SYNERGISM OF MINERAL-OIL IN THE INSECTICI DE TOXICITY FOR SCROBIPALPULOIDES ABSOLUTA (LEPIDOPTERA, GELECHIIDAE)

Using the immersion method for tomato leaves in insecticide solution, a series of bioessays was carried out in order to evaluate the possibl e synergistic effects of mineral oils in the insecticides abamectin, c artap, phentoate and permethrin to 3(rd) and 4(th) instar larvae of to mato leafminer. Different concentrations of the insecticides in water with and without 0.5% of mineral oil were prepared. Tomato leaves were immerged in insecticide solutions for 5s, dried in air, put in Petri dishes and infected with 40 larvae of Scrobipalpuloides absoluta (Meyr ick, 1917), kept at 25 degrees C and 70% RU. Mortality was evaluated 2 4 hours later and through the ratios between insecticide CL(50) and in secticide + mineral oil CL(50), potency enhancement of insecticides we re verified for all compounds ranging from 2.40 to 6.46 times. Through the ratio between CLs(99) the greater synergistic effects were observ ed in the mixtures abamectin plus mineral oil (15.96 times) and permet hrin plus mineral oil (7.11 times) and lower synergistic effects were observed in the mixtures cartap plus mineral oil (2.14 times) and phen toate plus mineral oil (1.79 times).