The effect of biorational insecticides on the citrus aphids and their predator, Coccinella septempunctata L.

Abstract

To determine selective effectiveness for specific pesticides on biological control species, we evaluated the contact toxicity of different treatments including 10 ml l^-1 dishwashing liquid, Dayabon 5, 6, 7, 8, 9 and 10 ml l^-1, Palizin 1.5, 2.5 and 2.5 ml l^-1, Palizin 1.5, 2 and 2.5­+­Citrol oil 5 ml l-1, Tondoxir 2 and 3­+­Bartar soap 1 ml l^-1, Malathion 2 ml l^-1 and control (water) on the adult aphids of the most important citrus gardens and their predator, Coccinella septempunctata L. in the laboratory conditions. The results revealed that the Palizin treatment 2.5­+­Citrol oil 5 ml l^-1, caused the highest rate of the mortality of the citrus green aphid, Aphis spiraecola Patch, 1914 in 36 hours. Concentrations of 7 to 10 ml l^-1, Dayabon and Palizin 2.5­+­Citrol oil 5 ml l^-1, as well as 3 ml^-1 Tondexir + Bartar soap 1 ml^-1 had the highest mortality of the citrus brown aphid, Aphis citricidus (Kirkaldy, 1907), 36 hours after treatment (100 %). In addition, the treatments of Palizin 2 ml^-1­+ Citrol oil of 5 ml^-1, as well as 2 ml l^-1 Tondexir­+­Bartar soap 1 ml l^-1 and concentrations of 5 ml l^-1 and 6 ml^-1 of Dayabon produced the same amount of the mortality of the citrus black aphid, Toxoptera aurantii (Boyer de Fonscolombe, 1841). Tondexir 3 ml l^-1­+­Bartar soap 1 ml l^-1 in 24 hours after treatment caused the highest rate of the mortality of the cotton aphids, Aphis gossypii Glover, 1877 (83.88 %). Malathion treatment caused a 100 % mortality of the predator ladybird 36 hours after treatment, while the lowest amount was observed in the Dayabon at 10 ml l^-1 with 33.34 % mortality.