Aleurodicus dispersus Russell, 1965

Hernández-Suárez, Estrella, Martin, Jon H., Gill, Raymond J., Bedford, Ian D., Malumphy, Christopher P., Betancort, J. Alfredo Reyes & Carnero, Aurelio, 2012, 3212, Zootaxa 3212, pp. 1-76 : 32-33

Aleurodicus dispersus Russell

( Figures 39, 86–88, title page image)

Aleurodicus dispersus Russell, 1965: 49–54 .

Distribution in the Canary Islands: LANZAROTE: Puerto del Carmen, Playa Blanca, Fariones, Costa Teguise, Arrecife. FUERTEVENTURA: Corralejo, Cañada del Río. GRAN CANARIA: Arucas, San Agustín, Playa del Inglés, Las Palmas de Gran Canaria, Maspalomas, Puerto de Mogán. TENERIFE: Santa Cruz, Puerto Cruz, Punta del Hidalgo, Playa San Juan, Los Gigantes, Güímar, Bahía del Duque, Parque Eólico, Las Américas, Los Cristianos, Arona, Adeje, Guía de Isora, Las Américas, San Miguel, Santiago del Teide, Santa Cruz, Puerto de la Cruz. LA GOMERA: San Sebastián. EL HIERRO: Las Puntas. Elsewhere: Neotropical Region: widely distributed; Neartic Region: U.S.A. (Florida); Palaeartic Region: 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, Taiwan, Thailand, Vietnam; Austro-Oriental and Pacific Regions: widely distributed; Australia: Queensland.

Host plants in the Canary Islands: Acacia sp. , Acalypha wilkesiana , Acokanthera oblongifolia , Aloe arborescens , Archontophoenix alexandrae , Bauhinia variegata , Beta vulgaris , Bougainvillea sp. , Bougainvillea spectabilis , Brachychiton discolor , Capsicum annuum , Carica papaya, Coccoloba uvifera , Cocos nucifera , Cordia myxa , Eugenia uniflora , Dracaena draco , Ficus elastica , Ficus lyrata , Ficus microcarpa , Ficus sp. , Ficus rubiginosa var. rubiginosa and var. glabrescens , Hibiscus rosa-sinensis , Howea forsteriana , Lantana camara , Limonium sp. , Mackaya bella , Mangifera indica , Musa acuminata , Musa sp. , Myoporum laetum , Myrica faya , Nerium oleander , Passiflora edulis , Phoenix canariensis , Phoenix sp. , Plumeria alba , Psidium guajava , Psidium sp. , Punica granatum , Roystonea regia , Schefflera sp. , Schinus terebinthifolius , Senecio petasitis , Solandra maxima , Solanum argentinum , Solanum sp. , Spathodea campanulata , Strelitzia alba , Strelitzia nicolai , Terminalia catappa , Vitis vinifera , Washingtonia filifera , Washingtonia robusta , Yucca aloifolia , Yucca sp. Other host plant listed: this species is extremely polyphagous.

Comments: Native to the Neotropical Region, Aleurodicus dispersus is a notorious polyphagous pest commonly known as the “spiralling whitefly” [spelt “spiraling” in the USA]. It is one of the best-known of all Aleurodicus species because, through the 1980s and 1990s, it became almost pan-tropical in distribution, and caused much economic damage on its first arrival in many places ( Martin, 1990 and personal observations).

Aleurodicus dispersus can be distinguished from most other Aleurodicus species by having 4 pairs of large abdominal compound pores but no smaller compound pores on abdominal segments VII or VIII, and by having a band of submarginal notched pores continuous posterior to vasiform orifice, with such pores absent from the median part of abdominal segment VII ( Fig. 39).

In the description of A. dispersus , the holotype was selected from material from Florida; however, specimens from Schinus terebinthifolius in Gran Canaria were listed as paratypes by Russell (1965). Manzano et al. (1995) highlighted the rapid expansion of this whitefly within the Canary Islands and its extraordinarily wide range of hosts. It is now present in all the islands of the archipelago ( Hernandez-Suárez et al., 2002).

The presence of A. dispersus in the Canary Islands probably obscured the introduction of a second species into the archipelago, A. floccissimus Martin et al. (q.v., below), because they are very similar in appearance in the field (compare Figs 86–88 with Figs 89–91). However, A. dispersus can be distinguished from A. floccissimus in both adult and pupal stages. Adults of A. dispersus possess four grey spots on the fore wings ( Fig. 87) and the puparial stages are smaller than in A. floccissimus . In the Canary Islands puparia of A. floccissimus almost always possess a pair of small compound pores on abdominal segment VIII, underneath the lingula ( Fig. 40), a character that immediately distinguishes them from those of A. dispersus : however, in the absence of these small compound pores A. floccissimus may be distinguished by the many fewer notched pores in the subdorsal / submedian area, and by the axial processes of the abdominal compound pores usually directed posterolaterad in slide-mounted specimens. Also, the two species have characteristic waxy secretions that enable them to be distinguished one from the other when these secretions are in perfect condition (perfect puparia of A. dispersus are shown in Fig. 88). The spiralling whitefly is naturally controlled in the Canaries by Encarsia hispida (De Santis) ( Hymenoptera : Aphelinidae ) and also by the introduced Encarsia guadeloupae Viggiani ( Hernández-Suárez et al., 2003; Nijohf et al., 2000).