Antifeedant, horizontal transfer and repellent activities of free and microencapsulated food grade antioxidants against postharvest pest insects (Oryzaephilus surinamensis (LINNAEUS, 1758) and Tribolium castaneum (HERBST, 1797)) (Coleoptera: Silvanidae, T

GARCÍA, D.; NESCI, A.; GIRARDI, N.; PASSONE, M.A.; ETCHEVERRY, M.

Polish Journal of Entomology

Sciendo

Año: 2019 vol. 88 p. 101 - 117

0032-3780

The aims of this work were to evaluate antifeedant, horizontal transfer and repellentactivities of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), free andmicroencapsulated, at different doses against Oryzaephilus surinamensis and Tribolium castaneumon peanut kernels. In general, negative values for the percentage feeding deterrence index (FDI)were found for Oryzaephilus surinamensis in the presence of these chemical treatments, suggestinga phagostimulant activity. In addition, untreated individuals died within 20 days of coming intocontact with insects previously exposed to both antioxidants (BHA and BHT) and formulations (FBHA and F-BHT), regardless of the dose, while the insects in the controls died after this time.Since this work revealed evidence for the transfer of both free and microencapsulated antioxidantsfrom treated to untreated individuals, we can confirm that horizontal transfer of these compoundstakes place between treated and untreated insects. The evaluated compounds showed no repellentactivity against O. surinamensis, which continued unaffected with its life cycle on both treated anduntreated peanuts. On the other hand, Tribolium castaneum exhibited high FDI values, especiallyfor the formulations, with mean values of 0.68 and 0.91 for F-BHA and F-BHT, respectively. Nohorizontal transfer was observed for this insect, but repellency was higher than 80% for free andencapsulated BHT. We can conclude that the mechanism of insecticidal action of antioxidants andtheir formulations was dependent on the type of insect evaluated. The insecticidal effect on Oryzaephilus surinamensis could have been due to the direct intake of the chemical compoundsadded, whereas the negative effect on Tribolium castaneum could have been caused by starvation