Insecticidal Activity of Lavandula dentata L. Essential Oil on Anticarsia gemmatalis (Hübner, 1818)

Abstract

Anticarsia gemmatalis, commonly known as soybean caterpillar, causes important economic losses in soybean crops. Synthetic pesticides are the standard practice to control this insect. However, the indiscriminate use of these substances has increased the resistance of this pest. Thus, it is necessary to search for different control alternatives that are also more environmentally friendly. The objective of this work was to evaluate the chemical composition of Lavandula dentata L. essential oil (EO) and its activity on A. gemmatalis. The major compounds of essential oil were 1,8-cineole (31.5 wt.%), camphor (16.6 wt.%), and fenchone (15.9 wt.%). Bioassays were performed with third-instar caterpillars. EO concentrations of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0% v/v were diluted in Tween-80 ® 0.5% v/v and incorporated into the artificial diet given to caterpillars. Water, Tween-80 ® 0.5% v/v, and novaluron 0.075% w/v were added as negative and positive controls. For the aversion tests, soybean leaf discs were immersed in solutions with HIGHLIGHTS  The insecticidal activity of L. dentata EO was tested on A. gemmatalis. The calculated LC50 of L. dentata EO was 0.197% v/v for A. gemmatalis. The EO was applied on soybean leaves to verify its deterrent effect on the insect. EO at 0.4% v/v has already had a deterrent effect on the caterpillars. 2 Vicenço, C. B.; et al.

Lavandula dentata Essential Oils: A Bio-Insecticide for an Agroecological Approach to Protecting Chickpea Seeds against Callosobruchus maculatus

“…For example, the insecticidal activity evaluation of some aromatic plants, including L. dentata showed that L. dentata EO at the concentration of 0.6% v/v resulted in 100% mortality after 24 h of exposure to Anticarsia gemmatalis. 30 Wagner et al (2021) 31 reported a significant fumigant potential of Lavandula dentata EO against adults of Sitophilus zeamais, Tribolium castaneum and Epicauta atomaria. In the same vain, a potent toxic effect has been reported for L. angustifolia EO against Acanthoscelides obtectus (100% mortality at 2 and 80 μL/L of air).…”