Hadden, 1909
Diagnosis
Scale cover of adult female in life 1.0-2.0 mm in diameter, elongate oval, quite flat, white or grey, with yellow-brown subterminal or terminal exuviae PACINL3.jpg . Scale cover of male similar in colour to that of adult female, but smaller and more elongate (Williams and Watson, 1988) PACINL2.jpg and PACINL.jpg .
Body of slide-mounted adult female membranous, subcircular to broadly oval, with two-barred ducts; submarginal duct tubercles present on each side of the cephalothorax and the first abdominal segment; eyespot small, rounded and inconspicuous; fringed plates extending as far forward as abdominal segment 2; and membranous derm pockets absent PACINS.jpg . Pygidium with three pairs of rounded unilibulate lobes, fourth and fifth lobes with slight points; 3 plates present between lobes 3 and 4 on each side; with 1 or 2 submedian macroducts within the frame formed by the perivulvar pores PACINP.jpg .
McKenzie, 1945, gives a detailed morphological description, illustrations and a key to the many species of Parlatoria.
Host range
Parlatoria cinerea is a polyphagous species that has been recorded from hosts belonging to 9 plant families (Borchsenius, 1966; Williams and Watson, 1988). Citrus species are favoured hosts. Hosts include species of: Annona muricata, Bougainvillea, Citrus spp., Cupressus, Gardenia, Jasminum, Malus sylvestris, Mangifera indica, Rosa, Viburnum and Vitis vinifera.
Affected plant stages: vegetative growing, flowering, fruiting and post-harvest stages
Affected plant parts: mainly on stems and branches PACINL1.jpg , but sometimes on leaves and fruit; rarely, on roots of Citrus
Biology and ecology
Gravena et al., 1993, reared P. cinerea in the laboratory at 24°C, 65% relative humidity and a light:dark regime of 12:12 hours. They found that on average, egg incubation lasted 6.15 days; the crawler stage, 5.63 hours; the first nymphal instar, 6.87 days; the second nymphal instar 18.97 days; and each female laid 32.68 eggs.
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.
Parlatoria cinerea often occurs together with P. pergandii on Citrus (Williams and Watson, 1988). Heavy infestations form encrustations on Citrus branches (Claps et al., 2001a).
Symptoms
In Rarotonga, mixed infestations of P. cinerea and P. pergandii on Citrus caused gumming and flaking of the bark (Walker and Deitz, 1979); the infestations on the bark were mainly P. cinerea (94% of the insects), and 60% of those on the stems.
Economic impact
Parlatoria cinerea has been recorded as a pest of Citrus in several countries in the South Pacific region (Williams and Watson, 1988). In the Cook Is, combined heavy infestation of Citrus by P. cinerea and P. pergandii was associated with gumming, flaking and splitting of the bark, causing dieback of whole branches and sometimes killing the tree (Walker and Deitz, 1979). P. cinerea causes significant damage to Citrus plantations in Brazil (Sao Paulo) and Argentina (Claps et al., 2001a).
Detection and inspection methods
Examine the bark of Citrus and the other hosts listed above, for elongate oval, quite flat, white or grey scale covers, each with yellow-brown subterminal or terminal exuviae.
Natural enemies
Parasitoids:
- Aphytis hispanicus, in Brazil (Sao Paulo), Israel
- Encarsia inquirenda, in Israel
Predators:
- Chrysoperla externa, attacking eggs and early instars, in Brazil
- Cybocephalus micans, in Israel
- Hemisarcoptes coccophagus, attacking all stages apart from eggs, widespread including Israel; introduced to: New Zealand
Distribution
See Parlatoria cinerea distribution.
Microscopic examination of slide-mounted adult females is required for authoritative identification to species.
Comments
Parlatoria cinerea is a tropicopolitan species that was described from Tahiti but is probably not native there; its country of origin is still uncertain (Williams and Watson, 1988). It is not present in the USA (Miller, 1996) and has not been recorded from Australia, New Zealand, most of Africa, or from most of Europe.
Europe
Italy: present, no further details (Danzig and Pellizzari, 1998)
?Spain: presence/distribution uncertain (Amparo Blay Golcoechea, 1993)
Asia
China: present, no further details (Danzig and Pellizzari, 1998)
Guangdong: present, no further details (Tao, 1999)
Hainan: present, no further details (Tao, 1999)
Indochina: present, no further details (Tao, 1999)
India
Karnataka: The Natural History Museum collection, London, UK
Punjab: The Natural History Museum collection, London, UK
Israel: present, no further details (Izraylevich et al., 1995)
Japan: present, cannot read any further details (Kawai, 1980; Tao, 1999)
Honshu: present (2001 data from S. Kawai photograph)
Malaysia
West Malaysia: The Natural History Museum collection, London, UK
Maldive Is: present, no further details (Watson et al., 1995)
Taiwan: present, no further details (Takagi, 1969)
Africa
Uganda: The Natural History Museum collection, London, UK
Western Hemisphere
Argentina: abundant on Citrus (Claps et al., 2001a)
Corrientes: present, no further details (Claps et al., 2001a)
Jujuy: present, no further details (Claps et al., 2001a)
Salta: present, no further details (Claps et al., 2001a)
Santa Fe: present, no further details (Claps et al., 2001a)
Tucumán: present, no further details (Claps and Terán, 2001; Claps et al., 2001a)
Brazil
Guanabara: present, no further details (Silva et al., 1968)
Paraíba: present, no further details (Claps et al., 2001a)
Paraná: 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: abundant on Citrus plantations (Claps et al., 2001a)
Caribbean Islands: present, no further details (Tao, 1999)
Central America: present, no further details (Danzig and Pellizzari, 1998)
Chile: occasional (Claps et al., 2001a)
?Antofagasta: presence doubtful (Claps et al., 2001a)
Tarapacá: present, no further details (Claps et al., 2001a)
Colombia: present (Kondo, 2001)
Dominica: The Natural History Museum collection, London, UK
Mexico: present, no further details (Miller, 1996; Tao, 1999)
Trinidad: The Natural History Museum collection, London, UK
Oceania
Cook Is: present (Williams and Watson, 1988)
New Caledonia: present (Williams and Watson, 1988)
Niue: present, no further details (Williams and Watson, 1988)
Pitcairn: present, no further details (Williams and Watson, 1988)
Solomon Is: The Natural History Museum collection, London, UK
South Mariana Is: Guam, Saipan (Beardsley, 1966)
Tahiti: present, no further details (Beardsley, 1966; Danzig and Pellizzari, 1998)
Vanuatu: present (Williams and Watson, 1988)
Wallis Is: present, no further details (Cohic, 1959)
Western Samoa: present (Williams and Watson, 1988)