Aleurodicus, Douglas

Martin, Jon H., 2008, A revision of Aleurodicus Douglas (Sternorrhyncha, Aleyrodidae), with two new genera proposed for palaeotropical natives and an identification guide to world genera of Aleurodicinae, Zootaxa 1835 (1), pp. 1-100 : 14-15

ALEURODICUS Douglas

Aleurodicus Douglas, 1892: 32 . Type species Aleurodicus anonae Morgan, 1892: 32 , by subsequent designation by Quaintance, 1908: 8. [Synonymised with A. cocois Curtis (1846: 284–285) by Mound & Halsey, 1978: 228.]

Aleurodicus (Lecanoideus) Quaintance & Baker, 1913: 70 . Type species Aleurodicus (Lecanoideus) giganteus Quaintance & Baker, 1913: 70 , by original designation. [Synonymised with Aleurodes mirabilis Cockerell (1898: 225) by Martin, 2004: 18.]

Lecanoideus Quaintance & Baker ; as full genus, Costa Lima, 1928: 133 (by inference). Syn. nov.

DIAGNOSIS.

PUPARIA—characters of most diagnostic importance are given in bold. As interpreted here, Aleurodicus comprises species displaying the following combination of characters (Fig. A): 12 pairs of submarginal setae present (including the nominal caudal pair); submedian cephalothoracic setae present (some species with cephalic and three thoracic pairs, all similar to submarginal setae, others with cephalic pair wanting, and the dispersus / flavus / coccolobae / charlesi assemblage usually possess only meso- and metathoracic pairs of submedian setae which are also much smaller than submarginal setae); anterior marginal setae absent; submargin and/or dorsal disc usually punctuated by pores of several types, but loculate pores (Fig. B x) absent; 4 pairs of large subdorsal abdominal compound pores, evenly spaced on segments III – VI, usually each with an axial process extending beyond the pore mouth; most species also additionally with one or two much smaller abdominal pairs of compound pores, on segments VII and/or VIII; two pairs of cicatrices present on thoracic area (scars of third-instar compound pores); lingula always protrudes beyond vasiform orifice, its four subapical setae on the protruding part; ventrally, each leg bears a large and distinct claw, antennae long, curved and reaching at least to middle legs, often to hind legs ( Figs 69 , 71 ). [2nd-instar with 3 pairs of compound pores, on cephalus, prothorax and last abdominal segment; 3rd-instar with 3 pairs of cicatrices in same positions.]

ADULTS—with 7-segmented antennae; forewings with R forked (Figs 138–140); antennae of males only with tiny and discreet sensoria; abdominal wax plates numbering 4 pairs in females (Fig. 141) and 3 pairs in males.

COMMENTS. Confusion over the identity of the type species of Aleurodicus was investigated by Martin (1997), confirming it to be Aleyrodes cocois Curtis —see comments on Aleurodicus cocois , p. 26.

Species with the characters detailed in the diagnosis above, but whose puparial margins are usually variably deflexed, the submargin punctuated by a broad band of crowded simple pores of only the wide-rimmed type ( Figs 69 , 70 ), and whose compound pore axial processes are usually directed mesally when slidemounted, have hitherto been placed in the genus Lecanoideus Quaintance & Baker (1913) – see Martin, 2004: 16, key couplet 10. Lecanoideus was raised to a full genus by Costa Lima (1928), but with no reasons stated. Lecanoideus was discussed by Martin et al. (1997: 1269–1270), who concluded that there was little justification for its status as a full genus, but who decided to preserve the status quo pending further investigations. Subgenera are not generally accepted by whitefly workers ( Martin & Mound, 2007: 5), precluding that option for Lecanoideus , in the author’s opinion. Aleurodicus inversus (described from Belize) is somewhat intermediate in form, reinforcing the decision, here, to regard Lecanoideus Quaintance & Baker (1913) as a junior synonym of Aleurodicus (1892) syn. nov. .

Amongst extensive material that had remained unidentified within the USNM collection, prior to being loaned to the author for this study, were three species labelled as belonging to a new genus closely related to Aleurodicus . These three species are included in Aleurodicus (as defined by Martin, 2004, and followed here), and all three had been recently described – as A. niveus Martin (2004) , A. rugioperculatus Martin (2004) and A. talamancensis Martin (2005) . These three species belong to two discreet groups within Aleurodicus (see key couplet 30, p. 19) in the same way as do members of the A. dispersus -group (see diagnosis, above), but there is no evidence to support the proposal of a new genus, in the author’s opinion – echoing the situation with Lecanoideus discussed above. Notably, A. niveus had been intercepted on imported orchids for many decades, while remaining undescribed (see discussion of A. niveus , p. 38).

The five pairs of exceptionally large simple pores observed in most species of a palaeotropical aleyrodine genus, Dialeuropora Quaintance & Baker , led Chen (1997) to describe a new species from China as Aleurodicus photiniae . However, the even spacing of the five pairs of large pores in puparia of most species of Dialeuropora is completely different from the cephalic pair + separate abdominal grouping seen in Aleurodicus species , and photiniae was transferred from Aleurodicus to Dialeuropora by Martin & Mound (2007): specimens bearing type data (discovered in BMNH accessions) have confirmed this decision.

Figures

FIGURE 69 Aleurodicus floccissimus (Martin et al.) comb. nov., puparium, Tenerife, with arrow (a) indicating tiny 8th abdominal compound pore almost underlying lingula.

FIGURE 70 A. mirabilis (Cockerell), puparium, Ecuador, posterior detail with deflexed submarginal detail shown bottom-left, dorsal submarginal detail inset bottom-right, deflexed margin as dashed line, lingula & mesal boundary of submarginal band of wide-rimmed pores as dotted lines.

FIGURE 71 Aleurodicus dispersus Russell, puparium, after Russell (1965), with inset detail of (a) modified 8-shaped pore, (b) double-rimmed notched pore, (c) wide-rimmed pore, (d) minute wide-rimmed pore and (e) wide-rimmed notched pore.