(Newstead, 1898)
Diagnosis
In life, female scale cover circular, flat, 1.0-2.0 mm diameter, grey or light brown with yellow subcentral exuviae DYNBRL4.jpg . Male scale cover similar to that of the female but elongate oval with yellow subterminal exuviae DYNBRL6.jpg and DYNBRL.jpg . Body of living female yellow (Gill, 1997).
Body of adult female pyriform, prosoma without any constrictions, membranous throughout life DYNBRS.jpg . Anus smaller than a median lobe, situated more than 2.4x its diameter from base of median lobes. Pygidium with three pairs of rounded lobes, paraphyses absent or, if present, shorter than the lobes and quite slender. Plates and perivulvar pores present. Fourth lobes represented by sclerotized points or patches; margin lateral to fourth lobes smooth, without paraphyses, often somewhat sclerotized; abdominal segments III and IV each with fewer than 9 submarginal ducts on either side DYNBRP.jpg .
Host range
Dynaspidiotus britannicus has been recorded from hosts belonging to 23 genera in 18 plant families (Davidson and Miller, 1990). It is often found on species of Buxus, Hedera, Ilex and Laurus (Nakahara, 1982) and only occasionally feeds on conifers (Zahradník, 1990). Hosts include species of: Arbutus, Berberis, Buxus, Camellia, Ceratonia, Cinnamomum, Danae, Daphne, Elaeagnus, Firmiana, Hedera, Ilex, Jasminum, Laurus nobilis, Ligustrum, Lonicera, Malus, Myrtus, Olea, Palmae, Pinus, Pistacia, Pyrus, Rhamnus, Ruscus, Smilax, Sophora, Taxus, Viburnum and Ziziphus.
Affected plant stages: vegetative growing, flowering and fruiting stages
Affected plant parts: on leaves DYNBRL5.jpg , twigs and berries
Biology and ecology
Dynaspidiotus britannicus has one or two generations per year in California, and overwinters as second instars (Bene, 1984; Gill, 1997). 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
Gill, 1997, says D. britannicus infestations cause weakening of the host and stunting of the leaves. The toxicity of the saliva injected while feeding can cause necrosis of the feeding site DYNBRL2.jpg .
Economic impact
This species is known as a pest of ornamental plants (Zahradník, 1990), particularly in Italy (Battaglia and Viggiani, 1986). Danzig and Pellizzari, 1998, described it as a pest in the Palaearctic region. Gill, 1997, says D. britannicus is a 'B'-rated pest in California, and that infestations cause weakening of the host and stunting of the leaves. In Cyprus, Greece, Spain and Turkey it is a pest of olive (Argyriou, 1990).
Detection and inspection methods
Examine leaves, twigs and berries of the hosts listed above for circular, flat, grey or light brown scale covers with yellow subcentral exuviae.
Natural enemies
Parasitoids:
- Aphytis libanicus, attacking second instar nymphs, male pupae and and adult females, in Italy
- Coccidencyrtus dynaspidioti, in Italy
- Coccidencyrtus steinbergi, in Italy
- Encarsia aspidioticola, in Italy
- Encarsia citricola, attacking second instar nymphs and male pupae, in Italy
- Encarsia citrina, in Italy
Distribution
See Dynaspidiotus britannicus distribution.
Microscopic examination of slide-mounted adult females is required for authoritative identification to species.
Comments
Dynaspidiotus britannicus is a temperate species, probably of Palaeartic origin. In northern countries, it is only found under glass (Danzig and Pellizzari, 1998). The species has not been recorded from Australia, or from the Pacific islands. Hodgson and Hilburn, 1991, remark that the species does not appear to have become established in Bermuda.
Europe
Belgium: The Natural History Museum collection, London, UK
Cyprus: present, no further details (Danzig and Pellizzari, 1998)
Former USSR (under glass)
Crimea: present, no further details(Nakahara, 1982; Danzig and Pellizzari, 1998)
Georgia, Republic of: Black Sea coast (Nakahara, 1982; Danzig and Pellizzari, 1998)
Middle Asia: present, no further details (Nakahara, 1982; Danzig and Pellizzari, 1998)
France: present, no further details (Foldi, 2001; Danzig and Pellizzari, 1998)
Greece: present, no further details (Danzig and Pellizzari, 1998)
Italy: present, no further details (Longo et al., 1995; Danzig and Pellizzari, 1998)
Sicily: present, no further details (Longo et al., 1995)
Malta: present, no further details (Danzig and Pellizzari, 1998)
Portugal: present, no further details (Danzig and Pellizzari, 1998)
Madeira: present, no further details (Nakahara, 1982; Danzig and Pellizzari, 1998)
Spain: present in Grenada, Madrid, Pontevedra, Sevilla, Toledo and Valencia (Amparo Blay Golcoechea, 1993; Soria et al., 2000)
Balearic Is: present (Amparo Blay Golcoechea, 1993)
Switzerland: present, no further details (Kozár et al., 1994; Danzig and Pellizzari, 1998)
United Kingdom: present, no further details (Danzig and Pellizzari, 1998)
England: The Natural History Museum collection, London, UK
Wales: The Natural History Museum collection, London, UK
Asia
China; (Danzig and Pellizzari, 1998)
Jiangxi: present, no further details (Tao, 1999)
Yunnan: present, no further details (Tao, 1999)
Israel: present, no further details (Davidson and Miller, 1990; Danzig and Pellizzari, 1998)
Turkey: present, no further details (Davidson and Miller, 1990; Danzig and Pellizzari, 1998)
Africa
Algeria: present, no further details (Nakahara, 1982; Danzig and Pellizzari, 1998)
Egypt: present, no further details (Nakahara, 1982; Danzig and Pellizzari, 1998)
Morocco: present, no further details (Nakahara, 1982; Danzig and Pellizzari, 1998)
Western Hemisphere
Brazil: present, no further details (Davidson and Miller, 1990)
Rio de Janeiro: present, no further details (Claps et al., 2001a)
Rio Grande do Sul: present, no further details (Silva et al., 1968)
Canada
British Colombia: present, no further details (Nakahara, 1982)
Central America: present, no further details (Danzig and Pellizzari, 1998)
USA
California: now quite rare (Gill, 1997)
Illinois: present, no further details (Nakahara, 1982)
Indiana: present, no further details (Nakahara, 1982)
Massachusetts: present, no further details (Nakahara, 1982)
Michigan: present, no further details (Nakahara, 1982)
Oregon: common (Gill, 1997)
Pennsylvania: present, no further details (Nakahara, 1982)
Washington: common (Gill, 1997)
West Virginia: present, no further details (Nakahara, 1982)