Evaluation of the Insecticidal Potential of Heterotheca inuloides Acetonic and Methanolic Extracts against Spodoptera frugiperda and Their Ecotoxicological Effect on Poecilia reticulata

Abstract

For the management of Spodoptera frugiperda, botanical extracts have been used to reduce the environmental impacts of synthetic chemical pesticides. In the present investigation, the insecticidal activity of the acetonic and methanolic extracts of Heterotheca inuloides (Asteraceae) and of the main compound 7-hydroxy-3,4-dihydrocadalene on this pest as well as its ecotoxicological effect on Poecilia reticulata were evaluated. A greater insecticidal response was obtained from the acetonic extracts than from the methanolic extracts, with LC50 values of 730.4 ppm and 711.7 ppm for samples 1 and 2, respectively. Similarly, there was a lethal effect on 50% of the P. reticulata population at low concentrations in the acetonic extract compared to the methanolic extract. The sesquiterpene 7-hydroxy-3,4-dihydrocadalene has greater insecticidal activity by presenting an LC50 of 44.36 ppm; however, it is classified as moderately toxic for guppy fish.

Activity of Methanolic and Hydrolyzed Methanolic Extracts of Ricinus communis (Euphorbiaceae) and Kaempferol against Spodoptera frugiperda (Lepidoptera: Noctuidae)

“…These were chosen after completing the logarithmic bioassay. The selection criteria were the minimum and maximum biological response and then three concentrations were selected between them, and they were: 5000, 4000, 2000, 1000, 500, and 0 ppm, according to our previous studies [35,36], adding each concentration during the preparation of the artificial diet for S. frugiperda. To carry out the test, 20 #0 polyethylene PRIMO brand cups (Ecatepec, Mexico) were used, in which a piece of the food with an approximate volume of 1 cm 3 containing the corresponding concentration of each extract of R. communis was placed.…”