Effect of Esfenvalerate and Disulfoton on the Behavior of the Blackmargined Aphid, Black Pecan Aphid, and Yellow Pecan Aphid (Homoptera: Aphididae)

Abstract

Five concentrations (0.0, 0.06, 0.03, 0.003, and 0.0003 g [AI]/liter) of esfenvalerate (pyrethroid) and five concentrations (0.0, 0.50, 0.25, 0,025, and 0.0025 g [Al]/liter) of disulfoton (organophosphate) changed the behavior of the blackmargined aphid, Monellia caryella (Fitch), the black pecan aphid, Melanocallis caryaefoliae (Davis), and the yellow pecan aphid, Monelliopsis pecanis Bissell. Esfenvalerate increased aphid activity (walking and changing position) and decreased the time spent by aphids on insecticide-treated leaves. All concentrations increased the number of aphids leaving the leaves. Black pecan aphids and yellow pecan aphids left the leaves either by walking or dropping off, but blackmargined aphids left the leaves mainly by flying off. Disulfoton had less effect on aphid behavior than esfenvalerate. Only some concentrations of disulfoton increased aphid activity with more time spent walking, but the time of walking was much shorter than the time spent settling. The blackmargined aphid and the yellow pecan aphid were less susceptible to each insecticide than the black pecan aphid.