Toxicity of Silver Bionanoparticles on Tamarixia radiata (Hymenoptera: Eulophidae)

Abstract

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is one of the most important citrus pests worldwide. Its control is based mainly on chemical insecticides, whose efficacy decreases due to the development of resistance resulting from frequent applications and high doses. This has compromised the control effectiveness of the pest and affects natural enemies such as Tamarixia radiata Waterston (Hymenoptera: Eulophidae), a specific parasitoid of D. citri. Recently, nanoparticles have emerged as a promising alternative for insect control, but there is limited knowledge about their impact and compatibility with natural enemies; therefore, this research aimed to evaluate the effect of silver bionanoparticles (AgNPs) on the emergence, feeding, and morphometry of T. radiata in the constant environmental conditions. Toxicity tests of the nanoparticles consisted of immersion of parasitized D. citri nymphs, ingestion tests on T. radiata, and morphometric analysis of emerged adults to analyze parasitoid quality. Based on the immersion tests, relative to the control, AgNPs at 64 ppm yielded only 36% adult parasitoid emergence and 36% mortality in the feeding tests. Based on morphometric analysis, adults are considered suitable as biological control agents. This finding highlights the potential of AgNPs as a safe alternative in pest management, promoting the conservation of natural enemies; however, it is suggested to evaluate AgNPs in sublethal doses to determine their compatibility with T. radiata.