14 pairs of setae, the anteriormost and caudal pair stout and acute, 80­110 m long, the remainder blunt to faintly capitate, around 8 m long (similar to subdorsal pairs); all placed in extreme outer submargin except for 6th cephalothoracic pair which are displaced to inner submargin, adjacent to thoracic tracheal sculpturing; in one specimen, another submarginal seta is similar to caudal setae, but on one side only ( Fig. 7 ). Submargin defined by a series of very shallow ridges running mesad from margin, each submarginal seta at the apex of such a ridge. Longitudinal moulting suture reaches puparial margin; transverse moulting sutures almost reach margin and terminate opposite point of confluence of longitudinal and transverse sutures. Adjacent to thoracic tracheal openings at margin, cuticle distinctively sculptured as shown ( Fig. 6 ), with a smooth circular patch surrounded by folding. Dorsal disc generally unsculptured but with paired geminate pore / porettes as shown, mostly in three ranks abdominally. Pro­/mesothoracic, meso­/metathoracic and abdominal segmental divisions I/II to VI/VII well marked, terminating subdorsally; submedian depressions distinct. Abdominal segment VII slightly reduced medially. Posterior to vasiform orifice, a distinct and finely tuberculate ridge on either side of median line defines a narrow and smooth caudal furrow. Vasiform orifice elongate­cordate, slightly notched apically, the inner edges coarsely ridged as shown, and apparently very slightly elevated ( Fig. 7 ); operculum occupying about half length of orifice. Lingula head large, irregular and with a pair of large basal lobes; lingula almost fully occupying posterior part of orifice, without a pair of apical setae.

Ven te r. Cuticle diaphanous and smooth; tracheal folds completely unmarked. Ventral abdominal setae very fine, similar in length to operculum, their bases anterior to vasiform orifice by about an operculum­length. Middle and hind legs each with a fine, hair­like legbase seta. Antennal bases mesal to fore legs. Mouthpart basal setae long and hair­like.

OTHER INSTARS. Unknown.

MATERIAL EXAMINED. Holotype puparium, PHILIPPINES, Palawan, forested river valley above Irawan village , near Puerto Princesa, on Lastreopsis ? subsparsa ( Dryopteridaceae ), 11 February 1988 (J.H. Martin #5265 ) ( BMNH) . Paratypes: 5 puparia, same data as holotype ( BMNH) .

ETYMOLOGY. This species takes its name from its type locality, the island of Palawan in the western Philippines.

COMMENTS. This species is placed in Metabemisia with certain reservations. Only two species have hitherto been placed in this genus, M. distylii Takahashi (1963) (the typespecies) and M. filicis Mound (1967) . Of great importance in the decision to place palawana in Metabemisia is its great similarity to M. filicis in the distribution of geminate pore/porettes, the nature of the thoracic tracheal openings at the margin, and the pair of ridges which lead from the caudal setae to the vasiform orifice and thus create the caudal furrow ­ these ridges are unusual in both species, in the way they do not diverge towards the vasiform orifice. The vasiform orifice of M. palawana is much broader than in either of the two other members of the genus, the apparent absence of lingular setae in all six available specimens is unusual, and the submedian abdominal depressions are particularly distinct. However, although Takahashi did not enumerate the submarginal setae in his generic diagnosis, both M. distylii and M. filicis bear 10 pairs, including the caudal pair, compared with 14 pairs in M. palawana . It is well known that puparial setal lengths are highly variable in many whitefly species (e.g. the single enlarged pre­caudal seta on one specimen, depicted in figure 7), so the majority of submarginal setae being extremely small in M. palawana is not felt to be of as great significance as the total number.

Figures

FIGURES 6 ­ 7. Metabemisia palawana Martin sp. nov. (6) post­emergence pupal case with righthand cephalothorax removed to reveal ventral detail; (7) vasiform orifice and posterior dorsal detail of puparium.