A great number of cell lines from hemipteran, lepidopteran, and dipteran insects have been developed and characterized. Using the advent of new techniques and instruments in molecular biology as well as the advancement in biotechnology, the indigenous cell lines might prove useful in the development of alternatives to conventional chemical pesticides for agriculture and in the creation of vaccines and life-saving pharmaceuticals for human and animal diseases. Cell cultures of insects are used for the generation of vaccines, viral pesticides, and recombinant proteins, and in basic research in virology, endocrinology, molecular biology, genetics, and biochemistry. This paper summarizes information collected regarding the different insect cell lines developed and characterized thus far and also describes different applications in entomological research.