THE MINISTRY of Agriculture is considering using natural predators to control the ensign scale pests, also known as orthezia insects, that have been causing damage to croton, ixora bougainvillaea and other flowering plants in some residential areas of Kingston and St. Andrew for the last four years.
Phillip Chung, plant protection specialist in the Rural Agricultural Development Authority (RADA), says the ministry planned to acquire some lady beetles that would kill the ensign scale pests.
He said the beetles, to be brought in from California, USA, had been used successfully in the Eastern Caribbean to control the spread of the pink mealy bug.
Threatened plants
Ensign scale pests are tiny white insects and the males are usually seen flying around in swarms near to host flowering plants during the morning hours. Mr. Chung said reports indicated that plants, including gungo peas, baby's breath, West Indian cherry, poor man's orchid, allamanda, wild cocoa, bahamia and zauza grasses and mints have been affected by the pests. Also, they attack fruit trees such as mango and soursop. So far, he reported, the pests have killed croton plants only.
He said plants affected by the insects have black leaves caused by a mould that grows on a sugary substance produced by the pests. The insects weaken plants by absorbing foods from the tissues that transport nutrients.
The ensign scale is spread mainly by ants, birds and humans. Mr. Chung has appealed to persons not to dispose of affected plants in their garbage as this would help to spread the pests. Instead, he suggested, cuttings from damaged plants should be burnt or placed in a bag that was tied firmly and placed in the sun before disposal.
Residential areas
Mr. Chung said that so far there have been no reports that the pests have damaged agricultural crops. They have been seen only in residential areas, he said.
Noting that it was difficult to destroy the pests by using insecticides, he said an integrated-management approach had to be applied. This, he noted, involved inspecting plants to ensure that they were free of the pests.
To get rid of ants, which are carriers of the pests, Mr. Chung recommended that substances such as petroleum jelly or insect glue be applied to the base of the stem of affected plants. The plant should also be isolated, he said.
For large infestations, the plant protection specialist is advising householders to reduce the size of the infestation before spraying. He said spraying with orchard oil or liquid soap without ammonia was usually effective.
For more information on the ensign scale pests persons may call the RADA training unit at 927-1781 or contact the nearest RADA parish office.
