Euphorbia guyoniana aqueous extract efficiency against tomato leaf miner in southern East Algeria.
This work aimed to evaluate the efficiency of several spontaneous plants in Algeria by studying their bioinsecticidal effects to contribute them to organic agriculture. The aqueous extract of Euphorbia guyoniana was tested on larvae and adults of Tuta absoluta. Experimentation showed that this plant has a larvicidal effect which varies with doses and times. For the 100% dose, larval mortality rates were about 20±00, 36.67±5.77, 43.33±5.77, 52.5±5, and 76.67±5.77% after 24, 48, 72, 96, and 120 h, respectively. Values of 26.67±5.77, 30±00, 53.33±5.77, 72.50±5, and 86.67±5.77% were noted after the same durations, respectively, with 50% dose. As for dose of 25%, a mortality rate of 25±7.07% was obtained after 24 h only with contacting the larvae with the treated leaves. This value reached 85±5.77% at the end of the test (after 120 h). From these results, it appears that the toxicity of E. guyoniana against the larvae of T. absoluta increases with time of their contact with the extract but also with the highest dose (100%) to the least important (25%). This study also revealed that this aqueous extract disposed a repulsive effect on females of T. absoluta because the number of eggs laid on the treated leaves (06±1.41 eggs/leaflet) is less important than that obtained on the control (37.25±13.15 eggs/leaflet).