Effects of Butylated Hydroxytoluene (BHT) on Tribolium confusum (Coleoptera: Tenebrionidae)

Abstract

The objective of this study was to evaluate different doses of butylated hydroxytoleuene (BHT) against the confused flour beetle, Tribolium confusum Jacquelin du Val (Coleptera: Tenebrionidae). The effects on feeding behavior, growth, food consumption and total protein content of insects treated with different doses (1.48, 3.18, 6.36 and 9.54 mg g-1) of BHT were evaluated. Antifeedant activity was observed only at 1.48 mg g-1in the choice assay, with a feeding deterrence index (FDI) of 0.41; this concentration also deterred feeding by 41.6%. All treatments showed feeding suppression index (FSI) and feeding inhibition index (FII) as <0, suggesting that the insects were dissuaded from eating and moved away even at the lowest doses. Repellency was observed at 1.48 mg g-1. All insects were alive at the lowest dose, whereas mortality ranged from 40 to 86% between 3.10 and 9.50 mg g-1. Food intake was reduced at the lowest dose. Adults exposed to a diet containing BHT showed significantly lower efficiency of conversion (ECI) than the untreated insects, indicating that more food was metabolized for energy and less was converted to body mass. The treated insects lost more than half of their initial weights. The protein content of insects exposed to 1.48 mg g-1of BHT was similar to that of untreated insects. This study contributes to understanding the feeding behavior of T. confusum and facilitates the management of this insect in stored products.