Entomotoxic efficacy of fungus-synthesized nanoparticles against immature stages of stored bean pests

• Published in: Scientific reports Vol. 13; no. 1; p. 8508
• Main Authors: Helmy, Eman Ahmed Mohamed, San, Phyu Phyu, Zhang, Yao Zhuo, Adarkwah, Charles, Tuda, Midori
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 25-05-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/1647/334/1582; 631/1647/350; 631/601/1466; Animals; Beans; Chemical pest control; Coleoptera; Developmental stages; Eggs; Fabaceae; Fungi; Hatchability; Humanities and Social Sciences; Larva; Larvae; multidisciplinary; Nanoparticles; Pesticides; Pests; Science; Science (multidisciplinary); Seeds; Selenium; Silicon dioxide; Silver; Survival; Titanium dioxide; Zinc oxide
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-35697-1

Nanopesticides, particularly biosynthesized ones using organic reductants, hold great promise as a cost-effective and eco-friendly alternative to chemical pesticides. However, their efficacy on stored product pests, which can cause damage to dried grains, has not been extensively tested, especially on immature stages. Here, we biosynthesized six types of nanoparticles (NPs) using extracts from the fungus
Fusarium solani
: silver (AgNPs), selenium (SeNPs), silicon dioxide (SiO
2
NPs), copper oxide (CuONPs), titanium dioxide (TiO
2
NPs) and zinc oxide (ZnONPs) ranging in size from 8 to 33 nm. To test their efficacy on stored bean pests, they were applied to the eggs and larvae of pest beetles
Callosobruchus chinensis
and
Callosobruchus maculatus
(Coleoptera: Chrysomelidae: Bruchinae), which burrow into seeds as larvae. Susceptibility to the NPs was species-dependent and differed between developmental stages; eggs were more susceptible than larvae inhabiting in seeds. SeNPs and TiO
2
NPs reduced the hatchability of
C. chinensis
eggs by 23% and 18% compared to the control, respectively, leading to an 18% reduction in egg-to-adult survival by SeNPs. In
C. maculatus
, TiO
2
NPs applied to eggs reduced larva-to-adult survivorship by 11%, resulting in a 15% reduction in egg-to-adult survival. The egg mass of
C. chinensis
was 23% smaller than that of
C. maculatus
: the higher surface-area-to-volume ratio of the
C. chinensis
eggs could explain their higher acute mortality caused by the NPs compared to
C. maculatus
eggs. The biosynthesized SeNPs and TiO
2
NPs have potential for controlling major stored bean pests when applied to their eggs. This is the first to show the efficacy of biosynthesized SeNPs and TiO
2
NPs on stored product pests and the efficacy of
Fusarium
-synthesized NPs on insects.