Novel Lactone-Based Insecticides and IDrosophila suzukii/I Management: Synthesis, Potential Action Mechanisms and Selectivity for Non-Target Parasitoids

• Published in: Insects (Basel, Switzerland) Vol. 14; no. 8
• Main Authors: Mantilla Afanador, Javier G, Araujo, Sabrina H. C, Teixeira, Milena G, Lopes, Dayane T, Cerceau, Cristiane I, Andreazza, Felipe, Oliveira, Daiana C, Bernardi, Daniel, Moura, Wellington S, Aguiar, Raimundo W. S, Oliveira, Ana C. S. S, Santos, Gil R, Alvarenga, Elson S, Oliveira, Eugenio E
• Format: Journal Article
• Language: English
• Published: MDPI AG 01-08-2023
• Subjects: Biological research; Biology, Experimental; Chemical properties; Control; Drosophila; Lactones; Physiological aspects; Brazil
• ISSN: 2075-4450; 2075-4450
• DOI: 10.3390/insects14080697

Drosophila suzukii is an insect of global economic importance, including in the Neotropical region. Due to the difficulty in controlling this insect pest with conventional insecticidal molecules, it is necessary to search for novel alternatives. Here, we present the potential of synthetic lactone-based insecticides to control D. suzukii. Additionally, we demonstrate molecular predictions regarding the actions of these molecules on the nervous system of the target pest and on the nervous system of its parasitoid, Trichopria anastrephae. By using in silico approaches, we demonstrate that the lactone derivatives (rac)-8 and compound 4 predominantly affect the TRP channels of D. suzukii (TRPM) and exhibit less stable interactions with the TRP channels expressed in T. anastrephae. Drosophila suzukii, an invasive insect pest, poses a significant threat to various fruit crops. The use of broad-spectrum insecticides to control this pest can reduce the effectiveness of biological control agents, such as the parasitoid Trichopria anastrephae. Here, we evaluated the toxicity of newly synthesized lactone derivatives on D. suzukii and their selectivity towards T. anastrephae. We used in silico approaches to identify potential targets from the most promising molecules in the D. suzukii nervous system and to understand potential differences in susceptibilities between D. suzukii and its parasitoid. Of the nine molecules tested, (rac)-8 and compound 4 demonstrated efficacy against the fly. Exposure to the estimated LC[sub.90] of (rac)-8 and compound 4 resulted in a mortality rate of less than 20% for T. anastrephae without impairing the parasitoid’s functional parasitism. The in silico predictions suggest that (rac)-8 and compound 4 target gamma amino butyric acid (GABA) receptors and transient receptor potential (TRP) channels of D. suzukii. However, only the reduced interaction with TRP channels in T. anastrephae demonstrated a potential reason for the selectivity of these compounds on the parasitoid. Our findings suggest the potential for integrating (rac)-8 and compound 4 into D. suzukii management practices.