Effect of alternative insecticides sprayed with two flow rates against some scale insects on mango trees by using conventional motor sprayer at Qalubyia governorate, Egypt.
Hassan N. A., Radwan S. G., Ammar A. E. E., El-Sahn O. M. N.
Author Affiliation: Department of Scale Insects and Mealybugs, Plant Protection Res. Inst., ARC, Giza, Egypt.
Proceedings of the International Conference of Environmental Sciences (ICES), Ain Shamas University, Cairo, Egypt, 21-22 May 2013 : 62-79
Abstract : Two field experiments were conducted on mango trees at El-Kanater El-Khairiya, Qalubyia Governorate. The first experiment is to survey the most assail insect pests started from January 2010 to December 2010 (one year). The results exhibit eight insect species belonging to three families; Diaspididae, Coccidae and Monophlebidae The white mango scale insect, Aulacaspis tubercularis and the soft scale insect, Kilifia acuminata appeared with high density (40.60% & 38.78%) of scale insect population, causing sever reduction in quantity and quality of mango crop followed by Insulaspis pallidula (6.05%), Parlatoria pergandii (4.60%). The second experiment was done at the 23rd December (2010) based on three principles: The first principle: to compare between two flow rates spraying; low flow rate (3.600 L/min) and high flow rate (7.400 L/min) by using mineral oils (alboleum with rate of 2.5% as a winter oil), (diver 1.5% as a summer oil) and admiral 0.005% (Which is analog of juvenile hormone) for controlling four previous pests on mango trees. The obtained data show that the modified spraying (3.600 L/min) produced larger numbers of droplets than traditional method (7.400 L/min) with all tested insecticides but traditional spraying produced higher volume mean diameter (VMD) of droplets. Admiral has superior number of droplets (891 droplets/cm2) and has the most percent of stability (82.6%) when it compared with the other two tested insecticides. The second principle: study the effecting of the spraying flow rates on tested insecticides. The results showed that, alboleum oil has same reduction efficiency when sprayed by two flow rates (86.16% and 87.46% reduction) while, diver oil appeared best action when sprayed by high flow rate (89.42%) reduction. In contrary, the best action of admiral appeared with low flow rate spraying (90.90%) reduction. The third principle: Study of the susceptibility of the four insect species to tested insecticides with both flow rates, the results refer to susceptibility of different stages of insects were varied according to the spraying volume e.g. A. tubercularis was receding and reduced when insecticides sprayed by modified spraying volume (3.600 L/min.) while K. acuminata, P. pergandii and I. pallidula have changeable susceptibility whereat the highest reduction in all stages of insects occurred when they treated by mineral oils with classical flow rate (7.400 L/min.) but admiral recorded its maximum reduction with the low flow rate volume.