(Newstead, 1906)
Diagnosis
In life, scale cover of adult female approximately circular, white and transparent, with dark, oval exuviae (Cunningham, 1989) AUTUL2.jpg . Scale cover of male smaller, rectangular, white with three raised longitudinal ridges; exuviae terminal AUTUMALE.jpg . Exposed body of gravid adult female 1.5-2.0 mm long, brownish. Adult male winged.
Slide-mounted adult female with swollen, angular or quadrate prosoma; body widest at prominent lateral tubercles, almost level with anterior spiracles; posterior spiracles usually associated with spiracular pores; gland spines and macroducts absent from thorax and head AUTUS.jpg . Pygidium with median lobes zygotic, without any setae or gland spines between their bases; abdominal segment VI bearing 1 or 2 submedian macroducts on each side; and pore prominences between pygidial lobes well developed AUTUP.jpg . Often on mango; does not feed on grasses.
Host range
Aulacaspis tubercularis has been recorded mainly from hosts belonging to four plant families: Palmae, Lauraceae, Rutaceae and Anacardiaceae (Borchsenius, 1966), particularly on mangoes (Mangifera spp.), coconuts and cinnamon. Hosts include species of: Cinnamomum verum, Citrus, Cocos nucifera, Cucurbita, Dietes, Dimocarpus, Laurus nobilis, Litsea, Mangifera indica, Phoebe, Persea americana, Persea, Pittosporum and Zingiber officinale.
Affected plant stages: seedling, vegetative growing, flowering, fruiting and post-harvest stages
Affected plant parts: leaves AUTUDAM2.jpg , young stems and fruits AUTUDAM3.jpg
Biology and ecology
Cunningham, 1989, reported around 50 eggs per female A. tuberculatus in an Australian survey. Adult females may produce 0-18 eggs per day for 8-12 days (up to 80-200 eggs in total) on mangoes in Ghana, where breeding continues through the wet and dry seasons; males develop from egg to maturity in 23-28 days, a slightly shorter development time than for females (van Halteren, 1970). The male:female ratio was observed as 11:1, which is uncommon among scale insects (van Halteren, 1970).
First instar crawlers are responsible for dispersal; they may crawl several centimetres before settling or may be dispersed passively by wind. Male crawlers settle in groups of 10-80, often near females; these groups are conspicuous due to the white scale covers they produce (van Halteren, 1970).
Symptoms
Infested areas of mango leaves turn pale-green or yellow AUTUDAM1.jpg and ultimately die AUTUDAM2.jpg . Infested mango fruits have conspicuous pink blemishes around the feeding sites of the scales AUTUDAM3.jpg .
Economic impact
Aulacaspis tubercularis injures the leaves and fruits, affecting the commercial value of the fruits and their export potential. Infested mango fruits have conspicuous pink blemishes around the feeding sites of the scales. In nurseries, severe early-stage infestation retards growth. Young trees are particularly vulnerable to excessive leaf loss and death of twigs due to scale, during hot dry weather. Aulacaspis tubercularis presents significant pest problems on mangoes in South Africa (Colyn and Schaffer, 1993; Joubert et al., 2000). It is also a problem on mangoes in Australia, East and West Africa, North and South America and the Caribbean Islands (Peña et al., 1997).
Detection and inspection methods
Look for white scales, 1.5-3 mm in diameter, on leaves and twigs, using a magnifying lens in good light. A pin can be used to remove the scale cover of female scale. Dead scales have no body fluids to escape when pricked. Look for a mass of pink eggs and crawlers under the scales (Cunningham, 1989).
Phytosanitary risk
Aulacaspis tubercularis is mentioned on quarantine lists (Burger and Ulenberg, 1990). Williams and Watson (1988) considered A. tubercularis to be a potential pest of mango in the South Pacific region, and emphasized the need for strict quarantine procedures. Strict controls on movement of infected planting material and fruits are required if A. tubercularis is to be prevented from colonising the rest of the South Pacific area (Williams and Watson, 1988) and other tropical countries.
Natural enemies
Viljoen, 1986, discussed the natural enemies of mango scale present in South Africa. Encarsia sp. [Aspidiotiphagus], was recorded parasitizing A. tubercularis on mangoes in South Africa, where parasitism of female scales averaged 17.7% (Schoeman, 1987). The coccinellid predators Rhyzobius lophanthae and Chilocorus nigrita are common in South Africa, where they have been introduced, but are generally not sufficient in themselves to keep scale insect populations below economically damaging levels (Viljoen, 1986).
Van Halteren, 1970, reported that parasitism by hymenopterous parasitoids was common on mangoes in Ghana, and reported attacks by an unnamed dipterous parasite.
Parasitoids:
- Aphytis sp., attacking: larvae, adults, in India
- Aphytis chionaspis, in Thailand; introduced to South Africa
- Aphytis mytilaspidis, attacking: larvae, adults, in Taiwan
- Encarsia citrina, attacking: larvae, adults, in South Africa
Predators:
- Aleurodothrips fasciapennis, attacking: eggs, larvae, adults, in South Africa
- Chilocorus nigrita, attacking: eggs, larvae, adults, introduced to South Africa
- Rhyzobius lophanthae, attacking: eggs, larvae, nymphs, adults, introduced to South Africa
- Rhyzobius pulchellus, attacking: nymphs, adults, in Vanuatu, New Caledonia
- Sukunahikona prapawan, in Vanuatu
Distribution
See Aulacaspis tubercularis distribution.
Microscopic examination of slide-mounted adult females is required for authoritative identification to species.
Comments
Aulacaspis tubercularis is a tropical species that may have originated in Asia; it has been pread by the transport of infested plant material, and is now widespread in many mango-growing countries. It has not been recorded from most of the tropical Pacific islands.
Europe
Italy: present in the south (Porcelli, 1990; Longo et al., 1995)
Asia
China: present, no further details (Danzig and Pellizzari, 1998)
Guangdong: present, no further details (Tao, 1999)
Hainan: present, no further details (Tao, 1999)
Hong Kong: The Natural History Museum collection, London, UK
Sichuan: present, no further details (Tao, 1999)
India: present, no further details (Takagi, 1970)
Andaman Is: present, no further details (IIE, 1993)
Bihar: The Natural History Museum collection, London, UK
Gujarat: The Natural History Museum collection, London, UK
Karnataka: present, no further details (IIE, 1993)
Kerala: present, no further details (IIE, 1993)
Sikkim: The Natural History Museum collection, London, UK
Uttar Pradesh: The Natural History Museum collection, London, UK
West Bengal: The Natural History Museum collection, London, UK
Indonesia
Java: present, no further details (Williams and Williams, 1988; IIE, 1993)
Sarawak: The Natural History Museum collection, London, UK
Iraq: present, no further details (Takagi, 1970; IIE, 1993)
Israel: present, no further details (Danzig and Pellizzari, 1998)
Japan: present, no further details (Danzig and Pellizzari, 1998)
Malaysia
West Malaysia: present, no further details (IIE, 1993)
Sarawak: present, no further details (IIE, 1993)
Pakistan: present, no further details (IIE, 1993)
Sri Lanka: present, no further details (IIE, 1993)
Taiwan: present, no further details (IIE, 1993; Wong et al., 1999)
Thailand: present, no further details (Williams and Williams, 1988)
Vietnam: present, no further details (Waterhouse, 1993)
Africa
Benin: present, no further details (IIE, 1993)
Côte d'Ivoire: present, no further details (IIE, 1993)
Egypt: present, no further details (IIE, 1993; Danzig and Pellizzari, 1998)
Gambia: present, no further details (IIE, 1993)
Ghana: present, no further details (IIE, 1993)
Kenya: present, no further details (IIE, 1993)
Liberia: present, no further details (IIE, 1993)
Madagascar: present, no further details (Williams and Williams, 1988)
Malawi: present, no further details (IIE, 1993)
Mauritius: present, no further details (Williams and Williams, 1988; IIE, 1993)
Mozambique: present, no further details (IIE, 1993)
Réunion: present, no further details (Williams and Williams, 1988)
Rodrigues: present, no further details (Williams and Williams, 1988)
Sierra Leone: present, no further details (IIE, 1993)
South Africa: present, no further details (IIE, 1993; Joubert et al., 2000)
Tanzania: present, no further details (IIE, 1993)
Zanzibar: present, no further details (IIE, 1993)
Togo: present, no further details (IIE, 1993)
Uganda: present, no further details (IIE, 1993)
Zambia: present, no further details (IIE, 1993)
Zimbabwe: present, no further details (IIE, 1993)
Western Hemisphere
Antigua: present, no further details (IIE, 1993)
Aruba: present, no further details (Schotman, 1989)
Barbados: present, no further details (IIE, 1993)
Brazil
Guanabara: present, no further details (Silva et al., 1968)
Gioás: present, no further details (Claps et al., 2001a)
Minas Gerais: 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 (IIE, 1993; Claps et al., 2001a)
Sao Paulo: present, no further details (Claps et al., 2001a)
British Virgin Islands: present, no further details (Schotman, 1989)
Colombia: present, no further details (Mosquera, 1973; IIE, 1993; Kondo, 2001)
Dominica: The Natural History Museum collection, London, UK
Dominican Republic: present, no further details (IIE, 1993)
Grenada: present, no further details (Schotman, 1989)
Guyana: present, no further details (IIE, 1993)
Jamaica: present, no further details (Schotman, 1989)
Martinique: present, no further details (Schotman, 1989)
Puerto Rico: present, no further details (IIE, 1993)
Saint Lucia: present, no further details (Schotman, 1989)
Suriname: present, no further details (IIE, 1993)
Trinidad: present, no further details (IIE, 1993)
Venezuela: present, no further details (IIE, 1993)
Oceania
Australia: present, no further details (CSIRO, 2001)
Vanuatu: present, no further details (Chazeau, 1979)