*Division of Entomology, Horticultural Research and Development Institute, Department of Agriculture, Gannoruwa, Peradeniya, Sri Lanka
**Department of Agricultural Biology, University of Ruhuna, Mapalana, Kamburupitiya, Sri Lanka
The populaton of mango hoppers was estimated in two mango orchards at Gannoruwa (50–75 trees) and Kundasale (100–125 trees) located in the mid-country wet zone of Sri Lanka. The samples were taken at weekly intervals from nine and six randomly selected trees in orchards at Kundasale and Gannoruwa respectively. The population dynamics of 3 species of mango leaf hoppers Amritodus brevistylus Leth, Idioscopus niveosparus Leth and Idioscopus clypealis Leth (Homoptera:Cicadellidae) were studied. The population of I. niveosparus and A. brevistylus begins to increase in February with a peak in March-April in both locations. The peaks for I. clypealis was observed in March and September at Gannoruwa and April and October in Kundasale. These population peaks coincided with the occurrence of major or minor flowering seasons of mango. For A. brevistylus, there was another population peak in June. This species breeds on vegetative shoots and their population increase; coincides with the occurrence of vegetative flush.
The effectiveness of neem oil and chemical insecticides fenthion, buprotezin and Imidocloprid were tested against the mango trees just after flowering and again 10 days later. Among the insecticide tested Imidocloprid (1 ml/litre) was most the effective. The optimum time to control mango hoppers in mid-country wet zone with insecticides is when the population of mango hoppers begins to increase during February-March.
