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The global spread of Fall Armyworm (FAW, Spodoptera frugiperda) has posed significant challenges to crop productivity and food security, with current pest management relying heavily on synthetic pesticides. This study explores the green synthesis of neem extract and neem oil-based Azadirachtin nanopesticides using cellulose acetate (CA) as a carrier polymer, focusing on their efficacy against FAW. The objective was to assess whether CA-NEP (neem extract nanopesticides) and CA-NOL (neem oil nanopesticide) formulations were effective at FAW control with minimal ecological impact. The nanopesticides were synthesized by electrospinning at concentrations of 5 %, 10 %, 20 %, 33 %, and 50 % (w/w) and characterized using Scanning Electron Microscopy and Fourier Transform Infrared spectroscopy. Azadirachtin content was quantified using Liquid Chromatography-Mass Spectroscopy. CA-NEP and CA-NOL followed first-order, and Korsmeyer-Peppas release kinetics, respectively. Feeding bioassays showed high FAW mortality rates, with 20 %-50 % CA-NEP achieving greater than 40 % mortality in less than 3 days and 50 % CA-NEP reaching 100 % mortality by day five. The mortality rates of FAW due to feeding on CA-NOL-treated corn leaves reached 40 % after 4 and 6 days, respectively, for 50 % and 33 % CA-NOL. Placing nanopesticide fibers next to corn seeds during planting significantly reduced FAW leaf damage. The lethal dose 50 (LD50) analyses showed that 13 % CA-NEP is the optimal concentration for FAW control. Environmental safety assessments on earthworms showed no acute or chronic toxicity, indicating that the nanopesticides suit ecologically sensitive areas. Therefore, these nanopesticide formulations provide a promising, eco-friendly alternative for sustainable FAW control and management with enhanced efficacy and safety. 

The electrospinning method is increasingly in demand due to its capability to produce fibers in the nanometer to micrometer range, with applications in diverse fields including biomedical, filtration, energy storage, and sensing. Many of these applications demand control over fiber layout and diameter. However, a standard flat plate collector yields random fibers with limited control over diameter and density. Other viable solutions offering a higher level of control are either scarce or substantially expensive, impeding the accessibility of this vital technique. This study addresses the challenge by designing an affordable laboratory-scale electrospinning setup with interchangeable collectors, enabling the creation of targeted fibers from random, aligned, and coiled. The collectors include the standard flat plate and two additional designs, which are a rotating drum and a spinneret tip collector. The rotating drum collector has adjustable speed control to collect aligned fibers and exhibits stability even at high rotational speeds. The spinneret tip collector was designed to produce helically coiled fibers. The setup was validated by directed fiber formation using polycaprolactone (PCL), a biodegradable and FDA-approved polymer. Overall, the uniqueness of the design lies in its affordability, modifiability, and replicability using readily available materials, thus extending the reach of the electrospinning technique.