Abstract
The aim of the present work was to largely identify the scale insects and fungi living on mango leaves in order to find out from their biology whether there is a possible relationship between the two groups of organisms so that specific recommendations for their control can be made. A white hard scale insect Aulacaspis tubercularis Newstead (Diaspididae) and a green soft scale insect Kilifia acuminata Signoret (Coccidae) as well as four saprotrophic fungi belonging to the genera Alternaria Nees: Fr., Cladosporium Link., Helminthosporium Link ex Fr. and Stemphylium Wallr., were detected based on their morphological features in accordance with the identification keys and descriptions of scale insects and fungi. The infestation of mango leaves with the saprotrophic fungi was interpreted as a secondary infection due to the primary infection with the scale insects as honeydew producers on which the fungal spores develop and reproduce. Therefore, it is recommended to control the scale insects at an infection rate of 10% or more by means of which the application of fungicides could be dispensed. Furthermore, it cannot be ruled out that the climatic changes (e. g. fluctuating temperatures, increased relative humidities and greenhouse gases) as well as the increasing use of pesticides with their associated changes in the build-up of resistance, entomological and fungal biodiversities and in the balance sheets to the natural enemies are of greater importance as to provide a possible explanation for the seasonal fluctuations in the qualitative and quantitative mango crop failures.