Claude Wilson, Outlook WriterA 'SOAP POWDER-LIKE, doodad' is how one local plant specialist described this denizen of local horticulture. It is widely known as 'White Fly' but in scientific circles it is the Ensign Scale (orthezia insiginis) that is wreaking havoc in ornamental gardens across Jamaica.
These seemingly lifeless Ensign Scales were hardly known in Jamaica until 10 years ago when gardeners in the Vineyard Town area of St. Andrew first noticed a flaky white 'stuff'" spreading out from the under leaves of their treasured crotons. Today, the white denizen is spreading like wildfires across the country, showing up on plants once considered susceptible.
"Most of us have seen this thing-a-ma-gig kill our crotons and thereafter any plants in sight. It sucks the lifeblood out of anything it touches. Just as you thought that it did not like a particular plant, you soon find out that it loves that plant with the same passion as the croton," says Hilda Vaughn, an exasperated Corporate Area horticulturalist.
A Rural Agricultural Development Authority (RADA) information guide indicates that the pest, over the last decade, has spread across Kingston, moved through St. Thomas, Portmore, and Spanish Town, throughout the North Coast to as far as Westmoreland.
White Fly is taking the pleasure out of today's home gardening.
SAP
Phillip Chung, RADA's plant protectionist, refers Outlook to his own study, Ensign Scale: A Pest of Growing Concern in Residential Areas, in which he demonstrates that the pest sucks the sap from the host plant, weakening it, causing wilting, leaf curl, and death of leaves, branches and leaf plant.
"The pests infest a very large number of plants but chiefly crotons, ixora, bougainvillea, poor man's orchid, gungo peas and Joseph coat."
Hilda Vaughn adds hibiscus, musseanda, lantana, and dieffenbachia to the growing list of plants being bled to death by the Scales.
The male does not feed on the plants or cause any damage and is what gardeners observe flying around infested plants early in the morning giving rise to its common name, White fly. On the other hand, the crawling females are the sedentary 'cloud of white' that settle on the underside of leaves piercing, sucking and weakening the plant. Females lay thousands of eggs that hatch into young Scales, their constant attacks, without any control, eventually kill the plant.
Compounding the assault on the plants, the Scales excrete sugary honeydew as they feed, that is food for the ants that are often seen mingling among the Scales. Interestingly, the ants actively protect the Scales from predators. The honeydew also promotes the growth of the black-looking fungus called sooty mold that interferes with the plant photosynthesis.
SUSTAINABLE CONTROL
Local plant protectionists speak more of sustainable control and little of total eradication.
"Sustainable control requires a natural enemy which we have been trying to import for some time now but have not been able to find funds for that purpose," Phillip Chung told Outlook.
In the meantime, the plant protection specialist is recommending a combination of physical and chemical control methods to mount an effective campaign against the White Fly/Ensign Scale. He says gardeners should remove infested parts of plants and place in garbage bags being careful not to shake off any scales or to burn or place in the sun for two to three days as the heat will kill the insects.
Gardeners should spray the entire plant, including the undersides of leaves, every five to seven days using a recommended insecticide in combination with three to five tablespoons of dishwashing liquid in a gallon of water.
Among the recommended insecticides to be used in rotation are Karate, Diazinon, Malathion, Dimethoate, and the new and highly effective Actara.
"You cannot get rid of the scales completely, it will reoccur," Mr. Chung advises. "You can, however, get good control of it by following the methods laid down."
