The species Spodoptera littoralis, commonly known as the cotton leafworm, is one of the most destructive agricultural pests in tropical and subtropical regions. Due to its polyphagous behavior, it feeds on at least 87 types of plants, including important crops like tomatoes, bell peppers, cotton, and corn, resulting in significant losses for farmers. Currently, the main method of controlling this pest involves using synthetic chemical insecticides with low selectivity. However, improper use of these chemicals can cause environmental damage and lead to the development of resistant strains, making pest control challenging and necessitating the exploration of new alternatives. In recent years, there has been extensive research on the use of plant extracts for pest control. As part of this trend, this study aims to evaluate the potential of ethanolic extracts from leaves and inflorescences of Achyrocline satureioides, a native South American species, as an alternative control agent for Spodoptera littoralis. The ethanolic extract of A. satureioides was prepared through maceration, and a Bioassay was conducted with five replications using sixth instar S. littoralis larvae. The Food Deterrence methodology was employed, where Petri plates were coated with agar and divided into four areas, each containing four leaf discs (1 cm²) of Capsicum annuum. Two of the discs were treated with 10 μL of the extract, while the other two received 10 μL of water. Two larvae were placed on each plate and allowed to feed until they consumed 75% of the control or sample. The results demonstrated that the concentration of 10 mg/mL of the extracts from A. satureioides leaves and inflorescences inhibited 37.23% and 22.72% of S. littoralis feeding, respectively. This indicates that the extracts have an inhibitory effect on the feeding behavior of this caterpillar. As a result, they show promise as potential candidates for further studies aimed at developing formulations that can enhance their effectiveness as environmentally friendly alternatives for pest control.