Toxicity and repellency of garlic (Allium sativum L.) extract grown in Iran against Tribolium castaneum (Herbst) larvae and adults

Abstract

Plant materials, such as essential oils and extracts, are useful tools for insect pest control. In this study, we report the repellent activity and fumigant toxicity of garlic extract Allium sativum L. (Amaryllidaceae) against larvae and adults of the red flour beetle, Tribolium castaneum (Herbst) (Col., Tenebrionidae). Experiments were carried out at 27 ± 1 °C and 60 ± 5% RH in darkness. Results showed that mortality increases with increasing garlic extracts concentration and time. LC₅₀ values for larvae at 24 and 48 h were 267.37 and 145.8 μl/l air, and for adults, they were 127.90 and 90.8 μl/l air, respectively. The concentration of 225.8 μl/l air of the garlic extract yielded was 83.3% mortality of larvae after 48 h. The garlic extract had a strong repellent activity towards T. castaneum when tested in a filter paper arena test. After 4 h exposure to a low concentration (2.13 μl/cm²) of garlic extracts, more than 95% repellence was achieved. Our results indicate lethal and repellent effects of garlic extracts on T. castaneum.

Keywords:

• fumigant toxicity
• red flour beetle
• repellence