Signoret, 1869
Diagnosis
In life, scale cover of adult female 1.5-2.5 mm diameter, circular and slightly convex, translucent dirty white or light tan with yellowish or tan subcentral exuviae DIABOL5.jpg . Male scale cover pure white, with 3 low, longitudinal carinae and yellow, terminal exuviae DIABOL4.jpg ; males often congregate in small groups, associated with white, woolly wax. Body of living female bright yellow DIABOL4.jpg , with horn-like lateral lobes on either side of the cephalothorax (Gill, 1997). Adult male winged (Ghauri, 1962).
Body of slide-mounted adult female less than twice as long as wide, body widest at prothorax or head; a pair of lateral tubercles present on prosoma DIABOS.jpg . Pygidium with median lobes not zygotic, set well apart and inset to form an apical notch, with a pair of setae between their bases; bases of marginal segmental setae on pygidium not obviously enlarged and sclerotized; submedian macroducts absent from pygidium; 1 or 2 submarginal macroducts as big as marginal macroducts, present on each side of pygidium DIABOP.jpg .
Host range
Diaspis boisduvalii has been recorded from hosts belonging to 44 genera in 15 plant families (Davidson and Miller, 1990). In Argentina it is mainly found on native plants (Claps et al., 2001a). Orchids DIABOL1.jpg and monocotyledonous plants such as palms and bromeliads (e.g. pineapple) are particularly favoured hosts. Hosts include species of: Acacia, Aechmea, Agave, Ananas sativus, Anguloa, Baccharis, Bactris, Bulbophyllum, Casearia, Cassia, Cattleya, Cedrela, Chamaerops, Citrus, Cocos, Coelogyne, Copernicia, Corypha, Ctenanthe, Cymbidium, Epidendrum, Euterpe, Guzmania, Harrisia, Hedera, Heliconia, Howea, Jodina, Laelia, Latania, Ligaria, Livistona, Loranthus, Mangifera indica, Maranta, Marantaceae, Maytenus spp., Maxillaria, Miconia, Miltonia, Musa, Myrsine, Nannorrhops, Nectandra, Odontoglossum, Oncidium, Opuntia, Orchidaceae, Palmae, Pandanus, Persea americana, Phoenix, Phormium, Phorodendron, Pitcairnia, Pleiochiton, Psidium guajava, Rhynchostylis, Rosa, Roystonea, Rubiaceae, Schinus, Strelitzia, Tillandsia, Trachycarpus, Vanda and Washingtonia.
Affected plant stages: vegetative growing, flowering and fruiting stages
Affected plant parts: leaves, pseudobulbs of orchids, and twigs
Biology and ecology
In California, D. boisduvalii has multiple generations each year, with a single generation taking about 50 days in optimal conditions. Each female produces about 200 eggs (Gill, 1997). From egg to egg-laying female takes about 50 days (Bohart, 1942).
Crawlers are the primary dispersal stage and move to new areas of the plant or are dispersed by wind or animal contact. Mortality due to abiotic factors is high in this stage. Dispersal of sessile adults and eggs occurs through human transport of infested plant material.
Symptoms
Toxic saliva injected while feeding causes necrosis of tissue at the feeding site DIABOL4.jpg . Small infestations on orchids cause extensive discolouration and large populatons usually kill the host (Gill, 1997) DIABOL2.jpg .
Economic impact
In Brazil, D. boisduvalii is of economic importance on several hosts (Claps et al., 2001a). It is a pest of banana in the Canary Is and the West Indies (Chua and Wood, 1990). Danzig and Pellizzari, 1998, described the species as a pest in the Palaearctic region. Foldi, 2001, listed D. boisduvalii as an occasional pest in France. In California and other parts of the world it is a serious pest of orchids in greenhouses, forming large, encrusting infestations that are difficult to control.
Detection and inspection methods
Examine leaves, pseudobulbs and twigs for circular, slightly convex, translucent dirty white or light tan scale covers with yellowish or tan subcentral exuviae. Small infestations on orchids cause extensive discolouration. DIABOL2.jpg
Natural enemies
The natural enemies of D. boisduvalii have not been studied.
Distribution
See Diaspis boisduvalii distribution.
Microscopic examination of slide-mounted adult females is required for authoritative identification to species.
This species is often found on pineapple, where it could be confused with Diaspis bromeliae; however, D. boisduvalii has only 2 enlarged submarginal macroducts on each side of the pygidium, whereas in Diaspis bromeliae there are 6 or more on each side.
Comments
CSIRO, 2001, stated that Diaspis boisduvalii was native to Tasmania, but Gill, 1997, suggested it was probably a New World species; most species of Diaspis are thought to be of New World origin. Diaspis boisduvalii is now widely distributed throughout the tropics and subtropics, and occurs under glass in temperate areas (Nakahara, 1982, Danzig and Pellizzari, 1998).
Europe: under glass, no further details (Beardsley, 1966)
Belgium: The Natural History Museum collection, London, UK
Former USSR
Georgia, Republic of: present, no further details (Danzig and Pellizzari, 1998)
France: present, no further details (Foldi, 2001; Danzig and Pellizzari, 1998)
Italy: in the south (Longo et al., 1995; Danzig and Pellizzari, 1998)
Sicily: in the south (Longo et al., 1995)
Malta: present, no further details (Danzig and Pellizzari, 1998)
Poland: The Natural History Museum collection, London, UK
Portugal: present, no further details (Danzig and Pellizzari, 1998)
Madeira: The Natural History Museum collection, London, UK
Spain: present in Madrid and Malaga (Amparo Blay Golcoechea, 1993; Soria et al., 2000a)
Canary Is: present, no further details (Danzig and Pellizzari, 1998)
Switzerland: present (Kozár et al., 1994)
United Kingdom: restricted to a few botanical collections, under glass (C.P. Malumphy, Central Science Laboratory, UK, pers. comm.)
England: The Natural History Museum collection, London, UK
Wales: The Natural History Museum collection, London, UK
Asia
China: present, no further details (Danzig and Pellizzari, 1998)
Fujian: present, no further details (Tao, 1999)
Hainan: present, no further details (Tao, 1999)
India
Sikkim: The Natural History Museum collection, London, UK
Iran: present, no further details (Seghatoleslami, 1977; Danzig and Pellizzari, 1998)
Japan: present, no further details (Kawai, 1980)
Korea: present, no further details (Danzig and Pellizzari, 1998)
Malaysia: The Natural History Museum collection, London, UK
Sabah: The Natural History Museum collection, London, UK
Singapore: The Natural History Museum collection, London, UK
Sri Lanka: The Natural History Museum collection, London, UK
Taiwan: present, no further details (Wong et al., 1999)
Turkey: present, no further details (Danzig and Pellizzari, 1998)
Vietnam: The Natural History Museum collection, London, UK
Africa
Côte d'Ivoire: The Natural History Museum collection, London, UK
Egypt: The Natural History Museum collection, London, UK
Ghana: The Natural History Museum collection, London, UK
Kenya: The Natural History Museum collection, London, UK
Mauritius: present, no further details (Williams and Williams, 1988)
Nigeria: The Natural History Museum collection, London, UK
South Africa: The Natural History Museum collection, London, UK
Sudan: The Natural History Museum collection, London, UK
Uganda: The Natural History Museum collection, London, UK
Western Hemisphere
Antigua: The Natural History Museum collection, London, UK
Argentina: widespread (Claps et al., 2001a)
Buenos Aires: present, no further details (Claps et al., 2001a)
Catamarca: present, no further details (Claps et al., 2001a)
Córduba: present, no further details (Claps et al., 2001a)
Entre Rios: present, no further details (Claps et al., 2001a)
Jujuy: present, no further details (Claps et al., 2001a)
Formosa: present, no further details (Claps et al., 2001a)
La Rioja: present, no further details (Claps et al., 2001a)
Rio Negro: present, no further details (Claps et al., 2001a)
Salta: present, no further details (Claps et al., 2001a)
Santiago del Estero: present, no further details (Claps et al., 2001a)
Tucumán: present, no further details (Claps et al., 2001a)
Bahamas: The Natural History Museum collection, London, UK
Barbados: present, no further details (Bennett and Alam, 1985)
Belize: The Natural History Museum collection, London, UK
Bermuda: quite frequent (Hodgson and Hilburn, 1991)
Brazil: widespread (Claps et al., 2001a)
Guanabara: present, no further details (Silva et al., 1968)
Minas Gerais: present, no further details (Claps et al., 2001a)
Pará: present, no further details (Claps et al., 2001a)
Paraná: present, no further details (Silva et al., 1968)
Piauí: present, no further details (Claps et al., 2001a)
Rio de Janeiro: present, no further details (Claps et al., 2001a)
Rio Grande do Sul: present, no further details (Claps et al., 2001a)
Sao Paulo: present, no further details (Claps et al., 2001a)
Colombia: present, no further details (Mosquera, 1973; Kondo, 2001)
Costa Rica: The Natural History Museum collection, London, UK
Dominica: The Natural History Museum collection, London, UK
Ecuador: The Natural History Museum collection, London, UK
Grenada: The Natural History Museum collection, London, UK
Guyana: The Natural History Museum collection, London, UK
Honduras: The Natural History Museum collection, London, UK
Jamaica: The Natural History Museum collection, London, UK
Mexico: present (Miller, 1996)
Nevis: The Natural History Museum collection, London, UK
Panama: The Natural History Museum collection, London, UK
St Lucia: The Natural History Museum collection, London, UK
Trinidad: The Natural History Museum collection, London, UK
USA: reported from most states (Nakahara, 1982)
California: common outdoors in south (Gill, 1997)
Hawaii: present on Oahu, Hawaii, Maui and Kauai (Heu, 2002)
Oceania
Australia
Tasmania: present, no further details (CSIRO, 2001)
Cook Is: present (Williams and Watson, 1988)
Fiji: present (Williams and Watson, 1988)
New Zealand: present, no further details (Charles and Henderson, submitted)
Palau Is: present (Beardsley, 1966)
Solomon Is: present (Williams and Watson, 1988)
Tahiti: present, no further details (Doanne and Hadden, 1909)