Visual and gustatory responses of spodoptera frugiperda (Lepidoptera: Noctuidae) larvae to artificial food dyes

Visual and gustatory responses of Spodoptera frugiperda Hübner (Lepidoptera: Noctuidae) larvae to artificial food dyes were studied. The objective was to determine the ability of these substances to attract and elicit feeding of insect larvae to assess their feasibility for improving the efficacy of ingested insecticides. The artificial food dyes lemon green, lemon yellow, orange red, chlorophyll and carmine red were used. Different blends were prepared with each dye to evaluate larval visual responses to color, larval preferences to color compared with a control, and larval gustatory responses. Only lemon green and lemon yellow dyes visually evoked the attraction of significant percentages of the larvae, but the other colorants did not elicit responses different from the control. Gustatory response tests indicated that larvae preferred to feed on gelatinized blends containing chlorophyll. The gelatinized blend containing lemon green dye was a strong gustatory repellent, and none of the other dyes evoked negative gustatory responses. Adding the artificial food dye lemon green to an insecticidal formulation could enhance insect attraction, while adding chlorophyll could enhance ingestion of the formulation. The study of sensory aspects of insect behavior can be useful for maximizing the efficiency of insecticidal formulations.