July 2011. A problem in Antigua in a plot of Antigua black pineapple in the southeastern end of the island. The crop is destined for export to Norway, and recommendations for approved pesticides and application rates is being sought. There is also numerous black ants, these have not being identified, but are moving among the mealybugs. The plants also show signs of wilting. They were planted 12 months ago and are just staring to flower, and some plots have young fruit. The crop is rainfed; soil type is a loam, with a slightly acidic pH.
This is not the first time that Antigua has had problems with pineapples, mealybugs, ants and mealybug wilt. See Summaries of past messages:
A post from Vanuatu is relevant here:
It leads to an IRA done in 2002 by Biosecurity Australia. Pests of concerns and treatments are provided in that document for entry of pineapples into Australia.
A Guide is available for the Caribbean: Robin G, Pilgrim, R, St. Luce M (2007) Sustainable Production of Export Grade Pineapple in Dominica. CARDI, PSC# DO/003/04, ISBN: 978-617-013-4
A member involved with Jatropha cultivation in Cambodia also agreed that black ants are a problems, and carry mealybugs around. Removal of the ants is the first priority. Mice gum around the tree was recommended, preventing the ants from climbing the stems or trunks. When that is done, natural control by fungi or parasitoids usually follows. Ants were also said to be a problems in bamboo cultivation, te black motre than the red, as it was more difficult to find their nests.
Another member (sent directly to the moderators) thought that the infestation might be the Grey pineapple mealybug, Dysmicoccus brevipes, which is known to be associated with Pineapple wilt disease. The ants are probably contributing to the problem by dispersing and defending the mealybugs. Control of the ants may allow natural enemies to reduce the mealybug population. However, heavy pesticide use may worsen the situation by destroying the natural enemies of the mealybugs.