Photo 2. Plants showing pink, rolled, leaves typical of pineapple mealybug wilt disease. The ""wilt" symptoms are due to root decay, caused by virus infection.
Photo 3. The two stunted plants in the foreground are showing symptoms of pineapple mealybug wilt disease.
Photo 5. Adult pineapple mealybug, Dysmicoccus brevipes. Note the fringe of waxy filaments around the body.
Dysmicoccus brevipes. A closely related species, the grey pineapple mealybug, Dysmicoccus neobrevipes also occurs. Several viruses in the ampelovirus group are associated with pineapple mealybug wilt disease (see Fact Sheet no. 380), and are spread by these Dysmicoccus species.
Worldwide. In the tropic, subtropics and some temperate regions. Asia, Africa, North, South and Central America, the Caribbean, Europe (restricted), Oceania. Dysmicoccus brevipes is recorded from American Samoa, Australia, Cook Islands, Fiji, French Polynesia, Guam, Kiribati, Marshall Islands, New Caledonia, Niue, Northern Mariana Islands, Palau, Papua New Guinea, Samoa, Solomon Islands, Tokelau, Tonga, Tuvalu, US (Hawaii), Vanuatu, and Wallis & Futuna. Dysmicoccus neobrevipes is recorded from Fiji and Samoa. In Oceania, pineapple mealybug wilt disease has been reported from Australia, Cook Islands Fiji, and the USA (Hawaii).
Wide; the mealybug infests more than 100 genera in more than 50 plant families. Waterhouse lists the following as the most important crops: banana, betel nut, coffee, groundnut (peanut), oil palm, Pandanas, pineapple, rice, sisal, soybean, sugarcane, and grasses and other weeds.
Damage is done by Dysmicoccus brevipes in three ways: directly (i) as they feed on the sap of the roots and lower (underground) stem and cause poor growth; and indirect by (ii) reducing photosynthesis - sooty moulds grow on their waste called honeydew that falls from the mealybugs onto the leaves and fruit, causing them to turn black; and, most importantly, (iii) spreading Pineapple mealybug wilt-associated virus(es), which causes pineapple mealybug wilt disease. Leaves on plants with pineapple wilt disease turn red, then pink, curl inwards and lose their stiffness, the roots die, and the plants collapse and rot (Photos 1-4). Fruit from infected plants are small. It is possible that several viruses are involved, and that both infection from viruses and feeding by mealybugs are needed for symptoms to develop.
Dysmicoccus brevipes reproduces without fertilisation, giving birth to about 250 living young. The first stage nymphs are called 'crawlers'. There are three moults over a period of 3-4 weeks before adults occur. The adults are about 2.5 mm long and 1 mm wide, oval, covered in a thick white wax, pink-orange beneath, with short waxy projections at the edge of the lower surface (Photos 5&6). This mealybug feeds and lives on the lower stem and roots.
Spread occurs as the crawlers move about by themselves or are carried from plant to plant by ants. They are also spread over longer distances on the wind and on the bodies of other animals. All the life stages are spread in consignments of fruit and propagating material traded nationally and internationally.
Dysmicoccus neobrevipes is similar except it is grey, not pink, and is found on aboveground parts of the plant, stem and roots.
Dysmicoccus brevipes and Dysmicoccus neobrevipes transmit Pineapple mealybug-associated wilt virus and that makes this a very important pest. The disease is a serious threat to pineapple production worldwide. In the Pacific, the disease has been reported from Cook Islands and Fiji.
Look for mealybug infestations on the roots, and stems beneath ground. Look for oval mealybugs, covered in white wax, but pinkish beneath. Look for short projections of waxy outgrowths around the edges of the body.
There are a large number of predators and parasitoids of Dysmicoccus brevipes, including ladybird (coccinellid) beetles, particularly Cryptolaemus species, and wasps (encyrtids). In many countries, biological control is effective when ants (Pheidole, Iridomyrmex and Solenopsis) are controlled.
Importation of pineapple plants for planting from countries where pineapple mealybug wilt disease occurs should not be permitted unless they are kept under observation in closed post-entry quarantine and tested for pineapple viruses (ampeloviruses and badnaviruses, in the Closteroviridae and Caulimoviridae families, respectively). CULTURAL CONTROL
The control measures recommended below are for the control of the mealybug, and also for the control of Pineapple mealybug wilt-associated virus(es) that they are thought to spread.
AUTHOR Grahame Jackson
Information from Waterhouse DF (1998) Biological control of insect pests: Southeast Asian prospects. ACIAR Monograph no. 51, 548 pp. Canberra; and from CABI (2015) Dysmicoccus brevipes (pineapple mealybug). Crop Protection Compendium. (www.cabi.org/cpc). Photos 1&2 United States National Collection of Scale Insects Photographs, USDA Agriculture Research Service, Bugwood.org. Photos 3&4 United States National Collection of Scale Insects Photographs, USDA Agricultural Research Service, Bugwood.org. Photos 5&6 John Thomas, Department of Agriculture and Forestry, Queensland Government.
Produced with support from the Australian Centre for International Agricultural Research under project PC/2010/090: Strengthening integrated crop management research in the Pacific Islands in support of sustainable intensification of high-value crop production, implemented by the University of Queensland and the Secretariat of the Pacific Community.
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