Elucidating Efficacy of Ingested Positively Charged Zein Nanoparticles Against Noctuidae

Abstract

A meridic diet overlay bioassay using empty, positively charged zein nanoparticles ((+)ZNP) was performed on soybean looper (Chrysodeixis includens (Walker)), tobacco budworm (Heliothis virescens (F.)), and velvetbean caterpillar (Anticarsia gemmatalis Hübner) (Lepidoptera: Noctuidae). Assessment of effects on mortality and development weights 7 d after ingestion of (+)ZNP were evaluated on larvae of each species. Treatments involved different concentrations, with H. virescens and A. gemmatalis offered 0 and 3,800 ppm (+)ZNP, whereas C. includens colonies were offered 0, 630, 1,260, and 2,520 ppm (+)ZNP. Mortality of A. gemmatalis and C. includens increased after ingestion of the highest (+)ZNP concentrations, while H. virescens neonate mortality was unaffected. Neonate and third-instar weights of A. gemmatalis and C. includens, and neonate H. virescens, decreased with high (+)ZNP concentrations. Following mortality results from A. gemmatalis neonates, a concentration response test was performed using a range of (+)ZNP concentrations. The LC50 for A. gemmatalis was 1,478 ppm. The potential of (+)ZNP as a pest management tactic is discussed.

Zein and lignin-based nanoparticles as soybean seed treatment: translocation and impact on seed and plant health

“…This is the first experiment to document the effect of ZNP and LNP treated seeds on an insect pest. Previous research has indicated that positively charged ZNPs significantly impact C. includens mortality at high concentrations (200 PPM) when reared on the treated diet; positively charged ZNPs appear to have a defined LC 50 value of 1478 PPM for Anticarsia gemmatalis (Hübner), another lepidopteran insect pest (Bonser et al 2020). The results from current study, however, suggest that the nanoparticle seed treatments did not affect the mortality of lepidopteran larvae following consumption of leaf tissue of treated seeds.…”

“…As another example, research found that antifungal seed treatments of chitosan-polyacrylic acid nanoparticles on Callosobruchus maculatus (F.), Callosobruchus chinensis L., and Aphis gossypii Glover demonstrated a significant decrease in fecundity by nearly 80% and insect growth by at least 70% (Sahab et al 2015). The research presented in this paper suggests that ZNP-and LNP-treated seeds do not (Bonser et al 2020). The experiment in this paper gives evidence that antifungal seed treatments of ZNP and LNP will not negatively affect insects.…”

“…Non-target impacts of nine different soybean seed treatments were tested on first instar C. includens (Walker) (Lepidoptera: Noctuidae) through foliar consumption. The C. includens colony used in this experiment, LSU1, was reared in the Entomology Department at Louisiana State University at 26 °C, 50% RH, and 14:10 (L:D) photoperiod on artificial meridic diet (Southland Products Inc., Lake Village, AR, USA) (Bonser et al 2020). Soybean plants were grown at the LSU AgCenter Plant Material Center Greenhouse under greenhouse conditions (25 ± 5 °C, 50 ± 5% RH, and 14:10 L:D).…”

Elucidating the insecticidal mechanisms of zein nanoparticles on Anticarsia gemmatalis (Lepidoptera: Erebidae)

“…We have shown in previously published research that zein nanoparticles can negatively impact insects, though the specific mechanisms remain unclear (Bonser et al 2020, 2022). It was hypothesized that zein nanoparticles were unpalatable and might be acting as an antifeedant (Bonser et al 2020), substances that modify behavior to deter feeding (Isman 2002), or will increase oxidative stress.…”

“…These nanoparticles are also an environmentally-safe option when compared to the toxicity presented by their metal alternatives (Jeng and Swanson 2006, Schrand et al 2010, Medici et al 2021). Some biopolymer nanoparticles without entrapped pesticides, such as those made from the corn protein, zein, have insecticidal capabilities without the potential environmental toxicity that inorganics have (Bonser et al 2020). However, because biopolymer nanoparticles require surfactants as part of the manufacturing process to increase solubility, distribution, and stability (Astete and Sabliov 2006, Chuacharoen and Sabliov 2019, Cortés et al 2021, Mendez et al 2022), there is a concern that these surfactants may have negative environmental consequences.…”