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 is one of the most important pests in world soybean crop. The most common intervention is the application of agrochemicals, such as novaluron and glyphosate. Among biological control agents, much attention has been drawn to entomopathogenic fungi, as Metarhizium rileyi. Here, we examined the changes that occur in the immune system (total and differential hemocyte count), secondary effects (caterpillar morphology), and oxidative metabolism after the caterpillars were exposed to M. rileyi, novaluron or glyphosate. M. rileyi was able to induce changes in the width, length, and weight of A. gemmatalis pupae, along with an increased in the number of defense cells. Novaluron prompt changes the insect’s immunity, and glyphosate caused milder immunological effects. However, it caused significant secondary effects including malformations in pupae and adults, and an increase in nitric oxide (NO) levels. Mortality observed when treating insects with novaluron and malformations due to glyphosate treatments did not occur due to oxidative stress. However, when insects were exposed to M. rileyi, we verified significantly increased levels of NO and concluded that these insects died due to oxidative stress. Our data provide evidence that contributes to better understanding the mechanism of herbicide-fungus interaction in the management of Anticarsia gemmatalis.