Aleurodicus dispersus Russell

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 : 28-29

Aleurodicus dispersus Russell

( Figs 3 , 71 , 122)

Aleurodicus dispersus Russell, 1965: 49–54 . Holotype puparium, U.S.A. (Florida) [USNM, paratypes examined].

DISTRIBUTION. Neotropical Region - widely distributed; Nearctic Region - U.S.A. (Florida); Palaearctic Region - Canary Islands, Madeira; Ethiopian Region - Cameroun, Congo, Benin, Ghana, Guinea-Bissau, Kenya, Nigeria, Sao Tomé, Tanzania, Togo; Malagasian Region - Mauritius; Oriental Region - Hainan ( China), India, Maldives, Sri Lanka, Thailand, Vietnam; Austro-oriental and Pacific Regions - widely distributed; Australia - Queensland.

MATERIAL EXAMINED. Paratype puparia, U.S.A., Florida, Key West , on Cocos nucifera , 12.vi.1964 (Weems) ( BMNH); numerous samples from most countries listed above ( BMNH) .

COMMENTS. A. dispersus is one of only three or four known Aleurodicus species whose puparia possess only 4 abdominal pairs of compound pores on the puparial abdomen, being entirely without pairs of smaller compound pores on abdominal segment VII or VIII: the others are A. mirabilis and some populations of A. floccissimus (q.v.) [which belong to a different species-group, see key], and A. coccolobae which may be the closest relative of dispersus (living puparia of dispersus and coccolobae may be compared in figures 122 and 123). A third described member of the dispersus -group ( A. flavus Hempel , q.v.) has additionally just one pair of tiny compound pores, situated on abdominal segment VII, but otherwise strongly resembles A. dispersus . Two species here described also appear to belong to the small dispersus assemblage of species – see A. charlesi (p. 22) and A. spectabilis (p. 42).

A. dispersus was unusual in remaining undescribed for many years, despite the accumulation of numerous samples in the USNM collection, most of them interceptions at United States port quarantine facilities (see also discussion of A. niveus , p. 38); yet A. dispersus is now the best-known of all members of the Aleurodicinae . It is probable that A. dispersus (the so-called “spiralling whitefly”) is native to the Caribbean and northern South America. Although many of the paratypes are from these native areas, Russell chose a sample from Florida from which to select the holotype. This curious technicality qualifies A. dispersus as one of several neotropical whiteflies to have been described from material sampled in an area of probable introduction. This choice of holotype may have been the result of most other specimens, then available to Russell, being isolated quarantine interceptions with imprecise originating locality data. Since its description, the spiralling whitefly has become almost pan-tropical in its distribution, its rapid radiation having begun in the 1980s ( Martin & Lucas, 1984; Martin, 1990). Winter temperatures appear to have, for the present, prevented its invasion extending into the Middle East and Mediterranean regions, and limited its expansion in Australia.

Figures

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.

FIGURES 1–4. Aleurodicus spp, puparia, photomicrographs. 1, A. araujoi Sampson & Drews. 2, A. coccolobae Quaintance & Baker. 3, A. dispersus Russell. 4, A. dugesii Cockerell.