Toxicity of essential oils form Lamiaceae against stored product pests

Abstract

The use of essential oils from Lamiaceae that have toxicities by contact, fumigant and repellency, are another option for protection in various stored insect pests, including wheat weevil, red flour beetle, cowpea weevil, lesser grain borer. The study of the toxicity of essential oils from Lamiaceae such as lavender, rosemary, thyme, basil, spearmint and mint. It was found that the lavender essential oil had contact toxicity to wheat weevil at 48 hours, with 449.05 µg/adult. It had fumigant toxicity in the absence of wheat contained with 11.88 mg/L and in the case of containing 100 g of wheat with 47.52 mg/L. They gave 100% of mortality. And then, it had repellent toxicity more than 80% on wheat weevil, with 0.441 mg/cm2 or more. For 60 µL/mL of rosemary essential oil found to cause mortalities with 100% of red flour beetle and 50% of cowpea weevil. As for the fumigant efficiency of thyme essential oil with 28.12 µL/L air was the killing agent which caused 90% of cowpea weevil mortality but the mortality of wheat weevil was 75% after 4.5 hours of exposure. Also found that 30 and 40 µL/L air of basil essential oil gave 100% of lesser grain borer mortality. The spearmint essential oil with 20 µL/L air caused only 70% of wheat weevil mortality. For mint essential oils with 50 µL/L air had repellency effective on red flour beetle. It can be seen that some of Lamiaceae essential oils have the potential to prevent stored insect pests. It can be used to develop insecticides and to replace the use of harmful synthetic chemicals.