The impact of carbon NPs on the accumulation of storage proteins and the generation advancement of the polyphagous insect pest tobacco cutworm Spodoptera litura (Fabricius)

Abstract

Spodoptera litura (Lepidoptera: Noctuidae) is globally considered one of the most important agricultural pests. It is a highly prevalent insect pest that severely damages several vegetables and crops, including cotton, castor, tobacco, beet, soybean, and cabbage. The implementation of integrated pest management (IPM) practices has led to a slight controlling of its population in the field; however, these practices are always linked with the high economic and environmental costs for eradication. In the last decade, many researchers have reported the control of this devastating insect via the utilization of nanoparticles (NPs); however, the mechanism behind its toxicity is still a gap area. In our study, we investigated the toxic impact of carbon nanoparticles (CNPs) on S. litura when administered orally. A range of immunomodulatory responses were observed, including a distorted morphology (such as abnormal pupa, distorted wings in insects, etc.) and reproductive physiology, weight reduction, and even insect death. Mass spectrometric analysis of differentially expressed proteins suggests significant downregulation of storage proteins in the larval hemolymph, which in turn resulted in an altered expression/synthesis of developmental and reproductive proteins, including vitellogenin (the major egg-filling protein required for developing embryo nourishment), in the treated insects. The poor accumulation of vitellogenin in developing eggs led to a disrupted life cycle and restricted population growth. This is the first study that provides insights into the molecular mechanism behind the toxicity offered by these tiny carbon particles.