Pink Hibiscus Mealybug |
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Background
The pink hibiscus mealybug (PHM), Maconellicoccus hirsutus (Green), is a serious economic threat to agriculture, forestry, and the nursery industry. This pest attacks many plants, trees, and shrubs. For example, it infests hibiscus, citrus, coffee, sugar cane, annonas, plums, guava, mango, okra, sorrel, teak, mora, pigeon pea, peanut, grape, maize, asparagus, chrysanthemum, beans, cotton, soybean, and cocoa, just to name a few of its hosts. Host plants extend to 76 families and over 200 genera.
This pest occurs in most tropical areas of the world including Asia, the Middle East, Africa, Australia, and Oceania. PHM arrived in Egypt from India in 1912 and in Hawaii in 1984. It has been detected in Mexico (1999), USA (California 1999, Florida 2002), Grand Cayman Island (2006), Anguilla (1996), Antigua & Barbuda, Aruba, Bahamas (2000), Barbados (2000), Belize (1999), British Virgin Islands (1997), Dominica (2001), Dominican Republic (2002), Grenada (1994), Guadeloupe (1998), Guatemala, Haiti (2002), Jamaica, Martinique (1999), Montserrat (1998), Netherlands Antilles (1996), Puerto Rico (1997), St Kitts & Nevis (1995), Saint Lucia (1996), Saint Vincent & Grenadines (1997), Trinidad & Tobago (1995), US Virgin Islands (1997), French Guiana (1997), Guyana (1997), Suriname (2001), and Venezuela (1999).
As it feeds, using a piercing and sucking process, the pink hibiscus mealybug injects into the plant a toxic saliva that results in malformed leaf and shoot growth, stunting, and, occasionally, death. Leaves show a characteristic curling, similar to damage caused by viruses. Heavily infested plants have shortened internodes leading to a “bunchy top” appearance. A heavy, black, sooty mold may develop on an infested plant's leaves and stems as a result of the mealybug's heavy honey-dew secretions. When fruits are infested, they can be entirely covered with the white, waxy coating of the mealybug. Infestation can lead to fruit drop, or fruit may remain on the host in a dried and shriveled condition. If flower blossoms are attacked, the fruit sets poorly. In plants such as peanuts, potatoes, and some grasses, the pest has been reported to attack the root systems.
Populations of the pink hibiscus mealybug can be suppressed by employing biological control agents. A number of natural enemies are known, including the ladybeetle predator Cryptolaemus montrouzieri and the parasitic wasps Anagyrus kamali and Gyranusoidea indica. At present, 21 parasites and 41 predators are known to attack this pest worldwide.
An on-line training is available through the link below.
Pink Hibiscus Mealybug - on-line training