Effect of synthetic amorphous silica powder on the cuticle of Tribolium castaneum and Sitophilus oryzae using hyperspectral imaging technique

Abstract

BACKGROUND Synthetic amorphous silica (SAS) is safe for human consumption. SAS damages insect cuticles. Qualitative measurement of cuticle properties of insects affected by SAS is essential to understand the mode of action and develop new pesticides. A hyperspectral reflectance imaging approach was used to directly indicate the impact of SAS on the insect cuticle. RESULTS There were significant differences in the LT95 values of hydrophobic and hydrophilic SAS against Tribolium castaneum and Sitophilus oryzae (P < 0.01). T. castaneum was more susceptible to hydrophobic SAS while no difference was found for S. oryzae exposed to both SAS types. In a hyperspectral study, the ventral reflectance of control groups was higher than that of SAS‐treated groups in both visible and short‐wave near‐infrared wavelength ranges. The SAS‐treated groups showed much higher dorsal reflectance. The differences in absorption characteristics of cuticular fat and protein may contribute to the varied performance. The effects of both SASs on insect cuticles was significant, as the 100% recognition rate of the back propagation neural network models suggested. Consistent with the assumption that the efficacy was different between the two SAS types, the lowest rates of the model for two treatment groups were 62.2 and 73.3% in the target and output class. CONCLUSION The efficacy varied considerably between the two insect species and the two SASs. Hyperspectral image analyzing coupled with back propagation artificial neural network accurately recorded how SAS impacts the insect cuticle via the effective wavelengths. These findings showed that SAS is a promising candidate for new pesticide products. © 2019 Society of Chemical Industry

Synthetic and Natural Insecticides: Gas, Liquid, Gel and Solid Formulations for Stored-Product and Food-Industry Pest Control

“…Currently, commercial dust formulations are usually classified into three basic categories: (i) inorganic or organic chemical (i.e., conventional) insecticide dusts, (ii) inert dusts of natural or synthetic origin [ 529 , 541 , 542 , 543 , 544 ], or (iii) various combinations of natural and synthetic dusts (e.g., kaolin/diatomite + DDT/HCH-lindane [ 545 ]). Organic insecticide dusts historically have contained a broad variety of neurotoxically active compounds (e.g., organochlorines, carbamates, organophosphates, pyrethroids, and natural pyrethrum extracts, piperonyl butoxide).…”

Journal of Plant Protection Research

“…Tribolium castaneum was more susceptible to hydrophobic synthetic amorphous silica (SAS) powder. When exposing S. oryzae adults, no significant difference was detected between LT 95 values of hydrophobic and hydrophilic SAS (Li et al 2020). Silica nanoparticles were found to be highly effective against S. oryzae which caused mortality rates of more than 90%, indicating the effectiveness of SiNPs as a stored product insect pest control agent (Debnath et al 2011).…”

A comparative study revealed hyperspectral imaging as a potential standardized tool for the analysis of cuticle tanning over insect development

“…It is also a non-destructive method, making it possible to analyze the cuticle of living insects. Only few studies using HSI have been conducted so far, but it has already proven its great potential for monitoring phenotypic changes after insecticide exposure [ 38 , 39 ], comparing structural properties of insect cuticle and biomimetic film [ 40 ], and classifying insect species [ 41 ] and ages [ 42 , 43 ].…”