Anticarsia gemmatalis is one of the main pests of the soybean crop, being controlled mainly with agrochemicals. The environmental and health risks, as well as the development of resistance by the pests, has led to the search for alternative control measures, aiming to use more eco-friendly procedures. The objective of this research was to evaluate the chemical composition and the bioactivity of Schinus molle and Schinus terebinthifolia essential oils (EOs) on A. gemmatalis. The major compound in both EOs was α-pinene (60.04 wt.% for S. molle and 38.49 wt.% for S. terebinthifolia). Bioassays were carried out with third instar larvae, with five replicates and each replicate with ten larvae, totaling 50 larvae per treatment. The oils were incorporated in the artificial diet (0.1, 0.5, 1.0, 1.5, and 2.0% v/v). The controls were: water, Tween-80 ® 0.5% v/v, and novaluron 0.075% v/v. According to the Probit method, the S. terebinthifolia EO presented a LC50 of 1.74% v/v (1.58-1.97% v/v); it was not possible to determine the LC50 for the S. molle EO. The mortality percentage after 24 and 48 h was 52% and 30% at 2.0% v/v for S. terebinthifolia and S. molle oil, respectively. HIGHLIGHTS  S. molle leaf had an EO yield of 0.3% m/v; S. terebinthifolia had 0.2% m/v.  Both EOs presented α-pinene as the major compound.  S. molle EO induced 30% mortality of A. gemmatalis in 72 h.  S. terebinthifolia EO induced 70% mortality of A. gemmatalis in 72 h.  The LC50 for S. terebinthifolia EO was 1.74% v/v (1.58-1.97% v/v). 2 Vicenço, C.B.; et al.

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.