Efficacy of some oils and botanicals in the management of Red flour beetle Tribolium castaneum (Herbst) on stored rice

Abstract

The present investigation entitled “Efficacy of selected oils and botanicals in the management of the red flour beetle, Tribolium castaneum (Herbst), on stored rice” was conducted during 2020-2021 in the Entomology Laboratory, SHUATS, Prayagraj, Uttar Pradesh, India. The study was designed using Completely Randomized Design (CRD) with three replications, involves eight treatments which includes untreated control viz., T₁ (Neem leaf powder), T₂ (Pepper powder), T₃ (Turmeric powder), T₄ (Neem oil), T₅ (Groundnut oil), T₆ (Castor oil) T₇ (Soybean oil) and T₀ (Untreated control) were evaluated against T. castaneum under ambient laboratory conditions. Studies on the biology of T. castaneum on rice were carried out at temperatures ranging from 30 to 35 °C and relative humidity of 65-70 per cent. Under these conditions, the complete life cycle from egg to adult was completed in 22 days. The lower and upper developmental temperature thresholds were observed at 30 °C and 35 °C, respectively. These findings indicate that under favorable environmental conditions, T. castaneum exhibits a short life cycle, which contributes to its rapid population build-up. Grain weight loss caused by adult T. castaneum was recorded at 30, 60, and 90 days after treatment application. The results revealed that treatment T4 (neem oil) resulted in the lowest percent weight loss (0.8%), which was significantly superior to all other treatments and statistically on par with T6 (castor oil), which recorded 1.46 percent weight loss. This was followed by T1 (neem leaf powder) with 1.8 percent loss, T7 (soybean oil) with 2.6 percent, T3 (turmeric powder) with 2.73 percent, and T5 (groundnut oil) with 2.8 percent grain weight loss.