Laboratorio de Zoología de Invertebrados II, Dpto de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina.
Pest Manag Sci. 2011 Aug;67(8):948-55. doi: 10.1002/ps.2138. Epub 2011 Mar 10.
Plant essential oils have been recognised as an important natural source of insecticide. This study analysed the chemical constituents and bioactivity of essential oils that were isolated via hydrodistillation from Origanum vulgare L. (oregano) and Thymus vulgaris L. (thyme) against eggs, second instar and adults of Nezara viridula (L.).
The major component of oregano was p-cymene, and, for thyme, thymol. The ovicidal activity was tested by topical application; the essential oil from thyme was more effective. The fumigant activity was evaluated in an enclosed chamber; the LC50 values for oregano were 26.8 and 285.6 µg mL(-1) for nymphs and adults respectively; for thyme they were 8.9 µg mL(-1) for nymphs and 219.2 µg mL(-1) for adults. To evaluate contact activity, a glass vial bioassay was used; the LC50 values for oregano were 1.7 and 169.2 µg cm(-2) for nymphs and adults respectively; for thyme they were 3.5 and 48.8 µg cm(-2) respectively. The LT50 analyses for contact and fumigant bioassays indicated that thyme was more toxic for nymphs and adults than oregano. Both oils produced repellency on nymphs and adults.
These results showed that the essential oils from O. vulgare and T. vulgaris could be applicable to the management of N. viridula.
植物精油已被认为是杀虫剂的重要天然来源。本研究通过水蒸气蒸馏法从牛至（Oreganum vulgare L.）和普通百里香（Thymus vulgaris L.）中分离出精油，并分析其化学成分和对美洲芫菁（Nezara viridula （L.））卵、二龄幼虫和成虫的生物活性。
牛至的主要成分是对伞花烃，而百里香的主要成分是百里酚。通过局部涂抹测试了杀卵活性，发现百里香油更有效。在密闭室中评估了熏蒸活性；牛至对二龄幼虫和成虫的 LC50 值分别为 26.8 和 285.6 µg mL(-1)；百里香的 LC50 值分别为 8.9 µg mL(-1) 和 219.2 µg mL(-1)。为了评估接触活性，使用玻璃小瓶生物测定法；牛至对二龄幼虫和成虫的 LC50 值分别为 1.7 和 169.2 µg cm(-2)；百里香的 LC50 值分别为 3.5 和 48.8 µg cm(-2)。接触和熏蒸生物测定的 LT50 分析表明，百里香对二龄幼虫和成虫的毒性大于牛至。两种油对二龄幼虫和成虫均具有驱避作用。
这些结果表明，牛至和普通百里香的精油可用于美洲芫菁的防治。
