Annually, phytophagous insects damage one fifth of the world’s total crop yield. Biotic stress affects the food security of any country by compromising the quality and quantity of the crop productivity. The yield loss due to insect infestation has devastating impacts on the society such as, hunger and poverty. The combined impact of the emergence and/or re-emergence of insect pests and rapidly growing human population calls for immediate inventions and the use of rigorous and integrated agricultural practices. The FAO estimated that plant diseases and pests are responsible for a 20–40% reduction in the global crop yields per year [1]. Researchers predicted a strong decline in the crop yield in response to climate change and weather pattern variations. Climatic changes might increase the risk that is caused by phytophagous pests, thereby turning them into a more harmful threat to the crops [2]. Over the past thousands of years, plant breeding has been exploited for constructing insect resistant crop varieties, however, it is laborious, time-consuming, has a stochastic nature, and the screening process is a very challenging practice [3]. Further, the unavailability of a resistance source in the gene pool has restricted the scope of breeding a resistant cultivar ^[4][5][4,5]. Under such a scenario, the use of toxic and cost-intensive agrochemicals appeared to be the only convenient solution for crop protection. Considering the toll these chemicals take on the ecosystem, there was an urge to develop genetically stable and fixed plant types [6].

Genome editing (GE) can play a pivotal role as it is a more promising and an environmentally friendly answer that can be used to deal with the situation. It all began with the gene-targeting experiments on the protoplast of Nicotiana tabacum which were performed in 1988 [7] and the findings in 1993 which supported that DNA double-strand breaks (DSBs) improved the gene-targeting efficacy [8]. Since then, the scientific orientation shifted towards the development of targeted genome editing techniques. The adoption of GE systems provided remarkable results in the field of the genetic improvement of crops. Genetic engineering rationalized the biological research world with the introduction of methods involving in vivo genome editing. The GE technique results in base substitutions and/or insertions/deletions (indels) in the target DNA. It includes several techniques, for instance, the use of zinc finger nucleases (ZFNs), transcriptional activator-like effector nucleases (TALENs), and the recently established clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 (Cas9) system. In contrast to TALENs and ZFNs, the CRISPR/Cas system is more direct and easier to handle as it requires a single guide RNA (gRNA) for target determination with the Cas9 nuclease ^[8][9][8,9]. In the recent past, the preference has shifted from breeding insect-resistant cultivars to making CRISPR/Cas9-mediated modifications in the agronomic traits or targeted mutagenesis in the insect genome. The constant modifications to gene knockout strategies, transgene integration, nucleotide substitution, transcription regulation, etc., have made the CRISPR/Cas system an easy-to-apply, cost-effective, and a widely used technique for manipulations at the genetic levels ^[10][11][12][10,11,12]. Biotic stress resistance is one of the traits that is improved by GE, which makes CRISPR/Cas system highly efficient in enhancing global food security, crop protection, and sustainable agriculture (Figure 1). On the subject of insects, many research groups have reviewed the application of various GE techniques, with special attention being paid to the CRISPR/Cas9 system in arthropods; in spite of this, no inclusive report is available twhichat covers all of the insect pests. The recent developments in the field of molecular biology and omics approaches presented that there has been a peak in the usage of CRISPR/Cas9 technology for insect pest management, and the data from these reports are not summarized in any previously published reviews. In this work, researchestudy, the authors emphasize and explain the prospects and applications of CRISPR/Cas technology in different insect groups for pest management. The CRISPR/Cas9 system has the potential of providing promising approaches for the control of insect pests. Therefore, summing up the CRISPR/Cas9-based control strategies against insect pests is significant in achieving global goals such as sustainable development.

Biotechnology and molecular biology have experienced a great transformation and advancement since the development of the CRISPR/Cas9 gene-editing system in the mammalian cells in the year 2012 [13]. With the discovery of the homology-dependent cleavage recombination mechanism, the utility of CRISPR/Cas9 was explored in genome editing, and it emerged as an assuring genome editing tool. The growing utility of gene-editing tools as a site-specific genome-editing approach offers infinite opportunities which may have an impact on important agronomic traits such as resistance to biotic stresses ^{[14][15][16][17]}[14,15,16,17]. The present text reviews the novel opportunities that CRISPR/Cas9 system offers and how it has attracted all of the attention by offering distinct advantages in the area of insect pest control thus ensuring a good crop yield and food security. A combination of gene editing tools and insect manipulation methods have been already used in Drosophila melanogaster Meigen, several tephritids, and mosquitoes which have answered some basic questions about insect biology. Recently, the technology has been utilized for the development of novel pest control strategies ^{[18][19][20][21]}[18,19,20,21], and it has been proven to be an efficient approach for pest management ^[22][23][24][22,23,24]. The advancements in genome editing methods paved the way for inventive pest control methods by the development of genetically modified insects. The CRISPR/Cas technology is evolving as it is very beneficial for efficient tailoring and gene manipulation. The components of the CRISPR/Cas tool (sgRNA and the Cas9 protein) can be delivered in the target organism in form of plasmid DNA, RNA, or a ribonucleo-protein (RNP) complex [25]. Some of the phytophagous insect orders that have been explored for pest management using genome editing by the CRISPR/Cas system are summarized in Table 1.