Effects of Paracoccus marginatus (Mealy bug) and Myzus persicae (Mite) attack on forming of Exacum ritigalensis (Binara / Ginihiriya) Flower

Abstract

Seeds of Exacum ritigalensis were taken in Pannala, Sri Lanka and potted in green house at the Department of Agriculture Biology, Faculty of Agriculture, University of Ruhuna, Sri Lanka. Four pots replicates were conducted on E. ritigalensis plants that were infested with Paracoccusmarginatus and four pots replicates were conducted on E. ritigalensis plants that were infested with Myzus persicae.Two pots were used as controls. Potting medium was taken 1:1:1; sand, compost and topsoil and one E. ritigalensis plants were cared in each pot. At the flowering stage, two adults ofParacoccusmarginatus which were taken from infected papaya plant (Carica papaya) and two aphids which were taken from infected tobacco plant (Nicotiana tabacum L.) introduced to the every branch of E. ritigalensis plants separately. Data were collected from maturity stage of the flower (after blooming 3days). Data regarding E. ritigalensis flowers diameter reduction were subjected to analysis mean average value and compared with the control. There were no significant difference of flowers which plant attacked by aphids and it was shown the reduction of number of flowers per bunch. Mealybugs and aphids severely damage to E. ritigalensis flower production. Researchers and farmers should have to use control measures to prevent mealybug and ants entering to the plantation.