Fig 1.
Scheme of the electrodes (El, E2, E3 and E4) in the cotton plant inserted into the stem; and R (reference electrode) inserted into the soil.
Fig 2.
Boxplot of time (h) of exposure of Bt and non-Bt cotton plants to different densities of A. gossypii emitting potentials of variation (VPs) (mV).
Bt and non-Bt cotton plants were infested at densities of 30 and 60 aphids/plant and in the absence of aphids (Control). Circle within the boxplot corresponds to mean of time for each treatment.
Fig 3.
Boxplot of amplitude (mV) of variation potentials in Bt and non-Bt cotton plants exposed to different densities of A. gossypii Bt and non-Bt cotton plants exposed to densities of 30 and 60 aphids/plant and in the absence of aphids (Control).
Circle within the boxplot corresponds to mean of time for each treatment. Asterisk out of the boxplot corresponds to outlier for each treatment.
Table 1.
Number of variation potentials emitted (mean ± SE) by Bt and non-Bt cotton plants when subjected to different exposure times and densities of A. gossypii/plant.
Fig 4.
Variation potentials emitted (no.) (MEAN ± SE) by Bt and non-Bt cotton plants at different time intervals (h) after infestation of 30 and 60 aphids / plant and control (absence of aphid).
Mean data (points) and error bars (SE) predicted by the generalized linear quasi-Poisson model, except for the plotted values for the control used in both cotton varieties (Bt or not Bt).
Table 2.
Number of variation potentials emitted (mean ± SE) by Bt and non-Bt cotton plants exposed to different aphid densities / cotton plant and photophase and scotophase on the 3rd assessment day.
Fig 5.
Multinomial distribution with occurrence rate of A. gossypii in the regions of non-Bt and Bt cotton plants at infestation times of 0 h, 24, 48 and 72 h with densities of 30 and 60 aphid/cotton plants.
The red circle diameter represents the intensity of aphid infestation on cotton plants.
Table 3.
Confidence intervals associated with the A. gossypii aggregation index (95% CI) in Bt and non-Bt cotton plants submitted to densities of 30 and 60 aphids/cotton plants quantified at 0. 24. 48 and 72 h after the infestation of cotton plants with aphids.