The present work was carried out to evaluate the quality of spray produced by Mi-2 helicopter and conventional motor sprayer using rates of application 40.0 and 2400 L/fed, respectively. A summer oil (Masrona super oil) was used for controlling red scale insect, Aonidiella aurantii (Order : Homoptera Fam : Diaspididae) and the white fly, Dialeu­rodes citri (Fam : Aleyrodidae) on sweet orange trees. Due to sufficient down wash created by the helicopter, good spray coverage coinciding to a great extent with the distribution of infestation on the treated trees resulted. The spectrum of oily droplets deposited on citrus trees was bigger in size with 11% and with about 50% less in number than the watery droplets that were recorded under airstrip conditions due to the viscosity factor. The average size and number of droplets collected un­der airstrip and orchard conditions were 340, pm-60 droplets/cm2 and 443, pm-33 droplets/cm2, respectively. The C.V. % of droplets distribu­tion number on spray collectors was 48%. The total spray lost on ground with aerial and ground application was 15% and 75%, respectively. A positive correlation was found be­tween aerial spray coverage and the control of red scale insect wher mortality percentage increased 1% more by increasing the droplet size with 4.0 pm. The daily performance of motor sprayer and Mi-2 helicopter was about 3.0 and 500 fed./day, successively. The price of aerial spray­ing of one feddan by aerial means was cheaper by about 56% than the price of motor sprayer. In additon to reducing dose amount with low vol­ume spray by helicopter to the fifth in comparison with motor sprayer. In general the helicopter was superior in controlling red scale insect on cit­rus than ground motor sprayer.